Abstract A case involving a large odontogenic cyst of the maxilla has been presented. This was successfully treated by an intraoral surgical procedure through a conservative approach. The final result was filling-in of the bone defect and retention of vital and nonvital mobile teeth (Figs. 11 and 12). From our clinical observations, we suggest that vital teeth should not be removed, even though roentgenographically they appear to be involved in the cyst cavity. Sometimes it is even desirable and practical to fill the root canals and retain nonvital teeth. In some cases the cyst is enucleated and an apicoectomy is performed. Bone will eventually fill in around these teeth.