2026 Poster Presentations
P460: STEP BY STEP DISSECTION AND SURGICAL APPLIED ANATOMICAL CORRELATIONS OF THE FACIAL NERVE: A REVIEW FOR THE NEUROSURGICAL TRAINEE USING 3D PHOTOGRAMMETRY
Eva M Wu, MD; Kaan Yagmurlu, MD; Mustafa Motiwala, MD; Nickalus R Khan, MD; University of Tennessee Health Science Center
Background/objective: The facial nerve is a complex structure that plays a crucial role in facial expression, conveying taste, and parasympathetic innervation to several glands. Its course from the brainstem to its extracranial terminal branches is often complex and can be highly variable, making the precise understanding of its anatomy difficult. Two dimensional photographs are traditionally how the anatomy of the facial nerve is depicted; however, these representations can be difficult for learners to understand the spatial relationship of the facial nerve to surrounding structures. 3D photogrammetry is a new visualization technique that constructs a realistic three-dimensional model from overlapping two-dimensional images. These three-dimensional models may allow for a better spatial understanding of the facial nerve and its relationship to surrounding structures. This study reviews the anatomy of the facial nerve using 3D photogrammetry and highlights the benefits of 3D photogrammetry in anatomical modeling and medical education.
Methods: A step by step dissection of one cadaver was performed to depict the entire course of the facial nerve from the brainstem to its terminal extracranial branches. At each sequential step a smartphone camera with photogrammetry software and SLR camera was used to capture photographs of the specimen. These images were then uploaded to a 3D photogrammetry application, and a three-dimensional model was created. This 3D Model was created at each step and captures the surgical anatomy of the facial nerve from its exit in the brainstem to its terminal motor branches in the parotid gland. A test to evaluate the anatomical knowledge of the facial nerve was given to medical students and residents before and after reviewing this model to measure its impact on learning the complex anatomy of the facial nerve.
Results: Five realistic models were created demonstrating an accurate 3D representation of the anatomy of the facial nerve. One model showed the extracranial portion of the facial nerve after parotidectomy (Figure 1). One model showed the course of the facial nerve in the temporal bone after a mastoidectomy was completed (Figure 2). One model showed the course of the facial nerve as seen through a middle fossa approach. One model showed the course of the facial nerve after a transotic approach was performed. The last model showed the course of the facial nerve from the brainstem to the cerebellopontine angle. The test showed significant improvement in medical students and residents scores of anatomical knowledge of the facial nerve once utilizing the 3D model of the facial nerve.
Conclusion: 3D photogrammetry allows for the creation of a three-dimensional model that realistically depicts the complex course of the facial nerve and its spatial relationship to surrounding structures. The use of 3D photogrammetry allows for a better understanding of the spatial anatomy of the facial nerve and can be a valuable tool in medical education.
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