Establishment of an Oronasal Fistula Mice Model
September 8th, 2023
This article outlines a step-by-step procedure for establishing a mice model with an oronasal fistula. The oronasal fistula was created by employing heated ophthalmologic cautery to damage the midline portion of the hard palate, resulting in the formation of an opening between the oral and nasal cavities.
Our research has focused on how to establish the stable and standardized mouse model of oronasal fistula. This protocol has also demonstrated the body weight changes, all size changes, and the histologic features of the oronasal fistula formation. The current experimental changes of establishing oronasal fistula models are the mice mortality by suffocation or blood loss, as well as the standardization of the wound size.
Our protocol significantly reduces the amount of bleeding in mice during surgery, relative to the traditional use of a biopsy punch. This reduces the risk of suffocation due to severe bleeding. Additionally, our experimental method is also simpler and less technically sensitive.
Our future research aims to focus on observing the inflammatory response during oronasal fistula formation. We also plan on developing novel strategies to reduce the inflammatory response while promoting palate wound healing to reduce the incidence of oronasal fistula. Begin by securing an anesthetized female mouse to a foam board covered with sterile sheets.
Then carefully tape the mouse in a supine position to a surgical platform. Position two needles in front of the orbital-ear plane. Place two more needles behind it.
Next place a rubber band around the needles and cross the incisors to hold the mouth open. Use microsurgical tweezers to prop open the corners of the mouth. Proceed to retrieve the heated ophthalmologic cautery.
Now position the cautery tip one millimeter from the midline intersection of the palate and first premolar to create a full thickness mucosal injury to the hard palate. Remove the cautery when the mucosa around the tip turns white. Heat the ophthalmologic cautery to 250 degrees Celsius in the Germinator for 10 minutes.
Then place it on the hard palate and enlarge the wound around the edges. Finally, use microsurgical scissors to excise any excess denatured soft tissue surrounding the wound. Afterward, apply sterile cotton to stop bleeding and prevent inhalation asphyxiation in the mouse.
Notable variability was observed in the size of the generated oronasal fistula. The wound size showed a significant variation on the seventh day post-surgery. A significant reduction in the body weights of the mice was also observed on day seven, which is approximately 25%Histological analysis of the oronasal fistula revealed a loss of hard palate mucosa, denuded bone, and oronasal fistula formation.
View the full transcript and gain access to thousands of scientific videos
Overview
This article outlines a protocol for establishing a stable mouse model of oronasal fistula. The method significantly reduces bleeding during surgery, minimizing risks associated with the procedure.
Key Study Components
Area of Science
- Neuroscience
- Animal Models
- Oral and Nasal Physiology
Background
- Establishing a mouse model for oronasal fistula is critical for studying related physiological changes.
- Previous methods have led to complications such as suffocation and blood loss.
- Standardization of the model is necessary for reproducibility in research.
- Improving surgical techniques can enhance animal welfare and experimental outcomes.
Purpose of Study
- To develop a reliable method for creating oronasal fistula in mice.
- To assess body weight and size changes post-surgery.
- To evaluate histological features of the oronasal fistula.
Methods Used
- Heated ophthalmologic cautery to create the oronasal fistula.
- Monitoring of body weight and size changes in mice.
- Histological analysis of the fistula formation.
- Comparison of bleeding levels with traditional biopsy punch methods.
Main Results
- The new protocol significantly reduces bleeding during surgery.
- Mortality rates due to suffocation or blood loss are minimized.
- Body weight and size changes are documented effectively.
- Histological features of the oronasal fistula are characterized.
Conclusions
- The established protocol provides a safer and more effective method for creating oronasal fistula in mice.
- Standardization improves the reliability of experimental results.
- This model can facilitate further research into oronasal conditions.
Frequently Asked Questions
Executive Industry Relevance
Establishing a reproducible oronasal fistula (ONF) mouse model addresses a critical need for standardized preclinical systems to study palate wound healing and fistula pathogenesis. This model enables mechanistic de-risking and supports predictive confidence for therapeutic hypothesis testing in oral and craniofacial research portfolios. Reliable ONF models facilitate translational continuity from early discovery through preclinical evaluation of wound healing interventions.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables interrogation of palate wound healing mechanisms and inflammatory responses in a controlled in vivo system.
- Supports biological de-risking by providing a standardized injury model for functional target validation.
- Facilitates predictive confidence in evaluating candidate interventions for ONF closure and tissue regeneration.
Screening & Assay Development
- Provides a validated animal model for quantitative assessment of wound size and healing kinetics.
- Enables reproducible measurement of anatomical and functional ONF closure for downstream screening workflows.
- Supports assay standardization by minimizing procedural variability and mortality risk.
Translational & Preclinical Research
- Aligns with disease-relevant modeling of oronasal fistula for translational biomarker exploration.
- Enables continuity from mechanistic discovery to preclinical validation of wound healing strategies.
- Supports risk-adjusted advancement of therapeutic candidates targeting oral and craniofacial tissue repair.
Pipeline & Workflow Integration
This ONF mouse model integrates into the discovery-to-preclinical continuum, supporting hypothesis testing, screening, and translational research for oral wound healing and fistula repair.
- Discovery Biology: Facilitates null hypothesis testing of wound healing pathways and inflammatory mediators.
- Screening: Provides quantitative, reproducible readouts of ONF size and healing for candidate evaluation.
- Analytics: Enables statistical comparison of intervention effects on wound closure and body weight changes.
- Translational Research: Models clinically relevant ONF pathology for preclinical assessment of novel therapies.
- Enterprise Reuse: Offers a standardized, scalable platform for repeated studies across research teams.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in palate wound healing research.
- Operational Value: Enhances reproducibility, standardization, and safety in animal model generation.
- Strategic Value: Improves go/no-go decision-making and capital efficiency by enabling robust preclinical evaluation.
- Portfolio Impact: Supports risk-adjusted prioritization of wound healing and tissue repair programs.
Implementation Considerations
- Requires expertise in microsurgical techniques and animal anesthesia.
- Needs access to ophthalmologic cautery and histological analysis infrastructure.
- Demands cross-team standardization of wound size and procedural steps.
- Adaptation to other mouse strains or injury models may require protocol optimization.
- Potential limitations include variability in wound healing and body weight changes post-surgery.
