Anatomical sizes of Orbital Index among Nigerians using Normal Plain Radiographs: A Five-year Retrospective Study in Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria

Abstract

This study examines Anatomical sizes of orbital index among Nigerians
using normal plain radiographs.It is a retrospective study of normal
plain skull radiographs collected from Radiology Department, Usmanu
Danfodiyo University, Sokoto, Nigeria over a 5-year period from
September 2004 to September 2009 to determine the various anatomical
sizes and shapes of the orbit. Radiographs were mounted on illuminators
or viewing boxes and measurements made with a metric rule (best foot
ruler, transparent plastic size 30cms/12”) and a marker (HB Pencil)
based on the method employed by Lloyd and Glynn (1975). Five hundred
(500) radiographs of the skull were collected from the archives of the
Radiology Department; Usmanu Danfodiyo University Teaching Hospital,
Sokoto, for the study. The radiographs were for subjects seen from
September, 2004 to September, 2009. Out of this number only 255 satisfied
the inclusion criteria. The age range of the subjects for the study is between
1-70 years. The most prevalent type of orbit seen on the right side based
on orbital index is the MegasemeOrbit which corresponds to the orbit
type seen in Caucasians as reported by Lloyd and Glynn (1975) then
followed by the Microsemetype. However, based on the orbital index
measurement, Microseme is the most prevalent on the left which is in
conformity with the predominant type of orbit seen in black race.