Hur Mi-Sun, Kim Ho-Jeong, Lee Kyu-Seok
From the Department of Anatomy, Kwandong University College of Medicine, Gangneung, South Korea.
J Craniofac Surg. 2014 Mar;25(2):614-6. doi: 10.1097/SCS.0000000000000452.
The trajectory of the medial fibers of depressor anguli oris muscle that pass deep to the depressor labii inferioris muscle (dDAO) and the anatomic relationship have not yet been examined. The aim of this study was to clarify the arrangement of the dDAO and its relationships with the surrounding structures. The dDAOs were investigated in 40 hemifaces from Korean cadavers. The dDAOs were observed in 18 of the 40 specimens (45%). The anatomic relationships of the dDAO were classified into the following 4 categories according to their connection with the incisivus labii inferioris muscle (ILI): (1) connected to the ILI and attached to the inferior border of the mandible lateral to the mentalis muscle (14 specimens, 35%), (2) connected to the ILI and intermingled with the lateral lower fibers of the mentalis muscle (2 specimens, 5%), (3) connected to the ILI but neither attached to the mandible nor intermingled with the mentalis muscle (1 specimen, 2.5%), and (4) not connected to the ILI but intermingled with the mentalis muscle (1 specimen, 2.5%). Therefore, in 17 specimens, the dDAOs were connected to the ILI (42.5%), in 14 specimens, they were attached to the inferior border of the mandible (35%), and, in 3 specimens, they were intermingled with the mentalis muscle (7.5%). The new anatomic data regarding the dDAO will contribute toward the understanding of movements of the mouth and lower face, which will be helpful when designing effective botulinum toxin type A therapies and performing various types of facial surgery.
降口角肌内侧纤维在下唇降肌深面的走行轨迹及其解剖关系尚未得到研究。本研究的目的是阐明下唇降肌的排列及其与周围结构的关系。在40例韩国尸体的半侧面部研究了下唇降肌。在40个标本中的18个（45%）观察到了下唇降肌。根据下唇降肌与降下唇切牙肌的连接情况，其解剖关系分为以下4类：（1）与降下唇切牙肌相连并附着于颏肌外侧的下颌骨下缘（14个标本，35%），（2）与降下唇切牙肌相连并与颏肌外侧下部纤维交织（2个标本，5%），（3）与降下唇切牙肌相连但既不附着于下颌骨也不与颏肌交织（1个标本，2.5%），（4）不与降下唇切牙肌相连但与颏肌交织（1个标本，2.5%）。因此，在17个标本中，下唇降肌与降下唇切牙肌相连（42.5%），在14个标本中，它们附着于下颌骨下缘（35%），在3个标本中，它们与颏肌交织（7.5%）。关于下唇降肌的新解剖学数据将有助于理解口部和下面部的运动，这在设计有效的A型肉毒毒素治疗方案和进行各种面部手术时将有所帮助。
