Normative data for interorbital distance in a paediatric Caucasian population

BACKGROUND: Orbital growth represents a key component of craniofacial development to investigate due to the many craniofacial abnormalities which can interfere with it. Defining orbital growth patterns is essential for distinguishing physiological from pathological orbital development. Normative orbital growth data in Caucasian paediatric populations remain scarce. OBJECTIVE: Our study aimed to determine interorbital distance in a healthy Caucasian children population. MATERIALS AND METHODS: A retrospective study was conducted in France, based on craniofacial CT scans measurements in patients aged from 3 months to 10 years. Measurements were taken at the neuro-ocular plane and included the bony inner interorbital distance (IOD), bony lateral orbital distance (LOD), and IOD/LOD ratio. Mean +/- SD was calculated for each age group, and comparisons between sexes and age groups were performed using the Mann-Whitney test (p < 0.05). RESULTS: A total of 466 CT-scans were analysed (216 females and 250 males). The mean IOD increased progressively, from 18.76 +/- 1.17 mm at 3 months to 22.79 +/- 1.73 mm at 10 years of age. The most important increase of IOD and LOD values was observed during the first 2 years of age (p < 0.01) and between 7 and 8 years of age (p < 0.05). The IOD/LOD ratio remained constant with age, showing isometric growth of the orbits. CONCLUSION: This study provides detailed normative data of orbital measurements in Caucasian children and highlights two critical periods of accelerated orbital growth.