Class II, division 1 treatment in patient with hyperdivergent growth and mandibular retrog- nathism: Association of mandib- ular advancement appliance and miniscrews - Part 1

Henrique Mascarenhas Villela

INTRODUCTION: The correction of Class II division 1 malocclusion in growing hyperdivergent patients with mandibular retrognathism requires a different approach from the traditional treatment, which usually does not provide good results. OBJECTIVE: This article presents a case report to illustrate an alternative protocol to correct this type of dentofacial deformity, associating miniscrews to restrain the maxillary vertical growth and a mandibular advancement appliance, to stimulate mandibular growth. CASE DESCRIPTION: Maxillary intrusion was performed in a female patient in the growth peak, by using miniscrews in the anterior region of the maxilla, between the lateral incisors and the canines in both sides, and in the posterior region of the maxilla, in the buccal surface, between the second premolars and the first molars, also in both sides, and in the lingual surface, between the first and second molars of both sides. This approach promoted a bigger intrusion in the anterior region of the maxilla, promoting an anticlockwise rotation of the occlusal plane of 4,5° (FHP.Ocl Pl decreased from 13° to 8,5°). In addition to the miniscrews, a rigid mandibular advancement appliance was used; fixed in the maxilla by using the archwire of the orthodontic appliance between the maxillary molars and between the mandibular first and second premolars. Besides this, miniscrews were placed in the mandibular arch between the second premolars and the first molars on both sides, in order to reinforce the anchorage. This association promoted a reduction in the divergence of mandibular plane of 4° (FMA decreased from 31° to 27°) and in the ANB (from 12° to 6°). The dental compensations were inhibited, in order to reinforce the orthopedic correction. The tipping of maxillary and mandibular incisors decreased 2° (IMPA decreased from 97° to 95° and 1-Pp decreased from 108° to 106°). The facial convexity decreased 6° (FCA decreased from 151° to 157°). As soon as the mandibular advancement appliance was installed, the patient’s face presented changes that made her feel better by the improvement in her profile. The prognostic for this treatment depends on the intrusion amount suffered by the maxilla, associated with the mandibular growth potential.

Keywords: Class II malocclusion. Fixed functional appliance. Miniscrews. Hyperdivergent. Mini-implant.

How to cite: Villela HM. Class II, division 1 treatment in patient with hyperdivergent growth and mandibular retrognathism: Association of mandibular advancement appliance and miniscrews - Part 1. Clin Orthod. 2020 Aug-Sept;19(4):34-44.

Tuesday, April 16, 2024 09:16