Influence of the occlusal splint on the muscle strength in the isometric movement of the upper limbs

目的：探讨咬合夹板在等长运动中能否提高上肢肌力。材料与方法：受试者为36名无颞下颌关节紊乱症状的男性大学生，年龄22~32岁，平均26.5岁。闭塞类型：正常闭塞14例(N组)，拥挤15例(C组)。对于每个受试者，制作了咬合夹板和安慰剂夹板。分别在牙尖间位(ICP)、牙合夹板(OS)和安慰剂夹板(PS)3种不同的咬合状态下，测量最大咬合力3s时上肢等长运动时的平均扭矩(AT)和峰值扭矩(PT)。在三种情况下，每种情况下都进行了三次测量。每次测量的间隔时间为5分钟。结果：三种情况下，各组的AT和PT平均值均无显著差异。但C组在OS时AT和PT的百分比均显著高于其他两种状态。这一结果清楚地描述了在等长运动中，佩戴咬合夹板增强了上肢的肌肉力量。咬合力由咬合夹板均匀分布(Maeda，1990)。拥挤时的咬合接触面积小于正常咬合和第111类(Kayukawa，1995)。咬合力可能通过戴咬合夹板更均匀地分布，这一点在拥挤的情况下可能会特别强调。

Purpose : The purpose of this study is to investigate whether the muscle strength of the upper limbs in the isometric movement can increase by use of occlusal splint.Materials and Methods : Subjects were 36 males university students without any signs of the temporomandibular dysfunction, from 22 to 32 years old (mean age 26.5 years old). Their occlusions were classified as 14 normal occlusion (group N) and 15 crowding (group C). For each subject, occlusal splint and placebo splint were fabricated. Average torque (AT) and Peak torque (PT) of the upper limbs in the isometric movement were measured during the maximum force biting of three seconds in three different conditions, such as at the intercuspal position (ICP), wearing the occlusal splint (OS) or the placebo splint (PS) on the upper dental arch. Measurements were carried out three times for each of three conditions. The intervals between each measurement were 5 minutes.Results : Mean values of both AT and PT in each group showed no significant differences among three conditions. However, in group C, percentages of both AT and PT at OS were significantly larger than those at the other two conditions.Discussion : In group C, percentages of both AT and PT at OS were larger than those at the other two conditions. This result clearly describes that wearing of the occlusal splint enhances the muscle strength of the upper limbs in the isometric movement. The occlusal force is evenly distributed by the occlusal splint (Maeda 1990). The occlusal contact area is smaller in crowding than in normal occlusion and Class 111 (Kayukawa 1995). The occlusal force might be more evenly distributed by wearing the occlusal splint, which might be emphasized especially in crowding.