Terapia ortopedico-funzionale della malocclusione di Classe III

Abstract

Objectives Early treatment of Class III malocclusion with orthopaedic and functional appliances has been advocated to control and modify the growth's direction and to reduce the need of treatment in the permanent dentition, when camouflage orthodontic treatment or surgery are the only options. Materials and methods The clinical success of early Class III treatment in most patients through growth modification, however, has resulted in the development of several strategies to treat Class III disharmony. Results The removable mandibular retractor produced a more significant anterior morphogenetic rotation of the mandible, due to a more upward and forward direction of condylar growth. Frankel's function regulator led to a downward and backward rotation of the mandible, a decrease in the SNB angle with a subsequent increase of the ANB angle, and the retrusion of the lower incisors. The Balters’ Bionator appliance caused mainly dento-alveolar changes in the growing craniofacial skeleton. Although such skeletal changes are statistically significant, they are less evident from a clinical point of view. The double-plate appliance showed a protrusion of the maxillary incisors and a retrusion of the mandibular incisors, a few sagittal skeletal effects with a satisfying control of vertical dental and skeletal changes. The SEC III caused an improvement of Wits appraisal, ANB angle, and overbite without backward mandibular rotation. The maxillary incisors were protruded. The chincup corrected the incisors relationship with proclination of the upper incisors and retroclination of lower incisors, and caused a redirection of mandibular growth in a downward direction with increase in facial height. Conclusions The early treatment of Classes III has always been and still is a controversial issue. Functional and orthopaedic therapies, if early administered, allow to control and change both the direction of growth and the relationships among osseous bases, whereas the orthodontic therapy is useful only to perform a dental compensation.