[Correlations between the occlusal plane angle and the risk of relapse after surgical orthodontic treatment of Angle Class III anomalies].

An important criterion in the diagnostic and therapeutic assessment of severe true mandibular prognathia (characterized by excessive growth of the mandible and hiperdivergent facial growth pattern) is the orientation of the occlusal plane compared with the facial benchmark represented by the Frankfurt horizontal line. This is because orthognatic surgery in this pathology (sagittal bilateral osteotomy) envisages not only the shortening of the mandible, but also the counterclockwise rotation of the mandible to restore facial and dento-alveolar harmony in the three planes (sagittal, transverse, vertical). The aim of the study is the analysis of the evolution of the maxillo-mandibular complex in relation to the occlusal plane after orthognatic surgery (sagittal osteotomy of the mandible and bilateral Le Fort I of the maxilla), in a group of 15 patients with a mean age 22+3 years diagnosed with skeletal class III malocclusion, hiperdivergent facial pattern, initial average value of the occlusal plane angle 130+0.60. t test applied for comparative statistical analysis for the linear and angular parameters considered in four therapeutic stages (initial presurgical, post surgical, one year post surgical) show statistically significant changes in parameters related to the mandibular length and rotation, without significant variations one year after the surgical phase.