Designs and Applications of Intraoral Appliances in Class III Malocclusion

Class III malocclusion results from skeletal disharmony and unfavorable incisor inclination. Early use of intraoral appliances in Class III malocclusion would improve the inclination of retroclined upper incisors and proclined lower incisors. Intraoral appliances used in the upper dental arch include the posterior bite plate containing an anterior spring and the Yanagisawa Class III (YC3) Shield. When using the posterior bite plate, the upper anterior teeth are pushed forward by the force of the spring. The YC3 Shield, developed by M. Yanagisawa, results in forward movement of the upper anterior teeth by tongue pressure. Intraoral appliances used for the lower arch are the inclined bite plate and 2x4 utility archwire. The upper anterior teeth are protracted by the inclined plane of the bite plate, and the lower anterior teeth are retracted by the force of a 2x4 utility archwire. Since the early use of intraoral appliances only improves the inclination and position of the anterior teeth, they are usually used in combination with extraoral protractors in treating early Class III malocclusion. Bone-anchored maxillary protraction (BAMP) was recently developed by H.J. DeClerck and coworkers. BAMP works as an extraoral protractor and provides orthopedic correction. It consists of Class III elastics and two pairs of temporary anchorage devices (TADs). BAMP is a novel intraoral treatment modality for growing patients with Class III malocclusion.

Keywords: Intraoral appliance, Bite plate, YC3 Shield, 2x4 utility arch, BAMP.