Ⅱ类骨面型发育加速期拔与不拔牙颌骨变化的研究

Study on mandibular changes of class Ⅱ jaw′s malocclusion patients firstly treated with unexacted and exacted treatment in fix appliance in acceleration stage of cervical vertebrae maturation

目的了解Ⅱ类骨面型患者于颈椎发育加速期行不拔与拔牙固定正畸治疗后颌骨及牙的变化情况。方法24例Ⅱ类骨面型患者于颈椎发育加速期行固定正畸,治疗前、后摄头颅定位侧位X片,并对19项颌骨及牙的测量项目作分析。结果①24例患者治疗前、后上、下齿槽座点及颏前点下移,下颌升支、下颌体长、前后面高及前下面高增加,颌骨不调关系改善,下颌平面角未发生显著性变化。②治疗后两组仅下前牙倾斜度变化量差异有显著性,不拔牙组下前牙更唇倾,余测量项目的变化量差异无显著性。结论Ⅱ类骨面型错牙合患者颈椎发育加速期是开始固定正畸治疗的较好时机,拔牙与不拔牙治疗对Ⅱ类颌骨不调关系的改善效果未发现明显差别。

Objective To investigate the jaw changes in class Ⅱ jaw＇s malocclusion patients who were firstly treated with unexacted and exacted treatment in fix appliance in the accelerated stage of cervical vertebrae maturation by cephalometric analysis before and after treatment. Methods For 24 class Ⅱ Jaw＇s malocclusion patients who were firstly treated with fixed appliance at the accelerated stage of cervical vertebrae maturation, their cephalometric films were taken before and after treatment. 19 mandibular and dental items were measured and analysed. Statistics paired-sample and Independent samples t test were performed in SPSS 10. 0. Results （1）After treatment,subspinale,supramental and pogonion points became lower, length of mandibular body, ascending ramus, anterior facial height, posterior facial height and low facial height became longer, maxillary-mandibular skeletal relationship was more ＂nomlalized＂ and the angle of mandibular plane was almost the same in 24 subjects. （2） Only the changed magnititude of the lower incisor oblique angle had obviously statiscal difference between two groups. The nonexacted group was bigger than exacted grnup. Other variables didu＇t have obviously stastistical difference. Conclusion The accelerated stage of cervical vertebrae maturation is the better time to start the fix treatment in class Ⅱ jaw＇s malocclusion patients and there isn＇t obvious difference in the improved effects of class Ⅱ jaw .