生长发育高峰前期与高峰期安氏Ⅲ类错(牙合)颞下颌关节CBCT比较分析

目的 应用锥形束CT(CBCT)分析安氏Ⅲ类错(牙合)不同CVM分期颞下颌关节(TMJ)的生长发育差异.方法 分别对60名恒牙早期均角安氏Ⅲ类患者和60名恒牙早期正常(牙合)在牙尖交错位进行CBCT扫描,按颈椎CVM分期进行分组,使用Invivo5软件对影像重建并进行数据测量.通过SPSS22.0软件采用LSD法分析比较生长发育高峰前期与高峰期的髁突生长发育差异.结果 安氏Ⅲ类错(牙合)组相比正常(牙合)组中髁突绝大多数位于关节凹前位.安氏Ⅲ类错(牙合)组CS3-CS4期与CS1-CS2期生长变化差值显示髁突上间隙、前间隙减小量、后间隙增长量与正常(牙合)组相比有统计学差异(P<0.05);髁突前后径减小量、髁突高度增长量与正常(牙合)组相比有统计学差异(P<0.05);关节窝深度、关节后斜面角减小量、关节窝前后径增长量与正常(牙合)组相比有统计学差异(P<0.05).结论 安氏Ⅲ类错(牙合)生长发育高峰期相对于高峰前期髁突绝大多数位于关节凹前位且在关节凹中的位置更靠前上.髁突垂直向发育过度,更为细长,关节凹浅而宽.

A comparative study of the temporomandibular joint in Class III malocclusion patients between prepuberty and puberty peak by CBCT

Objective To analyze the growth and development difference of the temporomandibular joint(TMJ) in different CVM stages of Class III malocclusion patients. Methods The samples included 60 average-angle Class III malocclusion patients and 60 normal occlusion subjects in early permanent dentition. CBCT images were obtained in intercuspal position. The samples were divided into different groups according to the cervical spine CVMS stages. The images were reconstructed to 3D images using Invivo5 software. The data were statistically analyzed. Results Most of the condyle in Class III malocclusion group was located anterior to the glenoid fossa.The difference of growth (CS3-CS4 and CS1-CS2 phases) in Class III malocclusion group showed decreased superior joint space (SS), anterior joint space (AS) and increased posterior joint space(PS) of condyle compared with the normal occlusion group. Significant difference was also found in decrease of anteroposterior diameter of the condylar process and height increase between the two groups.The depth of glenoid fossa, the decrease of posterior oblique angle of articulation and the increase of anteroposterior diameter of glenoid fossa presented were different between the two groups(P < 0.05). Conclusion In Class III malocclusion patients, condylar position in articular fossa during puberty peak was anterior and superior and the majority of the condyle was located in the anterior fossa.The condyle showed over-developed in vertical and more slender.The articular fossa was wide and shallow.