A cone-beam computed tomography study on crown-root morphology of maxillary anterior teeth in Class Ⅱ,division 2 malocclusion
10.3969/j.issn.1671-167X.2016.01.019
- VernacularTitle:安氏Ⅱ类2分类错牙合上前牙冠根形态的锥形束CT分析
- Author:
Min LI
;
Siwei WANG
;
Yijiao ZHAO
;
Yi LIU
- Publication Type:Journal Article
- Keywords:
Malocclusion,Angle classⅡ;
Cone-beam computed tomography;
Crown-root angle;
Sur-face-shaft angle
- From:
Journal of Peking University(Health Sciences)
2016;48(1):105-110
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To study crown-root morphology of maxillary anterior teeth in ClassⅡ,division 2 malocclusion using cone-beam CT (CBCT)combined with computer aided measurement technology to provide guidance for clinical treatment.Methods:The samples which consisted of 36 cases radiographed with CBCT techniques were selected and divided into two groups (1 8 each )based on the type of maloc-clusion presented:ClassⅡ,division 2 group (groupⅡ2)and ClassⅠgroup (groupⅠ).The measure-ments of crown-root morphology including crown-root angle and surface-shaft angle were got by Multiple Planer Reconstruction of CBCT data uploaded into InvivoDental software 5.0.The data were processed with SPSS 20.0 software package and t test was employed for comparison of angular measurements. Results:In group Ⅰ,crown-root angles of maxillary central incisor,maxillary lateral incisor and maxillary canines were 1 79.08°±3.31 °,1 76.55°±2.77°and 1 84.20°±2.51 °respectively, surface-shaft angles were 21 .00°±2.63°,1 9.63°±2.35°and 1 9.36°±2.30°respectively. While in group Ⅱ 2 ,crown-root angles of maxillary central incisor,maxillary lateral incisor and maxillary canines were 1 76.80°±2.62°,1 74.1 3°±3.28°and 1 81 .79°±2.88°respectively, surface-shaft angles were 23.20°±2.95°,22.29°±2.1 9°and 20.61 °±2.34°respectively. Compared with group Ⅰ,significant statistical differences were observed with the exception of sur-face-shaft angle of maxillary incisor.There was significant difference in crown-root angle between group Ⅱ2 and 1 80 °.Conclusion:The maxillary anterior teeth in ClassⅡ,division 2 malocclusion exhibited significant crown-root morphology which would influence the torque after orthodontic treat-ment.Special attention should be paid to the position of maxillary anterior teeth roots during ortho-dontic treatment for Class Ⅱ,division 2 malocclusion.The ideal position of tooth movement should be decided by the root rather than the location of the crowns.
