USE OF BONE FOR OBLITERATION OF THE NASOFRONTAL DUCT WITH THE OSTEOPLASTIC FLAP - A CAT MODEL

The management of the frontal sinus remains controversial for traumati c and inflammatory disease. The osteoplastic flap with fat obliteratio n has become the treatment standard, although late failures with infec tion and mucocele formation may arise. Theories for mucocele formation include regrowth of residual mucosa from the sinus and ingrowth of mu cosa from a nonobliterated nasofrontal duct. A study to evaluate the m eans of nasofrontal duct obliteration was developed. Three cat groups were evaluated at 1, 2, and 3 months. Group 1 had the duct and sinus o bliterated with fat. Group 2 had the duct obliterated with bone and th e sinus with fat. Group 3 had only the duct obliterated with bone. The re was no mucosal ingrowth in any of the sinuses for the intervals stu died. In group 1, fat volume was seen to decrease over time with repla cement by fibrous tissue within the duct. Groups 2 and 3 developed pro gressive obliteration of the duct with new bone formation. One may inf er that fat obliteration alone does not provide a predictable stable s ituation as fat atrophies within the duct and may allow mucosal ingrow th. Bone obliteration was shown to be progressive within the duct from osteogenesis. This is the first experimental model to correlate clini cal observations of the use of bone for sinus obliteration. This study concluded that bone obliterates the nasofrontal duct better than the accepted standard of fat, independent of the material used to oblitera te the sinus.