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.

Anatomic and anthropometric analysis of 72 lower lateral nasal cartilages from fresh Persian (Iranian) cadavers.

BACKGROUND: Understanding the anatomy of nasal cartilage, which varies by ethnic group, is important for surgical correction of nasal tip deformities. OBJECTIVES: The authors measure the size and shape of the lower lateral cartilages (LLC) in Persian cadavers to provide summary guidelines. METHODS: A total of 72 cartilage dissections were performed on 36 fresh Persian cadavers. All soft tissue was removed from the lateral crura cartilages. The lateral, middle, and medial distances from the caudal edge of the lateral crus to the alar rim were measured at the junction of the middle and lateral crura. Measurements were obtained for alar cartilage, alar flaring, divergence angle, and other parameters. Comparisons were made between sexes and select ethnic groups. RESULTS: Significant gender differences were observed for the middle (P=.03) and medial crura (P=.02), but not the lateral crura (P=.05). Approximately 87% of lateral crura were convex, and 86% of middle crura were flat. The medial crus was convex in 58.3% of the cadavers, with no significant gender difference. We noted occasional asymmetry between the middle and medial crura. Measurements for Persians differed from those of Asians and African Americans, but were similar to those of Caucasians. The shape of Persian alar cartilage is distinct from other ethnicities. CONCLUSIONS: Alar cartilage anatomy varies across ethnic groups, and attention to the differences is recommended during preoperative planning and intraoperative technique when treating the nasal tip.

Anatomic variations of midfacial muscles and nasolabial crease: a survey on 52 hemifacial dissections in fresh Persian cadavers.

BACKGROUND: The midfacial region is a challenging area for plastic surgeons and may vary among different races. OBJECTIVES: The aim of this study was to determine the patterns of midfacial muscles in Persian (Iranian) subjects. METHODS: Hemifacial fresh cadaver dissection was performed. For each cadaver, demographics, side of dissection, variation in midfacial muscles (levator alae nasi, levator labii superioris, zygomaticus major [single and bifid], zygomaticus minor, and risorius), midfacial pattern (based on Pessa classification), nasolabial shape (concave, convex, straight) and length were obtained. RESULTS: Fifty-two hemifacial dissections were performed on 27 cadavers, of which 22 were male (81.4%). The mean age of the subjects was 40.1 +/- 14.8 years. The mean of nasolabial length was 46.4 +/- 8.3 mm (ranged from 28 to 63 mm). Straight form of nasolabial crease was the most frequent type (n = 26.50%). Levator alae nasi, levator labii superioris, and zygomaticus major were found in 100% of the subjects; however, it was not the same regarding other muscles. The incidence of bifid zygomaticus major was 19.2% (10 hemifacials) in our series. Midfacial pattern type 3 was the most common in our study, which found this type in 21 hemifacials (40.3%). We also found a new type of facial pattern in three cadavers. In this type, which is relatively similar to the type 5 of Pessa's classification, zygomaticus minor was absent and the zygomaticus major was bifid. CONCLUSIONS: This study revealed that midfacial pattern and nasolabial crease shape are different between Persian (Iranian) and Western subjects. It seems that based on these differences and some other unknown anatomic diversity between different races, some of the defined cosmetic frames may need minor revisions to be applicable for Persian faces. More studies in this field are recommended.