Use of Simple Skull Radiographs in Orbital Correlations in Nigeria

Introduction: Anthropometric measurements have been carried out in many studies to segregate people into races, ethnicity and various biological traits in the past. Such studies include cephalometry being deployed because of its significance in forensic and clinical evaluations of individuals. The objective of this study is to determine the correlation between the shape types of the orbit with different age groups and their prevalence using simple skull X-rays.

Materials and Methods: Plain X-rays of the skull with posteroanterior exposures were obtained for a retrospective period of 5-year period from 2004 to 2009. The selected radiographs were those based on clear recognition of their orbital margins assessed by 2 experienced Radiologist who determined the shapes of the orbits as being oval, circular or quadrangular. Out of total of five hundred (500) plain X-rays of the skull obtained, only 255 satisfied the inclusion criteria.

The data was analyzed statistically using INSTAT software to compare the mean values in relation to age distribution of the subjects with the Student’s T-Test. Chi-Square (with Yates correction) was used for the comparison of proportions.

Results: In the first 30 years of postnatal life, the oval shape orbit had been found to be more predominant with values of 22(64.7%), 17(30.9%), and 27(38.0%) respectively. As from the age of 30 to 70 years, the circular type had values of 16(34.0%), 8(33.3%), and 8(61.5%) respectively in each of the decades. Between the age of 60 to 70 years, the oval and circular types had equal prevalences.

Conclusions: In addition to the known oval and quadrangular (triangular) types of orbital shape, this study revealed a 3rd type of orbit which we described as circular in shaped. The oval type of orbit is found to be more common from birth to age of 30 years but from but from 40 to 70 years the circular type predominates.