The extratemporal facial nerve and its branches: analysis of 42 hemifacial dissections in fresh Persian (Iranian) cadavers.

BACKGROUND The facial nerve controls facial muscles and expressions. Variability in branching patterns of the nerve creates variability in facial animation, which is evident in facial plastic surgery both between patients and ethnic groups and between sides of the face. Identifying relationships between the main trunk of the facial nerve and its network of branches to soft tissues/bony fixed points contributes to safer aesthetic and reconstructive techniques. OBJECTIVE The authors evaluate facial nerve branches in Persian (Iranian) cadavers, propose classification of the extratemporal nerve, determine topography of the nerve using fixed facial points, and define a new fixed point. METHODS Twenty-one cadavers were dissected, for a total of 42 hemifaces. Bicoronal and preauricular to submandibular incisions were made to deglove the face. Coded data were analyzed using a statistical program. The average of various quantitative and qualitative data points was analyzed. Averaged quantitative variables were compared between groups. The primary fixed index to specify the main trunk of the facial nerve was a point on a line from the upper edge of the tragus to the tip of the mastoid. RESULTS The study confirmed the variable branching pattern of the extratemporal facial nerve. Temporal branches on the zygomatic arch numbered 1 to 3. Distance from the nearest branch to the tragus was 20.62 ± 3.84 mm on the right and 21.33 ± 3.10 mm on the left. The variability in distribution may explain different facial expressions among ethnic groups. CONCLUSIONS Research using cadavers may improve facial surgery procedures and clarify variability in the facial nerve branching patterns among different ethnic groups.