Ⅱ类Ⅰ分类错患者不拔牙矫治的疗效评价

目的:评价使用头颈帽、固定矫治器治疗Ⅱ类Ⅰ分类错不拔牙患者治疗后的变化。方法:本研究中的18例患者在治疗前、治疗结束时和保持期结束时照头影侧位X片,采取记存模型。治疗开始的平均年龄为11.9±2.6岁,治疗时间为2.8±1.2年。治疗后上下颌使用Hawley保持器保持1~1.5年。结果:头影侧位X片测量显示上颌发育受到限制,上颌切牙内倾,覆覆盖减小,下颌切牙前倾;治疗结束时下颌轻度向后旋转。保持期后,上颌稳定,下颌前移,覆盖显著增加(P<0.01)。模型显示治疗期间上下颌紊乱指数明显减小。保持期后,下颌尖牙间的宽度显著减少(P<0.01)。结论:头颈帽、固定矫治器治疗的Ⅱ类Ⅰ分类错●不拔牙患者,所取得的上颌生长方向的效果是稳定的,但是治疗所诱导的下颌旋转效果却趋于复发到原来的方式,保持期后牙齿有各种的变化。

Evaluation of posttreatment changes in class division patients after nonextraction orthodontic treatment

Objective:To evaluate changes in patients with class division malocclusions treated with cervical headgear and full fixed orthodontic appliances without extractions.Methods:Lateral cephalograms and dental casts of 18 patients were obtained at the beginning and the end of treatment and at the postretention period.Pretreatment records were taken at 11.92.6 years,and the mean treatment time was 2.81.2 years.All patients were asked to use maxillary and mandibular Hawley retainers for 1~1.5 year.Results:The assessment of cephalometric findings showed that maxillary growth was restricted,maxillary incisor inclination,overjet and overbite were decreased,the mandibular incisors were proclined.A slight mandibular posterior rotation occurred at the end of treatment.At the postretention period,the maxilla remained stable,the mandible moved anteriorly and the overjet increased slightly(1.25mm,P<0.01).The dental cast changes indicated that both maxillary and mandibular irregularity index values decreased significantly during treatment.Mandibular intercanine width decreased 0.47mm(P<0.01) during the postretention period.Conclusion:The redirection of maxillary growth remained stable in patients with class malocclusions treated with cervical headgear and fixed orthodontic appliances and without extractions,but treatment-induced mandibular rotations tended to return to their original patterns.Various dental changes occurred during the postretention period.