Publication

Abstract : Fossa foclacrimal sac, houses lacrimal sac and its lower end (orbital opening) continues through nasolacrimal canal to open into the inferior meatus of nose. Surgical procedures like dacryocystostomy and dacryocystorhinostomy are performed extranasally and endoscopic endonasal dacryocystostomy is done intranasally. Lacrimal bone and frontal process of maxilla, contributing to the formation of fossa, were observed for their morphological features. (based on examination of 734 orbits from 528 skulls) Shapes of maximum number of fossae observed were found to be oval, and contribution by maxilla and lacrimal bone was in variable proportions. The two extremes were also observed where the fossae were entirely formed by maxilla, orlacrimal bone and remaining fossae have been contributed in variable proportions. Anterior bauhdary yeas observed, to be formed by maxilla in 99% of cases and by lacrimal in 0.81 % cases. Posterior boundary was observed to be`formed by lacrimal in 98% of cases and by maxilla in 0.01 % fossae, in which the lacrimal bone was either present behind the boundary of the fossa or absent. From this study it is concluded that one should scan the contribution of the fossa for lacrimal sac by maxilla and lacrimal, as it is essential for endoscopic endonasal dacryocystorhinostomy. Presence of perilacrimal ossicles which are perhaps the detached segments of lacrimal bone and lacrimal bone being rudimentary and absent in some of the cases, are suggestive of the frontal process of maxilla increasing in size and the lacrimal bone gradually vanishing in the process of evolution.