Terminal Branching Pattern of Facial Nerve Seen in Adult Cadavers: An Anatomical Study

Abstract

Introduction: There are twelve cranial nerves and seventh one is the Facial cranial nerve, which supplies the muscles of facial expression. It gives of five terminal branches, which form a plexus with in the parotid gland. These branches exhibit variations in their branching pattern. Detection of the main trunk of facial nerve and its branches is important in all surgeries of this area, to avoid any injury that may lead to the loss of function of this nerve. This study has elaborated the branching and communications among the terminal branches of facial nerve in parotid gland. Objectives: To study the anatomical variations in the terminal branching and communicating pattern of the seventh cranial nerve and to observe the division pattern of the facial nerve trunk in parotid area. Study Design: It was carried out at Department of Forensics and Department of Anatomy in King Edward Medical University Lahore. Period: The study commenced in March 2014 after approval of the synopsis by the Advance Studies and Research Board of KEMU and was successfully completed in December 2015. Methodology: Dissection of one hundred hemi-faces in the Departments of Forensic and Anatomy at King Edward Medical University Lahore. Adult cadavers of both sexes were included and with mutilated face were excluded. A Descriptive Cross-sectional type of study. Collected data was analyzed in SPSS 13. Simple frequency/percentages tables and charts were used to presents the outputs. Chi-Square, Student t-test and ANOVA were used. Results: Branching and Communicating Pattern according to occurrence were: Type I, 9%, Type II, 39%, Type III, 20%, Type IV, 25%, Type V, 6%, Type VI, 1%. 95% cases showed bifurcation. Conclusion: Most common branching pattern was Type II (39%), and least common was Type VI (1%). Surgery of Zygomatic region must be done carefully due to complexity of branching in this area.

An Anatomic Study of the Facial Nerve Trunk and Branching Pattern in an African Population

“…5,7,9, [16][17][18]23 The third in place were types II, III, IV, and VI as was the observation in our population. 5, 7,9,12,[16][17][18]23,24 The branching pattern types VI, I, II, and V were the least frequent among Caucasians Indians, Pakistani, Thai, Koreans, Malaysians, and Arab similar to our study 5,7,9,17,19,22,24 . Types IV and VI occurred at the same frequency (15%) with the least being type V (5%) (►Table 1).…”

“…17,18 In other reports from Thailand and India, types II and V were the highest, respectively. 19,24 Type I, the classical textbook pattern, was found to have been one of the least common patterns, which was not the case in this population. 23 The second most frequent in our population was type II (22.5%), like in Iraqi study.…”

“…6,31,32 Khaliq et al in another study from Indian reported single trunk of FN in 95 and 8.57% of bifurcation, while Rana et al reported single trunk (2%) and trifurcation (3%). 18,19 With regard to furcation of the main trunk, 14 were similar, while 6 were not (►Table 4). There was no significant difference between the left-and right-side furcation types.…”

“…5, 9,16 Similarly, studies from India and Pakistan, by Malik et al 17 and Khaliq et al, 18 had higher percentages of types I and III, while types V and VI were rare. 17,18 Rana et al, from Pakistan, observed type IIs and IV to be the most common and type VI was the least 19 (►Table 1). The differences in the frequencies are probably due to population from various racial background which renders comparisons between different studies with populations complex.…”

Variations in Facial Nerve Branches and Anatomical Landmarks for Its Trunk Identification: A Pilot Cadaveric Study in the Lithuanian Population

“…Thuku et al concluded type I as the most common in the African population [26]. Rana et al, Quadros et al, and Bendella & colleagues found type II as the most common in Pakistan, Indian, and German subjects, respectively [27-29] (Table 5).…”