Genesis of tooth grinding under sleep-like states in animals

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K17145
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 57050:Prosthodontics-related
• Research Institution: Osaka University
• Principal Investigator: Higashiyama Makoto 大阪大学, 歯学研究科, 招へい教員 (50781663)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 睡眠時ブラキシズム / ウルトラディアンリズム / 顎運動 / 脳波

Outline of Final Research Achievements

This study investigated the oromotor activity under urethane anesthesia in guinea pigs. The results showed that cortical brain states changed cyclically after intraperitoneal injection of urethane. Brain states were classified into NREM-like, REM-like and transition states according to the delta and theta cortical activities. In relation to the changes of the brain states, the patterns of jaw movements were altered. Repetitive lateral jaw movements were found to occur in cluster. The jaw movements were associated with the intense masseter muscle contractions but not with digastric muscle contractions. Moreover, this episode often occur with tooth grinding noise.

Free Research Field

睡眠

Academic Significance and Societal Importance of the Research Achievements

本研究から、ウレタン麻酔下で生じる周期的な脳波活動状態の変化に伴って、顎の運動を調節する神経ネットワークの活動モードが変化することから、脳内全体の活動のバランスの変化が、無意識下で発生する歯ぎしりの発生要因であることを示唆する点で学術的に重要である。本研究成果は、歯ぎしり発生の神経メカニズムを明らかにする解明したり、治療法や診断方法を開発するうえで有用な新しい実験系を開発できた点で意義がある。