New population-specific cephalic index standards for Malaysian subadults: prevalence, growth patterns, and clinical...

Population-specific Cephalic Index (CI) classifications are lacking for Malaysian subadults. This study aimed to develop a new CI classification and determine the prevalence of deformational brachycephaly using Computed Tomography (CT) images.

A total of 520 CT images from subadults aged 0- to 20-years were included in the study. Two cranial measurements were obtained: the maximum Cephalic Length (CL) and the maximum Cephalic Width (CW), derived from axial CT images. The CI was subsequently calculated using the formula: CW/CL × 100. In addition, a simple linear regression analysis was performed to evaluate the relationship between CI and age.

The modified CI ranges for the Malaysian subadult population were defined as follows: dolichocephalic ≤ 78.8, mesocephalic 78.9-89.0, brachycephalic 89.1-94.0, and hyperbrachycephalic ≥ 94.1. The predictive equation derived was y = 87.08-0.47x +0.01ײ (y = CI and x = Age in years). A significant negative correlation was found between age and CI (r = -0.101, p < 0.001), with the index decreasing by approximately 0.026 per year. This indicates a natural trend towards a less brachycephalic head shape with maturation.

This new, population-specific classification provides an essential reference tool for clinicians and researchers to accurately detect, manage, and treat cranial deformities in Malaysian subadults, with significant applications in pediatrics, anthropology, and forensic medicine.