[The impact of extractions on profile esthetics: a statistical study]

This study assesses and compares the impact of orthodontic treatment with premolar extractions on the profile of the soft tissues in hyper- and normodivergent patients from our Moroccan population which is characterized by a high rate of hyperdivergency. This retrospective study was performed on a sample of 60 adults (30 hyperdivergents and 30 normodivergents). Pre-treatment and end-of-treatment headfilms were used to take sagittal and vertical measurements of soft tissue using the Frapier method which takes the Björk-Nielsen implant line as superimposition landmark. The results of this study show marked improvements on the soft tissues, even though the mean differences are occasionally non-or only slightly significant. In contrast, the vertical dimension has little incidence on the results obtained. The response to treatment of hyperdivergent patients, even when displaying a greater initial esthetic deficit, is similar to that of normodivergents. In certain areas, the improvement was occasionally greater, notably at the soft-tissue pogonion, the mento-labial angle and the naso-labial angle.