Purpose: In the management of patients with craniomaxillofacial deformities, it is imperative to understand normal anthropometric growth of the cranium. Although there have been advances in three-dimensional (3D) computed tomography (CT) images, there is an absence of normative growth curves of interorbital distance (IOD) in a diverse population of healthy children using current imaging technology. The goal of this study is to establish normative craniometric growth curves in a healthy population of children (ages 0-18 years).
Methods: CT scans of 115 patients who underwent cranial imaging at a tertiary children’s hospital were included. Patients with head trauma, hydrocephalus or pathologic cranial dysmorphology (plagiocephaly/craniosynostosis) were excluded. Patients were stratified into 23 age groups of 5 patients each (0-2 months, 3-5 months, 6-8 months, 9-11 months, 12-17 months, 18-23 months, and yearly from 2-18 years). Primary outcomes of IOD were analyzed using CT scans. IOD was defined as the distance between the two dacrya (the dacryon is the point of junction of the maxillary, lacrimal, and frontal bones on the medial wall of the orbit), this measurement was taken in the axial plane at the level where the dacryon was first observed to be the most prominent. Primary outcomes were plotted across age intervals, along with best-fit logarithmic curves.
Results: IOD ranged from 15.9 mm to 22.8 mm in our cohort overall. The mean IOD was 15.9 mm at birth, peaked to 22.8 mm at the 18 year period, and was shorter in all female cohorts. The transition from the 3-5 month old cohort to the 6-8 month old cohort experienced the greatest increase with an average increase of 7.6% across both gender groups (p = 0.022). There was a statistical difference in IOD between males and females at ages 17 years of age (22.8 mm vs 17.2 mm, p = 0.047) and 18 years of age (22.6 mm vs 18.2 mm, p = 0.041).
Conclusion: Establishing normal interorbital distance growth curves and during growth and development is important to contextualize cranial pathology, and to define an anatomic end-point in craniofacial reconstruction.