Classification for mandibular deviation and facial asymmetry and its clinical significance

Abstract

Judged from the clinical manifestations, etiological mechanisms and jaw morphological structures, malocclusions with mandibular deviation and facial asymmetry are classified into three main categories, i.e., those with mandibular positioning factors, those with mandibular condyle defects, and those with jaw congenital deformities. In the first category, three subtypes, including mandibular rotation caused by dentitional irregularities, by dental compensation and by habitual posturing, are further defined. In the second category, mandibular deviation caused by condylar asymmetrical resorption or hyperplasia are defined as the two subtypes. The third category is further divided into two subtypes, i.e., jaw and facial asymmetry resulting from maxillary or mandibular structural deformities. The prime goal of orthodontic therapy is to displace and restore the deviated mandible to its right position, followed by correction of occlusal intercuspation. As an important procedure of the whole treatment protocol, It is critical to detect and localize the correct mandibular position by manipulation and then register it by wax pattern and articulator transferring. For the cases with mandibular functional elements and condylar asymmetrical length, the treatment modalities include orthopedic repositioning of the mandible by using occlusal and bite plane, SGTB and SGHB therapies; for cases with growth and developmental anomalies, orthognathic intervention should be an optimal solution.