功能矫治器对青春期骨性Ⅱ类患者上气道结构的影响

Effect of functional appliance on upper airway in adolescent patients with skeletal Class Ⅱ malocclusion

目的 :研究功能矫治器作用下青春期骨性Ⅱ类下颌后缩患者上气道结构的变化。方法 :选取处于生长发育高峰期的骨性Ⅱ类下颌后缩患者(实验组)及骨性Ⅰ类均角型患者(对照组)各30例,男女各半。实验组患者使用肌激动器(Activator)治疗,促进下颌骨向前下生长,平均治疗时间12个月;对照组患者同期进行非减数固定矫治。所有患者在功能矫治器治疗前、后,固定矫治前及中期拍摄锥形束CT(CBCT)图像,检测患者治疗前、后骨性指标及上气道线距,并与参考标准对比。观察后鼻棘点(PNS)到第3颈椎(C3)下缘范围内的气道形态,三维重建并测量相应组织结构。应用SAS 8.0软件包对数据进行统计学分析,独立样本t检验比较实验组治疗前各测量项目与参考标准及对照组患者之间的差异,配对t检验比较所有患者治疗前、后各测量项目的差异。结果:治疗前,实验组患者骨性测量指标SNB及APDI显著小于参考标准,ANB、Wits及OJ显著大于参考标准和对照组患者;上气道线距中,MPW和PAS显著小于参考标准和对照组患者。上气道经三维重建后容积及最小横截面积显著小于对照组患者。经Activator引导下颌前伸后,实验组患者骨性测量指标及上气道线距均与参考标准接近,上气道经三维重建后容积及最小横截面积显著增大,与对照组患者无显著差异。对照组患者治疗前、后骨性指标、上气道线距及三维重建指标无显著差异。治疗前、后2组患者不同性别之间上气道指标无显著差异。结论:骨性Ⅱ类下颌后缩患者多伴有上气道缩窄。Activator引导下颌骨前伸,可改善患者骨性Ⅱ类下颌后缩的骨性特征,改善口咽腔和舌根后咽腔部位的狭窄,使上气道容积及最小横截面积增大,缓解上气道缩窄现象。

PURPOSE： To investigate the effect of functional appliance on upper airway in adolescent patients with skeletal ClassⅡmalocclusion based on cone-beam CT （CBCT）. METHODS： Thirty adolescent patients （male：female=1： 1） with skeletal Class Ⅱ malocclusion and their 30 counterparts with skeletal Class I malocclusion were selected. Skeletal Class Ⅱmalocclusion patients were treated with Activator for 12 months on average, meanwhile skeletal Class I malocclusion patients＂ were treated with fixed appliance without extraction. Cone-beam CT （CBCT） films were taken before and 12 months after treatment. Films of skeletal ClassⅡ malocclusion patients were measured （items about skeletal and upper airway, and the outline of upper airway depicted with 3D reconstruction） and compared with the reference standards and the measurements of their counterpart patients with skeletal Class I malocclusion. Independent t test was performed in inter-group comparison and paired t test was performed in inner-group comparison using SAS 8.0 software package.RESULTS： Before treatment, patients with skeletal Class Ⅱmalocclusion showed decreased SNB and APDI value, increased ANB, Wits, and OJ compared with standard value and value of skeletal Class I malocclusion patients. In addition, decreased MPW and PAS value, and downsized volume of upper airway and transverse diameter minimum were found in skeletal Class Ⅱ malocclusion patients. After treatment with Activator, patients with skeletal Class Ⅱ malocclusion showed increased MPW and PAS value, and enlarged volume of upper airway and transverse diameter minimum. All values of skeletal items of patients with skeletal Class Ⅱ malocclusion showed trends to get close to the reference standards and the values of skeletal Class I malocclusion patients. There was no significant difference between different genders of the two groups. CONCLUSIONS： Patients with skeletal Class Ⅱ malocclusion have constructed upper airways. Treatment with Activator can increase the MPW and PAS values and enlarge volume of upper airway and transverse diameter minimum. Functional appliance can ameliorate the narrowness of upper airway for skeletal ClassⅡ patients.