Maxillary arch distalization using interradicular miniscrews and the lever-arm appliance: A case report

This case report shows the successful treatment of a patient with Class II Division 1 maxillary arch distalization using the lever-arm appliance and interradicular miniscrews. A 15-year-old male patient had a convex profile, a Class II malocclusion, increased overjet, and crowding in the upper and lower arches. Treatment was started with the placement of skeletal anchorage for distalization of the upper arch. Miniscrews were implanted into the interradicular space between the maxillary second premolar and first molar, and buccally at the mucogingival junction as well as on the palatal side. The lever-arm appliance was used to bilaterally distalize the posterior segments in the upper arch. Leveling and alignment followed by retraction of the maxillary premolars, canines, and incisors were carried out to achieve normal overjet and relief of the crowding. Total treatment time for this patient was 24 months. Three-dimensional virtual maxillary models were acquired at pretreatment (T0) and posttreatment (T1) using a three-dimensional laser scanning system. Models were superimposed using the surface 3-points method and were used to evaluate treatment results in three dimensions. This report suggests that interradicular miniscrews, together with the lever-arm appliance, are useful to allow three-dimensional control while distalizing the maxillary molars for correcting a Class II malocclusion.