Segmental alveolar distraction for the correction of unilateral open-bite caused by multiple ankylosed teeth: a case...

Ankylosed teeth fail to erupt to meet their counterparts in the opposite jaw. In cases where ankylosis occurs in multiple teeth, the occlusion shows an open bite. This article describes a case of unilateral open bite caused by multiple ankylosed teeth, where treatment involved segmental alveolar bone distraction. A 25-year-old female patient presented with a left-sided unilateral open bite. On the left-hand side, only the lower incisors were not ankylosed. On the right, the maxillary first molar was ankylosed. All these ankylosed teeth were positioned below the occlusal plane. Her mother and brother also had multiple ankylosed teeth, and a familial cause was considered. Orthodontic tooth movement was considered impossible and segmental osteotomy on the left maxillary alveolar bone and downward bone distraction were performed as an alternative. A distractor consisting of orthodontic bands, wires and screws was devised and worn in the left mandibular dentition. Multi-bracket orthodontic appliances were also used for distraction. The amount of vertical movement was 7 mm at the premolar region. Five months after distraction, the multibracket appliance was removed, and fixed and removable retainers were placed. Eight months after distraction, prosthodontic restorations on the occlusal surfaces of the ankylosed teeth were made to obtain the final occlusion. The unilateral open bite was successfully treated and a good occlusion was obtained. The occlusion has shown good long-term stability for more than 3 years.