Labiomental groove and lip thickness effects in large overjet facial-profiles

Dental malocclusions and dentofacial appearance are related to both hard- and soft-tissue developmental variation. The objectives of this study are to compare dentofacial cephalometric measurements in patients with normal overjet (Control group: OJ=2-4mm) with others with large overjet (Investigation group: OJ>4mm), and to determine the correlations between variation in each of labiomental groove and lower lip thickness, and variation in other measurement variables (OJ, ANB, L1-Md, L1-APog, SN-Md). Groups were matched for size, gender, age and ethnicity. Cephalometric analysis and measurements were obtained according to Al-Sharood, 2003 (J Dent Res, 82, Spec Iss C600-8). ANOVA and linear regression analysis tests were used for comparative and correlative purposes, respectively. Reliability of measurements was tested, and the significance level was P<0.05. Significant differences between groups were found. Lower lip thickness was negatively correlated to variation in ANB, MD-SN (Investigation group) and L1-Apog (Control group), and positively to OJ (Controls). Whereas, labiomental groove was not related to any variable in investigation group and was negatively correlated by lower lip thickness values in control group. Large overjet therefore, has an effect on labiomental groove, lower lip thickness and facial appearance in general, which may be in an expected or unexpected manner during clinical estimation.