Forehead contour and hypotelorism in patients with metopic craniosynostosis: Comparing minimally invasive and open treatments

Background: Patients with metopic craniosynostosis and trigonocephaly are classically treated with a fronto-orbital advancement. In contrast, a minimally invasive treatment entails a narrow ostectomy of the fused suture, followed by postoperative helmet molding. The goal of this project was to investigate the results of patients treated with minimally invasive techniques by quantifying the deformity of the forehead contour a year after their operation and comparing these measurements to patients who underwent an open operation as a control. Methods: The 1-year postoperative computed tomography (CT) scans of patients treated with minimally invasive techniques for metopic craniosynostosis (n=10) were compared to CT scans of patients treated with an open operation (n=20). The straight line measurements between the zygomaticofrontal (ZF) sutures and between the dacryon bilaterally were recorded to assess the degree of hypotelorism. An axial plane two-dimensional angle between frontotemporale bilaterally and the glabella (FTR-G-FTL) was used as a measurement of the severity of trigonocephaly. Results: The average age of patients at surgery for minimally invasive cases was 3.4±0.5 months old (mean ± standard error of the mean) compared with the age of patients for open cases at 11.3±0.6 months old. Seventy percent of the patients were males and 30 % were females in both the minimally invasive and open groups. The mean distance between the ZF sutures was 76.3±1.9 mm in the minimally invasive group and 75.9±1.2 mm in the open group (p=0.90). The mean distance between the dacryon bilaterally was 15.1±1.0 mm in the minimally invasive group and 14.5±0.6 mm in the open group (p=0.63). The FT R-G-FTL angle was 118.5°±13.2° in the minimally invasive group and 113.1°±2.0° in the open group (p=0.21). Conclusions: In this small, retrospective series, minimally invasive treatment of metopic craniosynostosis appears to have equivalent results to open fronto-orbital advancement in terms of the acuity of trigonocephalic forehead angle and hypotelorism at 1-year follow-up. Additional studies are being conducted to better quantify, validate, and compare these measurements. The end goal is to elucidate the best methods of quantifying normal forehead contours and to determine if minimally invasive treatment is equivalent to the open approach. Level of Evidence: Level IV, therapeutic study. © 2013 Springer-Verlag.