摘要
目的:观察恒牙期骨性Ⅲ类错病例在拔除下颌第二磨牙矫治后患者牙、、面垂直关系的变化。方法:恒牙期骨性Ⅲ类错畸形病例16例,男4例、女12例。年龄13.4～17.2岁,平均15.0±1.6岁。所有病例在拔除下颌第二磨牙后采用直丝弓矫治器进行掩饰治疗。对治疗前后X线头颅侧位片上反映垂直向关系的角度、线距及比例进行测量分析。结果:与矫治前相比,矫治后UM-PP增加1.83mm、LM-Gn增加5.38mm(P<0.05),UM-S及LM-MP无显著改变。SN-OP减小4.57°,SN-PP增加1.45°,差异具有统计学意义(P<0.05),SN-MP无显著改变。ANS-Me和Na-Me分别增加了2.22mm和2.77mm(P<0.05),但Na-ANS、S-Gn、ANS-Me/Na-Me及S-Go/Na-Me均无显著改变。结论:恒牙期骨性Ⅲ类错病例在拔除下颌第二磨牙矫治后下颌平面角无显著改变。但上颌第一磨牙伸长,平面出现逆时针旋转,同时腭平面发生了顺时针旋转。下颌第一磨牙远中移动显著,而上颌第一磨牙近远中位置保持不变,从而使磨牙关系得到基本改善。上颌磨牙的伸长导致前下面高及总面高有所增加,提示在矫治的过程中应采取措施保持上磨牙高度的稳定,从而避免前面高的增加。
Objective：The purpose of this investigation was to assess the vertical changes occurring in skeletal patients treated orthodontically with mandibular second molar extractions.Method： Sixteen patients with skeletal class Ⅲ malocclusion were included in the study. All patients were treated with straight wire fixed appliances after mandibular second molar extractions. The pretreatment and posttreatment lateral cephalometric radiographs were digitized using dental software （Dental Studio NX）and several cephalometric variables were examined to evaluate the vertical changes occurring as a result of orthodontic treatment. Result： After active treatment, UM-palatal plane （mm） and LM-Gn horizontal （mm） increased 1.83mm and 5.38mm respectively （P〈0.05）, but there were no statistically significant differences in UM-S horizontal （mm） and LM-mandibular plane （mm）. SN-OP angle decreased 4.57° and SN-PP angle increased 1.45° （P〈0.05）, there was no significant change in SN-GoGn angle. After treatment, ANS-Me （mm） and Na-Me （mm） increased 2.22 mm,2.77 mm respectively （P〈0.05）, but the change of Na-ANS （mm）, S-Go （mm）, ANS-Me / Na-Me% or S-Go / Na-Me% was no significant. Conclusion：These results suggest that there is no decrease in the mandibular plane angle in patients with skeletal class Ⅲ malocclusion after mandibular second molar extractions. During treatment period, the upper first molar extruded and the occlusal plane rotated counterclockwise, the palatal plane clockwise. The lower first molar moved dramatically to the distal, but the upper first molar remained nearly unchanged, therefore class Ⅰ molar and canine relationships were established in all cases.
出处
《临床口腔医学杂志》
2007年第12期760-762,共3页
Journal of Clinical Stomatology
关键词
骨性Ⅲ类错(牙合)
第二磨牙拔除
垂直高度
skeletal class Ⅲ malocclusion
second molar extraction
vertical dimension
