[Orthodontic approach to asymmetry]

From an orthodontic point of view, asymmetries can be gathered in three great clinical entities: mandibular lateral deviations, dental asymmetries without skeletal involvement, skeletal asymmetries. Once the therapeutic aims and the principles of the orthodontic approach of these dysmorphoses have been recalled, the authors present the various orthodontic means implemented in this type of treatment. Four cases treated illustrate those types of treatment. Vertical non-surgical asymmetry may have an obvious local origin, for instance, a unilateral damage to a nerve. but usually, there is no evident origin. Frequently the occlusal slippage of a severe sagittal or a vertical malformation, which may evolve as a borderline surgery case, is suspected to be the real cause. In these cases, the diagnosis is always late, with the ending growth. The treatment needs peculiar strong asymmetric mechanics and, sometimes, unilateral mixed extractions. The post-treatment occlusion can be unstable; for this reason, the finishing steps must be carefully conducted. Four clinical case reports develop these points ov view. Multidisciplinary treatments prove very useful to solve three types of clinical situations. In the adult patient, facial esthetics are indicated in severe dentofacial asymmetries. Esthetic improvements of dental nature are still required in deviated smiles, or frontal tippings of the occlusal plane. In addition, asymmetrical intermaxillary relationships will lead to functional anomalies: TMJ disorders, dental wear or lingual dysfunctions. Finally, multidisciplinary treatments in the adult concern the occlusal transverse anomalies, the lateral crossbites, the Class II subdivisions, the deviations of the inter-incisor midlines or unilateral edentulousness. The various plans of treatment, as well as the orthodontic mechanics used, are illustrated in the following development by clinical cases.