One-Piece Fronto-orbital Distraction With Midline Splitting But Without Bandeau for Metopic Craniosynostosis: Craniometric, Volumetric, and Morphologic Evaluation.

Abstract

Distraction osteogenesis has gained popularity in the treatment of different types of craniosynostosis. We aimed to present the technique of 1-piece fronto-orbital distraction with midline splitting osteotomy but without bandeau for the treatment of metopic craniosynostosis, and the protocol of outcome evaluation using craniometric, volumetric, and morphologic parameters based on 3-dimensional computer simulation. This retrospective study included 9 patients with isolated metopic craniosynostosis who underwent surgical correction with distraction osteogenesis between December 2015 and February 2018. The osteotomy was designed in the form of 1-piece fronto-orbital distraction without separation of the orbital bandeau accompanied by midline splitting osteotomy. This was followed by the application of 2 pairs of cranial distractors to produce anterolateral expansion. The 3-dimensional files from preoperative and postdistraction computed tomographic data were used for the measurement of craniometric, volumetric, and morphologic parameters. The postdistraction craniometric measurement revealed a 12.52% increase in the interfrontal angle. Moreover, there were increases in the bifrontal diameter, diagonal diameters, and interorbital distance. Volumetric measurements revealed an increase in the total cranial volume by 228.1 ± 110.19 cm. The anterior compartmental volume increased by 33.24%. Morphologic evaluation in the form of curvature analysis showed shrinkage of the surface area of abnormal curvature from 29.5 ± 6.71 cm preoperatively to 3.85 ± 3.66 cm after distraction. The technique of 1-piece fronto-orbital distraction with midline splitting osteotomy but without bandeau is an effective surgical option for the treatment of metopic craniosynostosis. The postdistraction outcomes demonstrated the correction of various forms of dysmorphology in metopic craniosynostosis.