Assessing the surgical anatomy of the ethmoid sinus in adult Nigerians using computerized tomography scan

We undertook this study to describe the morphology and anatomical variations of ethmoidal sinus in adult Nigerians using computerized tomographic scan, bearing in mind the significance of this sinus in inflammatory pathologies of the other paranasal sinuses and endoscopic sinus surgery. This was a descriptive study of computerized tomographic scans of the paranasal sinuses of 114 subjects constituting 228 ethmoids. All the slides were examined to identify the ethmoidal sinuses and the various anatomical variations. The dimensions of the ethmoids were also measured. There were 83 (72.8%) males in this study. The mean age was 45.6 ± 19.3 years. The means of the length, anterior width, posterior width and height of the ethmoid were 41.4, 11.8, 16.7 and 30.1 mm, respectively. Keros Type III olfactory fossa was found in 163 sides (71.5%). Agger nasi cell was the commonest variation present in 102 sides (44.7%). The most frequent pattern of attachment of uncinate process seen is to the lamina papyracea (191, 32%). We concluded that the dimensions of the ethmoids among the Nigerians studied are similar to findings in other studies. The predominant type of olfactory fossa depth and pattern of insertions of uncinate process suggest that the study population may be at higher risk of certain complications during functional endoscopic sinus surgery (FESS).   Key words: Anatomical variations, olfactory fossa, Nigerians.