Abstract
Clear aligners are a well-established alternative to conventional fixed orthodontic appliances for treating mild-to-moderate malocclusion. This case report details the successful treatment of a 14-year-old female patient with Class II malocclusion, crowding, and dental crossbite using extraction and the Invisalign® system. Achieving satisfactory anterior guidance by correcting the anterior crossbite and reducing the overjet and overbite was the primary treatment goal. Secondary treatment objectives included upper and lower midline alignment, leveling and alignment of arches, and achieving a Class I canine relationship for adequate canine guidance. Two sets of clear aligners were chosen; the first for alignment and the second for refinement. Extraction of teeth 14 and 24 were performed during the first aligner treatment phase, with space closure achieved by the distal movement of canine and posterior teeth mesialization. The second set of aligners refined the dentition by correcting the posterior open bite and extrusion of posterior teeth. Treatment duration was 13.5 months. By the end of treatment, the Invisalign system in conjunction with tooth extraction established an ideal overbite and overjet, corrected the crossbite, and achieved a Class I canine relationship with minimal disruption to the patient’s esthetic appearance. In addition, root axes were parallel and well controlled, despite extractions and space closure. Awareness of the dental biomechanics when clear aligners and extraction are used may be imperative for yielding successful outcomes for patients with Class II malocclusion and extractions.