Influence of unilateral mandibular first molar loss on the activities of masticatory muscles
- VernacularTitle:单侧下颌第一磨牙缺失对咀嚼肌肌电的影响
- Author:
Qianqian FAN
;
Nan WANG
;
Aibing HOU
- Publication Type:Journal Article
- Keywords:
first molar;
masticatory muscles;
surface electromyography
- From:
Acta Universitatis Medicinalis Anhui
2016;51(5):703-706,707
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the electromyographic changes in the anterior temporal and masseter muscles of patients with long-term unilateral mandibular first molar loss. Methods Eighteen patients with one-year or more than one-year loss of unilateral mandibular first molar were selected as experimental group,and eighteen volunteers from similar places,had similar dietary habits in the same age and gender with normal occlusion were recruited as control group. Surface electromyography was used for the evaluation of the electrical activities of bilateral anterior temporal and masseter muscles in mandibular postural position ( MPP ) , maximal clenching in intercuspal position ( ICP) and masticating situations. The data were analyzed using SPSS 17. 0 software package to compare the differ-ences among groups. Results The average electrical activities of anterior temporal and masseter muscles in MPP of experimental group were significantly higher than the contral group,and the missing side was higher than the non-missing side ( P <0. 05 ) . The average electrical activities of anterior temporal and masseter muscles in maximal clenching and masticating were significantly lower than the control group,especially in the masticating situation( P<0. 05 ) . The asymmetry index of anterior temporal muscles and masseter muscles in MPP and maximal clenching were significantly different(P<0. 05). Conclusion Long-term loss of unilateral mandibular first molar can affect the electrical activities of the anterior temporal muscles and masseter muscles in the experimental group,especially for the missing side and in the masticating situation. These results also suggest that it might be one of the potential factors on mastication system disorders.
