Effect of Dentofacial Morphology of Skeletal Class II Malocclusion on Depth of Curve of Spee in Hypodivergent Growth Pattern

Abstract

AbstractIntroduction: The Curve of Spee is an anteroposterior compensatory curve formed by the occlusal alignment of teeth in the sagittal plane. Attaining flat COS is one of the keys to normal occlusion. The aim was to evaluate the effect of depth of COS on various factors (overjet, overbite, lower arch crowding, position and inclination of the upper and lower incisors, interincisal angle and intermolar angle) in subjects with skeletal Class II and hypodivergent growth pattern.Materials and Method: A total of 30 subjects aged 15-25 years with skeletal Class II malocclusion and hypodivergent growth pattern were selected and divided into three groups based on the depth of the Curve of Spee(COS): Group I (COS 0-2 mm), Group II (COS >2 ≤4 mm), and Group III (COS >4 mm) as seen in study models. Overjet, overbite, lower arch crowding were measured on study models. Various cephalometric parameters included interincisal angle, intermolar angle, LI-NB angle and LI-NB linear. Data were tabulated and comparison was made by using one-way ANOVA followed by Tukey's test.Results: Statistically significant differences were found in lower incisor inclination (P = 0.024*), lower incisor position (P = 0.022*), and overbite (P = 0.024*) between groups with variable depth of COS.Conclusion: Adequate consideration must be given to depth of Curve of Spee while correcting overbite and lower incisor position in subjects with skeletal Class II malocclusion and hypodivergent growth pattern.