Anterior Synostotic Plagiocephaly: A Quantitative Analysis of Craniofacial Features Using Computed Tomography.

Abstract

The premature fusion of one coronal suture causes anterior synostotic plagiocephaly (ASP), which results in overt craniofacial dysmorphology that could be challenging to correct. This study aimed to document and compare the morphometry of the anterior cranial fossa (ACF), orbit, and ear on the ipsilateral (synostotic) and contralateral (nonsynostotic) sides in a select cohort of South African patients with ASP, using computed tomography (CT) scans. The dimensions of the ACF, orbit and the position of the ear on the ipsilateral and contralateral sides were measured using a set of anatomical landmarks on 2-dimensional CT scans of 18 consecutive patients diagnosed with nonsyndromic ASP. The differences between the ipsilateral and contralateral sides were calculated and expressed as a percentage of the contralateral side. All ACF parameters decreased significantly on the ipsilateral side when compared to the contralateral side, resulting in the volume of the ACF being the most affected (-27.7%). In terms of the orbit, on the ipsilateral side, the length-infraorbital rim, height, and surface area parameters increased significantly, with the height being the most affected (24.6%). The remaining orbital parameters (length-supraorbital rim, breadth and volume) decreased significantly, with the length-supraorbital rim parameter being the most affected (-10.8%). The ipsilateral ear was found to be displaced anteriorly (9.33mm) and caudally (5.87mm) from the contralateral ear. These measures may be useful to surgeons during corrective surgery by indicating the degree of the asymmetry on each side, making it easier to plan the technique and extent of surgical correction of the affected structures.