Establishment of Objective Clinical Parameters for Assessment of Trigonocephaly: Are Caliper-Derived Clinical Measures Adequate?

Abstract

Objective clinical parameters characterizing the severity of trigonocephaly are essential given the concern for computerized tomography (CT) scans and radiation in infants. The present study seeks to develop a clinical tool by which to characterize trigonocephaly. Retrospective cohort study. Tertiary academically affiliated children's medical center. A retrospective review identified patients with trigonocephaly for whom surgery was recommended (group 1) and those with metopic ridging without significant trigonocephaly (group 2). Normal age-matched controls were also evaluated (group 3). Cranial vault caliper measurements were compared across groups. Two ratios measuring anterior vault constriction were developed: (1) bitemporal width at the mid-forehead to the biparietal width, and (2) bitemporal width at the lateral brow to the biparietal width. Bitemporal width to biparietal width (ratio). Caliper measures were obtained from 19 patients in group 1, 8 patients in group 2, and 19 patients in group 3 (controls). Cranial indices were not significantly different across groups. The bitemporal width at the mid-forehead to the biparietal width ratio was significantly lower in group 1, with no difference between groups 2 and 3. The bitemporal width at the lateral brow to the biparietal width ratio was significantly different between all 3 groups, with group 1 < group 2 < group 3, respectively. Bitemporal to biparietal ratios are a quantitative, objective clinical measure that can be used to differentiate patients with significant trigonocephaly from those with metopic ridging but no significant cranial deformity. These findings suggest that caliper-derived indices can assist in characterizing surgically relevant cranial vault deformities secondary to metopic synostosis and may circumvent CT-based analysis.