Nonsurgical and nonextraction treatment of a skeletal class III adult patient with severe prognathic mandible.

AIM: A patient with a skeletal Class III malocclusion, prognathic mandible, anterior open bite, large tongue, and temporomandibular disorders is presented. Treatment objectives included establishing a stable occlusion with normal respiration, eliminating temporomandibular disorder symptoms, and improving facial esthetics through nonextraction and nonsurgical treatment by creating a favorable perioral environment, restoring the harmony to the tongue and perioral environment, improving masticatory muscle function, and creating adequate tongue space for establishment of normal respiration.

SUBJECT AND METHODS: The patient was a Japanese adult male, who had previously been advised to have orthognathic surgery, with tongue-size reduction. An expansion plate was used to expand the maxillary dentoalveolar arch. Distalization of the mandibular arch was achieved by reduced excessive posterior vertical dimension, through uprighting and intruding the mandibular posterior teeth and rotating the mandible slightly counter-clockwise. The height of the maxillary alveolar process and the vertical height of symphysis were increased slightly. The functional occlusal plane was reconstructed by uprighting and intruding the posterior teeth with a full-bracket appliance, combined with a maxillary expansion plate, with short Class III and vertical elastics in the anterior area. Myofunctional therapy involved sugarless chewing gum exercises.

RESULTS: The excessive posterior vertical occlusal dimension was reduced slightly, creating a small clearance between the posterior maxilla and mandible. At the same time, the interferences in the posterior area were eliminated by the expansion of the maxillary dentoalveolar arch. As a result, the laterally displaced mandible moved to a more favorable jaw relationship, with distalization of the mandibular arch. The functional occlusal plane was reconstructed and an almost-normal overjet and overbite were created. Adequate tongue space for normal respiration was established during the early stage of treatment, by 7 months. A stable occlusion, with adequate posterior support and anterior guidance, was established and maintained at more than 4 years posttreatment.