Abstract
In the treatment of cleft lip and palate patients, mostly upper anterior prosthetic appliances are needed for obtaining proper lip support and improving the facial profile. But the longitudinal change in amount of forces exerted on those appliances by lips has not been studied yet.
The purpose of this study was to measure the upper lip press u re on prosthetic appliance longitudinally. As for the preliminary study, lip pressure during rest and some functional events were recorded by miniature pressure sensors attached to tooth surface and compared with those results of control non-cleft lip and palate subjects. Maximum value and potential energy of those lip pressure were analyzed. Muscle activities of orbicularis oris and masseter on both sides were also recorded simultaneously with surface electrodes. Three cleft lip and palate patients with removable prosthetic appliances and three non-cleft lip and palate subjects with natural dentition were selected.
Following results were obtained.
1. Larger values of maximum lip pressure were measured in cleft lip and palate patients than control subjects for events like pushing lips forward.
2. Larger amount of potential energy of lip pressure were obtained in the event of pulling upper lip downward in the cleft lip and palate patients.
3. Overall activities of orbicularis oris in cleft lip and palate patients were smaller than those of control subjects.
