正畸治疗骨性Ⅲ类错(牙合)对下颌平面角小的成年女性患者颞下颌关节的影响

Effects of orthodontic treatment on temporomandibular joint in adult female low-angle patients with skeletal class Ⅲ malocclusion

目的分析正畸矫治前后成年女性骨性Ⅲ类错(牙合)低角患者颞下颌关节的变化,探讨非手术正畸治疗对成年骨性Ⅲ类错(牙合)低角患者颞下颌关节的影响。方法选取16例成年女性骨性Ⅲ类错(牙合)低角患者,18～23岁,采用 OPA-K 滑动直丝弓技术矫治,矫治前后拍摄双侧闭口矫正许勒位片和头颅侧位 X 线片,进行颞下颌关节间隙测量和头影测量分析。对矫治前后的测量数据进行配对 t检验。结果与矫治前相比,矫治后关节前间隙线距和面积分别增加0.27 mm(P<0.001)、0.70 mm^2(P<0.01),关节后间隙线距和面积分别减小0.24 mm、0.67 mm^2(P<0.001),线性百分比由22.13%减少为9.64%(P<0.001),关节后前间隙面积之比由1.56减小为1.19(P<0.01),关节前间隙与关节后间隙趋于相等。头影测量发现,与矫治前相比,矫治后点 Co、Ar、Go 及 Pg 相对前颅底均明显后移(P<0.05)。结论成年骨性Ⅲ类错(牙合)低角患者非手术矫治后髁突由下前位向后向上移至中位,关节结构趋于协调和稳定,有利于颞下颌关节紊乱病症状的缓解。

Objective To investigate the effects of orthodontic treatment on temporomandibular joint （TMJ） in adult low-angle patients with skeletal class Ⅲ malocclusion. Methods Sixteen adult female low- angle patients with skeletal class Ⅲ malocclusion were included in the study. All patients were treated with OPA-K straight wire technique. Lateral cephalometric and corrected transcranial projection films were taken before and after treatment. Cephalometric analysis was carried out. All data were analyzed statistically. Results After orthodontic treatment, the linear measurement and area of anterior space in TMJ increased by 0. 27 mm（ P 〈 0. 001 ） and 0. 70 mm^2 （ P 〈 0. 01 ）, respectively, while the posterior space decreased by 0. 24 mm and 0. 67 mm^2,respectively（P 〈0. 001 ）. Linear ratio decreased from 22. 13% to 9. 64% （P 〈0. 001 ）, and area proportion decreased from 1.56 to l. 19（P 〈0. 01 ）. Anterior space became equal to the posterior space. Cephalometric analysis showed that point Co, Ar, Go and Pg were all retruded （P 〈 0. 05 ）. Conclusions After orthodontic therapy, the condyle moved posteriorly to normal concentric position, which would be helpful in alleviating temporomandibular disorders（TMD） symptom in adult lowangle patients with skeletal class Ⅲ malocclusion.