Orbital development as a function of age in indigenous North American skeletons

Infants with orbital hemangiomas and vascular malformations often develop expanded orbits or regional hyperostosis. Treatment in these cases depends, in part, on the stage of orbital development at the time of intervention; yet, orbital development with respect to age is not well-known. The authors sought to determine the rate of orbital development and the age of orbital maturation in a single ethnic population.

Skeletons recovered in North America and housed at the Peabody Museum of Archaeology and Ethnology, Harvard University, were inspected. The age of specimen was determined by dentition. Orbital volume was measured using 1-mm glass beads and a graduated cylinder. Linear measurements were taken with calipers and paper rulers. The measurements were plotted against age, and statistical analysis was performed. Relevant literature was reviewed.

Of the hundreds of skeletons examined, 42 were sufficiently intact for orbital measurement. The specimens represented a period of up to 1000 years. Thirty-two were pediatric (defined prenatal to 18 years) and 10 were adults. Mean adult orbital volume was 26.2 ml. Based on the regression analysis, 60% of adult orbital volume was achieved at 4.35 years, 75% at 9.36 years, and 90% at 17.13 years of age. Linear dimensions progressively increased with age.

This largest direct-measure study of pediatric orbital volume suggests that orbital growth continually decelerates from birth until maturity at 22 years. With 50% of orbital growth occurring by 16 months of age, surgeons removing periocular vascular anomalies after that age should consider concurrent skeletal management.