Anterior two-thirds calvarial remodelling: operative technique for the correction of metopic synostosis in toddlers

Abstract

Premature closure of the metopic suture results in deformation of the anterior calvarium. Trigonocephaly is expressed in various forms--from a simple midline ridge of the forehead to a severe keel-shaped deformity--often requiring specific surgical correction for aesthetic improvement and cognitive and linguistic function advancement. This article presents a surgical technique used over 5 years to treat trigonocephalic toddlers in Korea. Retrospective analyses were performed on eight patients with metopic synostosis treated at St. Mary's Hospital (Seoul) during 2002-2006. The study included reviews of preoperative and postoperative computed tomography scans, operative techniques, clinical outcomes and complications. Operative techniques included fronto-orbital bandeau tilting after expansion with a midline wedge-bone graft, detriangulation of foreheads with an inward bending at lateral orbital wall, multiple zigzag osteotomy of frontal bone, barrel-stave osteotomy of parietal bone and the occasional application of calcium phosphate cement (BoneSource, Leibinger Inc., Michigan, USA) to refine the forehead shape. The average age of the patients at time of surgery--due to late referral to medical care--was 25.1 months. Two patients had concomitant bicoronal synostosis requiring coronal suture resection with anterior two-thirds calvarial reconstruction. The central angle measurements improved from a preoperative average of 118 degrees to 134 degrees ; interorbital distances widened from 18.8mm to 20.9 mm. Mean follow-up was 2.6 years, and no neurological sequelae or other significant complications were encountered. Moderate-to-severe trigonocephaly requires surgical correction involving anterior two-thirds calvarial remodelling with fronto-orbital advancement and frontal-bone remodelling. The described operative approach, especially in toddlers, minimises bone defects by adopting multiple zigzag osteotomy of the frontal bone. This modality results in significant improvements in skull form and high patient/parent satisfaction.