Kim Hong-San, Pae Calvin, Bae Jung-Hee, Hu Kyung-Seok, Chang Brian M, Tansatit Tanvaa, Kim Hee-Jin
Division in Anatomy and Developmental Biology, Department of Oral Biology, Human Identification Research Center, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, South Korea.
Surg Radiol Anat. 2015 Mar;37(2):147-51. doi: 10.1007/s00276-014-1330-6. Epub 2014 Jun 27.
Detailed explanations of the insertion, interaction patterns, and arrangement of the risorius muscle fibers at the modiolus have still not been clearly shown. The aim of this study is to clarify the arrangement of the risorius muscle by means of topographic examination, and to evaluate the anatomical variations in its attachments and pattern of shape to other perioral muscles, and eventually to understand the various features of the facial animation of Asians.
Eighty embalmed Korean and Thai adult hemifaces from cadavers of both genders were dissected in this study. Detailed dissection at the modiolus revealed the insertion of the risorius muscle in relation to its attachments and fiber interaction forms.
When categorized into three common anatomical types--zygomaticus risorius (ZR), platysma risorius (PR), and triangularis risorius (TR). PR was most common with 45 % (36 cases) frequency. Risorius muscle also inserted into the modiolus in three distinct layers in relation to the depressor anguli oris: superficial, flush, and deep. Superficial attachment was most commonly found with 56.3 % (45 cases) frequency.
These results will provide critical information for future planning and performing of reconstructive, reanimation, and cosmetic surgical procedures for cases such as developmental defect, facial trauma, facial muscle paralysis, and restoring the natural personal appearances.
关于笑肌纤维在口角处的附着、相互作用模式及排列的详细解释仍未明确。本研究的目的是通过局部解剖检查来阐明笑肌的排列，并评估其附着点及与其他口周肌肉形状模式的解剖变异，最终了解亚洲人面部表情的各种特征。
本研究解剖了80例来自韩国和泰国成年男女尸体的防腐半侧面部标本。在口角处进行详细解剖，揭示了笑肌的附着及其纤维相互作用形式。
当分为三种常见解剖类型时——颧笑肌（ZR）、颈阔肌笑肌（PR）和三角肌笑肌（TR）。PR最为常见，出现频率为45%（36例）。笑肌在相对于降口角肌的位置也分为三层附着于口角：浅层、平齐层和深层。浅层附着最为常见，出现频率为56.3%（45例）。
这些结果将为未来针对发育缺陷、面部创伤、面部肌肉麻痹等病例进行重建、恢复活力及美容外科手术的规划和实施，以及恢复自然容貌提供关键信息。
