Elucidation of referred pain caused by myofacial pain of masticatory muscle

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K19106
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 57050:Prosthodontics-related
• Research Institution: Nihon University
• Principal Investigator: MASUDA Manabu 日本大学, 松戸歯学部, 専修医 (40822961)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 咀嚼筋筋痛 / 関連痛

Outline of Final Research Achievements

This study aimed to determine if standardized palpation of the right masseter and temporalis muscles can evoke referred pain in individuals without TMD and compare the mechanical sensitivities in response to three different stimulus levels of palpation force and three different stimulus duration of palpation time. Participants comprised 64 pain-free individuals. The right masseter and temporalis muscle were equally divided into 15 test sites. Mechanical sensitivity was assessed with three mechanical stimuli (0.5kgf, 1kgf, or 2kgf) applied to the 15 test sites with three different durations (2s, 5s, or 10s). If the participant reported referred pain after a stimulus, they indicated areas of referred pain on a digital drawing. Our present results indicate that referred pain from the masseter and temporalis muscles were duration- and intensity-dependent processes originating from local stimuli.

Free Research Field

歯科補綴学

Academic Significance and Societal Importance of the Research Achievements

補綴歯科治療において、咀嚼筋筋・筋膜痛を起因とした口腔顔面領域に生じる関連痛は診断をより困難なものとする。その口腔内の疼痛に対する検査および診断は非常に重要となるが、この咀嚼筋の筋・筋膜痛により生じる関連痛の発現機序は解明されておらず、またその検査方法も確立されていない。関連痛に関する検査方法の確立およびメカニズムの解明は、誤診や誤治療を防ぐためにも有用なものであり、臨床的意義は極めて高いものと考えられる。本研究では咀嚼筋から生じる関連痛の発現機序の一端を解明することを目的として、咬筋と側頭筋における加圧強度と加圧時間の相違が関連痛の発現頻度と発現部位に及ぼす影響を比較した。