Relationship between the maxillary incisors and upper lip before and after orthodontic treatment of deep-bite cases

Abstract

Using lateral cephalometric radiographs of 8 deep-bite cases and 21 cases with normal occlusion, we investigated soft tissue changes during orthodontic treatment to find the relationship between the maxillary incisors and upper lip. Significant differences were found at three horizontal points(U1, Prn and UL)when soft and hard tissue points were measured horizontally and vertically in deep-bite cases and in those with normal occlusion. A high correlation was found between the position of the maxillary incisors and upper lip. Recurrent lines showing the relationship between these positional changes were calculated. The results of this study are useful in determining soft tissue position when planning orthodontic treatment.