ABSTRACT: The purpose of this study was to review our institution's experience using helmet molding therapy in children with isolated non-syndromic sagittal craniosynostosis before placement of cranial springs and provide objective measurements of craniometric changes to help determine its role in treatment.Patients who underwent preoperative helmet molding therapy for sagittal craniosynostosis were retrospectively reviewed. Three-dimensional surface tomography scans were used to measure head circumference, cranial width, cranial length, cranial index (CI), and cranial vault asymmetry.Seventeen patients underwent orthotic helmeting therapy before spring mediated cranial vault expansion. Patients spent a median of 48 days (interquartile range [IQR] 32, 57) in preoperative orthotic helmeting therapy. There were increases in both cranial width and length post-helmeting (median: 107.5 mm [IQR 104.8, 110.4] versus 115.6 mm [IQR 114.5, 119.3]; P < 0.001) (median: 152.8 mm [IQR 149.2, 154.9] versus 156.8 mm [IQR 155.0, 161.5]; P < 0.001), respectively. There was a greater increase in cranial width (P = 0.015). Consequently, patients' CI improved after preoperative helmeting (median: 0.702 [IQR 0.693, 0.717] versus 0.739 [0.711, 0.752]; P < 0.001). There was no evidence of growth restriction from helmeting (pre-helmeting Head circumference [HC]: median 96.8 percentile [IQR 90.6, 99.9] versus post-helmeting HC: 98.7 percentile [IQR 94.7, 99.8]; P = 0.109).Preoperative helmeting in patients with non-syndromic isolated sagittal craniosynostosis can be used to improve CI before surgical correction. Significant benefits can be achieved in shorter preoperative helmeting durations than previously reported with no evidence of cranial growth restriction, which supports its feasibility and utility in children undergoing spring mediated cranial vault expansion.