A Novel Vector Control Device in Horizontal Bone Transport

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Bone grafting is the most frequently used technique for cleft palate repair. The major shortcoming of this method is the difficulty of achieving complete soft tissue coverage in cases with large defects. Buccal or tongue flaps are used most commonly in such cases, but the outcome is not always ideal. Alveolar distraction may be a more promising method for overcoming such problems. 1-4 This article describes a new method developed to treat cases with large defects and presents a case to illustrate the use of this protocol. Materials and Methods Chromium-cobalt crowns with double tubes for the molars and semicircular tubes for other teeth were prepared separately for each segment. Care was taken to orient the tubes in the same horizontal plane. The cast segments were connected by two 1.5-mm stainless steel arch wires. The arches were extended distally from the tubes to accommodate the planned anterior movement of the distraction segments. To avoid mucosal irritation, double tubes were placed as mesially as possible on the molar crowns. The anchoring segments were connected by a transpalatal bar. A custom-designed tooth-borne distractor was positioned occlusally on the arch (Fig 1). Case Report A 16-year-old female patient presented with absence of the premaxilla and bilateral complete cleft lip and palate. The etiology was uncertain. The treatment plan was reconstruction of the premaxilla and correction of the sagittal jaw relationship, using the alveolar distraction protocol to improve the patient’s facial profile and appearance (Fig 2). Treatment started with leveling and alignment of the dental arches, leaving a space of 3 mm between the maxillary second premolar and first molar to avoid root exposure during osteotomy. SURGICAL METHOD First, a cast metal appliance was cemented. The next day, surgery was performed under general anesthesia. The segments were mobilized by making vertical incisions between the maxillary second premolars and first molars, followed by horizontal osteotomies above the roots. During this process, the palatal mucosa was left intact. Arches and distractors were inserted intraoperatively, and the distractors were activated with five full turns (5 mm) to observe the mobility of the discs. The distractors were then closed, the segments were ligated tightly, and the flaps were sutured. After a 5-day latency period, activation was started at a rate of one half turn (0.5 mm) twice a day. The patient was monitored weekly until the 2 segments contacted at the midline. Activation was continued bilaterally until the desired amount of premaxillary augmentation, including 30% overcorrection, was achieved (Fig 3).