Dmytrenko Maryna I
Department Of Orthodontics, Higher State Educational Establishment Of Ukraine "Ukrainian Medical Stomatological Academy", Poltava, Ukraine.
Wiad Lek. 2018;71(2 pt 2):295-298.
Introduction: Rate of distal occlusion (up to 40%) and dental crowding (up to 65%) is the largest in the structure of orthodontic pathology. The aim of the study was to investigate bioelectrical activity of temporal and masticatory muscles and to set parameters of electromyographic indexes in patients with distal occlusion and dental crowding in permanent occlusion.
Materials and methods: Bioelectrical activity of temporal and masticatory muscles in 11 patients aged 16-24 years was determined before orthodontic treatment. Distal occlusion complicated by severe degree of dental crowding was revealed in this group of patients. These patients comprised the treatment group. The control group consisted of 10 subjects (mean age 21,3 ± 1,25 years) with physiological occlusion.
Results: It was found that functional state of temporal and masticatory muscles in patients with distal occlusion complicated by dental crowding changes during permanent dentition. It was determined that in clenching state, according to ACTIV index, temporal muscles are more active, due to the lack of activity of masticatory muscles (ACTIV =-20,73% ± 8,01%). Moreover it is worthy of notice, that functional muscle symmetry (index SIM TА/MМ) at rest in presence of distal occlusion is lower than in subjects with physiological occlusion (p <0,05).
Conclusions: According to index АCTIV TА/MМ it was established the dominance of temporal muscle activity due to lack of activity of masticatory muscles in patients with distal occlusion complicated by dental crowding and it was determined lower overall muscle symmetry index than in individuals with physiological occlusion.
引言：在正畸病理学结构中，远中咬合率（高达40%）和牙列拥挤率（高达65%）是最高的。本研究的目的是调查远中咬合和牙列拥挤的恒牙期患者颞肌和咀嚼肌的生物电活动，并设定肌电图指标参数。
材料与方法：对11例年龄在16 - 24岁的患者在正畸治疗前测定其颞肌和咀嚼肌的生物电活动。该组患者均表现为远中咬合并伴有严重牙列拥挤。这些患者组成治疗组。对照组由10名具有生理咬合的受试者（平均年龄21.3 ± 1.25岁）组成。
结果：发现伴有牙列拥挤的远中咬合患者在恒牙列期颞肌和咀嚼肌的功能状态发生改变。经测定，在紧咬状态下，根据ACTIV指数，由于咀嚼肌活动不足，颞肌更为活跃（ACTIV = -20.73% ± 8.01%）。此外，值得注意的是，存在远中咬合时，静息状态下肌肉功能对称性（指数SIM TA/MM）低于具有生理咬合的受试者（p <0.05）。
结论：根据ACTIV TA/MM指数，确定了伴有牙列拥挤的远中咬合患者中，由于咀嚼肌活动不足，颞肌活动占主导地位，并且确定其整体肌肉对称指数低于具有生理咬合的个体。
