Malocclusion in Adults: Biomechanical Considerations

cents has always relied on growth modification. The majority of treatment modalities, such as functional appliances, are directed at stopping or redirecting maxillary growth and simultaneously stimulating mandibular growth.1-3 On the other hand, in adult patients with severe Class II malocclusions, generally involving extremely deficient mandibles, orthognathic surgery is often the only possible treatment. Although camouflage may be attempted by extracting premolars, the soft-tissue objectives may be impossible to meet. Even so, a recent study has shown that patient satisfaction with camouflage treatment was similar to that achieved with surgical mandibular advancement.4 In Class II patients with mild-to-moderate skeletal discrepancies, dental compensation may well be the treatment of choice. Common treatment procedures for such patients include flaring of incisors, interproximal tooth reduction, and extractions. Treatment of an adult Class II patient requires careful diagnosis and a treatment plan involving esthetic, occlusal, and functional considerations.5-7 The treatment objectives must include the chief complaint of the patient, and the mechanics plan should be individualized based on the specific treatment goals. At the University of Connecticut, we have designed multifunctional orthodontic wires capable of simultaneously performing different orthodontic tooth movements. Because both the force system and the side effects of these “smart” wires are now well understood, we can usually avoid the need for headgear and Class II elastics. This article describes our treatment of Class II, division 2 adult patients requiring premolar extractions. Division 2 cases are often characterized by severe deep bites, lingually inclined upper central and lower incisors, and labially flared maxillary lateral incisors. These patients also tend to exhibit problems with the upper and lower occlusal planes, such as deep curves of Spee. The soft-tissue drape of the lips often conforms to the malocclusion, so that the lips may be redundant with a deep mentolabial sulcus. Because of the deep bite and supraeruption of the maxillary incisors, the gingival margins of the maxillary anterior teeth are usually malaligned, and the lingually inclined mandibular incisors may have excessively high gingival margins (Fig. 1).