균형측 교합장애로 인한 하악운동 및 저작근 활성도의 변화에 관한 연구 = A STUDY ON THE CHANGE OF MANDIBULAR MOVEMENT AND MASTICATORY MUSCLE ACTIVITY REFLECTED BY BALANCING-SIDE OCCLUSAL INTERFERENCE

다국어 초록 (Multilingual Abstract)

The purpose of this study was to investigate the influence of balancing interference on the mandibular movement and masticatory muscle activity. 5 subjects(male, average age of 24.3) without dysfuction in masticatory system were selected. The balancing interference was provided by construction of cast metal crown and onlay on the upper and lower first molars. Clinical examination, changes of mandibular displacement and velocity, and muscle activity were recorded and analyzed by means of BioPak system(Bioresearch Inc., Milwaukee Wisconsin, USA).
The results were as follows ;
1. In clinical examination, various symptoms were reported by all subjects after application of interference. Almost symptoms were subsided after elimination of interference.
2. In the border movements in frontal plane, lateral border movement toward non-interference side was changed according to the interference after application of interference. Immediately after removal of interference, border movements' pattern was recovered as same as before experiment.
3. Duringguru chewing on the non-interference side, horizontal movement was decreased immediately after application of interference(p<0.05). 1 week after application of interference, horizontal movement was more decreased in 3 subjects and showed a chopping type masticatory stroke. But in 2subjects, horizontal movement was increased to avoid interference.
4. In EMG of the mandibular rest position, no significant changes were showed in the experiment period(p>0.05).
5. During gum chewing on the interference side, the activity of opposite temporal muscle was increased immediately after application of interference(p<0.05). 1 week after application of interference, The activity of ipsilateral temporal muscle and left and right masseter muscles was increased (p<0.05). 1 week after elimination of interference increased muscle activity was recovered about the same level as before experiment.
6. During gum chewing on the non-interference side, 1 week after application of interference, the activity of ipsilateral temporal muscle was increased (p<0.05). 1 week after elimination of interference, increased muscle activity was returned about the same level as before experiment.