Precise Minimally Invasive Extraction of Impacted Teeth: Standardized Techniques and Management Practices

Summary

A standardized protocol enables precise, minimally invasive extraction of impacted third molars, optimizing surgical accuracy, minimizing complications, and enhancing healing outcomes across varying impaction classes.

Abstract

Impacted mandibular third molars frequently pose surgical challenges due to their complex anatomical positioning, particularly when classified as Pell and Gregory Class II or III. Traditional extraction methods often result in significant soft tissue trauma, prolonged operative times, and increased postoperative morbidity. This study presents a standardized, minimally invasive surgical protocol for the extraction of impacted mandibular third molars, designed to enhance precision, reduce trauma, and improve patient outcomes. The technique includes a controlled 1 cm mesial vertical incision, atraumatic flap elevation, conservative bone contouring, and segmental tooth sectioning. Thirty patients were treated using this protocol, with mean operative times of 16.8, 18.9, and 22.7 min for Class I, II, and III impactions, respectively. Postoperative pain scores significantly declined from 3.1 ± 1.1 at 24 h to 1.7 ± 0.9 at 48 h (p < 0.0001), with no major complications observed. The results support the reproducibility, efficiency, and safety of this protocol for diverse impaction types.

Introduction

Impacted mandibular third molars, commonly referred to as impacted wisdom teeth, are teeth that fail to erupt into the dental arch within the expected developmental window, often due to lack of space, obstruction by adjacent teeth, or unfavourable angulation. These impactions are highly prevalent worldwide, with estimates suggesting that up to 72% of individuals experience some form of mandibular third molar impaction during their lifetime^1,2,3. The Pell and Gregory classification system is a widely adopted framework for evaluating the difficulty of impacted mandibular third molar extractions. It categorizes impactions based on the relationship of the tooth to the anterior border of the mandibular ramus^4,5. In Class I, the third molar is positioned entirely anterior to the ramus, with adequate space to accommodate the crown, making surgical access relatively straightforward^6,7. Class II impactions occur when the distal portion of the crown is partially covered by the ramus, indicating limited space and necessitating moderate bone removal^8,9. While in Class III, the third molar is completely embedded within the ramus, lacking sufficient space for eruption^10,11. These cases are often deeply impacted and present the greatest surgical challenge due to their proximity to the inferior alveolar nerve and the need for extensive bone contouring and segmental tooth sectioning⁹.

Traditional extraction techniques for impacted mandibular third molars often involve extensive soft tissue reflection, ostectomy, and tooth elevation using rotary instruments or chisels¹². One common approach is the envelope flap technique, which involves a long crestal incision extending along the gingival margin of adjacent teeth to allow wide surgical access^13,14. Another widely used method is the triangular flap technique, incorporating a vertical releasing incision to improve visibility and mobility of the flap^15,16. These techniques typically require substantial bone removal to expose the impacted crown, particularly in Class II and III impactions, followed by elevation or tooth sectioning using rotary burs or elevators. While effective, these traditional methods are often associated with increased operative times, greater postoperative pain, higher risk of nerve injury, alveolar osteitis, and delayed healing due to the extensive manipulation of hard and soft tissues^17,18.

In response to these challenges, minimally invasive techniques have been developed to reduce surgical trauma and improve patient outcomes¹⁹. Orthodontic-assisted extrusion allows safer repositioning of teeth near the inferior alveolar nerve before extraction, significantly lowering nerve injury risks^20,21. In addition, the inward fragmentation technique (IFT), which employs 3D-planned sectioning to remove the tooth internally with minimal bone removal²², and piezoelectric surgery, which enables precise, low-trauma bone cutting and reduces the risk of nerve injury compared to rotary instruments²³. Advances such as robot-assisted surgery²⁴ and 3D-printed surgical guides²⁵ further enhance precision and reduce tissue damage. Xu and Zhang conducted a study comparing these approaches for the extraction of impacted mandibular third molars, finding that the minimally invasive method resulted in shorter operation times and fewer intraoperative and postoperative complications²⁶. These advancements underscore the importance of adopting minimally invasive techniques in the extraction of impacted teeth. By minimizing surgical trauma and preserving surrounding anatomical structures, these methods not only enhance patient comfort but also contribute to improved healing and reduced complication rates.

This study aims to present a standardized, step-by-step approach for the precise, minimally invasive extraction of impacted teeth, focusing on controlled incisions, careful bone contouring, and segmental tooth removal. Our goal is to enhance surgical accuracy, minimize complications, and improve postoperative recovery through structured protocol implementation.

Protocol

This study was approved by the Ethics Committee of The Second Affiliated Hospital of Zhejiang University (Approval No. 2025-1114). All participants provided written informed consent before their inclusion in the study, following the Declaration of Helsinki.

1. Patient preparation

NOTE: This study enrolled systemically healthy adults aged between 18-40 years with radiographically confirmed mandibular third molar impactions classified as Pell and Gregory Class I, II, or III. Inclusion required the absence of associated pathology and the availability of preoperative imaging. Exclusion criteria comprised any systemic condition compromising wound healing, active local infection, history of mandibular surgery, pregnancy, and current use of medications affecting bone turnover or soft tissue repair.

1. Perform preoperative examinations, including assessing the position of the impacted tooth, the status of the apex, and obtaining a panoramic X-ray.
2. Educate the patient about the procedure, potential complications, and postoperative care.
3. Administer local anesthesia with 2% lidocaine or 4% articaine, covering the gingiva, periosteum, and surrounding soft tissues of the impacted tooth. Confirm adequate anesthetization by probing the mucosa and periosteum with a blunt instrument; proceed only if no pain response is elicited.

2. Surgical steps

1. General surgical precautions
   NOTE: Use sharp instruments and high-speed burs with irrigation and caution near vital structures. Follow sterilization protocols for all instruments and materials.
   1. Verify the inferior alveolar nerve position using cone-beam computed tomography (CBCT), where the canal appears as a dark tubular space with bright borders, allowing evaluation of its proximity to the tooth roots.
   2. Design the incision, then use a periosteal elevator to carefully raise the mucoperiosteal flap, gently reflecting and retracting the tissue to minimize trauma.
   3. Once proper anesthetization is confirmed, make a 1 cm vertical incision in the mesial direction of the impacted tooth with a No. 15 surgical blade, extending to the periosteal layer (Figure 1).
   4. Make the incision long enough to fully expose the surgical site, which includes the area covering the crown of the impacted third molar and the nearby alveolar bone, while keeping soft tissue damage to a minimum.
   5. Use a periosteal elevator to carefully separate the gingiva and mucoperiosteal flap, gradually exposing the mesial, distal, buccal, and lingual bone structures around the impacted tooth.
2. Tooth sectioning
   1. Use a high-speed turbine handpiece (200,000-400,000 rpm, torque 0.02-0.05 N·cm) with a long fissure bur to section the impacted tooth at the mesial-distal junction. Cut to the root bifurcation, ensuring the cut direction aligns with the root axis to avoid damaging the surrounding bone (Figure 2).
   2. Confirm complete sectioning by clearing the area with suction and adequate lighting to visualize a distinct dark line between the segments. Then, use a dental probe to gently move each part and check for independent mobility, confirming full separation.
3. Bone contouring and the distal root removal
   1. If necessary, remove a small amount of bone covering the tooth root using a round or long fissure bur mounted on a high-speed handpiece (200,000-400,000 rpm) with copious sterile saline irrigation, to reduce resistance during extraction.
   2. Insert a straight elevator into the gap between the tooth segments and gently rotate to loosen the distal root.
   3. Once loosened, extract the distal root using a straight elevator (Figure 3).
4. The mesial root removal, cleaning, and inspecting the socket
   NOTE: Visually identify the mesial root by its separation line, color contrast, or mobility under light and suction.
   1. Place a triangular elevator into the distal socket, using a lever action to carefully extract the mesial root (Figure 4).
   2. If needed, use a bone chisel or other dental instruments, such as a periotome, luxator, or small straight elevator, to further separate the root.
   3. Remove inflammatory granulation tissue and any remaining root fragments from the socket using a curette or suction tip.
      NOTE: The inflamed tissue appears reddish, friable, and distinct from the pale surrounding bone and is visualized under direct illumination and suction.
   4. Rinse the socket with 10-20 mL of saline to ensure no foreign matter remains.
      NOTE: Maintain saline at room temperature (20-25 °C) before use.
   5. Inspect the socket for integrity, checking for bone damage and confirming that the alveolar septum is intact (Figure 4).
5. Gingiva repositioning and wound suturing
   1. Reposition the gingiva and mucoperiosteal flap to cover the incision, ensuring soft tissue edges align properly.
   2. Use 4-0 or 5-0 absorbable sutures to close the incision, placing 1-2 stitches to control bleeding and minimize wound exposure (Figure 5).
      NOTE: Store sutures between 15-30 °C in a dry, sterile environment.

3. Postoperative care and management

1. Control postoperative bleeding and postoperative education
   1. Place a sterile cotton pad at the incision site and instruct the patient to gently bite down for 30 min to control bleeding.
   2. Advise the patient to avoid rinsing, sucking, or consuming spicy foods within the first 24 h post-surgery.
   3. Encourage the patient to start using warm salt water or a mouthwash to clean the mouth 48 h after surgery.
   4. Instruct the patient to avoid vigorous physical activities and keep their head elevated to reduce the risk of bleeding.
2. Medications
   1. Routinely prescribe antibiotics (such as 500 mg of amoxicillin, 3 times daily for 3-5 days) to prevent infection post-surgery.
   2. If necessary, provide nonsteroidal anti-inflammatory drugs (such as 400 mg of ibuprofen every 6-8 h as needed for pain, not exceeding 2400 mg/day) to manage postoperative pain.
3. Follow-up plan
   1. Schedule a follow-up appointment one week after surgery to check the healing progress and assess for any complications (such as dry socket, infection, etc.).
4. Waste management
   1. Dispose of blood-soaked gauze, tissues, and gloves in designated biohazard containers.
   2. Discard used anesthetic syringes and needles in approved sharps disposal containers.
      NOTE: Follow institutional and regulatory guidelines for all clinical waste handling and disposal.

Results

A standardized minimally invasive protocol was applied in a clinical cohort of 30 patients undergoing extraction of impacted mandibular third molars. Patients ranged in age from 19 to 34 years (mean age 26.2 ± 4.3 years), as age may affect surgical difficulty and healing. The cohort included 17 males and 13 females. According to the Pell and Gregory classification, 10 cases were Class I, 12 were Class II, and 8 were Class III impactions, as determined from the radiological images and intr...

Discussion

The presented protocol for minimally invasive extraction of impacted mandibular third molars marks a significant advancement in oral surgical practice, prioritizing surgical precision, procedural safety, and the preservation of critical anatomical structures. A key determinant of its success is the carefully designed incision combined with precise and controlled flap elevation. The mesially positioned vertical incision, limited to approximately 1 cm, reduces soft tissue trauma and allows targeted access to the impacted t...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
2% Lidocaine	China Otsuka Pharmaceutical Co., Ltd	DB09-3.1004
4% Articaine	Jiangsu Hengrui Pharmaceuticals	H20066184
4-0 or 5-0 Absorbable sutures	Tianjin Jinyao Group Co., Ltd.	TJJY-AS405
Amoxicillin	Shenzhen Gaozhuo Pharmaceutical Co., Ltd.	H44021345
Bone chisel	Tianjin Zhengtian Medical Instrument Co., Ltd.	TJZT-OC080
Fissure bur	Beijing Leiton Medical Device Co., Ltd.	BLT-DT006
Ibuprofen	Teyi Pharmaceutical Group Co., Ltd.	H44021099
Periosteal elevator	Shandong Shinva Medical Instrument Co., Ltd.	SHIN-PS012
Saline	CSPC Pharmaceutical Group Limited	CSPC-SS500
Sterile cotton pad	Zhende Medical Company Co., Ltd.	ZD-SW150
Straight elevator	Shanghai Medical Instruments (Group) Ltd., Corp.	SIM-RH300
Triangular elevator	Shanghai Medical Instruments (Group) Ltd., Corp.	SIM-EL450
Turbine handpiece	Foshan Anke Medical Technology Co., Ltd.	ANKE-TH200