Coronal Ring Involvement in Patients Treated for Unilateral Coronal Craniosynostosis

Abstract

The etiopathology of the clinical entity normally referred to as unilateral coronal synostosis is commonly used to connote unilateral fusion of the frontoparietal suture. However, other sutures in the coronal ring may exhibit synostosis concomitant with or independent from frontoparietal synostosis and give rise to similar clinical phenotypes. This study retrospectively analyzes high-resolution computed tomographic data sets to determine patency of sutures within the coronal ring. Computed tomographic scan digital data from 33 infants who subsequently underwent surgical correction of unilateral coronal synostosis were assessed for sutural patency using Analyze imaging software. The frontosphenoidal suture was subdivided into intraorbital frontosphenoidal and extraorbital frontosphenoidal portions, and the patency of the frontoethmoidal suture was also assessed. Patients were sorted into two groups on the basis of the status of their frontosphenoidal sutures: group 1 had patent frontosphenoidal but synostotic frontoparietal sutures (n = 21) and group 2 had both frontosphenoidal and frontoparietal synostoses. Observer reproducibility was tested. The vertical and horizontal dimensions of the bony orbit and the endocranial base deflection angle were measured with the observer blinded with regard to sutural status group. Frontoethmoidal synostosis was not noted in any patients in either group. Two patients had no frontoparietal suture synostosis with isolated intraorbital frontosphenoidal and extraorbital frontosphenoidal suture closures. Suture diagnosis reproducibility was 99 percent. In group 1, the ipsilateral-to-contralateral vertical orbit dimension ratio averaged 1.11, whereas in group 2 it averaged 1.04 (p < 0.05). The ratio of horizontal orbit measurements was not significantly different between groups. In both groups, the endocranial base was deflected ipsilateral to the synostotic frontoparietal suture, with an average angle of 12 degrees in group 1 and 17 degrees in group 2 (p < 0.005). The extent of synostosis along the coronal sutural ring contributes to the dysmorphology of the orbit and the endocranial base deflection in patients whose clinical phenotypic diagnosis is unilateral coronal synostosis.

Isolated frontosphenoidal synostosis: a rare cause of synostotic frontal plagiocephaly

“…These physical findings are consistent with other cases. 4,7,8,11 Dundulis et al reported a case of IFS with the above-noted findings but with chin point deviation to the affected side 5 ( Table 1). The clinical diagnosis of IFS can be challenging since this entity has physical findings of both DP and the more common hemicoronal ring fusion, UCS.…”

Frontosphenoidal synostosis: a rare cause of unilateral anterior plagiocephaly

“…The typical harlequin deformity described in coronal synostosis, with verticalization of the orbit, is usually not seen and has not been diagnosed in our series. According to Dundulis et al [10], this deformity might be related with a compensatory growth at the patent frontosphenoidal suture in case of coronal synostosis, as the distortion is lessened when there is a complete coronal and frontosphenoidal synostosis. This may explain the absence of harlequin's eye in isolated frontosphenoidal synostosis.…”

“…Isolated frontosphenoidal synostosis, with a patent coronal suture, would have a different starting point and has been described in few cases [10,11,16]. Its recognition is important to assure the child a proper treatment.…”

“…A few cases of isolated frontosphenoidal synostosis have been described by Francel et al [11], Rogers et al [16], and Dundulis et al [10].…”

Plagiocephaly due to Frontosphenoidal Suture Synostosis: Report of 2 Cases and Literature Review

“…Anterior plagiocephaly is the second most frequent type of nonsyndromic craniosynostosis [1,2,3]. It is described as a unilateral flattening of the forehead which is mostly secondary to unilateral coronal suture synostosis, but in some rare instances other sutures may be involved with specific clinical and radiological features.…”