A comparative study between traditional head measurement and structured light three-dimensional scanning when measuring infant head shape

BACKGROUND: This study aimed to evaluate the correlation and consistency between traditional head measurement and structured light three-dimensional (3D) scanning parameters when measuring infant skull shape. METHODS: A total of 76 infants aged 3 months to 2.5 years old were included in the study. Head circumference (HC) was measured with a tape measure. The transverse, anteroposterior, and oblique diameters were measured using a spreading caliper, and the cranial vault asymmetry index (CVAI) and a cranial index (CI) of symmetry were calculated; 76 cases were measured successfully. The above indexes were measured using a structured light 3D scanning system (71 cases were measured with success). Thus, in the end, the valid data of 71 cases were analyzed, and the measurements of the two approaches were compared. RESULTS: The 95% confidence interval of traditional head measurement and structured light 3D scanning was between 0.633 and 0.988. Pearson’s correlation coefficient indicated a high correlation between the two methods (r=0.793–0.980). The correlation coefficients of the transverse diameter, anteroposterior diameter, and HC, and the CI of symmetry were higher than 0.9. The lowest correlation coefficient for the CVAI was 0.793. The P values of the above measurement data were all <0.001, which indicated that they were closely related. A Bland–Altman plot indicated reasonable consistency between the two methods. CONCLUSIONS: Both traditional head measurement and structured light 3D scanning are suitable for the measurement of infant head shape. However, while traditional head measurement using a spreading caliper is economical and simple, making it suitable for general screening at a basic level, structured light 3D scanning can deliver additional parameters, which is useful for infants with an abnormal head shape. The latter is also convenient for designing a customized helmet for skull correction when needed.