Maxillary molar distalization with miniplates assessed on digital models: A prospective clinical trial

Introduction: The purpose of this prospective study was to evaluate the effects of maxillary molar distalization in patients treated with a miniplate skeletal anchorage system. Methods: Thirty-one miniplates were placed on the infrazygomatic crests of 17 nongrowing patients consecutively selected for Class II treatment with skeletal anchorage. Three weeks after surgery, a 150-g force was applied to distalize the molars. No appliances were placed in the mandible. Models made before treatment and after molar distalization were scanned. Linear measurements were made on the digitized casts. Molar movement was measured on the superimposed maxillary arches before and after distalization, coregistered on the untreated mandibular models. Results: A molar hyper Class I relationship was reached in all patients 7.0 ± 2.0 months after miniplate loading. The maxillary molars were moved distally a mean distance of 3.27 ± 1.75 mm. In patients without contact between the maxillary and the mandibular incisors, overjet decreased by 0.99 ± 1.32 mm. Intermolar width increased by 2.78 ± 1.38 mm. Conclusions: Maxillary molar distalization with miniplates for skeletal anchorage is an efficient, noncompliance-dependent, and predictable treatment modality for patients with Class II molar relationship.