2000 Volume 63 Issue 3 Pages 175-189
I observed 252 patients with postoperative maxillary cysts clinically and with the scanning electron microscope. Forty-nine cases of the cysts that were closely related to the teeth were further divided into three types based on clinical findings. Type 1 was designated as the postoperative radicular cyst, and had apparently healthy, pulpless roots penetrating the cyst. The cyst formation of this type is believed to occur from pulp necrosis caused by apical root injury at the time of radical surgical procedures for maxillary sinusitis. The necrosis leads to apical periodontitis, apical granuloma, and finally development of the radicular cyst. Ninety-six latent cysts(45.7%)which were clinically silent were found contralateral to the side of the operation. Five of these were surgically treated. Fluid aspirates taken from 4 of the cases were all viscous and represented mucinous secretions. The presence of the ciliated cells was confirmed in all cases observed by scanning electron microscopy(SEM). These findings suggest that some cases of the latent cysts develop into apparent cysts. SEM observation of the surface patterns of 80 cysts were carried out and the epithelia was classified into 5 types based on the number of ciliated cells. Type 1:abundant ciliated cells, type 2:moderate ciliated cells, type 3:sparse ciliated cells, type 4:no ciliated cells, and type 5:no epitheleum. Although ciliated cells were present in 57 of the cysts, there were large variations in their number. Several theories has been proposed to explain the development of the postoperative maxillary cyst. This study seems to indicate that the sinus obstruction theory is the most probable for unilocular cysts, although it does not explain multilocular cysts. Obstruction between the cystic wall and nasal cavity, and the presence of ciliated cells on the cystic wall are important in the sinus obstruction theory.
