Facial asymmetry in unicoronal craniosynostosis: automated three-dimensional quantification of surgical outcomes

Craniosynostosis is the premature closure of one or more cranial sutures which may result in functional and aesthetic complications. Non-syndromic unicoronal craniosynostosis commonly leads to facial asymmetry. This study aimed to quantify changes in facial asymmetry before and after surgical treatment using an automated 3D technique. A retrospective study was performed including 32 patients treated at Radboud University Medical Center Nijmegen between 2011 and 2024. Pre- and postoperative three-dimensional facial photographs were analysed, and asymmetry was quantified using regional root-mean-square (RMS) values. Patients were treated with either minimally invasive endoscopic-assisted craniosynostosis surgery (EACS) or open cranial vault reconstruction (OCVR). In the EACS group, the mean ages at preoperative and postoperative imaging were 4.4 ± 2.0 and 14.4 ± 3.3 months, respectively, while in the OCVR group these were 9.0 ± 3.2 and 21.3 ± 5.5 months. Facial asymmetry significantly decreased after surgery across all regions (P < 0.001). Overall RMS values decreased from 3.36 mm preoperatively to 2.44 mm postoperatively after EACS and from 3.33 mm to 2.46 mm after OCVR, corresponding to a reduction of 27-29% (P < 0.001). The greatest improvement was observed in the upper facial region, with a mean reduction of 1.47 mm (P < 0.001). In conclusion, surgical treatment of unicoronal craniosynostosis results in a substantial reduction of facial asymmetry, particularly in the upper face, with comparable improvements for both surgery groups.