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.