title: Morphological evaluation of the human facial muscles.
abstract: The facial muscles are composed of striated muscle fibers, as well as other skeletal muscles, and can produce more delicate and complex expressions. We studied 12 facial muscles of 10 Japanese cadavers (8 males and 2 females, average 74.7 years old) by histological techniques. We measured the cross-sectional area of the muscle belly (mm2), number of muscle fibers per mm2, total number of muscle fibers, and muscle fiber size (microm2). The depressor anguli oris m. was predominant for the cross-sectional area and the total number of muscle fibers than other facial muscles. For the muscle fiber size, muscles inserted to the angle of the mouth were larger than those inserted to the lip. The orbicularis oculi and orbicularis oris muscles were the smallest facial muscles. The muscle fiber sizes in the facial muscles were less than other skeletal muscles.
authors.affiliation: Department of Anatomy, Showa University School of Medicine, Tokyo, Japan. jito@med.showa-u.ac.jp
authors.forename: Junji
authors.initials: J
authors.lastname: Ito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Moriyama
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Shimada
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005145:Face; D005152:Facial Muscles / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000166:cytology*