Neuromuscular assessment before and after surgical-orthodontic treatment of open-bite skeletal malocclusions

Aims: The aim 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. Materials and Methods: The study utilized 82 patients, 30 with skeletal class III malocclusions and 22 with skeletal class I malocclusions and 30 skeletal class II. All the patients originally had an anterior open bite without vertical overlap of the central incisors. 62 patients had undergone bimaxillary orthognathic surgery; 20 patients only Le Fort I osteotomy. Were assessed anterior and posterior tongue position, lip competence, lip-to-incisors relationship, masticatory muscle activity breathing mode, mandibular kinesiology, postural otovestibular symptoms. Results: Statistically strong correlation were found between anterior and posterior tongue positions and occlusion (p<0.001). 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. Muscular spasms, postural and otovestibular symptoms significantly were diminished (p<0.001).