顎口腔系の状態と全身状態との関連に関する研究 垂直的顎間関係位の変化が背筋力に及ぼす影響

Abstract

The present study was carried out to compare back strengths and electoromyogram of all related muscles among 8 healthy subjects as well as among different maxillomandibular relation for the purpose of investigating influences of postural changes in vertical maxillomandibular relation on the back strengths. The results obtained are described below:1. Back Strength1) In the opening position, back strengths were small in all subjects.2) In the intercuspal position, back strengths tennded to increase when a splint was worn.3) In other maxillomandibular relations, back strengths tended to increase when a 2-, 5- or 10-mm splint was worn, but tended to decrease when a 15-mm splint was worn.4) Many of the subjects showed the maximum strengths when they wore a 2- to 10-mm splint.2. Muscular Activity1) In comparison with the activity of the masseter muscle measured in the opening position and the intercuspal position, its activities tended to markedly increase in other maxillomandibular relations. In comparison with those measured in other maxillomandibular relation, its activities tended to increase when a 2-, 5- or 10-mm split was worn.2) Although the activity of the sternomastoid muscle measured in the opening position tended to decrease in all subjects in comparison with those measured in other maxillomandibular relations, no certain tendencies were observed on comparison of its activity measured in the intercuspal position.3) There were no certain tendencies in activities of the trapezius muscle in all maxillomandibular relations.4) There were no certain tendencies in activities of muscles of the upper and lower extremitis, including the gastrocnemius muscle.