RESUMO
UNLABELLED: Does an advanced or retracted position of the upper and lower incisors lead to modifications in lip position? The aim of our study was to evaluate modifications in lip position following orthodontic treatments. MATERIAL AND METHODS: This study concerned 100 patients who underwent treatment in the dento-facial orthopedic unit in Casablanca. Profile headfilms at the start and at the end of orthodontic treatment were compared using Frapier's analysis. The Student test was applied to evaluate the variations in the cephalometric measurements. RESULTS: We noted a non-significant increase in the nasolabial angle (P = 0.274), a significant decrease in the sagittal position of the lower vermillion border (PsVei) (P < 0.001) and the sagittal position of the soft-tissue supramentale (PsSmc) (P < 0.001), and a significant increase in the vertical position of the soft-tissue menton (PvMec) (P = 0.035). CONCLUSION: The results of this study demonstrate marked improvements in the situation of soft tissues. We suggest further investigation to throw light on the relationship between tooth movement and soft tissue, increasing the size of the sample and taking growth into account.