采用锥形束CT分析安氏Ⅱ类1分类错患者Twin-block矫治前后颞下颌关节的变化

摘要

Objective This study aims to evaluate the temporomandibular joint (TMJ) changes in patients with class Ⅱ division 1 subdivision malocclusions before and after Twin-block treatment using a cone-beam CT (CBCT). Methods Twenty subjects with class Ⅱ division 1 subdivision malocclusions were included in this study. Hand-wrist radiographs were conducted in the FG-G stage. CBCT was performed to determine the changes in the TMJ before and after the Twin-block treatment. The InVivoDental software was used to calculate the relevant parameters from the three-dimensional CBCT images. The acquired data were then analyzed. Results After treatment, the sagittal condylar anterior spaces were reduced, whereas the sagittal condylar superior and posterior spaces as well as the coronal condylar superior space increased (P<0.01). The condylar height, sagittal condylar angles, and condylar anteroposterior diameters also increased (P<0.01). Conclusion After the Twin-block treatment, new bone deposition was observed on the condyle. The condyle height also increased and resulted in adjustments in the condyle position within the glenoid fossa to more downward and forward positions. CBCT can quantify TMJ changes and provide an objective assessment to orthodontic treatment.%目的： 运用锥形束CT（CBCT）分析安氏Ⅱ类1分类错(牙合)在Twin-block矫治前后颞下颌关节位置及形态结构在三维方向上的变化。方法 选取20例处于生长发育高峰前期或高峰期的安氏Ⅱ类1分类错(牙合)患者，拍摄其功能矫治前后双侧颞下颌关节的CBCT片，运用InVivoDental软件对CBCT片进行三维重建并测量线距和角度，对测量结果进行统计学分析。结果 与治疗前相比，治疗后矢状向关节前间隙减小，关节上间隙和后间隙增大，冠状向关节上间隙增大（P<0.01）；髁突高度、矢状向髁突角度、横断面髁突前后径增加（P<0.01）。结论 采用Twin-block矫治器治疗安氏Ⅱ类1分类错(牙合)患者后，髁突在关节窝的位置和髁突部分骨性结构发生了一定程度的改变，髁突有新骨沉积，高度增加，在关节窝内的位置更向下和向前。CBCT的应用使颞下颌关节结构的变化得以量化，能对正畸治疗效果进行客观评价。