论文部分内容阅读
目的对比拔除第一双尖牙或第二双尖牙矫治对青少年骨性Ⅰ类错面部垂直高度的影响。方法选择拔除第一双尖牙或第二双尖牙矫治的青少年病例各30例。两组样本的性别、年龄以及疗程相互匹配。对两组治疗前后的头颅侧位片进行测量分析,比较两种不同拔牙模式治疗前后牙、颌、颅面部垂直向上的变化。统计学分析采用配对t检验。结果双尖牙减数治疗后MP-SN、PP-SN、MP-PP、Y轴角和S-Go/N-Me无显著性变化;S-Go、N-Me均增加,差异呈高度显著性;下颌升支、下颌体以及下颌的综合长度均增加,差异有显著性;上下磨牙及上前牙治疗后伸长,差异有显著性;但是上述各项测量值治疗前后的变化量,在两组之间并无显著性差异。下前牙垂直向的变化差异较大。结论虽然拔除第二双尖牙组上下磨牙的近中移动量大于拔除第一双尖牙组,两者之间的差异有显著性,但是这两种拔牙模式均不会引起骨性Ⅰ类错下颌平面的旋转,以及面部垂直高度的降低。
Objective To compare the effects of removing the first bicuspid or second bicuspid on the facial vertical height of skeletal Class Ⅰ malocclusion in adolescents. Methods Thirty cases of adolescents with the first bicuspid or second bicuspid extraction were selected. The gender, age and course of treatment of the two groups matched each other. Before and after treatment of the two groups of cephalometric films were measured and analyzed to compare the two different extraction mode before and after treatment of teeth, jaw, craniofacial changes in the vertical upward. Statistical analysis using paired t test. Results There was no significant change of MP-SN, PP-SN, MP-PP, Y-axis angle and S-Go / N-Me after treatment with bidentate premolar. S-Go and N-Me increased significantly The total length of mandibular ascending branch, mandibular body and mandible increased, the difference was significant; the upper and lower molar and the anterior teeth after treatment, the elongation was significant; however, the above-mentioned measured values before and after treatment changes in There was no significant difference between the two groups. Vertical changes in the lower anterior teeth vary widely. Conclusions Although there is a significant difference in the amount of proximal and distal movement between the upper and lower teeth of the second pair of canines when compared with those of the first pair of canines, neither of these two types of tooth extraction can cause skeletal Class Ⅰ malocclusion Mandibular plane rotation, and facial vertical height reduction.