Predictability and stability of orofacial deformities correct by orthognathic surgery

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 91 patients, 42 males and 49 females, aged 18 to 36 years, 37 with skeletal class III, 22 with skeletal class I and 32 skeletal class II malocclusions. 64 patients had undergone bimaxillary orthognatic surgery; 27 patients only Le Fort I osteotomy. Results demonstrated that statistically strong correlation were found between anterior and posterior tongue positions and occlusion. Lack of anterior contact and of a strong interdigitation allowed tongue interpositioning. The activity of the masticatory muscles and habitual mouth posture were correlated to open bite, over jet and over bite. The interlabial distance was significantly correlated with mentalis muscle activity. After surgical correction of anterior skeletal open bite, surely the adaptive changes in the orofacial complex of adults, contribute to cause the relapse. The occlusion should be as stable and optimal as possible to eliminate reasons for relapse.