成人骨性Ⅲ类错（牙合）伴下颌偏斜髁突形态和位置的锥形束CT观察

A cone-beam CT study on morphology and position of condylar processes in skeletal Class Ⅲ adult patients with mandibular deviation

目的 利用锥形束CT研究成年骨性Ⅲ类错（牙合）伴下颌偏斜患者髁突形态和位置特点,以期为临床诊断和治疗提供依据.方法 选择骨性Ⅲ类错（牙合）伴下颌偏斜的成年患者20例（偏斜组）和正常（牙合）成人20名（健康对照组）,进行锥形束CT头颅扫描和三维影像重建.在髁突最大轴面测量髁突内外径、前后径、内外径-正中矢状线交角、最大轴面面积、轴面中心-正中矢状线距.在髁突中心冠状面测量关节内、中、外间隙和髁顶高度.在髁突中心矢状面测量关节前、上、后间隙.在三维重建影像上测量髁突垂直高度和髁突体积.采用配对t检验比较每组两侧差异.结果 相比偏斜对侧,偏斜组偏斜侧髁突垂直高度小（1.89±1.34） mm、体积小（77.90±51.37） mm3,最大轴面面积小（10.70±5.10） mm2,髁顶高度小（0.63±0.16） mm,差异均有统计学意义（P＜0.05）;关节后间隙和外间隙分别较偏斜对侧小（0.35±0.10）和（0.58±0.18） mm,两侧差异均有统计学意义（P＜0.05）.结论 骨性Ⅲ类错（牙合）伴下颌偏斜患者双侧髁突在三维形态和位置方面均有一定程度的不对称性.

Objective To evaluate the morphology and position of condylar processes in skeletal Class Ⅲ adult patients with mandibular deviation.Methods Twenty skeletal Class Ⅲ adult patients with mandibular deviation were selected as the deviated group and twenty adults with normal occlusion were selected as the control group.Cone-beam CT（CBCT） scans of their temporomandibular joints were taken.The original data were reconstructed and rebuilt.A series of measurements of the condylar morphology and location were performed.The collected data were analyzed using paired t-test.Results In the deviated group,the deviated sides were smaller than the contralateral sides in the perpendicular height,volume,maximum area of axial plane and the height of condylar head.The contralateral condyle was positioned more posteriorly and laterally [（0.35 ± 0.10） and （0.58 ± 0.18） mm] than the deviated condyle （P〈0.05）.Conclusions Adult skeletal Class Ⅲ patients with mandibular deviation hadsome extent of condyle asymmetry in both morphology and location.