Correctly setting the eyes within the orbits is an important first step in craniofacial identification. As several estimators often exist for each eyeball attribute, clarification of their accuracies in out-of-group samples is critical. In this study, we use CT scans from 58 individuals to assess standard errors (SEE) for published estimators, cross-validate methods and examine the linear regression utility of orbit volume for estimating eyeball protrusion. Our results confirm the eyeball to be positioned closer to the superior and lateral orbital walls (2.5 or (b) inferior to the superior orbital margin by 44.1% of the orbit height (SEE = 1.6 mm). Orbit volume weakly correlated with anterior eyeball protrusion (r = 0.33), but the relationship was not statistically significant (p = 0.14). The correlation direction contradicted Gerasimov’s reports (positive, not negative). Linear regression using the volume of an elliptical cone, calculated from three orbit-associated measurements, reduced protrusion SEE to 2.4 mm. Near equivalent accuracy by mean exophthalmos and its far greater simplicity, however, awards the mean value more practicality for casework. Eyeball estimators were assessed by CT and standard errors of the estimate (SEE). For globe protrusion, mean exophthalmos (16.2 mm) produced the lowest SEE (2.9 mm). The globe was more superior and lateral in the orbit (2.5 & 5.6 mm, respectively). Orbit volume weakly correlated with globe protrusion, r = 0.33 (p > 0.05). A 3D elliptical cone, as a proxy to orbit volume, slightly decreased SEE (2.4 mm).
Humphrey et al. (Fri,) studied this question.