Elucidation of mechanism about alleviation effect of fatigue and pain by mouthguard wearing

Research Project

Project/Area Number	15K11203
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Prosthodontics/ Dental materials science and
Research Institution	Nihon University
Principal Investigator	WAKAMI Masanobu 日本大学, 松戸歯学部, 准教授 (60297851)
Co-Investigator(Kenkyū-buntansha)	成田紀之日本大学, 松戸歯学部, 客員教授 (10155997)
Project Period (FY)	2015-04-01 – 2019-03-31
Project Status	Completed (Fiscal Year 2018)
Budget Amount *help	¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000) Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000) Fiscal Year 2016: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000) Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Keywords	マウスガード / 筋疲労 / 筋痛み / 平均周波数 / 筋活動 / 筋電図 / ｆMRI / 咬合様相 / 筋疲労感 / 筋痛み感 / 筋活動量 / 咬筋 / f-MRI / 疲労 / 痛み / 周波数 / f-NIRS
Outline of Final Research Achievements	The wearing of the mouthguard improves the occlusal contact area. It is inferred that the stimulation to the brain from baroreceptors of the teeth in the periphery increased, and the activity of the nerve motor unit and synchronization occurred.Therefore, it is presumed that the mass activity of the masseter muscle has increased.It showed significant activity that clenching by wearing a mouthguard is significant for primary motor area (M1), premotor area (PMo), supplementary motor area (SMC), middle cingulate cortex (MCC), and posterior cingulate cortex (PCC) from the results of fMRI. It is considered that enhancement of motor cortex activity by MG in this study may limit senses of fatigue and pain via motor cortex activatious by wearing of the mouthguard.
Academic Significance and Societal Importance of the Research Achievements	マウスガードの装着による効果は，スポーツプレー中に生じる外力の衝撃を吸収することにより，歯や顎の骨の外傷だけでな，脳震盪の予防，さらに，運動能力が向上するなど，マウスガードの装着効果が期待されている。コンタクトスポーツでは，外力に対して頭部を固定し体幹を安定させるため噛みしめを必要とすることは十分に想定される。マウスガードの装着による噛みしめが，歯の破折による精神的ストレスを軽減し，安定した噛み合わせにより，スポーツ競技中に生じる噛みしめによる顎の筋肉の痛みや疲労の自覚を軽減させ，スポーツパフォーマンスを向上させる。