Cephalometric comparison of soft-tissue morphology between extraction and nonextraction orthodontic treatment in borderline cases
- VernacularTitle:临界病例拔牙与不拔牙矫治对颅颌面软组织形态的影响
- Author:
Tian-Min XU
;
Yan LIU
;
Wei HUANG
;
Jiu-Xiang LIN
;
- Publication Type:Journal Article
- Keywords:
Tooth extraction;
Orthodontics;
corrective;
Softtissue;
Jaw
- From:
Journal of Peking University(Health Sciences)
2003;0(06):-
- CountryChina
- Language:Chinese
-
Abstract:
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.
