Results: 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.
Conclusions: 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.
Purpose: 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.
Materials and methods: 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.
Bibliographical noteFunding Information:
We are grateful to the donors of the cadavers and bereaved families. This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MEST) (No. 2011-0007612). The authors have no conflict of interest to declare in this paper. We thank Sang-hoon Kwon at New York University College of Arts and Science and So-yeon Kim at Madeira School, Virginia for assisting in revising manuscript and anatomical procedure.
© 2014, Springer-Verlag France.
All Science Journal Classification (ASJC) codes
- Pathology and Forensic Medicine
- Radiology Nuclear Medicine and imaging