Cephalometric evaluation of maxillary central incisor crown-root morphology in different skeletal malocclusion.

OBJECTIVES

To compare the collum angle (CA) and labial surface angle (LSA) of the maxillary central incisors across different skeletal malocclusion classes and between genders.

METHODS

This cross-sectional study screened lateral cephalogram of 504 patients above 18 years seeking for orthodontic consultation. Skeletal classification was based on ANB angle, Wits appraisal and Beta angle; Class II cases were further divided by maxillary incisor inclination to the SN plane. Landmarks were digitised using tpsDig, and measurements were obtained via a custom Python script. CA and LSA were compared across skeletal classes using ANOVA and between genders using t-tests.

RESULTS

The data of 432 patients (213 males, 219 females) were analysed after eligibility assessment. The mean CA were found to be 1.45°, -1.44°, 4.80°, and 1.20° for Class I, Class II with proclined incisors, Class II with retroclined incisors and Class III respectively, with a statistically significant difference in ANOVA (f = 7.9, p < 0.001). Similarly, mean LSA were 20.55°, 21.35°, 22.11°, and 20.83° for Class I, Class II with proclined incisors, Class II with retroclined incisors and Class III respectively, with no significant intergroup difference in ANOVA (f = 1.135, p = 0.335). No significant gender difference was found with t-test for the CA (t = 0.577, p = 0.564). However, the LSA was significantly greater in females compared to males (t = − 2.158, p = 0.031).

CONCLUSIONS

Skeletal Class II patients with retroclined incisors exhibited a greater CA compared to other skeletal classes. The LSA was slightly greater in females than in males.