Orbital asymmetry in development: an anatomical study.

The aim of this study was to analyze the human orbital asymmetry during development. One hundred twenty-seven identified human dry skulls, with sex, age, date and cause of death record, in good preservation state, were used. Bones that had evidence of trauma, malformations or other pathology were excluded. The sample was divided into 4 age groups: I--intra-uterine life (n=20), II--newborn up to 2 years old (n=43), III--three up to 20 years old (n=27) and IV--21 up to 76 years old (n=37). The skulls were photographed in normal frontalis and images were analyzed with the software AutoCAD 2002 in real scale. The obtained measurements were: greater horizontal diameter (HD), greater vertical diameter (VD), orbital perimeter and orbital base area. All skulls showed asymmetry in all measures, except 4 of them that showed symmetry in VD and perimeter. The asymmetry occurred in all ages, being calculated as a percent rate for VD--2.73%, HD--4.48%, area--4.77% and perimeter--2.47%. There was predominance in asymmetric rate in female skulls and only in the group II the difference between gender was statistically significant (p<0.05). The right orbit presented larger measures. The asymmetric rate was assumed as the normal anatomic pattern.