Elucidation of the mechanism of orbicularis oris and facial expression muscles and investigation of the basis for acquiring normal facial expressions

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K06877
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45060:Applied anthropology-related
• Research Institution: Kansai Medical University
• Principal Investigator: MASUOKA Hiromu 関西医科大学, 医学部, 講師 (00600496)
• Co-Investigator(Kenkyū-buntansha): 福井 充香 関西医科大学, 医学部, 任期付助教(専修医) (10809974)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 口輪筋 / 口唇裂 / 鼻中隔下制筋

Outline of Final Research Achievements

In this study, we attempted to elucidate the true anatomical structure by using ultrasound diagnostic equipment to capture the movements and interactions of the muscles around the lips. We analyzed the muscle functions associated with lip protrusion. In addition, we investigated the movement and action of muscles that are affected congenitally or by surgery in patients with cleft lip. Although it was not possible to verify the number of cases to obtain statistical data due to the spread of COVID-19, results were obtained that were consistent with the theory regarding left-right differences in facial expressions of children with cleft lip. In children with cleft lip, it was thought that distortion of the mouth and nose occurs due to insufficient action of the depressor septum muscle, which controls lip protrusion.

Free Research Field

口唇口蓋裂

Academic Significance and Societal Importance of the Research Achievements

本研究では、口唇の動きを中心とした表情表出が、どのような口唇周囲筋の作用により得られているか、表情筋の個々の作用とその位置関係について研究を行った。口輪筋の機能的構造と鼻中隔下制筋の作用部位の同定により口唇突出の作用機序についての理論的推測ができた。それらの結果を口唇裂患児の口唇突出動作時における口唇および鼻部の変形の特徴に照らし合わせることで検証を行うことができた。得られた成果は今後の口唇裂治療において筋肉の作用機序を考慮した術式改善につながり、患児のより表情豊かな自然に見える治療結果を得るための糸口となると考えている。