Influence of lip support on the soft-tissue profile of complete denture wearers

Complete dentures change the soft-tissue profile, although the exact relationship remains unclear. This study examined the relationship between the presence and degree of lip support provided by dentures and the lateral views of the facial appearance of edentulous patients. The subjects were five edentulous patients (three men and two women). Their facial appearances with experimental record blocks, with and without their complete dentures, were measured using a three-dimensional laser measuring system. The experimental record block for each subject had different conditions in the anteroposterior direction anteriorly but the same vertical dimensions posteriorly. The lateral digital facial images were displayed on a computer monitor, and the linear and angular measurements were analysed using image analysis software. The nasolabial angle was smaller and the labial points projected more with excessive lip support versus with deficient support. Moreover, the counter of the nose was affected by the labial flange of the record base, particularly in the facial appearance of one subject with highly atrophic residual ridges. The lip support affected the lower facial soft-tissue profile, including the lower part of the nose; the nasolabial angle and positional relationship between the lips and Ricketts's esthetic plane (E plane) are useful indexes for examining lip support.