The perceived impact of extraction and nonextraction treatments on matched samples of African American patients.

Abstract

Orthodontic patients of African descent often seek some measure of reduction in profile protrusion. Lip retraction, however, seems to imply a need for premolar extraction. But in a nonextraction era, what does orthodontics have to offer the bimaxillary protrusion patient? To a considerable extent, it depends on what the patient wants and what treatment can provide. The present study was designed to address these questions by comparing the esthetic impact of extraction and nonextraction therapy on two morphologically similar samples of African American patients with Class I and II malocclusions. In addition to the patients, four panels of judges (black and white orthodontists and black and white laypersons) were asked to compare the pretreatment and posttreatment profile tracings and to quantify their perceptions of the esthetic impact of the change that occurred during treatment. Although there was a strong correlation among the various groups' ratings, there were a number of statistically significant differences. Premolar extraction led to a modest reduction in dental and soft tissue protrusion; nonextraction, by way of contrast, produced an increase. Presumably in response to these changes, all panels, independent of race or education, tended to prefer the posttreatment profiles, especially the posttreatment extraction profiles. There was, however, a significant interaction between race and treatment. The perceived effects of nonextraction treatment were modest and largely unrelated to the pretreatment profile, whereas the impact of premolar extraction was a highly significant function of initial protrusion: convex profiles were improved, but relatively straight profiles were made worse. The various panels, however, differed in their estimate of the point at which a profile might benefit from extraction (ie, profile reduction). For our white panelists, that point was reached when the lower lip was about 2 mm in front of Ricketts' E-plane. For our black panelists, the equilibrium point came at +4 mm. These findings imply that there is significant interaction among the type of treatment, the race of the patient, and both the race and professional background of the observer. Facial beauty, it would seem, is in the hand of the orthodontist, as well as in the eye of the beholder and the face of the beheld.