Mandibular alterations and facial lower third asymmetries in unicoronal synostosis

PURPOSE: Maxillary and mandibular alterations in children affected by anterior synostotic plagiocephaly have, until today, received only scarce attention. The goal of this paper is to focus on the mandibular alterations, persisting after the early correction of anterior plagiocephaly during the first year of life. METHODS: Maxillary and mandibular metric measurements were performed on high resolution, thin slices CT scans; all images were reconstructed into 3D models which were used to perform the metrical assessments. RESULTS: Twelve patients were selected; all of them had been treated in early age with a neurosurgical intervention and had reached the end of maxillo-mandibular growth at the time of the evaluation. Significant discrepancies were documented between the two affected sides, with all measured distances being shorter on the synostotic side than the nonsynostotic one, the only exception being the vertical dimension of the mandibular ramus. DISCUSSION: Mandibular alterations resulted to be characterized by lower jaw hypoplasia on the side of the affected suture and anterior displacement of the glenoid fossa; these two entities compensated each other uncompletely, ending in a rotation of the mandibula towards the synostotic side.