影响正畸治疗后牙弓稳定性的相关因素探讨

目的　探讨影响正畸治疗后牙弓稳定性的相关因素。方法　对正畸治疗后 2 4～ 97个月 (平均 5 0 .0 5个月 ) 74例错牙合畸形患者治疗前后及保持后模型进行牙弓测量。结果　保持后 ,大部分测量项目男性大于女性 ,但减少百分率无显著差异 ;不同的矫治器类型 (除上下尖牙宽度P <0 .0 5外 )、错牙合类型 (除上牙弓长P <0 .0 1外 )和保持时间组间牙弓测量项目差异无显著性 (P >0 .0 5 ) ;保持后下 3- 3长度减少百分率非拔牙组 (13.4 4 % )和青少年组 (8.93% )分别大于拔牙组 (7.2 2 % )和成年组 (4 .10 % )。结论　保持停止后 ,尖牙间长度、宽度随着年龄的增大不断减少 ;下颌骨的向前生长和过度扩弓是导致下前牙拥挤复发的主要原因之一。

The study of correlative factors influencing stability in dental arch out after retention of orthodontic treatment

Objective To investigate correlative factors influencing stability in dental arch out of retention after orthodontic treatment.Methods The dental arches were measured on pre-, post-treatment and 24-97 months out of retention study models of 74 cases with malocclusions.Results Out of retention, most dental arch measurements were greater in male than in female,whereas no significant differences were noted in percentage reduction.There was no significant differences in the dental arch measurement between the various malocclusion classes(except upper dental arch length P< 0.01 ),the various appliances(except intercanine width in both jaws P< 0.05 ),and the various length of retention.Percentage reduction of lower intercanine length was respectively greater in non-extraction ( 13.44% ) and adolescent groups ( 8.93% ) than that in extraction ( 7.22% ) and adult groups ( 4.10% ) out of retention.Conclusion The dimensions of intercanine width and length continuously decreased with age increased out of retention. Mandibular forward growth and excess expansion of the dental arches were one of main causes of mandibular anterior crowding relapse.