Symptoms and Physiological Responses to Prolonged, Repeated, Low-Level Tooth Clenching in Humans

2014 Fiscal Year Final Research Report

• Project/Area Number: 24592894
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Prosthetic dentistry
• Research Institution: Hokkaido University
• Principal Investigator: OHATA Noboru 北海道大学, -, 名誉教授 (60002185)
• Co-Investigator(Kenkyū-buntansha): ARIMA Taro 北海道大学, 大学院歯学研究科, 講師 (80346452)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 顎関節症 / 筋筋膜疼痛 / 咀嚼筋痛

Outline of Final Research Achievements

The aim of this study was to investigate if a low-level but long-lasting tooth-clenching task initiates TMD symptoms. Eighteen healthy participants (24.0±4.3 years) performed and repeated an experimental 2-hour tooth-clenching task at 10% maximal voluntary occlusal bite force at incisors for three consecutive days (Days 1-3). The task evoked pain in the masseter/temporalis muscles and temporomandibular joint after 40.0±18.0 min with a peak intensity of 1.6±0.4 on 0-10 numerical rating scale after 105.0±5.0 minutes (Day 1). On Day 2 and Day 3, pain had disappeared but the tasks, again, evoked pain with similar intensities.The area under the curve of pain NRS in the masseter on Day 2 and Day 3 were smaller than that on Day 1 (P = .006). Prolonged, low-level tooth clenching evoked short-lived pain like TMD. This intervention study proposes that tooth clenching alone is insufficient to initiate longer lasting and self-perpetuating symptoms of TMD.

Free Research Field

歯科補綴理工学