骨性Ⅲ类错[牙合]术前正畸治疗后颞下颌关节关节盘及髁突位置和形态观察

Observation of position and morphology of temporomandibular joint disc and condyle after preoperative orthodontic treatment for skeletal classⅢmalocclusion

目的:探讨术前正畸对Ⅲ类错牙合病人关节盘及髁突位置和形态的影响。方法:选取40例骨性Ⅲ类错牙合畸形病人为研究对象。在颞下颌关节磁共振图像上测定关节上间隙、前间隙、后间隙,判定髁突位置;通过测量髁突头长度、宽度和高度,判定髁突形态;通过直接观察判定关节盘位置和形态。比较骨性Ⅲ类畸形病人术前正畸前后关节盘及髁突位置和形态变化。结果:骨性Ⅲ类错牙合病人正畸前左侧和右侧关节上间隙均小于正畸后,正畸前左侧和右侧关节前间隙、后间隙、内间隙均大于正畸后,但差异均无统计学意义(P>0.05);正畸后左侧和右侧关节间隙指数较正畸前均有增加,趋向前位,仍处于中心范围,差异均无统计学意义(P>0.05)。病人正畸后左侧和右侧髁突头宽度、髁突头高度、髁突头长度较正畸前均有减小趋势,但差异均无统计学意义(P>0.05)。病人颞下颌关节关节盘位置为后型的病例最多,正畸后该类型的病例有所减少,正畸前后四种关节盘位置的病人比例差异均无统计学意义(P>0.05)。正畸前病人关节盘形态为双凹形的病人最多,其次为双平面型,正畸前后两种关节盘形态病人的比例差异无统计学意义(P>0.05)。结论:目前制定的术前正畸方案,对于Ⅲ类错牙合病人的关节盘及髁突位置和形态的影响不大。

Objective:To investigate the influence of preoperative orthodontic treatment on the position and morphology of the articular disc and condyle in patients with classⅢmalocclusion.Methods:Forty patients with skeletal classⅢmalocclusion were selected as the study subjects.On the MRI of temporomandibular joint,superior joint space,anterior joint space and posterior joint space were detected to determine the position of condyle;condylar length,condylar width and condylar height were measured to determine the shape of condyle;the position and shape of the articular disc were determined through direct observation.The changes in the position and morphology of the articular disc and condyle before and after orthodontic treatment in patients with skeletal classⅢmalocclusion were compared.Results:In patients with skeletal classⅢmalocclusion,the superior joint space in the left and right sides before orthodontic treatment was smaller than that after orthodontic treatment;the anterior joint space,posterior joint space and medial joint space in the left and right sides before orthodontic treatment were bigger than those after orthodontic treatment,but the differences of which were not statistically significant(P>0.05).After orthodontic treatment,the joint space index in the left and right sides increased compared with before orthodontic treatment,which tended to the anterior position,and still in the central range,but the difference of which was not statistically significant(P>0.05).After orthodontic treatment,the condylar width,condylar height and condylar length in the left and right sides decreased compared with before orthodontic treatment,but the difference of which was not statistically significant(P>0.05).The number of patients with posterior temporomandibular joint disc position was the highest,the number of cases of this type decreased after orthodontic treatment,and there was no statistically significant difference in the proportion of patients with four different joint disc positions before and after orthodontic treatment(P>0.05).Before orthodontic treatment,patients with a double concave joint disc shape were the most common,followed by a double planar joint disc shape,and there was no statistically significant difference in the proportion of patients with two different joint disc shapes before and after orthodontic treatment(P>0.05).Conclusions:The current preoperative orthodontic plan has little effect on the position and morphology of the articular disc and condyle in patients with classⅢmalocclusion.