Evaluation of Maxillary Central Incisor and Canine Exposures in Resting Position of the Maxillary Lip for Determining the Anterior Level of Occlusal Plane

Abstract

Introduction: The exposure of the maxillary anterior teeth affects the anterior level of occlusal plane, esthetics, and speech. Previous data suggests approximately 2 mm of exposure of the maxillary central incisors in the resting position of the maxillary lip.
Aim: This study aimed to evaluate the relationship between the vertical position of the maxillary central incisors and canines and the maxillary lip in Indian dentulous subjects according to age, sex, and lip length.
Material and method: A total of 540 (272 male and 268 female) Indian adults between 21 and 60 years of age were included in the study. The exposures of the maxillary central incisors and canines were measured using a ruler with the maxillary lip in the rest position. Additionally, the maxillary lip length of each subject was also measured.
Result: Data were analyzed using analysis of variance and Student’s t-test. The tooth exposure was inversely proportional to lip length. Statistically significant differences in the exposures of the maxillary central incisors and canines were observed between the age groups 20-30 years and 30-40 years and 40-50 years for maxillary central incisors. However, no significant differences were observed between the age groups 50-60 years for maxillary central incisors and between 40-50 years and 50-60 years for maxillary canines.
Conclusion: Maxillary central incisor exposure is highly variable while maxillary canine exposure showed lesser variations with age, sex, and lip length.