成人上颌扩弓后牙颌结构的变化

目的探讨上颌扩弓对成人牙颌结构的影响。方法成人上颌扩弓组11例和非上颌扩弓矫治组(对照组)17例。测量矫治前、主动矫治结束时及保持2年时双侧上颌第一磨牙交角、临床牙冠高度、上颌第一磨牙间宽距、上颌中切牙根尖点宽距、上颌宽距、下颌平面角以及前下面高。结果保持2年较矫治前扩弓组上颌第一磨牙交角减小7.50±10.21°,对照组减小0.64±5.06°;扩弓组第一前磨牙临床牙冠高度增加0.61±0.45 m m,对照组增加0.21±0.51 mm;扩弓组上颌第一磨牙间宽距增加7.30±0.56mm,上颌中切牙根尖点宽距增加0.91±0.28mm,上颌宽距增加2.75±0.35mm;对照组上颌第一磨牙间宽距增加0.32±0.21mm,上颌中切牙根尖点宽距减少0.25±0.18mm,上颌宽距增加0.89±0.25mm,两组相比5项指标均具有显著性差异。结论成人上颌扩弓可以有效扩大上颌牙弓及上颌宽距,不会导致明显的下颌后下旋转和牙龈退缩。

Dental and skeletal changes after maxillary expansion in adults

Objective To evaluate the effects of maxillary expansion on dentoskeletal structures in adults.Methods Maxillary expansion by a Hass expander was used in 11 adults.Seventeen adult orthodontic patients who did not require maxillary expansion served as control.Model measurements and cephalometric measurements including first molar angulation,first premolar and first molar clinical crown height,upper intermolar width,upper incisor interapex width,maxillary width,MP-SN,ANS-Me were taken before treatment,end of treatment and 2 years after treatment,respectively.Results Significant difference was found in the first molar angulation,the first premolar clinical crown height,upper intermolar width,upper incisor interapex width and maxillary width between the two groups.Conclusion Maxillary expansion in adults is an effective method without significant opening rotation of the mandible and gingival recession.