Masticatory function in patients with jaw deformity before and after orthognathic surgery

分析了正颌治疗前后下颌前突患者和正常咬合成人的咀嚼功能。用三磷酸腺苷颗粒、硅胶印模和口香糖测定咀嚼效率。在电荷耦合器件相机的帮助下，通过从存储在图像分析系统中的咬合硅胶记录的照明图像中计算咬合接触的数量和面积来评估咬合接触。用肌电图分析咀嚼口香糖时的咀嚼节奏和活动。在使用ATP颗粒咀嚼效率方面，术前组的平均值约为对照组的一半。术后组略高于术前组，但两组间无统计学差异。同样，在硅胶印模咀嚼效率方面，术前组的平均值也低于对照组，术后无明显变化。另一方面，使用口香糖咀嚼效率在颌骨畸形组和对照组之间没有统计学差异。术前组的咬合接触数和面积约为对照组的一半或更少，术后无明显变化。统计上，咀嚼效率与咬合接触次数和面积有相关性。结果表明，虽然正颌治疗大大改善了上、下牙的咬合关系，但术后咬合不够紧密。在枪咀嚼的循环时间上，颌骨畸形组与对照组比较，差异无统计学意义，但颌骨畸形组的循环时间变异系数显著高于对照组。颌骨畸形组的综合肌电活动明显低于对照组。少

Masticatory function was analyzed in patients with mandibular prognathism before and after orthognathic treatment and in adults with normal occlusion. Masticatory efficiency was measured using ATP granules, silicone impression and chewing gum. Occlusal contact was evaluated by calculating the numger and area of occlusal contacts from the illuminated images of a silicone record of the occlusion that was stored in the image analysis system with the aid of a charge-coupled device camera. Masticatory rhythm and activity during gum chewing was analyzed using EMG.In the masticatory efficiency using ATP granules, the mean value of the preoperative group was approximately half that of the control group. The value for the postoperative group was slightly higher than that for the preoperative group, but there was no statistical difference between the two groups. Likewise, in the masticatory efficiency using silicone impression the mean value of the preoperative group was also less as compared wi … More th that of the control group, and that did not show significant change postoperatively. On the other hand, in the masticatory efficiency using chewing gum there were no statistical diggerences between the jaw deformity groups and the control group. The number and area of occlusal contacts in the preoperative group were also approximately half or less as compared with those of the control group, and they did not show significant changes postoperatively. Statistically, there were correlations between the masticatory effisiency and the number and area of occlusal contacts. The results indicate that although the occlusal relationship of the upper and lower teeth were greatly improved by orthognathic treatment, the postoperative occlusion is not tight enough. In the cycle time during gun chewing, there was no statistical difference between the jaw deformity group and the control group, but the coefficient of variation of the cycle time for the jaw deformity group was significantly highwr than that for the control group. Integrated electromyographic activity of the jaw deformity group was significantly less as compared with that of the control group. Less