Determination of the radioanatomical factors related to the position of facial nerve in accessing jugular foramen and carotid artery in temporal bone

Abstract

Introduction: Preservation of the facial nerve is of great importance in temporal bone surgeries. We intend to investigate the measurements of the radioanatomical factors related to the position of the facial nerve in accessing jugular foramen and internal carotid artery (ICA) in temporal bone of patients who were candidates for temporal high resolution computed tomography (HRCT) scan. Methods: In this correlation cross-sectional study, samples were selected from patients referred to Amir Alam Hospital who were previously candidates for temporal HRCT. Radioanatomic factors were evaluated in three axial, coronal and sagittal views. Analyzes were performed using descriptive statistics, correlation analysis and factor analysis. Results: A total of 173 samples were investigated. The most reliable radioanatomical factor based on coefficient of variation (CV) was the distance of the 7th nerve to the temporomandibular joint (TMJ) in the inferior to the cochlea in the sagittal view (variable name S2) (CV = 8.1%) and then the distance from the 7th nerve to the TMJ in the inferior section of the cochlea in the axial view (variable name AI3) (CV = 8.4%). Based on correlation analysis and then confirmatory factor analysis, three common latent factors were identified (overall R2 = 0.999). Conclusion: The results of this study can be used for two purposes. First, the direct use of the estimated measures in surgical operations, and the second is more advanced modeling to choose the approach in the surgical operation and how to implement that approach. For the first aim, the two factors AI3 and S2 were the most reliable radioanatomical factors in different people. For the second aim, the three-dimensional understanding of the obtained measurements and the further identification of the anatomical nature of the latent factors can help in choosing the approach in surgery.

Keywords

• Radioanatomical factors
• Facial nerve
• Temporal bone
• Jugular foramen
• Surgical approach
• Medical anthropology