Radiological study of cyst-like lesions in the maxillary sinus.

Abstract

Cyst-like radiopacities are sometimes seen in the radiolucent maxillary sinus in pantomograms. The lesions appear as round or domeshaped images and panoramic radiographic views of the maxillary sinus tend to show these shadows more clearly than most other projections. The cyst-like opacities have been diagnosed as polyp, mucocele, mucosal or mesothelial cyst, mucous cyst, retention cyst and pyocele. Radiographic differentation between polyp and cyst is difficult; however, polyps tend to occur more frequently on the antral roof (1) while mucoceles are seen more often on the floor and lateral wall of the sinus (2). The mucous cyst is seen with a broad base and convex free margin (3). It is not usually associated with infection, thus there is no thickening of the mucosa (4). The mucous cyst may rupture and disappear spontaneously. Reports on the incidence of these cyst-like radiopacities vary from 2 to 10 percent (1, 5, 6, 7, 8, 9, 10). Some authors feel that mucoceles are rarely found in the maxillary sinus (11-16). Some diagnosticians consider these lesions asymptomatic while others associate symptoms of headache, pain or tenderness with these lesions (1, 2, 7, 17, 18). One author states that the only major findings of maxillary sinus mucoceles are bulging of the turbinates with subsequent occlusion of the nasal passage (19). The cyst-like lesions are thought to be non-odontogenic in origin (2, 20). However, the opposite view is also expressed. This article reports a study of the incidence, size and location of cyst-like opacities in the maxillary sinus in a group of asymptomatic japanese subjects.