[Imaging studies and surgical approach to postoperative maxillary cysts]

Surgical treatment for postoperative maxillary cysts (POMC) can be performed using the peroral method, or the endonasal method which is less invasive. Recently, the percentage of cases in which the endonasal method is employed has increased with the widespread use of endoscopy and advancement in imaging techniques. However, the peroral method is still necessary in some cases. During the 5-year period from July 1994 to June 1999, we operated on 29 patients (31 sides) for POMC. The endonasal method was used for 22 sides, and the peroral method was needed for the remaining 9 sides. Following analysis of the CT scans and MR images, we concluded that it is difficult to employ the endonasal method in the following cases; 1) Cysts located in the lateral or anteroinferior portion of the maxillary sinus 2) Small cysts 3) Cysts with a bony wall.