Objective Analysis of Fronto-Orbital Dysmorphology in Unilateral Coronal Craniosynostosis

Abstract

Correction (and over-correction) of asymmetries of the orbital shape and brow position in unilateral coronal craniosynostosis (UCS) is critical to successful fronto-orbital advancement.Here we quantify and three-dimensionally assess fronto-orbital irregularities in UCS patients compared to controls.Twenty-three patients with UCS evaluated at the Children's Hospital of Pittsburgh between 2006 and 2016 were age and gendermatched to controls. Computed tomography scans were reconstructed and evaluated for orbital metrics. A three-dimensional heat map of orbital regions was generated and evaluated for shape differences.Brow protrusion of the orbit ipsilateral to the synostotic suture did not differ significantly from healthy controls. Orbital height was significantly increased while orbital width was decreased on the UCS ipsilateral side compared to the contralateral side and controls. The ipsilateral cornea was overprojected relative to the brow and the infraorbital rim, but similar to controls relative to the lateral rim. The contralateral orbit had increased brow protrusion with decreased orbital height. The cornea was underprojected relative to the brow, but overprojected relative to the lateral orbital rim and similar to controls at the infraorbital rim. Three-dimensional comparison demonstrated significant overprojection of the contralateral brow, with some more mild and inconsistent underprojection of the lateral aspect of the ipsilateral brow.Key orbital and brow differences exist between the affected and unaffected sides in UCS. This study provides quantitative data that further characterize the orbital dysmorphology observed in UCS and identifies unique aspects of the diagnosis that should be taken into consideration during surgical planning.

Craniofacial reconstructions in children with craniosynostosis

“…In the vast majority of nonsyndromic craniosynostosis, a single skull remodelling procedure is sufficient, but it has to be performed in ideal intervals of time. For scaphocephaly the ideal age for surgery in our experience was between three and six months of age [3,15,16]. By performing the procedure so early, the brain has enough growth potential to shape the skull on its own.…”

“…The frontoorbital advancement (FOA) is used for metopic and coronal craniosynostosis [12][13][14] and the posterior vault expansions for lambdoid craniosynostosis [6,7]. Biparietal or total cranial vault remodelling techniques are used in scaphocephaly [3,15,16]. In syndromic cases, Chiari malformation, intracranial hypertension, hydrocephalus and central or peripheral apneas are often present and must be considered during the planning of the correct treatment [8][9][10].…”

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

“…Previous studies observed side-to-side asymmetry in orbital volume, with the volume on the ipsilateral side being significantly lower than the volume on the contralateral side. 3,8,16,[18][19][20] Different authors used their preferred orbital boundaries when segmenting the orbital cavity to calculate the volume. In this study, the anterior boundary of the orbit was defined as the inner surface of the eyelid (Fig.…”

“…Since Calandrelli et al3 classified their patients using the Di Rocco and Velardi15 classification scheme, they found a steady decrease in the volume on the ipsilateral orbits as the severity of ASP increased. Dvoracek et al8 reported on orbital height and breadth—they found that the height significantly increased, and the breadth significantly decreased on the ipsilateral orbit. Marsh et al17 and Mesa et al21 found that the SOR of the ipsilateral orbit was higher than the SOR of the contralateral orbit.…”

“…Anterior synostotic plagiocephaly results in pronounced side-to-side craniofacial asymmetry, consisting of a spectrum of features, varying from mild to severe asymmetry 7. It involves vertical, transverse, and sagittal facial asymmetry, as well as lower facial asymmetry, resulting in a “C-shaped” malformation that is always visible on the face 4,8. This asymmetrical appearance results in constricted growth on one side and compensatory growth on the other side of the skull 7.…”