Zygomaticomandibularis muscle.
The aim of this study was to elucidate the precise anatomy of the zygomaticomandibularis muscle through cadaveric dissection and magnetic resonance imaging (MRI). Five fresh human cadavers and 10 fixed cadavers were dissected. Nine preserved human cadavers were used for the MRI study. Four volunteers took MRIs of their head as well. Zygomaticomandibularis muscle was found in all the cadaveric specimens. It is a fan shaped muscle. The length of the muscle is 25.1 +/- 4.6 mm, and the width at the zygomatic arch is 16.6 +/- 4.2 mm. The thickness is approximately 4.8 +/- 1.9 mm. It originates from the deep layer of the deep temporal fascia approximately 1 cm above the zygomatic arch and is inserted into the superior border and outer surface of the mandible between the coronoid process and mandibular notch. The deepest layer of the masseter muscle covers the lateral surface of zygomaticomandibularis. We believe that this muscle functions as coordinator of the temporalis and masseter in mammals with strong masticatory power but is a degraded or rudimentary muscle in humans.
Hwang
Kun
K
Department of Plastic Surgery, Inha University Hospital, 7-206 Sinheung-dong, Jung-gu, Incheon, Korea. jokerhg@inha.ac.kr
Lee
Dae Kwang
DK
Kim
Hyung Jin
HJ
Shin
Yong Ho
YH
Chung
In Hyuk
IH
D002102:Cadaver; D005205:Fascia / Q000033:anatomy & histology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008410:Masticatory Muscles / Q000033:anatomy & histology*