Clarification of the mechanism for orofacial pain contributes to the development of new treatment

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K10160
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57030:Conservative dentistry-related
• Research Institution: Nihon University
• Principal Investigator: SHIMIZU Kohei 日本大学, 歯学部, 准教授 (10508609)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 関連痛 / 歯痛錯誤 / 歯髄炎 / 異所性疼痛

Outline of Final Research Achievements

Hsp70 is expressed in the pulpal tissue following tooth pulp exposure. Hsp70 is axonally transported from the inflamed tooth pulp of the lower first molar to the trigeminal ganglion. The transported Hsp70 is released into the intercellular space in the trigeminal ganglion. The Hsp70 binds to the toll-like receptor 4 of trigeminal ganglion neurons innervating the tongue and promotes IL-1RI expression. Simultaneously, the accumulated macrophages following tooth pulp inflammation generate and release IL-1β in the extracellular space in the trigeminal ganglion. Larger amounts of IL-1β bind to the larger number of IL-1RI of trigeminal ganglion neurons innervating the tongue. The IL-1β/IL-1RI signaling facilitates TRPV1 expression. Enhanced expression of TRPV1 on the tongue-innervating trigeminal ganglion neurons promotes neuronal excitability and results in mechanical and heat hypersensitivity of the tongue.

Free Research Field

歯内療法学

Academic Significance and Societal Importance of the Research Achievements

本研究を推進することは顎顔面領域の慢性疼痛の神経機構解明に対する糸口をつかむことができ，さらには新たな治療方法，治療薬剤の開発にもつなげることができる。また近年，日本の財政圧迫の一因として医療費の過剰問題が挙げられるが，本研究領域を推進し，歯科医学教育の診査・診断法そのものに変革を起こし発信することで，患者は不必要な治療や，ドクターショッピングを行うことなく最短期間で症状改善および治癒に至ることとなり，結果それは医療費の抑制効果につながる。本研究テーマを遂行することによる患者貢献および経済的影響は非常に大きいと考えられる。