Contributing factors to relapse after surgical correction of skeletal open-bite

The aim of this study was to evaluate the adaptive changes and the functional behavior of soft tissue and orofacial muscles after surgical correction of skeletal open-bite and to show their influence on occlusion and their contribution to relapse. The study utilized 37 patients, 19 with skeletal class III malocclusions and 18 with skeletal class I malocclusions. Twenty-seven patients had undergone bimaxillary orthognatic surgery; 10 patients only Le Fort I osteotomy. Were assessed anterior and posterior tongue position, lip competence, lip incisor relationship, masticatory muscle activity and breathing mode. Lack of anterior contact and of a strong interdigitation allow tongue interpositioning. The activity of the masticatory muscles and habitual mouth posture were correlated to open-bite, over-jet and over-bite. It was concluded that the adaptive changes in the orofacial complex of adults, contribute to cause the relapse of anterior open-bite. The occlusion should be as stable and optimal as possible to eliminate reasons for relapse.