AbstractThe surgical approach to frontal sinus disease has been subject to much variation. Experimental evidence for new treatment modalities is quite limited. Frontal osteoplasty, while probably the best procedure to date, has up to a 25 percent failure rate. Possible complications include recurrent disease, incomplete bony obliteration (Macbeth technique), infection of the adipose implant, frontal bossing or depression, and laceration of the dura.Four experimental groups were designed using the canine frontal sinus model. Results indicated that stripping the mucosa in a normal sinus with intact periosteum and a patent nasofrontal duct willnotconsistently lead to normal mucosal regeneration. Second, the additional factor of removing the periosteum (as in osteoplasty by osteoneogenesis), leads to partial fibrous obliteration complicated by mucocele formation. Third, sinus obliteration by osteoneogenesis was much more consistent with concurrent closure of the nasofrontal duct. Fourth, intentionally leaving a strip of mucosa leads to failure of obliteration by osteoneogenesis 100 percent of the time. Finally, bony‐fibrous obliteration increases with time but is still incomplete after one year.In light of these results, fat obliteration with closure of the nasofrontal duct is probably more reliable than obliteration by osteoneogenesi