Intraparotid Branching Pattern of Facial Nerve- A Cadaveric Study from Tamil Nadu, India

Abstract

Introduction: Facial Nerve (FN) is the main motor nerve of muscles of facial expression. As it courses within the parotid gland, the FN divides into divisions and then into terminal branches. Various surgical procedures of this region may inadvertently injure the FN owing to its variant branching pattern, resulting in facial asymmetry. Aim: To analyse the branching pattern of FN in the parotid region of Indian origin. Materials and Methods: This was a descriptive, cross-sectional study done on 50 embalmed cranial halves, in the Department of Anatomy, PSG Institute of Medical Sciences and Research, Coimbatore, Tamil Nadu, India from October 2020 to March 2022. The inclusion criteria were well embalmed and preserved adult cadavers irrespective of age, sex and side. The exclusion criteria were any cadaver with anomalies of face, disfigurements, injuries of the face and already dissected cadavers. After piece meal dissection of the parotid gland, the Facial Nerve Trunk (FNT) was identified and its branching pattern studied and classified according to Davis RA et al., classification. The data thus obtained was analysed using statistical software Statistical Package for the Social Sciences (SPSS) 21.0. Results: The FNT bifurcated in 98% and trifurcated in 2% specimens. The branching pattern of FN based on Davis RA et al., system showed a frequency as follows: Type I: 0%, Type II: 8%, Type III: 26%, Type IV: 16%, Type V: 48% and Type VI: 2%. Conclusion: Type V branching pattern showed the highest frequency. Results inferred from this study might help surgeons in anticipating the variant course, branching and interconnections of the FNT in the parotid region and thus may aid in minimising iatrogenic nerve injuries to avoid unnecessary facial disabilities.