Changes in soft-tissue profile following extraction and complete denture treatment

Abstract

A longitudinal cephalometric radiographic investigation was designed to study the changes occurring in the soft-tissue profile of the lips in twelve subjects following extraction of all remaining teeth and complete denture therapy. Eight soft-tissue points on the contour of the upper and lower lips were selected for measuring the changes at four phases of the study. Measurements were made from these points perpendicular to two planes of reference—the optic plane and the vertical PNS plane. 1. The cephalometric technique used for measuring and analyzing the changes in the soft-tissue contour of the lips utilized direct measurements from the soft-tissue points perpendicular to two reference planes. This technique was found to be simple, accurate, and appropriate for this purpose. 2. Following extraction of the teeth there was a dramatic change in the contour of the lips. This was due to the loss of support by the teeth and reduction of rest face height. 3. The complete maxillary and mandibular dentures provided adequate support for the contour of the upper lip approximating the pre-extraction contour. 4. Measurements for the lower lip showed significant changes in the contour, at the four phases, with the teeth in occlusion and in rest position. These changes were closely associated with the changes occurring in face height. 5. After twelve months of wearing complete dentures, there occurred a gradual reduction in both vertical and horizontal dimensions of the contour of the lips due to the positional changes of the dentures over the supporting tissues.