第二磨牙纳入正畸治疗对咬合接触指标的影响

目的：对比第二磨牙是否粘接托槽纳入矫治，对治疗结束后咬合状况的影响。方法选择15例未将第二磨牙纳入矫治的患者与16例将第二磨牙纳入矫治的青少年患者，均为单纯拥挤的安氏I类错患者，常规直丝弓固定矫治结束时，运用T-ScanⅢ咬合分析仪记录两组患者的咬合接触时间、前伸、左侧、右侧分离时间、咬合力不对称指数、COF近中距离、前牙力百分比等七项指标。结果第二磨牙未纳入矫治组的前伸分离时间、左侧分离时间、右侧分离时间均明显大于纳入组(P<0．05)，前牙力百分比较大(P<0．05)，咬合接触时间与力中心点( COF)近中位置、咬合力不对称指数无统计学意义。第二磨牙未纳入组的干扰发生率为86．7%，纳入组的干扰发生率为25%。前牙力百分比与咬合接触时间存在线性相关关系。结论第二磨牙未纳入矫治，在治疗结束时，更易出现不良咬合、力分布不均匀等不利的因素，存在造成口颌系统功能紊乱的隐患。

Effect of second molar inclusion in orthodontic treatment on occlusal contact

Objective To compare the effect of whether the second molars were included in the orthodontic treatment on occlusion. Methods Fifteen adolescent patients were selected whose second molars were not included in orthodontic treatment and 16 adolescent patients whose second molar were included in the treatment. The occlusion time,the disocclusion time during protrusion,left and right and lateral movement,and the mesial location of center of force(COF) and the percentage of anterior bite force were measured by T-ScanIII system. Results When the second molars were not included,the disocclusion time during protrusion, left and right lateral movement were significantly longer than when the second molar were included(P<0. 05). The percentage of anterior bite force was larger. There was no significant difference in occlusion time. The mesial location of(COF)and the occlusion time were not significantly different between the two groups(P>0. 05). The incidence of occlusal interference was 86. 7% in second molar inclusion group and 25% in second molar non-inclusion group. There was a linear relationship between the percentage of anterior bite force and occlusion time. Conclusion There was the tendency of more occlusal interferences if the second molar was not included in orthodontic treatmen.