临界病例拔牙与不拔牙矫治对颅颌面软组织形态的影响

目的:比较拔牙或不拔牙矫治对临界病例颌面部软组织结构变化的影响.方法:以5位正畸专家临床判断出的33个临界病例为样本,在头颅定位侧位片上测量上述病例治疗前后颌面部软组织的变化,再根据这33名患者实际接受的拔牙还是不拔牙、以及拔第一双尖牙还是拔第二双尖牙治疗进行分组.33例中有12例采用了不拔牙治疗,13例采用了拔4个第一双尖牙治疗,8例采用了拔4个第二双尖牙治疗.用头影测量学上常用的15项软组织测量项目进行分析比较.结果:临界病例拔牙组与临界病例不拔牙组在治疗前的软组织侧貌没有一项具有统计学意义的差别;拔4个第一双尖牙组的患者颏部倾斜度(PosBs/FH)明显小于不拔牙组;而其软组织颌凸角(Ns-Sn-Pos)明显小于拔4个第二双尖牙组.治疗后拔4个第一双尖牙组与不拔牙组的软组织侧貌无一项有统计学意义的差别;但拔4个第二双尖牙组与不拔牙组之间有6项测量差异有统计学意义.拔牙与非拔牙相比,软组织变化量最大的是:颏部倾斜度(PosBs/FH)、下唇突度(LL-SnPos)和软组织B点相对于审美平面的突度(Bs-EP).结论:虽然治疗前拔第二双尖牙组与不拔牙组的软组织侧貌比较接近,但治疗后拔第一双尖牙组与不拔牙组的侧貌更加趋于相同;与不拔牙组相比,拔牙矫治对软组织侧貌改变更多的是下唇及颏部,而不是上唇突度.

Cephalometric comparison of soft-tissue morphology between extraction and non-extraction orthodontic treatment in borderline cases

Objective:To compare soft-tissue morphology changes by cephalometric measurements be-tween extraction and non-extraction orthodontic treatment in borderline cases.Methods:The samplesconsisted of 33 cases selected as borderline cases by 5 orthodontic specialists.They were divided into 21extraction cases(including 13 four first premolar extraction cases and 8 four second premolar extractioncases)and 12 non-extraction cases by checking patients' treatment records.Conventional cephalometricanalysis was made to compare soft tissue structures before and after orthodontic treatments and the samecomparison was made between two different extraction patterns.Results:No statistical difference wasfound in pretreatment soft-tissue morphology between extraction and non-extraction groups divided fromborderline cases.The PosBs/FH of the four first premolars extraction group was smaller than that of non-extraction group,and the Ns-Sn-Pos of the four first premolars extraction group was smaller than that offour second premolar extraction group.None of the post-treatment soft-tissue measures showed significantstatistical differences between four first premolars extraction group and non-extraction group,but therewere 6 items showed significant statistical differences between four second premolars extraction group andnon-extraction group.Compared with extraction and non-extraction treatments,the most significant soft-tissue changes were:PosBs/FH,LL-SnPos,and Bs-EP.Conclusion:Although pre-treatment soft-tissuemorphology of second premolar extraction group was close to that of non-extraction group,the post-treat-ment soft-tissue morphology of first premolar extraction group became closer to that of non-extractiongroup.Compared with non-extraction treatment,the more significant changes caused by extraction treat-ment were located in the lower lip and chin,but not the upper lips.