Medial Depression with Bony Dehiscence of Lamina Papyracea as an Anatomic Variation: CT Evaluation

ABSTRACT

PURPOSE: To evaluate the incidence and CT findings of the medial depression and bony dehiscence of lamina papyracea as an anatomic variation. MATERIAL AND METHODS: 1472 PNS CTs of the patients with symptoms of chronic sinusitis were retrospectively evaluated. RESULTS: The total incidence of depressed lamina papyracea as an anatomic variation was 3.5%(52/1472) on PNS CT. There was a statistically significant correlation between the increasing age and the incidence of delamina papyracea. Depression of lamina papyracea anterior to the basal lamella were more common those of the posterior depression. Associated findings were herniation of adjacent fatty tissue in all cases and the roedial bowing and hypertrophied configuration of the medial rectus muscle without significant herniation in 19 cases(34%). CONCLUSION: Nontraumatic, asymptomatic depression with bony dehiscence of lamina papyracea as an anatomic variation is not uncommon with the incidence of 3.5%. Recognition of its existence and degree may helpful in avoiding various ocular complication during ethmoid surgery.