Interim use of Hyrax Screw Assembly for Single-Step Closure of Small Alveolar Cleft before Anterior Maxillary Distraction Osteogenesis.

Abstract

Anterior maxillary distraction osteogenesis (AMDO) is often used for the correction of maxillary retrognathia in select cleft lip and palate cases. The restoration of alveolar arch continuity is desirable before the initiation of AMDO in these cleft maxillary deformities; however, AMDO is technically difficult in a patient with coexisting alveolar cleft where there is a discontinuity of the defect that presents a challenge in terms of adequate vector control of the movement of the anterior segment and the potential risk of tipping of teeth, which already have compromised anchorage/bone support on the cleft side. The treatment becomes more challenging when ongoing management is compounded by failed previous alveolar cleft grafting procedures, along with the patient's reluctance to undergo further grafting of alveolar clefts. This technical note demonstrates a novel application of the modification of the Hyrax screw where an initially fully opened Hyrax screw was utilised as an interim assembly for accomplishing the single-step closure of a small alveolar cleft before the commencement of anterior maxillary distraction osteogenesis. This technique may prove to be feasible for patients presenting with alveolar cleft defects of smaller widths of up to 5 mm and relatively well-aligned upper arches.