Application of Miniscrew Anchorage to Assist Scissors-Bite Correction

Abstract

Posterior complete buccal crossbite, also called scissors-bite or Brodie Bite, is usually difficult to be corrected. In most cases with the occlusion of complete buccal crossbite, the mandibular teeth are lingually tilted, and the maxillary teeth erupt past their antagonists. When using the conventional orthodontic treatment to correct the scissors-bite, extrusion of the molars and subsequent occlusal plane canting frequently occur. Applying miniscrew as direct skeletal anchorage can facilitate the scissors-bite correction without totally depending on patients' compliance. Two young female adults, with unilateral complete posterior buccal crossbite and Angle Class I malocclusion, were treated with fixed appliance, miniscrews, and a bite block. The miniscrews were inserted into the palatal region of the upper molar and the buccal region of the lower molar to provide the anchorage for simultaneous palatal/buccal tipping and vertical control of the molars. A bite block was placed on the contralateral side of the molar teeth to eliminate occlusal interference. The scissorsbite was corrected without canting of the occlusal plane. The mandibular plane angle was well maintained and periodontal health was not jeopardized.