In JoVE (1)

Other Publications (125)

Articles by Arun K. Gosain in JoVE

 JoVE Bioengineering

Quantification of Strain in a Porcine Model of Skin Expansion Using Multi-View Stereo and Isogeometric Kinematics

1Mechanical Engineering, Purdue University, 2Division of Plastic Surgery, Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, 3Mechanical Engineering, Bioengineering, Cardiothoracic Surgery, Stanford University

JoVE 55052

Other articles by Arun K. Gosain on PubMed

A 1-year Study of Osteoinduction in Hydroxyapatite-derived Biomaterials in an Adult Sheep Model: Part I

Plastic and Reconstructive Surgery. Feb, 2002  |  Pubmed ID: 11818845

The study presented here investigated hydroxyapatite biomaterials implanted in soft-tissue sites in adult sheep to determine whether these materials are osteoinductive and whether the rate of osteoinduction can be increased by manipulating the composition and porosity of the implants. For the study, 16.8-mm x 5-mm discs were prepared from mixtures of hydroxyapatite and beta-tricalcium phosphate. Five mixtures of hydroxyapatite-ceramic and hydroxyapatite-cement paste forms were studied: 100 percent hydroxyapatite-ceramic (Interpore), 60 percent hydroxyapatite-ceramic, 100 percent hydroxyapatite-cement paste, 60 percent hydroxyapatite-cement paste, and 20 percent hydroxyapatite-cement paste. Biomaterials were implanted in subcutaneous and intramuscular soft-tissue pockets in 10 adult sheep. Cranial bone grafts of equal dimension were implanted as controls. One year after implantation, the volume of all biomaterials and bone grafts was determined from a computed tomographic scan, and porosity and bone formation were determined using backscatter electron microscopy. Cranial bone and the 20 percent hydroxyapatite-cement paste implants demonstrated significant volume reduction in all sites after 1 year (p < 0.001). No significant difference in volume of the remaining four biomaterials was found. There was no significant change in pore size in the ceramic implants (range, 200 to 300 micro) and in the cement-paste implants containing 60 percent hydroxyapatite or more (range, 3 to 5 nm). Pore size in the cement-paste implants containing 20 percent hydroxyapatite increased significantly with resorption of the tricalcium-phosphate component, reaching a maximum of 200 to 300 micro in the periphery, where the greatest tricalcium-phosphate resorption had occurred. Both ceramic biomaterials demonstrated lamellar bone deposition within well-formed haversian systems through the entire depth of the implants, ranging from a mean of 6.6 percent to 11.7 percent. There was minimal bone formation in the cement-paste implants containing 60 percent hydroxyapatite or more. In contrast, cement-paste implants containing 20 percent hydroxyapatite demonstrated up to 10 percent bone replacement, which was greatest in the periphery of the implants where the greatest tricalcium-phosphate resorption had occurred. This study confirms the occurrence of true osteoinduction within hydroxyapatite-derived biomaterials, when examined using backscatter techniques. In this study, the rate of osteoinduction was greatest when a porous architecture was maintained, which was best achieved in ceramic rather than cement-paste forms of hydroxyapatite. Porosity and resultant bone formation in cement-paste implants can be improved by combining hydroxyapatite with a rapidly resorbing component, such as tricalcium phosphate.

Midface Distraction Following Le Fort III and Monobloc Osteotomies: Problems and Solutions

Plastic and Reconstructive Surgery. May, 2002  |  Pubmed ID: 11994576

Distraction osteogenesis has been used increasingly for midfacial advancement in patients with syndromic craniosynostosis and in severe developmental hypoplasia of the midface. In these patients, the degree of advancement required is often so great that restriction of the adjacent soft tissues may preclude stable advancement in one stage. Whereas distraction is an ideal solution by which to gradually lengthen both the bones and the soft tissues, potential problems remain in translating the distraction forces to the midface. In these patients, severe developmental hypoplasia may be associated with weak union between the zygoma and the maxilla, increasing the chance of zygomaticomaxillary dysjunction when using internal devices that translate distraction force to the maxilla through the zygoma. Eight cases are reported in which either internal or external distraction systems were used for midface advancement following Le Fort III (n = 7) or monobloc (n = 1) osteotomies. Cases of patients in whom hypoplasia at the zygomaticomaxillary junction altered or impaired plans for midface distraction were reported from three host institutions. Seven patients had midface hypoplasia associated with syndromic craniosynostosis, and one patient had severe developmental midface hypoplasia. The distraction protocol was modified to successfully complete midface advancement in light of weakness at the zygomaticomaxillary junction in seven patients. Modifications included change from an internal to an external distraction system in two patients, rigid fixation and bone graft stabilization of the midface in one patient, and plate stabilization of a fractured or unstable zygomaticomaxillary junction followed by resumption of internal distraction in four patients. Previous infection and bone loss involving both malar complexes precluded one patient from being a candidate for an internal distraction system. Using a problem-based approach, successful advancement of the midface ranging from 9 to 26 mm at the occlusal level as measured by preoperative and postoperative cephalograms was undergone by all patients. Advantages and disadvantages of the respective distraction systems are reviewed to better understand unique patient characteristics leading to the successful use of these devices for correction of severe midface hypoplasia.

The Current Status of Tissue Glues: I. For Bone Fixation

Plastic and Reconstructive Surgery. Jun, 2002  |  Pubmed ID: 12045598

Otoplasty in Children Less Than Four Years of Age: Surgical Technique

The Journal of Craniofacial Surgery. Jul, 2002  |  Pubmed ID: 12140412

The appropriate age for otoplasty remains controversial. Most surgeons wait until the child is aged 5 years or older to perform otoplasty. In this article, the results are reported in a series of 12 patients in whom otoplasty was performed before the age of 4 years. The approach used consists of a logical sequence for recreation of the antihelical fold, conchal reduction, reduction of the conchomastoid angle, and lobule setback. Follow-up in these patients ranges from 1 to 7 years, with a median follow-up interval of 3 years. No auricular growth disturbances were noted as a result of the surgery. Recurrent auricular prominence was noted in only 1 (8%) of the 12 patients, comprising 4.8% of the operated ears. Experience using this approach demonstrates that otoplasty can be performed from the age of 9 months or older with safety, reliability, and a high level of satisfaction on the part of the affected families.

The Current Status of Tissue Glues: Part II. For Adhesion of Soft Tissues

Plastic and Reconstructive Surgery. Nov, 2002  |  Pubmed ID: 12409784

The Vascular Supply of the Extended Tensor Fasciae Latae Flap: How Far Can the Skin Paddle Extend?

Plastic and Reconstructive Surgery. Dec, 2002  |  Pubmed ID: 12447045

The vascular supply of the tensor fasciae latae flap and of the lateral thigh skin was studied in 10 cadavers to evaluate whether the lateral thigh skin toward the knee could be incorporated into an extended tensor fasciae latae flap. Within each cadaver, vascular injection of radiopaque material preceded flap elevation in one limb and followed flap elevation in the contralateral limb. Flaps raised after vascular injection were examined radiographically to evaluate the vascular anatomy of the lateral thigh skin independent of flap elevation. When vascular injection was made into the profunda femoris, the upper two-thirds of the flaps was better visualized than the distal third. When the injection was made into the popliteal artery, the vasculature of the distal third of the flaps was better visualized. Flaps raised before vascular injection were examined radiographically to delineate the anatomical territory of the vascular pedicle that had been injected. In these flaps, consistent cutaneous vascular supply was only seen in the skin overlying the tensor fasciae latae muscle, confirming that musculocutaneous perforators are the predominant means by which the pedicle of the tensor fasciae latae flap supplies the skin of the lateral thigh. Extended tensor fasciae latae flaps were elevated bilaterally in one cadaver, and selective methylene blue injections were made into the lateral circumflex femoral artery on one side and into the superior lateral genicular artery on the contralateral side. Methylene blue was observed in the proximal and distal thirds of the skin paddles, respectively, leaving unstained midzones. The vascular network of the lateral thigh skin could be divided into three zones. The lateral circumflex femoral artery and the third perforating branches of the profunda femoris artery perfuse the proximal and middle zones of the lateral thigh skin, respectively. The superior lateral genicular artery branch of the popliteal artery perfuses the distal zone. The middle and distal zones meet 8 to 10 cm above the knee joint, where the skin paddle of the tensor fasciae latae flap becomes unreliable. These data indicate that if the aim is to incorporate the skin over the distal thigh in an extended tensor fasciae latae flap without resorting to free-tissue transfer, then either a carefully planned delay procedure or an additional anastomosis to the superior lateral genicular artery is required.

Surgical Excision of Pedunculated Supernumerary Digits Prevents Traumatic Amputation Neuromas

Pediatric Dermatology. Mar-Apr, 2003  |  Pubmed ID: 12657004

Nine patients divided into two groups were treated for pedunculated supernumerary digits or their sequelae. The first group consisted of three patients who had among them five traumatic amputation neuromas. In each case these lesions resulted from primary suture ligation of accessory digits in infancy. Secondary surgical excision of the vestigial digit with high ligation and retraction of the accompanying nerve tissue was required in all cases. The second group consisted of six patients who had 12 pedunculated supernumerary digits. Primary surgical excision of these digits was performed with high transection and retraction of the accompanying accessory digital nerve. All patients in this group had excellent cosmetic results with no postoperative neuroma formation. Adult family members who had undergone suture ligation of similar supernumerary digits in infancy accompanied seven of the nine patients in this series. On careful examination, each of these family members had signs and symptoms attributable to traumatic amputation neuromas. We feel identification and high transection of the accessory digital nerve is essential in the treatment of pedunculated supernumerary digits. This treatment prevents traumatic amputation neuromas and yields a better cosmetic result than the traditional method of suture ligation in infancy.

Airway Management in Patients with Isolated Pierre Robin Sequence During the First Year of Life

The Journal of Craniofacial Surgery. Jul, 2003  |  Pubmed ID: 12867857

Managing the airway of patients with Pierre Robin sequence is diagnostically and therapeutically challenging. Like many other pathologies, Pierre Robin sequence is best managed with a multidisciplinary team. Providing a comprehensive evaluation is important to detect patients who may have silent events during activities of early life. Children with airway obstruction should have a complete assessment to anatomically define the site of airway obstruction. Therefore, management options can be targeted to the specific deficiency. The present article outlines a treatment protocol for patients who present with isolated Pierre Robin sequence. The authors propose that initial diagnostic and therapeutic interventions remain relatively noninvasive. Using this protocol, more than 80% of patients with isolated Pierre Robin sequence who the authors have examined for airway obstruction in the neonatal period have been effectively treated with positioning or tongue-lip adhesion. While more aggressive and successful techniques have been reported, the authors have not found them necessary for the majority of patients with isolated Pierre Robin sequence. The following review details their approach to patients with Pierre Robin sequence.

Osteogenesis in Calvarial Defects: Contribution of the Dura, the Pericranium, and the Surrounding Bone in Adult Versus Infant Animals

Plastic and Reconstructive Surgery. Aug, 2003  |  Pubmed ID: 12900610

Guided bone regeneration is a promising means for reconstructing bone defects in the cranium. The present study was performed to better define those factors that affect osteogenesis in the cranium. The authors studied a single animal model, investigating the contribution of the dura, the pericranium, and the adjacent calvarial bone in the process of calvarial regeneration in both mature and immature animals. Bilateral, 100-mm2, parietal calvariectomies were performed in immature (n = 16) and mature (n = 16) rabbits. Parietal defects were randomized to one of four groups depending on the differential blockade of the dura and/or the pericranium by expanded polytetrafluoroethylene membranes. Animals were humanely killed after 12 weeks, and histometric analysis was performed to quantitate the area of the original bone defect, new bone formation, and new bone density. Bone formation was quantified separately both at the periphery and in the center of the defects. Extrasite bone formation was also quantified both on the dural and on the pericranial sides of the barriers. Bone regeneration was incomplete in all groups over the 12-week study period, indicating that complete bone healing was not observed in any group. The dura was more osteogenic than the pericranium in mature and immature animals, as there was significantly more extrasite bone formed on the dural side in the double expanded polytetrafluoroethylene barrier groups. In both the dural and the double expanded polytetrafluoroethylene barrier groups, dural bone production was significantly greater in immature compared with mature animals. The dura appeared to be the source of central new bone, because dural blockade in the dural and double expanded polytetrafluoroethylene groups resulted in a significant decrease in central bone density in both mature and immature animals. Paradoxically, isolation of the pericranium in mature animals resulted in a significant reduction in total new bone area, whereas pericranial contact appeared to enhance peripheral new bone formation, with the control group having the greatest total new bone area. The present study establishes a model to quantitatively study the process of bone regeneration in calvarial defects and highlights differences in the contribution of the dura and pericranium to calvarial bone regeneration between infant and adult animals. On the basis of these findings, the authors propose that subsequent studies in which permeability of the expanded polytetrafluoroethylene membranes is altered to permit migration of osteoinductive proteins into the defect while blocking prolapse of adjacent soft tissues may help to make guided bone regeneration a realistic alternative for the repair of cranial defects.

A Novel Approach to Correction of the Prominent Lobule During Otoplasty

Plastic and Reconstructive Surgery. Aug, 2003  |  Pubmed ID: 12900617

Pediatric Tissue Expansion: Indications and Complications

The Journal of Craniofacial Surgery. Nov, 2003  |  Pubmed ID: 14600628

Tissue expansion has become a major reconstructive modality in the past 30 years. Its application in the pediatric population has allowed the plastic surgeon to achieve functional and esthetic goals that were previously unobtainable. Tissue expansion is a major treatment modality in the management of giant congenital nevi and secondary reconstruction of extensive burn scars, allowing sensate tissue of similar color, texture, and thickness to be used to resurface the affected areas. One must be prepared for complications when using tissue expanders, however, because complications are inherent in the process of expanding skin utilizing repeated filling of implanted foreign bodies. Complication rates increase when serial expansion of the same tissues is performed repeatedly or if expanders are placed in the lower extremities. Outcomes are dependent on thorough planning, meticulous technique, close follow-up, and patient compliance. Tissue expansion has revolutionized plastic surgery in the last 30 years. This technique can be applied to a considerable breadth of reconstructive problems in the pediatric population. Tissue expansion has permitted the plastic surgeon to achieve the goals of reconstruction with tissue of similar color, texture, and thickness, with minimal donor site morbidity. Preservation of sensation in a durable flap has allowed the surgeon to achieve acceptable functional as well as esthetic goals simultaneously.

Microfocal CT: a Method for Evaluating Murine Cranial Sutures in Situ

The Journal of Surgical Research. Feb, 2004  |  Pubmed ID: 15013372

The murine model is a well-established surrogate for studying human cranial suture biology. In mice, all sutures with the exception of the posterior frontal (PF) suture remain patent throughout life. Histology is regarded as the gold standard for analyzing sutures. On this basis, PF suture fusion begins on day of life 25 and is complete by day 45. Cranial suture histology, however, requires sacrifice of the animal to obtain tissue for analysis. As a result, knowledge of the kinetics of cranial suture fusion is based on a patchwork analysis of many sutures from many different animals. The behavior of a single suture through time is unknown. Our goal is to develop a noninvasive means to repeatedly image mouse cranial sutures in vivo. As a first step, the present study was performed to evaluate microfocal computer tomography (micro-CT) technology for the use of capturing images of a mouse cranium in situ.

To Distract or Not to Distract: an Algorithm for Airway Management in Isolated Pierre Robin Sequence

Plastic and Reconstructive Surgery. Apr, 2004  |  Pubmed ID: 15083010

Approaches advocated for treatment of airway obstruction among neonates with Pierre Robin sequence include positioning, tongue-lip adhesion, mandibular distraction, and tracheostomy, with no established guidelines regarding which modality is appropriate for a specific patient. This report proposes an algorithm for the management of neonatal upper airway obstruction among patients with isolated Pierre Robin sequence. Data for 21 patients with isolated Pierre Robin sequence who were treated by one surgeon during a 9-year period were reviewed. Eighteen patients presented during the first 1 week of life and three patients presented late, between 12 and 33 months of age. Follow-up periods ranged from 9 to 70 months (median, 33 months). Successful airway management was achieved with positioning alone for 10 patients, with tongue-lip adhesion for seven of nine patients, with tracheostomy for two patients, and with mandibular distraction for three patients. Changes in the maxillary-mandibular discrepancy were significant with natural mandibular growth during the first 1 year of life (p < 0.0001). Oromotor studies performed 3 months or more after tongue-lip adhesion reversal (n = 9) demonstrated no appreciable deficits in tongue function, relative to other children with cleft lips/palates. A multidisciplinary team should evaluate all patients with isolated Pierre Robin sequence, to fully assess the maxillary-mandibular relationship, anatomically define the site of airway obstruction, and identify feeding difficulties. Patients should be evaluated for episodes of desaturation occurring spontaneously, during feeding, or during sleeping. Patients with desaturation should be further evaluated with double endoscopy (nasoendoscopy and bronchoscopy). If the airway obstruction is localized to the tongue base alone and cannot be controlled with positioning, then tongue-lip adhesion is the initial treatment of choice, because such patients demonstrate significant mandibular growth during the first 1 year of life. Mandibular distraction among neonates is reserved for failures of tongue-lip adhesion in which isolated tongue-base airway obstruction is documented. Neither of the patients who experienced failure of tongue-lip adhesion in this series would have been a candidate for distraction with the algorithm presented. Avoiding routine neonatal distraction serves to avoid facial scarring, nerve and tooth bud injury, and potential disturbances of intrinsic mandibular growth. Patients with persistent respiratory difficulties beyond age 9 months require reevaluation for multiple sites of airway obstruction. Mandibular distraction may be one of several modalities required to avoid tracheostomy for such patients.

TGF-beta1, FGF-2, and Receptor MRNA Expression in Suture Mesenchyme and Dura Versus Underlying Brain in Fusing and Nonfusing Mouse Cranial Sutures

Plastic and Reconstructive Surgery. May, 2004  |  Pubmed ID: 15114129

Recent studies have supported a functional role for the transforming growth factor beta-1 (TGF-beta1) and fibro-blast growth factor 2 (FGF-2) signaling cascades in the process of mouse cranial suture fusion. TGF-beta1 and FGF-2 protein expression have been shown to be elevated in the fusing posterior frontal suture versus the nonfusing sagittal suture. The authors evaluated simultaneous mRNA expression of TGF-beta1 and its R1 receptor and FGF-2 and its R2 receptor during mouse cranial suture fusion. They evaluated the suture mesenchyme-dura complex separately from the underlying brain to determine whether there is tissue-specific biologic activity (i.e., brain versus suture mesenchyme-dura) for each cytokine and receptor. Data were collected from 150 male CD-1 mice studied over five time periods from postnatal days 22 to 45. They utilized reverse-transcriptase polymerase chain reaction as a means to detect TGF-beta1, TGF-beta receptor 1 (TGF-betaR1), FGF-2, and FGF receptor 2 (FGFR2) mRNA expression in mouse cranial tissues, beginning with the period of initiation of posterior frontal cranial suture fusion (postnatal day 22) and extending through completion of posterior frontal suture fusion (postnatal day 45). Expression of FGF-2 was significantly greater in posterior frontal suture mesenchyme and dura compared with sagittal suture mesenchyme and dura during the period of initiation of posterior frontal suture fusion, localizing this cytokine's expression to posterior frontal suture mesenchyme and dura during the process of cranial suture fusion. TGF-beta1 and FGFR2 mRNA expression was found to be up-regulated in posterior frontal suture mesenchyme and dura relative to the underlying brain tissue throughout the study period, whereas TGF-betaR1 and FGF-2 mRNA expression was significantly elevated relative to the underlying brain only at time points corresponding to the initiation of posterior frontal suture fusion (between postnatal days 22 and 31). These results indicate that there is tissue-specific mRNA expression of TGF-beta1, FGF-2, and their receptors between suture mesenchyme and dura and the underlying brain, which correlates with the period of posterior frontal suture fusion in the mouse model. Differences in gene expression between suture mesenchyme and dura relative to the underlying brain may be an important regulator of cranial suture biology. Understanding these differences may eventually help to identify possible targets and time windows by which to most effectively modulate cranial suture fusion.

Biomaterials in Craniofacial Reconstruction

Clinics in Plastic Surgery. Jul, 2004  |  Pubmed ID: 15219744

Biomaterials have become an integral component of craniofacial reconstruction. Their increasing ease of use, long "shelf-life," and safety enables them to be used effectively and play an important role in reducing operating times. There are various biomaterials currently available and specific usages have been characterized well in the literature. This article reviews different biomaterials that can be used in craniofacial reconstruction,including autogenous bone, methyl methacrylate and hard tissue replacement,hydroxyapatite, porous polyethylene, bioactive glass, and demineralized bone.

Bioactive Glass for Bone Replacement in Craniomaxillofacial Reconstruction

Plastic and Reconstructive Surgery. Aug, 2004  |  Pubmed ID: 15277840

Prominent Ears in Children Younger Than 4 Years of Age: What is the Appropriate Timing for Otoplasty?

Plastic and Reconstructive Surgery. Oct, 2004  |  Pubmed ID: 15457011

The present study was conducted to determine whether otoplasty performed in children younger than 4 years of age has an acceptable long-term outcome. This two-part study consisted of (1) a questionnaire mailed to 481 members of the American Association of Plastic Surgeons to ask their opinion on the timing of otoplasty, and (2) a consecutive series of 12 patients who had otoplasty performed before the age of 4 years. The survey demonstrated that the majority (57 percent) of the respondents perform otoplasty on patients who are aged 5 years or older. The prospective series consisted of 12 patients ranging in age from 9 months to 3 years at the time of the procedure. Otoplasty was bilateral in nine patients and unilateral in three patients. Length of follow-up ranged from 21 months to 7(1/2) years, with a median follow-up of 41 months. Growth following otoplasty was evaluated in three patients who underwent unilateral otoplasty by measuring the length of both ears at the time of final follow-up. No difference in ear length was noted between the sides that were and were not operated on during a follow-up period of 46 to 63 months. Noticeable recurrence was noted in only one (8 percent) of 12 patients. In response to a follow-up questionnaire to the patients' families, all respondents (n = 10) stated that if again asked to choose the timing of otoplasty in their children, they would opt to have it performed at the same age of younger than 4 years. Otoplasty can be safely performed at ages younger than previously thought without interfering with growth of the operated ear.

A 1-year Study of Osteoinduction in Hydroxyapatite-derived Biomaterials in an Adult Sheep Model: Part II. Bioengineering Implants to Optimize Bone Replacement in Reconstruction of Cranial Defects

Plastic and Reconstructive Surgery. Oct, 2004  |  Pubmed ID: 15457027

The present study investigated hydroxyapatite biomaterials implanted in critical-size defects in the calvaria of adult sheep to determine the optimal bioengineering of hydroxyapatite composites to facilitate bone ingrowth into these materials. Five calvarial defects measuring 16.8 mm in diameter were made in each of 10 adult sheep. Three defects were filled with cement paste composites of hydroxyapatite and beta-tricalcium phosphate as follows: (1) 100 percent hydroxyapatite-cement paste, (2) 60 percent hydroxyapatite-cement paste, and (3) 20 percent hydroxyapatite-cement paste. One defect was filled with a ceramic composite containing 60 percent hydroxyapatite-ceramic, and the fifth defect remained unfilled. One year after implantation, the volume of all biomaterials was determined by computed tomography, and porosity and bone replacement were determined using backscatter electron microscopy. Computed tomography-based volumetric assessment 1 year after implantation demonstrated that none of the unfilled cranial defects closed over the 1-year period, confirming that these were critical-size defects. There was a significant increase in volume in both the cement paste and ceramic implants containing 60 percent hydroxyapatite (p < 0.01). There was no significant change in volume of the remaining cement paste biomaterials. Analysis of specimens by backscatter electron microscopy demonstrated mean bone replacement of 4.8 +/- 1.4 percent (mean +/- SEM) in 100 percent hydroxyapatite-cement paste, 11.2 +/- 2.3 percent in 60 percent hydroxyapatite-cement paste, and 28.5 +/- 4.5 percent in 20 percent hydroxyapatite-cement paste. There was an inverse correlation between the concentration of hydroxyapatite and the amount of bone replacement in the cement paste for each composite tested (p < 0.01). Bone replacement in 60 percent hydroxyapatite-ceramic composite (13.6 +/- 2.0 percent) was not significantly different from that in 60 percent hydroxyapatite-cement paste. Of note is that the ceramic composite contained macropores (200 to 300 microm) that did not change in size over the 1-year period. All cement paste composites initially contained micropores (3 to 5 nm), which remained unchanged in 100 percent hydroxyapatite-cement paste. Cement paste implants containing increased tricalcium phosphate demonstrated a corresponding increase in macropores following resorption of the tricalcium phosphate component. Bone replacement occurred within the macropores of these implants. In conclusion, there was no significant bone ingrowth into pure hydroxyapatite-cement paste (Bone Source, Stryker-Leibinger Inc., Dallas, Texas) in the present study. The introduction of macropores in a biomaterial can optimize bone ingrowth for reconstruction of critical-size defects in calvaria. This was demonstrated in both the ceramic composite of hydroxyapatite tested and the cement paste composites of hydroxyapatite by increasing the composition of a rapidly resorbing component such as beta-tricalcium phosphate.

Comparison of Canine Mandibular Bone Regeneration by Distraction Osteogenesis Versus Acute Resection and Rigid External Fixation

Plastic and Reconstructive Surgery. Nov, 2004  |  Pubmed ID: 15509937

The present study was performed (1) to explore the mechanism of skeletal healing following distraction osteogenesis of the mandible and to evaluate whether the same process is involved following acute mandibular resection and rigid external fixation, and (2) to examine the role of the periosteum in skeletal healing in both models. The study was performed using 16 mongrel dogs divided into two equal groups. In the first group, distraction of 20 mm was performed at a rate of 1 mm/day. In the second group, bone resection of 20 mm was performed, followed by rigid external fixation. The buccal periosteum was stripped in four dogs from each group, and the periosteum was left intact in the remaining four dogs. Dogs were euthanized after a survival period of either 2 or 3 months, and the new bone regenerate was evaluated. Analysis consisted of three-dimensional computed tomography scanning, histometric analysis, and immunostaining. Analysis of bone mineral content in the residual gap was conducted. Bone mineral content was increased in 3- versus 2-month survival for all groups (p < 0.05). The distracted groups had greater bone mineral content than their acutely resected counterparts, with the difference achieving statistical significance by 3-month survival (p < 0.05). Although periosteal preservation resulted in increased bone mineral content over time for all groups (p = 0.044), periosteal preservation had no significant effect on bone mineral content in the distracted groups. After periosteal stripping, however, bone mineral content was significantly increased in dogs that underwent distraction rather than acute resection and rigid external fixation (p = 0.022). Regarding histometric analysis, analysis of fibrous tissue content in the bone regenerate demonstrated that by 3 months the distracted groups had significantly less fibrous tissue in the new bone regenerate than did the acutely resected groups (p < 0.001). Regarding immunostaining, diffuse localization of transforming growth factor-beta1 was observed in all groups at 2 months, returning to nearly baseline levels by 3 months. These data demonstrate that significant bone formation in a segmental gap can be achieved after acute mandibular resection and rigid external fixation if the periosteum is preserved. However, after periosteal injury or stripping, significant bone formation can only be achieved by distraction osteogenesis. In both processes, bone formation is preceded by up-regulation of transforming growth factor-beta1.

Fibrous Dysplasia of the Face: Utility of Three-dimensional Modeling and Ex Situ Malar Recontouring

The Journal of Craniofacial Surgery. Nov, 2004  |  Pubmed ID: 15547373

A 20-year-old male with fibrous dysplasia involving the right fronto-orbital and malar regions showed no significant progression of disease by serial computed tomography (CT) scans over 6 years. Two prior attempts to recontour the right maxilla and zygoma in situ and to increase the right orbital volume had been unsatisfactory. To solve the problem of persistent right-sided proptosis and facial asymmetry, a three-dimensional model of the midface and orbits was made on the basis of a pre-operative CT scan. Removable components transformed the model of the affected right side of the midface into a mirror image of the unaffected side, giving a precise indication of where and how much bone needed to be removed. Surgical correction was performed using a right malar osteotomy in which the zygoma was mobilized in continuity with the lateral and inferior orbital rims. This approach gave direct access to the orbit, through which the lateral and medial orbital walls were re-contoured to increase intraorbital volume. The freely mobilized zygoma was then shaped to match the prefabricated model. The zygoma was repositioned, and the affected maxilla was recontoured to blend with the remodeled zygoma. Follow-up CT scan and physical examinations postoperatively demonstrate excellent facial symmetry and correction of right-sided proptosis. When there is no documented progression of fibrous dysplasia in the face over several years, three-dimensional modeling as a guide to ex situ malar recontouring can improve the accuracy of facial reconstruction. This approach also provides direct access to the orbit for the correction of bony orbital volume.

Tissue Expansion in Pediatric Patients

Clinics in Plastic Surgery. Jan, 2005  |  Pubmed ID: 15636763

Tissue expansion has become a well-recognized technique for reconstructing a wide variety of skin and soft tissue defects. Its application in the pediatric population has allowed the plastic surgeon to achieve functional and aesthetic goals that were previously unobtainable. This technique can be applied to a variety of reconstructive problems, including the management of giant congenital nevi and the secondary reconstruction of extensive burn scars. This article reviews the use of tissue expansion in the pediatric population, with particular emphasis on indications, operative technique, and regional considerations. The authors also address concerns that have been expressed about the complications associated with this technique.

A Volumetric Analysis of Soft-tissue Changes in the Aging Midface Using High-resolution MRI: Implications for Facial Rejuvenation

Plastic and Reconstructive Surgery. Apr, 2005  |  Pubmed ID: 15793457

The present study evaluated volumetric changes in the aging midface. Both young and old living subjects were studied using high-resolution magnetic resonance imaging (MRI) to investigate the distribution and volume of the muscle and subcutaneous components of the midface.

Cortical Adaptation to Restoration of Smiling After Free Muscle Transfer Innervated by the Nerve to the Masseter

Plastic and Reconstructive Surgery. May, 2005  |  Pubmed ID: 15861049

The child with Möbius syndrome presenting for facial reanimation presents a difficult challenge. When bilateral paralysis and paresis preclude use of the contralateral facial nerve, the authors' preferred donor nerve for reinnervation of free muscle transfer is a branch of the trigeminal nerve, the ipsilateral nerve to the masseter.

Detection of Apoptosis in Fusing Versus Nonfusing Mouse Cranial Sutures

The Journal of Craniofacial Surgery. Jul, 2005  |  Pubmed ID: 16077300

Apoptosis may be involved in maintenance of suture patency. In mice, the posterior frontal suture fuses by postnatal day 45, whereas all remaining cranial sutures remain patent. There are no published reports documenting differences in apoptosis between fusing and nonfusing mouse cranial sutures beyond postnatal day 6 either in vivo or in vitro. In the current study, we hypothesized that apoptosis is required for maintenance of suture patency. We predicted that after normal suture fusion in the mouse, the posterior frontal suture should have fewer apoptotic cells than the sagittal suture. We also hypothesized that all of the sutures should look similar with respect to the number and arrangement of apoptotic cells before suture fusion. The posterior frontal and sagittal sutures were studied on postnatal days 25 and 45. The fragmentation of DNA or terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling assay assay, as well as the presence of BCL-10, a specific apoptotic protein, were localized to the leading edge of the sagittal suture calvaria of postnatal day 45 mice. These apoptotic markers were not visualized within the fused posterior frontal suture of postnatal day 45 mice. Posterior frontal or sagittal suture mesenchyme of postnatal day 25 mice showed similar amounts of apoptotic cells. These data indicate that apoptotic cells are present in the patent sagittal suture beyond the period of posterior frontal suture fusion in the mouse. We conclude that apoptosis is an integral component to maintain suture patency in the mouse calvaria.

Biomaterials for Reconstruction of the Cranial Vault

Plastic and Reconstructive Surgery. Aug, 2005  |  Pubmed ID: 16079708

A 1-year Study of Hydroxyapatite-derived Biomaterials in an Adult Sheep Model: III. Comparison with Autogenous Bone Graft for Facial Augmentation

Plastic and Reconstructive Surgery. Sep, 2005  |  Pubmed ID: 16163093

The present study investigates onlay bone grafts and implants in a large-animal (sheep) model to determine whether there are composite biomaterials that can maximize long-term facial augmentation when compared with conventional bone grafts.

Giant Congenital Melanocytic Nevi of the Trunk and an Algorithm for Treatment

The Journal of Craniofacial Surgery. Sep, 2005  |  Pubmed ID: 16192877

Giant congenital melanocytic nevi (CMN) are rare, congenital, disfiguring lesions with a risk of degeneration to malignant melanoma. Giant CMN are associated with an increased risk of malignant degeneration. In a minority of cases, patients with giant CMN may have associated neurocutaneous melanosis with leptomeningeal involvement. Giant CMN of the trunk pose difficult diagnostic and reconstructive problems requiring complex multistage treatment. For high-risk cases, diagnostic evaluation in the form of neuro-imaging is an essential component of the planning phase. Although nonsurgical options for the treatment of giant CMN have been advocated, these modalities may decrease the burden of nevus cells but do not result in complete removal of these cells. The ability to monitor nevus cells that remain after nonsurgical management of giant CMN remains questionable. These nonsurgical options include dermabrasion, laser ablation, and chemical peel. In contrast, direct excision of the nevus is the mainstay of treatment of nonsurgical management of giant CMN. There are numerous surgical options to resurface the resultant cutaneous defect after excision of the nevus. The simplest of these options consists of serial excision and direct closure of the defect in stages. However, if the defect cannot be closed by direct cutaneous advancement, other options for wound resurfacing include split- or full-thickness skin graft, tissue expansion, and free tissue transfer. Tissue expansion should be viewed as a category of treatment options because expanders can be used to create an expanded full-thickness skin graft, local expanded flaps adjacent to the lesion, or expansion of a free tissue donor site. Given the diversity of reconstructive options that use tissue expansion, these techniques have evolved as the primary treatment method for giant CMN of the trunk. The authors outline an approach to the evaluation of giant CMN of the trunk, review the risks of melanoma and of neurocutaneous melanosis, describe their preferred treatment regimen, and offer a treatment algorithm for giant CMN of the trunk.

Aesthetic and Reconstructive Brow Lift: Current Techniques, Indications, and Applications

Ophthalmic Plastic and Reconstructive Surgery. Nov, 2005  |  Pubmed ID: 16304514

Recurrent Ectopic Calcification Involving the Maxillofacial Skeleton: A Potential Harbinger of Albright's Osteodystrophy

The Journal of Craniofacial Surgery. Jan, 2006  |  Pubmed ID: 16432403

We present a case of osteoma cutis as the initial presenting sign of Albright's osteodystrophy. Albright's osteodystrophy represents a challenge in both diagnosis and treatment because the phenotype manifests as a broad spectrum of biochemical and physical findings. The syndrome may be overlooked, particularly in the early phases when serum calcium and phosphorous levels may be normal. Although surgery is the treatment of osteoma cutis, recurrence is common, creating frustration for the patient's family and the surgeon. In the present case, a girl 4 months and 2 years of age presented with refractory ectopic calcification emanating from the maxilla and demonstrated repeated recurrence after surgical resection. This ectopic calcification was not adequately controlled until Albright's osteodystrophy was properly diagnosed and treated. A differential diagnosis and surgical approach to deal with recurrent ectopic calcification of the facial skeleton is outlined.

Real-time Reverse Transcriptase Polymerase Chain Reaction: an Improvement in Detecting MRNA Levels in Mouse Cranial Tissue

Plastic and Reconstructive Surgery. Jun, 2006  |  Pubmed ID: 16772922

Quantitation of messenger RNA levels has traditionally been carried out by Northern blot analysis. While this is regarded as the standard method, it is time-consuming and requires large quantities of RNA. Reverse-transcriptase polymerase chain reaction is a semiquantitative method that has been used as a more rapid and sensitive alternative to Northern blotting. Real-time reverse-transcriptase polymerase chain reaction is a quantitative technique that is gaining widespread acceptance as a rapid and reliable way of quantifying mRNA. Since both techniques are currently being used to evaluate gene expression in the murine cranial suture model, the present study was performed to compare the sensitivity and variability of real-time to conventional reverse-transcriptase polymerase chain reaction in this model.

An Approach to the Management of Common Vascular Malformations of the Trunk

The Journal of Craniofacial Surgery. Jul, 2006  |  Pubmed ID: 16877931

Vascular anomalies can be classified into two unique groups, hemangiomas and vascular malformations, based on their endothelial properties. The present review will focus on the four most common vascular malformations of the trunk presenting to the Plastic Surgeon: capillary malformations, lymphatic malformations, venous malformations, and arterovenous malformations. We define the trunk as chest, abdomen and back; the principles of breast reconstruction will not be discussed as they have been extensively covered in other publications. Diagnostic and therapeutic modalities will be discussed with pertinent case examples.

A Reinvestigation of Murine Cranial Suture Biology: Microcomputed Tomography Versus Histologic Technique

Plastic and Reconstructive Surgery. Sep, 2006  |  Pubmed ID: 16932170

Histology remains the standard form to analyze cranial suture in murine models, but this technique provides only limited "snapshots" of the entire suture and requires animal euthanasia with tissue destruction. Because of the bone complex microarchitecture, better methods are required to study the behavior of the cranial suture and its surrounding environment. The authors compared microcomputed tomography and histology as techniques to evaluate murine cranial sutures.

Management of the Black Hole in Velopharyngeal Incompetence: Combined Use of a Furlow Palatoplasty and Sphincter Pharyngoplasty

Plastic and Reconstructive Surgery. Apr, 2007  |  Pubmed ID: 17415248

Patients with velopharyngeal incompetence may have a combination of a large velopharyngeal gap and poor lateral wall motion on phonation, simulating a "black hole" on nasendoscopy. Pharyngeal flaps for treatment of velopharyngeal incompetence in these patients are of questionable efficacy, because poor lateral wall motion necessitates such a wide flap that nasal airway obstruction is likely.

Giant Congenital Melanocytic Nevi

Plastic and Reconstructive Surgery. Aug, 2007  |  Pubmed ID: 17632335

After studying this article, the participant should be able to: 1. Define what is meant by a giant congenital melanocytic nevus and understand its histologic properties. 2. Know the natural history and potential complications associated with a giant congenital melanocytic nevus. 3. Outline the nonsurgical and surgical options available to treat a giant congenital melanocytic nevus.

Neurofibromatosis: a Cause of Prepubertal Gynecomastia

Plastic and Reconstructive Surgery. Mar, 2008  |  Pubmed ID: 18317084

Atypical presentations of gynecomastia not associated with obesity are often underappreciated. Unilateral manifestation, prepubertal onset, and a history of associated disorders may contribute to a unique clinical presentation for which the diagnosis and management may remain uncertain. This report reviews neurofibromatosis as a cause for atypical presentation of gynecomastia in prepubertal boys to help establish guidelines for diagnosis and management.

Vascular Malformations

Plastic and Reconstructive Surgery. Apr, 2008  |  Pubmed ID: 18349599

After studying this article, the participant should be able to: 1. Understand the nomenclature and classification system of vascular malformations. 2. Evaluate these patients diagnostically. 3. Outline the surgical and nonsurgical options for treating these lesions.

Magnetic Resonance Imaging As an Aid in the Dynamic Assessment of the Velopharyngeal Mechanism in Children

Plastic and Reconstructive Surgery. Aug, 2008  |  Pubmed ID: 18626376

Pediatric Facial Burns

The Journal of Craniofacial Surgery. Jul, 2008  |  Pubmed ID: 18650717

Despite major advances in the area of burn management, burn injury continues to be a leading cause of pediatric mortality and morbidity. Facial burns in particular are devastating to the affected child and result in numerous physical and psychosocial sequelae. Although many of the principles of adult burn management can be applied to a pediatric patient with facial burns, the surgeon must be cognizant of several important differences. Facial burns and subsequent scar formation can drastically affect the growth potential of a child's face. Structures such as the nose and teeth may become deformed due to abnormal external forces caused by contractures. Serious complications such as occlusion amblyopia and microstomia must be anticipated and urgently addressed to avert permanent consequences, whereas other reconstructive procedures can be delayed until scar maturation occurs. Furthermore, because young children are actively developing the concept of self, severe facial burns can alter a child's sense of identity and place the child at high risk for future emotional and psychologic disturbances. Surgical reconstruction of burn wounds should proceed only after thorough planning and may involve a variety of skin graft, flap, and tissue expansion techniques. The most favorable outcome is achieved when facial resurfacing is performed with respect to the aesthetic units of the face. Children with facial burns remain a considerable challenge to their caregivers, and these patients require long-term care by a multidisciplinary team of physicians and therapists to optimize functional, cosmetic, and psychosocial outcomes.

Beyond the Vernacular: New Sources of Cells for Bone Tissue Engineering

Plastic and Reconstructive Surgery. Sep, 2008  |  Pubmed ID: 18766038

Recent developments in stem cell biology have led to the discovery of new sources of adult stem cells with potential for osteogenic differentiation.

Through-and-through Dissection of the Soft Palate for High Pharyngeal Flap Inset: a New Technique for the Treatment of Velopharyngeal Incompetence in Velocardiofacial Syndrome

Plastic and Reconstructive Surgery. Sep, 2008  |  Pubmed ID: 18766049

Patients with velocardiofacial syndrome often present with refractory velopharyngeal incompetence. Whereas the high wide pharyngeal flap has been advocated for these patients, poor visualization makes high inset of the flap technically difficult. We present a consecutive series of patients with velocardiofacial syndrome and severe velopharyngeal incompetence treated with high inset pharyngeal flap achieved by through-and-through dissection of the soft palate.

Application-specific Selection of Biomaterials for Pediatric Craniofacial Reconstruction: Developing a Rational Approach to Guide Clinical Use

Plastic and Reconstructive Surgery. Jan, 2009  |  Pubmed ID: 19116568

Biomaterials provide an invaluable alternative to autogenous bone graft for pediatric craniofacial reconstruction. However, there is no uniform agreement on the choice of biomaterial for different reconstructive needs.

Biomaterials in Craniofacial Surgery: Experimental Studies and Clinical Application

The Journal of Craniofacial Surgery. Jan, 2009  |  Pubmed ID: 19164984

The increasing variety of biomaterials available to the craniofacial surgeon today, with advantages of "off-the-shelf availability" and lack of donor-site morbidity, provides a formidable armamentarium for applications in reconstruction and augmentation. Although biomaterials are invaluable alternatives to autogenous bone graft, there is lack of uniformity in clinical application. In this article, we review our experience with the use of hydroxyapatite derivatives in animal studies and subsequently discuss our experience with the use of 3 classes of biomaterials (cement pastes, osteoactive biomaterials, and prefabricated polymers) for craniofacial reconstruction. We subsequently offer guidelines to dictate the choice of biomaterials for different applications, based on the site of reconstruction (onlay versus inlay reconstruction) and skeletal maturity.

Review of Pediatric Migraine Headaches Refractory to Medical Management

The Journal of Craniofacial Surgery. Jan, 2009  |  Pubmed ID: 19165008

The surgical treatment of migraine headache is a recent innovation that has broadened the potential patient population who may benefit from craniofacial surgical techniques to millions of affected adults. However, the population at risk in the pediatric age group has not been clearly established. The present retrospective review was performed to provide demographic information of the adolescent migraine in a major children's hospital. This information is essential before considering surgical treatment of migraine in this age group.

Induced Restrictive Lung Disease Secondary to Tissue Expansion in Ischiopagus Conjoined Twins (invited Discussion)

Plastic and Reconstructive Surgery. May, 2009  |  Pubmed ID: 19407640

The Presentation and Management of Hemangiomas

Plastic and Reconstructive Surgery. Jun, 2009  |  Pubmed ID: 19483535

After studying this article, the participant should be able to: (1) Define what is meant by either a classic (infantile) or atypical hemangioma and understand the natural history of each. (2) Identify the common phenotypic, histologic, and radiographic findings of a hemangioma. (3) Know the potential complications associated with hemangiomas. (4) Outline the options available to treat a hemangioma.

Giant Congenital Melanocytic Nevi

Plastic and Reconstructive Surgery. Jul, 2009  |  Pubmed ID: 19568135

: Giant congenital melanocytic nevi are rare lesions with the potential to regress into malignant melanoma and/or neurocutaneous melanosis. Appropriate investigations include a screening magnetic resonance imaging scan, neurologic evaluation, and serial clinical observations looking for the development of these complications. Numerous excisional and nonexcisional options have been described for the management of giant congenital melanocytic nevi.

Supplement: Advances in Pediatric Plastic Surgery

Plastic and Reconstructive Surgery. Jul, 2009  |  Pubmed ID: 19593888

Long-term Solutions for the Delivery of Craniofacial Care in India and the Developing World

The Journal of Craniofacial Surgery. Sep, 2009  |  Pubmed ID: 19816324

An international group of craniofacial surgeons was consulted to identify means of providing care of consistent quality to children with craniofacial anomalies in India and subsequently use this as a model for delivering craniofacial care to children in need throughout the developing world. Three senior craniofacial surgeons were selected from the Medical Advisory Board of the World Craniofacial Foundation to evaluate eligible centers in India. A subcommittee of 10 surgeons from the World Craniofacial Foundation Medical Advisory Board was formed to help develop summary recommendations based on this site visit. These centers were selected after contacting plastic surgeons and orthodontists involved in craniofacial and cleft care throughout India and asking the director of each center to complete a questionnaire documenting their current level of activity. Based on these responses, 3 potential craniofacial centers in India were identified. These sites were selected as potential locations for the development of craniofacial centers that could provide free care to indigent patients who otherwise could not receive treatment. The sites chosen consisted of a private hospital (southern India), a state-run government hospital (central India), and a federal government hospital (northern India). After the site visits, the directors of each of the 3 potential craniofacial centers in India were asked to complete a questionnaire helping to further identify their specific needs. The subcommittee of the World Craniofacial Foundation Medical Advisory Board then developed a set of summary recommendations to help guide the development of regional craniofacial centers in India. We feel that this process will facilitate access to care to indigent children with craniofacial anomalies who would not otherwise be eligible to receive appropriate care.

Assessment of Secondary Cleft Rhinoplasty Using Resorbable Plates at the Age of Primary School

The Journal of Craniofacial Surgery. Sep, 2009  |  Pubmed ID: 19816353

Secondary rhinoplasty after a cleft lip repair remains a significant challenge. We have developed a technique in which resorbable plates are used to support the cleft alar cartilage to minimize relapse. There are few guidelines by which one can objectively assess the outcome of cleft rhinoplasty over time. This study attempts to demonstrate a means by which the symmetry and form of the proposed rhinoplasty technique can be evaluated.

Surgical Management of Congenital Dermatofibrosarcoma Protuberans

Journal of the American Academy of Dermatology. Dec, 2009  |  Pubmed ID: 19925926

Congenital dermatofibrosarcoma protuberans (DFSP) is a rare tumor with varying clinical presentations that is commonly misdiagnosed. Treatment of congenital DFSP is complicated by delays in diagnosis and its propensity for subclinical spread. Of 61 reported cases, 11 (18%) were treated with Mohs micrographic surgery (MMS) and 46 (75%) were treated with wide local excision (WLE). One case was treated with imatinib, and the remaining 3 did not differentiate between receiving MMS or WLE. In the cases of congenital DFSP treated with MMS the clearance rate was 100% with an average follow-up of 4.3 years. The clearance rate seen with WLE was 89% with an average follow-up period of 1.9 years. The average margins taken during MMS (1.7 cm) were smaller than those taken with WLE (2.8 cm). Fifty percent of cases with available follow-up undergoing WLE required multiple surgeries. Based on superior cure rates with long-term follow-up, smaller surgical margins, and fewer surgical sessions, MMS should be considered as first-line treatment for congenital DFSP.

TGF-beta1 RNA Interference in Mouse Primary Dura Cell Culture: Downstream Effects on TGF Receptors, FGF-2, and FGF-R1 MRNA Levels

Plastic and Reconstructive Surgery. Nov, 2009  |  Pubmed ID: 20009832

Transforming growth factor (TGF)-beta1 and fibroblast growth factor (FGF)-2 have both been shown to have significant roles in the regulation of murine calvarial suture fusion. Methods to decrease gene expression of these cytokines and their respective receptors have been established, but because of side effects, clinical applications are limited. In this study, the authors examined the effect of TGF-beta1-specific small interfering RNA (siRNA) on the messenger RNA (mRNA) expression of TGF-beta1, its TGF-betaR1 and TGF-betaR2 receptors, and FGF-2 and its R1 receptor in murine dura cells.

Refinements of Tissue Expansion for Pediatric Forehead Reconstruction: a 13-year Experience

Plastic and Reconstructive Surgery. Nov, 2009  |  Pubmed ID: 20009842

Reconstruction of the forehead in children when 25 percent or more of the forehead is involved presents a complex reconstructive challenge because of the confluence of highly visible aesthetic units. The present study was performed to develop an algorithm for lesions involving 25 percent or more of the forehead.

Nonviral Transfection of Mouse Calvarial Organ in Vitro Using Accell-modified SiRNA

Plastic and Reconstructive Surgery. Feb, 2010  |  Pubmed ID: 19910849

Understanding the biology of cranial suture fusion and the precise role of involved molecules implicated in the process will help to identify key factors involved in regulation of suture fusion. Modulation of these key factors may serve as a tissue-engineering technique to replace the traditional surgical procedures for the correction of premature suture fusion. Modulation of gene expression by RNA interference is a widely used technique with high potential. Because there is no available report of calvarial organ transfection in vitro, the authors studied the development of a successful nonviral delivery technique of small inhibitory RNA (siRNA) to an in vitro calvarial organ culture system.

Discussion: Two-stage Palate Repair with Delayed Hard Palate Closure is Related to Favorable Maxillary Growth in Unilateral Cleft Lip and Palate

Plastic and Reconstructive Surgery. May, 2010  |  Pubmed ID: 20440169

Testing the Critical Size in Calvarial Bone Defects: Revisiting the Concept of a Critical-size Defect

Plastic and Reconstructive Surgery. Jun, 2010  |  Pubmed ID: 20517092

There is a clinical need for bone replacement strategies because of the shortfalls endemic to autologous bone grafting, especially in the pediatric patient population. For the past 25 years, the animal model that has been used to test bone replacement strategies has been the calvarial critical-size defect, based on the initial size of the bone defect. This study was undertaken to test the concept of the critical size in several different models. A review of the theoretical and scientific bases for the critical-size defect was also undertaken.

Maxillary Artery Pseudoaneurysm After Le Fort I Osteotomy: Treatment Using Transcatheter Arterial Embolization

The Journal of Craniofacial Surgery. Jul, 2010  |  Pubmed ID: 20613567

Life-threatening hemorrhage is a rare complication after Le Fort I osteotomy. However, owing to the gravity of this complication, all surgeons who perform Le Fort I osteotomy should be aware of the potential for this complication and options for its resolution. The following case report describes an episode of subacute, life-threatening bleeding, after a Le Fort I osteotomy for the treatment of midface hypoplasia. Emergent angiographic evaluation demonstrated an internal maxillary artery pseudoaneurysm with fistulous drainage via the cavernous sinus. This was treated by arterial embolization in which the pseudoaneurysm was packed with microcoils. This report reaffirms the importance of maintaining a high clinical suspicion for pseudoaneurysm as a possible etiology of delayed postoperative bleeding in patients after craniomaxillofacial surgery.

Vascular Anomalies and Lymphedema

Plastic and Reconstructive Surgery. Aug, 2010  |  Pubmed ID: 20679788

After studying this article, the participant should be able to: 1. Define the difference between vascular tumors and malformations. 2. Distinguish between the natural history of hemangiomas and that of vascular malformations. 3. Identify the different types of hemangiomas and vascular malformations and understand evaluation, treatment, and complications. 4. Understand the role of lymphaticovenular anastomoses in the treatment of extremity lymphedema.

Complications of Mandibular Distraction Osteogenesis

The Journal of Craniofacial Surgery. Sep, 2010  |  Pubmed ID: 20856049

Mandibular hypoplasia, retrognathia, and micrognathia are commonly encountered problems in pediatric plastic surgery. Mandibular distraction osteogenesis (MDO) is a relatively simple technique that allows for correction of the deformity with minimal morbidity. However, MDO can lead to a wide variety of complications.

The Cyrano Nose: Refinements in Surgical Technique and Treatment Approach to Hemangiomas of the Nasal Tip

Plastic and Reconstructive Surgery. Oct, 2010  |  Pubmed ID: 20885249

Nasal tip hemangiomas cause significant parental distress and can negatively affect the psychological development of a child. Treatment is controversial, with numerous modalities available for reconstruction. The authors outline their combined medical and surgical approach to treating nasal tip hemangiomas and describe their preferred surgical technique.

Unilateral Congenital Blepharoptosis Repair by Anterior Levator Advancement and Resection: an Educational Review

Plastic and Reconstructive Surgery. Oct, 2010  |  Pubmed ID: 20885254

Simple congenital blepharoptosis is caused by levator muscle dysgenesis and commonly presents unilaterally. A complete preoperative evaluation, including ophthalmic, neurologic, and levator function examinations, is essential for ensuring proper diagnosis and selecting the correct procedure. Correction is frequently delayed until the anatomical structures of the eye are fully developed and the child can cooperate with the preoperative examination between the ages of 3 and 5 years, except in cases of visual disturbances. After the preoperative evaluation, the proper treatment can be selected from commonly described procedures, including levator advancement, tarsomyectomy, and frontalis suspension.

History of the Kleeblattschädel Deformity: Origin of Concepts and Evolution of Management in the Past 50 Years

Neurosurgical Focus. Dec, 2010  |  Pubmed ID: 21121721

The history and evolution of surgical strategies for the treatment of Kleeblattschädel deformity are not well described in the medical literature. Kleeblattschädel anomaly is one of the most formidable of the craniosynostoses, requiring a multidisciplinary team for surgical treatment. The initial descriptions of this cloverleaf deformity and the evolution of surgical treatment are detailed in the present report. Two illustrative cases of Kleeblattschädel deformity, syndromic and nonsyndromic craniosynostoses treated by the senior authors, are also described along with insights into operative strategies.

Free Anterolateral Thigh Flap in Pediatric Patients

Annals of Plastic Surgery. Feb, 2011  |  Pubmed ID: 21178758

The anterolateral thigh (ALT) flap represents a workhorse flap in reconstructive surgery. We describe our clinical experience with this flap in the pediatric population. A total of 20 patients with an average age of 9.5 years underwent a free ALT flap reconstruction. All flaps were commonly raised on 2 perforators. About 5 flaps were employed for head and neck reconstruction, 7 for upper and 8 for lower limb reconstruction. Traumatic defects and congenital malformations represented the predominant etiology. Sizable perforators were found in all patients. The caliber was smaller compared to adults, and the course of the perforator was shorter. There were no complete flap losses and no significant donor-site morbidity. Donor-site closure required closure with split-thickness skin grafts in 6 cases. Hypertrophic scars developed in 4 patients. Secondary procedures included flap debulking (5) and Z-plasties (2). In conclusion, children have well-developed perforators supplying the ALT flap. With proper technique, this flap can be harvested and employed safely and reliably for reconstruction of varied defects in children.

An Evidence-based Approach to Craniosynostosis

Plastic and Reconstructive Surgery. Feb, 2011  |  Pubmed ID: 21285796

The Maintenance of Certification module series is designed to help the clinician structure his or her study in specific areas appropriate to his or her clinical practice. This article is prepared to accompany practice-based assessment of preoperative assessment, anesthesia, surgical treatment plan, perioperative management, and outcomes. In this format, the clinician is invited to compare his or her methods of patient assessment and treatment, outcomes, and complications, with authoritative, information-based references. This information base is then used for self-assessment and benchmarking in parts II and IV of the Maintenance of Certification process of the American Board of Plastic Surgery. This article is not intended to be an exhaustive treatise on the subject. Rather, it is designed to serve as a reference point for further in-depth study by review of the reference articles presented.

Volunteers in Plastic Surgery Guidelines for Providing Surgical Care for Children in the Less Developed World

Plastic and Reconstructive Surgery. Jun, 2011  |  Pubmed ID: 21311389

A significant need is met by volunteer groups who provide free reconstructive plastic surgery for underserved children in developing countries. However, at present there are no consistent guidelines for volunteer groups in plastic surgery seeking to provide high-quality and safe care.

Regulation of Osteogenesis and Survival Within Bone Grafts to the Calvaria: the Effect of the Dura Versus the Pericranium

Plastic and Reconstructive Surgery. Jul, 2011  |  Pubmed ID: 21399563

The present study evaluates the isolated role of dura and pericranium in the survival of fresh (osteoblasts viable) and frozen (osteoblasts nonviable) bone grafts.

Mechanical Analysis of Resorbable Plates for Long-term Soft-tissue Molding

The Journal of Craniofacial Surgery. Mar, 2011  |  Pubmed ID: 21403530

Resorbable plates are used with increasing frequency in pediatric craniofacial surgery. A recent innovation has been the use of these plates in long-term soft-tissue molding. However, these plates were not designed for these applications, and an unanswered question remains the mechanical rigidity and stability of the plate when placed in a prolonged out-of-plane bend.

Application of Micro-computed Tomographic Scanning to Characterize Patterns of Murine Cranial Suture Fusion

Plastic and Reconstructive Surgery. May, 2011  |  Pubmed ID: 21532414

In the murine model of suture fusion, it is widely accepted that the posterior frontal suture progresses from a state of patency on day 25 through complete fusion by day 45. The present study was performed to evaluate the process of normal posterior frontal suture fusion and to quantitate patterns of suture morphology in prefusion and postfusion mouse calvariae.

Molecular Signaling in Pathogenesis of Craniosynostosis: the Role of Fibroblast Growth Factor and Transforming Growth Factor-β

Neurosurgical Focus. Aug, 2011  |  Pubmed ID: 21806346

The interplay of signals between dura mater, suture mesenchyme, and brain is essential in determining the fate of cranial sutures and the pathogenesis of premature suture fusion leading to craniosynostosis. At the forefront of research into suture fusion is the role of fibroblast growth factor and transforming growth factor-β, which have been found to be critical in the cell-signaling cascade involved in aberrant suture fusion. In this review, the authors discuss recent and ongoing research into the role of fibroblast growth factor and transforming growth factor-β in the etiopathogenesis of craniosynostosis.

Volunteers in Plastic Surgery Guidelines for Providing Surgical Care for Children in the Less Developed World: Part II. Ethical Considerations

Plastic and Reconstructive Surgery. Sep, 2011  |  Pubmed ID: 21865995

Many international volunteer groups provide free reconstructive plastic surgery for the poor and underserved in developing countries. An essential issue in providing this care is that it meets consistent guidelines for both quality and safety-a topic that has been addressed previously. An equally important consideration is how to provide that care in an ethical manner. No literature presently addresses the various issues involved in making those decisions.

Discussion: Oral Prednisolone for Infantile Hemangioma: Efficacy and Safety Using a Standardized Treatment Protocol

Plastic and Reconstructive Surgery. Sep, 2011  |  Pubmed ID: 21866002

The Bioethics of Separating Conjoined Twins in Plastic Surgery

Plastic and Reconstructive Surgery. Oct, 2011  |  Pubmed ID: 21921746

The incidence of craniopagus twins approximates four to six per 10 million births. Although rare, surgical separation of conjoined twins poses significant technical and ethical challenges. The present report uses the case of craniopagus twins AD and TD to examine the bioethical issues faced by a multidisciplinary medical team in planning the separation of craniopagus twins. AD and TD are craniopagus twins conjoined at the head. TD's head is conjoined to the back of AD's head. Neurologically, AD has the dominant cerebral circulation. TD has two normal kidneys, whereas AD has none. AD depends on TD's renal function and, on separation, will require either a kidney transplant or lifelong dialysis. This case report reviews one approach to analyzing and solving complex ethical dilemmas in pediatric plastic surgery. The principles reviewed are (1) autonomy and informed consent, focusing especially on the role of children in the informed consent process; (2) beneficence and nonmaleficence, two intricately intertwined principles because separation could potentially cause irreversible harm to one twin while improving the quality of life for the other (as separation is not a life-saving procedure, is it ethical to perform a procedure with unknown surgical risk to improve children's quality of life?); and (3) justice (is it fair to allocate excessive medical resources for the twins' separation?). The present report explores the ethics behind such decisions with respect to the separation of conjoined twins.

Maintenance of Certification in Plastic Surgery: is There Anything in It for Me?

Plastic and Reconstructive Surgery. Oct, 2011  |  Pubmed ID: 21921774

Discussion. Measuring Quality of Life in Cleft Lip and Palate Patients: Currently Available Patient-reported Outcomes Measures

Plastic and Reconstructive Surgery. Nov, 2011  |  Pubmed ID: 22030514

Growing Skin: A Computational Model for Skin Expansion in Reconstructive Surgery

Journal of the Mechanics and Physics of Solids. Oct, 2011  |  Pubmed ID: 22081726

The goal of this manuscript is to establish a novel computational model for stretch-induced skin growth during tissue expansion. Tissue expansion is a common surgical procedure to grow extra skin for reconstructing birth defects, burn injuries, or cancerous breasts. To model skin growth within the framework of nonlinear continuum mechanics, we adopt the multiplicative decomposition of the deformation gradient into an elastic and a growth part. Within this concept, we characterize growth as an irreversible, stretch-driven, transversely isotropic process parameterized in terms of a single scalar-valued growth multiplier, the in-plane area growth. To discretize its evolution in time, we apply an unconditionally stable, implicit Euler backward scheme. To discretize it in space, we utilize the finite element method. For maximum algorithmic efficiency and optimal convergence, we suggest an inner Newton iteration to locally update the growth multiplier at each integration point. This iteration is embedded within an outer Newton iteration to globally update the deformation at each finite element node. To demonstrate the characteristic features of skin growth, we simulate the process of gradual tissue expander inflation. To visualize growth-induced residual stresses, we simulate a subsequent tissue expander deflation. In particular, we compare the spatio-temporal evolution of area growth, elastic strains, and residual stresses for four commonly available tissue expander geometries. We believe that predictive computational modeling can open new avenues in reconstructive surgery to rationalize and standardize clinical process parameters such as expander geometry, expander size, expander placement, and inflation timing.

Growing Skin: Tissue Expansion in Pediatric Forehead Reconstruction

Biomechanics and Modeling in Mechanobiology. Jul, 2012  |  Pubmed ID: 22052000

Tissue expansion is a common surgical procedure to grow extra skin through controlled mechanical over-stretch. It creates skin that matches the color, texture, and thickness of the surrounding tissue, while minimizing scars and risk of rejection. Despite intense research in tissue expansion and skin growth, there is a clear knowledge gap between heuristic observation and mechanistic understanding of the key phenomena that drive the growth process. Here, we show that a continuum mechanics approach, embedded in a custom-designed finite element model, informed by medical imaging, provides valuable insight into the biomechanics of skin growth. In particular, we model skin growth using the concept of an incompatible growth configuration. We characterize its evolution in time using a second-order growth tensor parameterized in terms of a scalar-valued internal variable, the in-plane area growth. When stretched beyond the physiological level, new skin is created, and the in-plane area growth increases. For the first time, we simulate tissue expansion on a patient-specific geometric model, and predict stress, strain, and area gain at three expanded locations in a pediatric skull: in the scalp, in the forehead, and in the cheek. Our results may help the surgeon to prevent tissue over-stretch and make informed decisions about expander geometry, size, placement, and inflation. We anticipate our study to open new avenues in reconstructive surgery and enhance treatment for patients with birth defects, burn injuries, or breast tumor removal.

Cosmetic Surgery in the Adolescent Patient

Plastic and Reconstructive Surgery. Jan, 2012  |  Pubmed ID: 22186528

Individuals younger than 18 years represent an increasing number of cosmetic surgery patients. The goals of this article are to address the unique psychological aspects of teens and cosmetic surgery; to understand literature related to adolescents and cosmetic surgery; and to consider methods for evaluating adolescents who present for cosmetic surgery, specifically focusing on nasal and breast procedures.

Use of Intraoral Miniplates to Control Postoperative Occlusion After High Condylectomy for the Treatment of Condylar Hyperplasia

The Journal of Craniofacial Surgery. Mar, 2012  |  Pubmed ID: 22421836

Mandibular condylar hyperplasia is a rare disorder, characterized by unilateral mandibular overgrowth with overeruption of the dentition on the affected side. Although the etiology is unclear, multiple surgical techniques have been described to correct the associated mandibular bone, occlusal, and soft tissue deformities. Often a condylectomy, to arrest mandibular growth, is combined with various orthognathic procedures to restore occlusion and facial harmony. Here we report our technique of isolated high condylectomy with simultaneous intraoral placement of maxillary and mandibular miniplates. Each plate has an intraoral extension that allows our orthodontists to develop vertical force vectors to intrude the maxillary and mandibular molar segments. Using this combined surgical and orthodontic technique, we were able to postoperatively control the occlusal cant, restore the dental midline, improve facial aesthetics, and resolve the patient's contralateral temporomandibular joint dysfunction without concomitant orthognathic surgery. As a result of our findings, we are currently using, and would recommend, this technique for patients requiring surgical-orthodontic intervention for other conditions.

Distinguishing Anatomic Features of Pediatric Facial Trauma

The Journal of Craniofacial Surgery. May, 2012  |  Pubmed ID: 22565864

Propranolol Induces Regression of Hemangioma Cells Through HIF-1α-mediated Inhibition of VEGF-A

Annals of Surgery. Jul, 2012  |  Pubmed ID: 22580939

To investigate the mechanism of propranolol on regression of infantile hemangiomas.

Giant Nevus Sebaceus: Definition, Surgical Techniques, and Rationale for Treatment

Plastic and Reconstructive Surgery. Aug, 2012  |  Pubmed ID: 22842426

A reduction in the reported incidence of malignant degeneration within nevus sebaceus has led many physicians to recommend serial clinical evaluation and biopsy of suspicious areas rather than prophylactic surgical excision. Unfortunately, no well-defined inclusion criteria, including lesion size and location, have been described for the management of nevus sebaceus.

Current Approaches to Management of Nonsyndromic Craniosynostosis

Current Opinion in Otolaryngology & Head and Neck Surgery. Aug, 2012  |  Pubmed ID: 22894999

Surgical alternatives to traditional cranial vault remodeling for the treatment of craniosynostosis are being discussed in recent plastic and neurosurgical literature. This review highlights recent developments and discusses the risks as well as benefits of each.

Discussion: How "successful" is Calvarial Reconstruction Using Frozen Autologous Bone?

Plastic and Reconstructive Surgery. Nov, 2012  |  Pubmed ID: 23096612

Interstitial Pneumonitis After Betadine Aspiration

The Journal of Craniofacial Surgery. Nov, 2012  |  Pubmed ID: 23147337

Disinfection of the face and mucosa lined surfaces of the nose and mouth using a povidone-iodine (PI) or Betadine solution is common practice among head and neck surgeons. Povidone-iodine, which is a highly effective broad-spectrum antibiotic effective against bacteria, viruses, fungi, and protozoa, decreases the risk of postoperative surgical wound infection. We report a case of PI aspiration causing an acute chemical pneumonitis after preoperative disinfection of the oral cavity and nasopharynx in preparation for cleft palate repair. As a result of the inflammatory response, the patient required positive pressure mechanical ventilation and a prolonged stay in the pediatric intensive care unit. The patient was safely extubated on hospital day 7 and discharged on hospital day 10 without any long-term sequelae on follow-up. We also review the 3 other reported cases of PI aspiration pneumonitis. Based on our case report and literature review, we conclude that PI aspiration is associated with a high rate of morbidity; however, this should not preclude the use of PI before surgery, given its effectiveness as an oral disinfectant and the exceedingly low incidence of aspiration.

Stretching Skin: The Physiological Limit and Beyond

International Journal of Non-linear Mechanics. Oct, 2012  |  Pubmed ID: 23459410

The goal of this manuscript is to establish a novel computational model for skin to characterize its constitutive behavior when stretched within and beyond its physiological limits. Within the physiological regime, skin displays a reversible, highly nonlinear, stretch locking, and anisotropic behavior. We model these characteristics using a transversely isotropic chain network model composed of eight wormlike chains. Beyond the physiological limit, skin undergoes an irreversible area growth triggered through mechanical stretch. We model skin growth as a transversely isotropic process characterized through a single internal variable, the scalar-valued growth multiplier. To discretize the evolution of growth in time, we apply an unconditionally stable, implicit Euler backward scheme. To discretize it in space, we utilize the finite element method. For maximum algorithmic efficiency and optimal convergence, we suggest an inner Newton iteration to locally update the growth multiplier at each integration point. This iteration is embedded within an outer Newton iteration to globally update the deformation at each finite element node. To illustrate the characteristic features of skin growth, we first compare the two simple model problems of displacement- and force-driven growth. Then, we model the process of stretch-induced skin growth during tissue expansion. In particular, we compare the spatio-temporal evolution of stress, strain, and area gain for four commonly available tissue expander geometries. We believe that the proposed model has the potential to open new avenues in reconstructive surgery and rationalize critical process parameters in tissue expansion, such as expander geometry, expander size, expander placement, and inflation timing.

A 9-year Comparison of Practice Profiles of Candidates for Primary and Recertification Examinations of the American Board of Plastic Surgery Relative to Economic Indicators

Plastic and Reconstructive Surgery. Mar, 2013  |  Pubmed ID: 23446593

This study compared the practice profiles of plastic surgeons applying for recertification/maintenance of certification with those applying for primary certification by the American Board of Plastic Surgery between 2003 and 2011.

Volumetric Analysis of Simulated Alveolar Cleft Defects and Bone Grafts Using Cone Beam Computed Tomography

Plastic and Reconstructive Surgery. Apr, 2013  |  Pubmed ID: 23542257

Cone beam computed tomography allows for a significantly lower radiation dose than conventional computed tomographic scans, with generation of accurate images of the maxillofacial skeleton. The authors investigated its accuracy in the volumetric analysis of alveolar cleft defects and simulated bone grafts.

Growth on Demand: Reviewing the Mechanobiology of Stretched Skin

Journal of the Mechanical Behavior of Biomedical Materials. Dec, 2013  |  Pubmed ID: 23623569

Skin is a highly dynamic, autoregulated, living system that responds to mechanical stretch through a net gain in skin surface area. Tissue expansion uses the concept of controlled overstretch to grow extra skin for defect repair in situ. While the short-term mechanics of stretched skin have been studied intensely by testing explanted tissue samples ex vivo, we know very little about the long-term biomechanics and mechanobiology of living skin in vivo. Here we explore the long-term effects of mechanical stretch on the characteristics of living skin using a mathematical model for skin growth. We review the molecular mechanisms by which skin responds to mechanical loading and model their effects collectively in a single scalar-valued internal variable, the surface area growth. This allows us to adopt a continuum model for growing skin based on the multiplicative decomposition of the deformation gradient into a reversible elastic and an irreversible growth part. To demonstrate the inherent modularity of this approach, we implement growth as a user-defined constitutive subroutine into the general purpose implicit finite element program Abaqus/Standard. To illustrate the features of the model, we simulate the controlled area growth of skin in response to tissue expansion with multiple filling points in time. Our results demonstrate that the field theories of continuum mechanics can reliably predict the manipulation of thin biological membranes through mechanical overstretch. Our model could serve as a valuable tool to rationalize clinical process parameters such as expander geometry, expander size, filling volume, filling pressure, and inflation timing to minimize tissue necrosis and maximize patient comfort in plastic and reconstructive surgery. While initially developed for growing skin, our model can easily be generalized to arbitrary biological structures to explore the physiology and pathology of stretch-induced growth of other living systems such as hearts, arteries, bladders, intestines, ureters, muscles, and nerves.

Secondary Cleft Nasoplasty at Primary School Age: Quantitative Evaluation of the Efficacy of Resorbable Plates

Plastic and Reconstructive Surgery. Oct, 2013  |  Pubmed ID: 24076684

Secondary cleft nasal deformity in children of primary school age can result in permanent impact to a child's self-esteem. The ideal technique and timing of addressing the deformity remain controversial, as harvest of septal cartilage affects nasal growth and limits future options.

Evidence-based Medicine: Cleft Palate

Plastic and Reconstructive Surgery. Dec, 2013  |  Pubmed ID: 24281590

After reading this article, the participant should be able to: 1. Describe recent changes in treatment of cleft palate. 2. Compare the efficacy of different surgical treatments. 3. Assess their own knowledge of cleft palate repair. 4. Determine where further individual in-depth study and development are warranted.

Surgical Management of Velopharyngeal Insufficiency

Clinics in Plastic Surgery. Apr, 2014  |  Pubmed ID: 24607193

The primary goal of cleft palate repair is to create an anatomically and functionally intact palate while minimally affecting maxillary growth and development. In order to produce normal speech, a child must have velopharyngeal competence, defined as the ability to completely close the velopharyngeal sphincter that separates the oropharynx and nasopharynx. The absence of this ability, termed velopharyngeal insufficiency (VPI), is seen in a wide range of patients following primary cleft palate repair. This article discusses patient assessment, treatment options, and the surgical management of VPI. Recent trends and future directions in management are also presented.

Priorities for the Education of Members of the American Society of Maxillofacial Surgery

The Journal of Craniofacial Surgery. May, 2014  |  Pubmed ID: 24670278

We present the complete results of our 2013 survey of the members of the American Society of Maxillofacial Surgery (ASMS). We surveyed all 799 members of the Society from around the world regarding educational themes and modalities they wish to add to future ASMS educational programs. We also asked our members about surgical modalities and care paths in which they have the most expertise. The objective of the survey was to provide data that can be used to improve the education and training of the ASMS members. The results suggest that some widely taught topics perhaps should be taught less, whereas coverage of other topics should be increased.

Reply: To Reduce the Secondary Revision Cleft Rhinoplasty Rate by Special Orbicularis Reconstruction

Plastic and Reconstructive Surgery. May, 2014  |  Pubmed ID: 24776586

Discussion: The Surgical Correction of Pierre Robin Sequence: Mandibular Distraction Osteogenesis Versus Tongue-lip Adhesion

Plastic and Reconstructive Surgery. Jun, 2014  |  Pubmed ID: 24867725

Application of Finite Element Modeling to Optimize Flap Design with Tissue Expansion

Plastic and Reconstructive Surgery. Oct, 2014  |  Pubmed ID: 24945952

Tissue expansion is a widely used technique to create skin flaps for the correction of sizable defects in reconstructive plastic surgery. Major complications following the inset of expanded flaps include breakdown and uncontrolled scarring secondary to excessive tissue tension. Although it is recognized that mechanical forces may significantly impact the success of defect repair with tissue expansion, a mechanical analysis of tissue stresses has not previously been attempted. Such analyses have the potential to optimize flap design preoperatively.

Characterization of Living Skin Using Multi-view Stereo and Isogeometric Analysis

Acta Biomaterialia. Nov, 2014  |  Pubmed ID: 25016279

Skin is our interface with the outside world. In its natural environment, it displays unique mechanical characteristics, such as prestretch and growth. While there is a general agreement on the physiological importance of these features, they remain poorly characterized, mainly because they are difficult to access with standard laboratory techniques. Here we present a new, inexpensive technique to characterize living skin using multi-view stereo and isogeometric analysis. Based on easy-to-create hand-held camera images, we quantify prestretch, deformation and growth in a controlled porcine model of chronic skin expansion. Over a period of 5 weeks, we gradually inflate an implanted tissue expander, take weekly photographs of the experimental scene, reconstruct the geometry from a tattooed surface grid and create parametric representations of the skin surface. After 5 weeks of expansion, our method reveals an average area prestretch of 1.44, an average area stretch of 1.87 and an average area growth of 2.25. Area prestretch is maximal in the ventral region with a value of 2.37, whereas area stretch and area growth are maximal above the center of the expander, with values of 4.05 and 4.81, respectively. Our study has immediate impact on understanding living skin to optimize treatment planning and decision making in plastic and reconstructive surgery. Beyond these direct implications, our experimental design has broad applications in clinical research and basic sciences: it serves as a simple, robust, low cost, easy-to-use tool to reconstruct living membranes, which are difficult to characterize in a conventional laboratory setup.

Primary Correction of Nasal Asymmetry in Patients with Unilateral Coronal Synostosis

Plastic and Reconstructive Surgery. Aug, 2014  |  Pubmed ID: 25068328

The optimal strategy for correction of significant nasal angulation in patients with unilateral coronal synostosis remains controversial. The authors report a novel technique for correction of significant nasal angulation in these patients, in which dissection of the nasal bones is limited to the site of the osteotomy, maintaining continuity with the soft-tissue envelope and the nasal cartilages.

Computational Modeling of Skin: Using Stress Profiles As Predictor for Tissue Necrosis in Reconstructive Surgery

Computers & Structures. Sep, 2014  |  Pubmed ID: 25225454

Local skin flaps have revolutionized reconstructive surgery. Mechanical loading is critical for flap survival: Excessive tissue tension reduces blood supply and induces tissue necrosis. However, skin flaps have never been analyzed mechanically. Here we explore the stress profiles of two common flap designs, direct advancement flaps and double back-cut flaps. Our simulations predict a direct correlation between regions of maximum stress and tissue necrosis. This suggests that elevated stress could serve as predictor for flap failure. Our model is a promising step towards computer-guided reconstructive surgery with the goal to minimize stress, accelerate healing, minimize scarring, and optimize tissue use.

Evidence-based Medicine: Orbital Floor Fractures

Plastic and Reconstructive Surgery. Dec, 2014  |  Pubmed ID: 25415098

After studying this article, the participant should be able to: 1. Explain the epidemiology, anatomy, and pathophysiology of orbital floor fractures. 2. Select the optimal timing of--and understand the indications for-operative repair of orbital floor fractures. 3. List advantages and disadvantages of the surgical approaches and materials available for orbital floor reconstruction. 4. Identify special considerations in treating pediatric patients presenting with orbital floor fractures.

Abstract 52: Mutating Fibroblast Growth Factor Receptor 1 (fgfr1) in Zebrafish to Create a New Model of Craniosynostosis

Plastic and Reconstructive Surgery. Mar, 2014  |  Pubmed ID: 25942163

Abstract 68: Identification of Twist Expression Patterns and Localized Manipulation of Fgfr1 Expression in Zebrafish Cranial Sutures

Plastic and Reconstructive Surgery. Mar, 2014  |  Pubmed ID: 25942179

Abstract 76: Modeling Craniosynostosis in Zebrafish Using the Genome Editing Technique CRISPR

Plastic and Reconstructive Surgery. Mar, 2014  |  Pubmed ID: 25942187

Double-Opposing Z-Palatoplasty for Secondary Surgical Management of Velopharyngeal Incompetence in the Absence of a Primary Furlow Palatoplasty

The Cleft Palate-craniofacial Journal : Official Publication of the American Cleft Palate-Craniofacial Association. Sep, 2015  |  Pubmed ID: 25244657

The present study was performed to identify factors that lead to a favorable outcome of postpalatoplasty velopharyngeal incompetence using the double-opposing Z-palatoplasty.

The Academic Scholar Award of the American Association of Plastic Surgeons: the First 20 Years

Plastic and Reconstructive Surgery. Feb, 2015  |  Pubmed ID: 25626829

This study evaluated the 20-year history of the American Association of Plastic Surgeons Academic Scholar Award from 1992 through 2012, to assess the program's value and justify future investment.

Multi-view Stereo Analysis Reveals Anisotropy of Prestrain, Deformation, and Growth in Living Skin

Biomechanics and Modeling in Mechanobiology. Oct, 2015  |  Pubmed ID: 25634600

Skin expansion delivers newly grown skin that maintains histological and mechanical features of the original tissue. Although it is the gold standard for cutaneous defect correction today, the underlying mechanisms remain poorly understood. Here we present a novel technique to quantify anisotropic prestrain, deformation, and growth in a porcine skin expansion model. Building on our recently proposed method, we combine two novel technologies, multi-view stereo and isogeometric analysis, to characterize skin kinematics: Upon explantation, a unit square retracts ex vivo to a square of average dimensions of [Formula: see text]. Upon expansion, the unit square deforms in vivo into a rectangle of average dimensions of [Formula: see text]. Deformations are larger parallel than perpendicular to the dorsal midline suggesting that skin responds anisotropically with smaller deformations along the skin tension lines. Upon expansion, the patch grows in vivo by [Formula: see text] with respect to the explanted, unexpanded state. Growth is larger parallel than perpendicular to the midline, suggesting that elevated stretch activates mechanotransduction pathways to stimulate tissue growth. The proposed method provides a powerful tool to characterize the kinematics of living skin. Our results shed light on the mechanobiology of skin and help us to better understand and optimize clinically relevant procedures in plastic and reconstructive surgery.

Evolution of Practice Patterns in Plastic Surgery Using Current Procedural Terminology Mapping: a 9-year Analysis of Cases Submitted by Primary and Recertification Candidates to the American Board of Plastic Surgery

Plastic and Reconstructive Surgery. Mar, 2015  |  Pubmed ID: 25719727

Understanding plastic surgery practice patterns allows the specialty to detect subtle shifts in the market and develop proactive strategies to maintain market share.

The Role of Smile Train and the Partner Hospital Model in Surgical Safety, Collaboration, and Quality in the Developing World

The Journal of Craniofacial Surgery. Jun, 2015  |  Pubmed ID: 26080141

The partner hospital model identifies hospitals in the developing world to educate and enable local surgeons to deliver effective cleft care. This study aimed to determine the outcomes of this model on safety, education, and quality of surgical care.

Early Postoperative Complications Following Gracilis Free Muscle Transfer for Facial Reanimation: A Systematic Review and Pooled Data Analysis

Journal of Reconstructive Microsurgery. Oct, 2015  |  Pubmed ID: 26220430

Multiple studies have detailed promising smile restoration following gracilis free muscle transfer for facial reanimation but information detailing the potential complications is lacking. The aim of this study is to systematically review the literature to evaluate the reported complication rate associated with this procedure. We also aim to determine the most common occurring complications.

Assessing the Impact of Blood Loss in Cranial Vault Remodeling: A Risk Assessment Model Using the 2012 to 2013 Pediatric National Surgical Quality Improvement Program Data Sets

Plastic and Reconstructive Surgery. Dec, 2015  |  Pubmed ID: 26267397

Most cranial vault remodeling for craniosynostosis is associated with substantial blood loss necessitating transfusion. The transfusion of over 25 ml/kg of red blood cells has long been considered an important safety threshold and has been proposed as a potential marker of health care quality, despite a lack of evidence. The authors sought to ascertain risk factors for transfusion in cranial vault remodeling and to quantify the effect of transfusion volume on postoperative complications.

Assessment of Head Shape by Craniofacial Teams: Structuring Practice Parameters to Optimize Efficiency

The Journal of Craniofacial Surgery. Sep, 2015  |  Pubmed ID: 26267560

Since the initiation of the "Back to Sleep Campaign" by the American Academy of Pediatrics in 1992, the incidence of referrals for positional plagiocephaly has increased by 600%. Although patients with positional plagiocephaly rarely require operative intervention, they often do require treatment with cranial molding helmets or positioning changes. The increased volume of patients makes the task of separating cases of craniosynostosis from positional head shape problems more difficult. The authors sought to determine how providers are handling this increased workload of head shape abnormality patients, especially with respect to the largest practices.

Classification and Management of Metopic Craniosynostosis

The Journal of Craniofacial Surgery. Sep, 2015  |  Pubmed ID: 26267575

In the craniofacial surgery literature, there is a wide disparity of opinions regarding the management of nonsyndromic metopic synostosis. With the lack of level I evidence to support a particular regimen, we aimed to elucidate the current state of practice among craniofacial surgeons with the hope of establishing a standard of care.

Thirty Years of Prenatal Cleft Diagnosis: What Have We Learned?

Plastic and Reconstructive Surgery. Sep, 2015  |  Pubmed ID: 26313826

Prenatal ultrasound diagnosis of cleft lip with or without cleft palate has received little attention in the plastic surgery literature despite its initial description more than 30 years ago. With more families presenting in the prenatal period, it is critical for plastic surgeons to understand the techniques in use today for prenatal cleft diagnosis as well as their associated limitations. Moreover, it is incumbent on surgeons to understand the implications of the diagnosis as well as how to appropriately counsel affected families, including how to handle questions pertaining to termination. A comprehensive review was initiated to educate plastic surgeons with respect to these aims. The following points may be inferred: (1) Based on the rates of associated anomalies in low-risk screened populations, as opposed to the high-risk groups in previous reports, prenatally detected clefts do not appear intrinsically different from historically described cohorts; (2) in the absence of structural anomalies, chromosomal anomalies in prenatally detected cleft patients are rare; (3) ultrasound detection rates are highly variable across studies (10 percent to 90 percent); (4) reporting errors range from 10 percent to 60 percent and largely relate to characterization of the secondary palate; (5) accuracy is improving with the adoption of newer technologies, including three-dimensional ultrasound; and (6) prenatal diagnosis enables counseling and a sense of preparedness for the majority of affected families and only rarely results in termination for isolated clefts.

Modeling Tissue Expansion with Isogeometric Analysis: Distinguishing True Skin Growth from Elastic Skin Stretch

Plastic and Reconstructive Surgery. Oct, 2015  |  Pubmed ID: 26397523

Assessing the Impact of Blood Loss in Cranial Vault Remodeling: A Risk Assessment Model Using the 2012-2013 Pediatric National Surgical Quality Improvement Program Datasets

Plastic and Reconstructive Surgery. Oct, 2015  |  Pubmed ID: 26397536

Genetics of Cleft Palate and Velopharyngeal Insufficiency

Journal of Pediatric Genetics. Mar, 2015  |  Pubmed ID: 27617110

Velopharyngeal insufficiency (VPI) can occur in the setting of an unrepaired or repaired cleft lip and palate. The rate of VPI has been documented as high as 33% in some studies with higher rates of recurrences following surgery associated with genetic syndromes such as 22q11.2 deletions. The primary cause of VPI in these groups is still identified as the anatomic abnormalities of the velum. In this review, the anatomy and physiology of the velum are discussed along with genetic mutations associated with VPI.

Neonatal Compartment Syndrome Associated With Disseminated Intravascular Coagulation

Annals of Plastic Surgery. Feb, 2016  |  Pubmed ID: 25910025

Neonatal compartment syndrome is a rare, but devastating limb-threatening condition that requires early recognition and timely surgical intervention. We discuss the clinical presentation and management challenges of a neonate with forearm compartment syndrome and disseminated intravascular coagulation.

The Incompatibility of Living Systems: Characterizing Growth-Induced Incompatibilities in Expanded Skin

Annals of Biomedical Engineering. May, 2016  |  Pubmed ID: 26416721

Skin expansion is a common surgical technique to correct large cutaneous defects. Selecting a successful expansion protocol is solely based on the experience and personal preference of the operating surgeon. Skin expansion could be improved by predictive computational simulations. Towards this goal, we model skin expansion using the continuum framework of finite growth. This approach crucially relies on the concept of incompatible configurations. However, aside from the classical opening angle experiment, our current understanding of growth-induced incompatibilities remains rather vague. Here we visualize and characterize incompatibilities in living systems using skin expansion in a porcine model: We implanted and inflated two expanders, crescent, and spherical, and filled them to 225 cc throughout a period of 21 days. To quantify the residual strains developed during this period, we excised the expanded skin patches and subdivided them into smaller pieces. Skin growth averaged 1.17 times the original area for the spherical and 1.10 for the crescent expander, and displayed significant regional variations. When subdivided into smaller pieces, the grown skin patches retracted heterogeneously and confirmed the existence of incompatibilities. Understanding skin growth through mechanical stretch will allow surgeons to improve-and ultimately personalize-preoperative treatment planning in plastic and reconstructive surgery.

The Impact of Age Upon Healing: Absolute Quantification of Osteogenic Genes in Calvarial Critical-Sized Defects

The Journal of Craniofacial Surgery. Jan, 2016  |  Pubmed ID: 26751427

The current study was performed to elucidate changes in growth factor expression over time in critical-sized calvarial defects in rats from infancy to skeletal maturity.

So You Have a Research Idea: A Survey of Databases Available for Plastic Surgery Research

Plastic and Reconstructive Surgery. Feb, 2016  |  Pubmed ID: 26818307

Plastic surgery research using large databases has increased dramatically over the past 20 years. With the magnitude and breadth of information available in these databases, researchers are able to more easily answer a wide variety of research questions. This study sought to provide a comprehensive comparative analysis of the relevant databases for plastic surgery research. Database information, data collection methods, acquisition details, and variable availability were collected for 19 large databases. Examples of potential future research utility were ascribed to each database based on this comprehensive analysis. With a greater understanding of the content, strengths, and limitations of these databases, researchers will be better equipped to select the most appropriate database to answer a specific research question.

Melanocytes Affect Nodal Expression and Signaling in Melanoma Cells: A Lesson from Pediatric Large Congenital Melanocytic Nevi

International Journal of Molecular Sciences. Mar, 2016  |  Pubmed ID: 27011171

Expression of Nodal, a Transforming Growth Factor-beta (TGF-β) related growth factor, is associated with aggressive melanoma. Nodal expression in adult dysplastic nevi may predict the development of aggressive melanoma in some patients. A subset of pediatric patients diagnosed with giant or large congenital melanocytic nevi (LCMN) has shown increased risk for development of melanoma. Here, we investigate whether Nodal expression can help identify the rare cases of LCMN that develop melanoma and shed light on why the majority of these patients do not. Immunohistochemistry (IHC) staining results show varying degree of Nodal expression in pediatric dysplastic nevi and LCMN. Moreover, median scores from Nodal IHC expression analysis were not significantly different between these two groups. Additionally, none of the LCMN patients in this study developed melanoma, regardless of Nodal IHC levels. Co-culture experiments revealed reduced tumor growth and lower levels of Nodal and its signaling molecules P-SMAD2 and P-ERK1/2 when melanoma cells were grown in vivo or in vitro with normal melanocytes. The same was observed in melanoma cells cultured with melanocyte conditioned media containing pigmented melanocyte derived melanosomes (MDM). Since MDM contain molecules capable of inactivating radical oxygen species, to investigate potential anti-oxidant effect of MDM on Nodal expression and signaling in melanoma, melanoma cells were treated with either N-acetyl-l-cysteine (NAC), a component of the anti-oxidant glutathione or synthetic melanin, which in addition to providing pigmentation can also exert free radical scavenging activity. Melanoma cells treated with NAC or synthetic melanin showed reduced levels of Nodal, P-SMAD2 and P-ERK1/2 compared to untreated melanoma cells. Thus, the potential role for Nodal in melanoma development in LCMN is less evident than in adult dysplastic nevi possibly due to melanocyte cross-talk in LCMN capable of offsetting or delaying the pro-melanoma effects of Nodal via anti-oxidant effects of MDM.

Separation of Craniopagus Twins over the Past 20 Years: A Systematic Review of the Variables That Lead to Successful Separation

Plastic and Reconstructive Surgery. Jul, 2016  |  Pubmed ID: 27348650

Attempted separation of craniopagus twins has continued to be associated with devastating results since the first partially successful separation with one surviving twin in 1952. To understand the factors that contribute to successful separation in the modern era of neuroimaging and modern surgical techniques, the authors reviewed and analyzed cases reported since 1995.

Rhinoplasty Video Library, Volume II: Structural Grafting for Definitive Management of the Unilateral Cleft Lip Nasal Deformity

Plastic and Reconstructive Surgery. Jul, 2016  |  Pubmed ID: 27348671

Evaluating the Rule of 10s in Cleft Lip Repair: Do Data Support Dogma?

Plastic and Reconstructive Surgery. Sep, 2016  |  Pubmed ID: 27556606

Cleft lip represents one of the most common birth defects in the world. Although the timing of cleft lip repair is contingent on a number of factors, the "rule of 10s" remains a frequently quoted safety benchmark. Initially reported by Wilhelmsen and Musgrave in 1966 and modified by Millard in 1976, this rule referred to performing surgery once patients had reached cutoffs in weight, hemoglobin, and age/leukocyte count. Despite significant advances in both surgical and anesthetic technique, the oft-quoted "rule of 10s" has not been systematically investigated since its inception.

The Morphogenesis of Cranial Sutures in Zebrafish

PloS One. 2016  |  Pubmed ID: 27829009

Using morphological, histological, and TEM analyses of the cranium, we provide a detailed description of bone and suture growth in zebrafish. Based on expression patterns and localization, we identified osteoblasts at different degrees of maturation. Our data confirm that, unlike in humans, zebrafish cranial sutures maintain lifelong patency to sustain skull growth. The cranial vault develops in a coordinated manner resulting in a structure that protects the brain. The zebrafish cranial roof parallels that of higher vertebrates and contains five major bones: one pair of frontal bones, one pair of parietal bones, and the supraoccipital bone. Parietal and frontal bones are formed by intramembranous ossification within a layer of mesenchyme positioned between the dermal mesenchyme and meninges surrounding the brain. The supraoccipital bone has an endochondral origin. Cranial bones are separated by connective tissue with a distinctive architecture of osteogenic cells and collagen fibrils. Here we show RNA in situ hybridization for col1a1a, col2a1a, col10a1, bglap/osteocalcin, fgfr1a, fgfr1b, fgfr2, fgfr3, foxq1, twist2, twist3, runx2a, runx2b, sp7/osterix, and spp1/ osteopontin, indicating that the expression of genes involved in suture development in mammals is preserved in zebrafish. We also present methods for examining the cranium and its sutures, which permit the study of the mechanisms involved in suture patency as well as their pathological obliteration. The model we develop has implications for the study of human disorders, including craniosynostosis, which affects 1 in 2,500 live births.

Postoperative Temporal Hollowing: Is There a Surgical Approach That Prevents This Complication? A Systematic Review and Anatomic Illustration

Journal of Plastic, Reconstructive & Aesthetic Surgery : JPRAS. Mar, 2017  |  Pubmed ID: 27894915

Temporal hollowing is a common complication following surgical dissection in the temporal region. Our objectives were to: (1) review and clarify the temporal soft tissue relationships - supplemented by cadaveric dissection - to better understand surgical approach variations and elucidate potential etiologies of postoperative hollowing; (2) identify if there is any evidence to support a surgical approach that prevents hollowing through a systematic review.

Discussion: The Drivers of Academic Success in Cleft and Craniofacial Centers: A 10-Year Analysis of over 2000 Publications

Plastic and Reconstructive Surgery. Feb, 2017  |  Pubmed ID: 28121886

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