Treatment of metopic craniosynostosis is performed by either fronto-orbital advancement (FOA) or endoscopic-assisted techniques. Interfrontal angle (IFA) is a validated measure of trigonocephaly, but requires a computed tomography scan. The most common direct measure to assess surgical outcome in patients with trigonocephaly is frontal width (ft–ft). The aim of this study is to determine if frontal width correlates with IFA and successful surgical correction 1 year after treatment. A review of current morphologic assessment techniques is also provided.
Three-dimensional computed tomography scans (preoperative and 1 year postoperative) of patients who underwent FOA (n = 13) or endoscopic (n = 13) treatment of metopic craniosynostosis were reviewed. Age-matched scans of unaffected patients served as controls. Frontal width was measured by a straight line between the bilateral frontotemporal points. Measurements were performed by 2 experienced observers and compared to IFA.
Mean frontal width at preoperative scan for endoscopic and open patients was 55 ± 0.6 and 64 ± 0.7 mm, respectively (Z-score 1.6 and −3.7). Mean frontal width at postoperative scan for endoscopic and open patients was 80 ± 0.4 and 81 ± 0.7 mm (Z-score 0.0 for both groups). Frontal width for endoscopic correction significantly correlated with IFA (r = 0.536, P = 0.005), as well as for the open patients (r = 0.704, P < 0.001).
Frontal width normalizes 1 year after operation, regardless of technique. Advantage of frontal width is that it can be measured in the clinic using a spreading vernier caliper. It correlates well with IFA and can be used as a metric for morphologic outcome.