Crown-root morphology of lower incisors in patients with class III malocclusion.
OBJECTIVE
The purpose of this study was to investigate the crown-root morphology of lower incisors in patients with class III malocclusion using cone-beam computed tomography.


METHODS
Cone-beam computed tomography images were analyzed from 53 adult class I patients (group 1), 37 preadolescent class III patients (group 2), and 66 adult class III patients (group 3) comprising 3 divisions (divisions 1, 2, and 3 corresponded to mild, moderate, and severe class III malocclusions). The size and crown-root angulations of lower incisors in different groups and divisions were statistically appraised with group 1 used as the control group.


RESULTS
No significant differences were found for the size of lower incisors among different groups and divisions (P > 0.05). Compared with group 1, the crown-root angulations of lower incisors in groups 2 and 3 were significantly larger (P < 0.01), and among 3 divisions, the lower incisors of division 3 rather than divisions 2 and 3 exhibited larger crown-root angulations (P < 0.01).


CONCLUSIONS
Attention should be paid to the enlarged crown-root angulations of lower incisors in class III patients during orthodontic and orthognathic treatment, especially in severe ones.
Center of Cranio-facial Orthodontics, College of Stomatology, Affiliated 9th People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
Bo
B
Wang
Guofang
G
Shen
Bing
B
Fang
Li
L
Zhang
D000293:Adolescent; D000328:Adult; D002648:Child; D054893:Cone-Beam Computed Tomography; D005260:Female; D006801:Humans; D007180:Incisor / Q000000981:diagnostic imaging*; D008297:Male; D008313:Malocclusion, Angle Class III / Q000000981:diagnostic imaging*; D011857:Radiographic Image Interpretation, Computer-Assisted; D018709:Statistics, Nonparametric; D019228:Tooth Crown / Q000000981:diagnostic imaging*; D014092:Tooth Root / Q000000981:diagnostic imaging*