RELATIONSHIP BETWEEN MUCOCELES AND CYSTS: REPORT OF A CYST OF THE MAXILLARY SINUS

There is a prevailing conception that a mucocele is caused by the occlusion of the ostium of a sinus. A gelatinous material is supposed to accumulate within the sinus. The subsequent rise in the intrasinus pressure is said to cause degeneration and absorption of the walls of the sinus. The clinical and pathologic features of a mucocele are indisputable. It is doubtful, however, whether occlusion of the ostium is the only factor in the production of a mucocele. It is not unlikely that some type of cystic degeneration of the mucosa precedes the mature and classic mucocele. It must have a favorable soil for its origin. According to this conception, both factors, cystic degeneration and ostial occlusion, are essential to the development of a mucocele. A cyst may grow until it fills the capacity of a sinus without producing a mucocele, as long as the ostium remains patent. Similarly,