In this study 850 cases of odontogenic cysts of the jaws, treated in Kaunas University of Medicine Hospital during the period of 1986-2004, were analyzed in order to evaluate the incidence of these cysts and other aspects of clinical and therapeutic interest such as their clinical features, changes they caused in the facial and mandible structures, and the teeth that had caused the pathology. Case histories of 455 men and 395 women had been analyzed. The age of the patients varied from 4 to 87 years, with the average of 35.8. More than half of the diagnosed cysts (63%) were present in the maxilla, 37% of them--in the mandible. The common complaints of the patients were bump, swelling, pain, discharge leaking from the fistula or alveolus after tooth extraction, increased teeth mobility, paresthesia; changes in the maxillofacial system - intraoral or facial asymmetry, inflated bone with sensation of an egg shell cracking revealed under palpation, swelling at the mucofacial fold, mobile teeth and fistula. While comparing the causative groups of antagonistic teeth in the maxilla and mandible, we found the proportion to be (in order from the right to the left): molars--1:1, premolars 1.3:1, fore teeth--3.3:1, fore teeth 3.8:1, premolars 1.2:1, molars 0.7:1. Odontogenic cysts may be present in both sexes; maxillary cysts are 1.5 times as frequent as mandibular cysts. The pathology may equally affect both sides of jaws, most cysts being diagnosed in the maxillary fore teeth area from tooth 13 to tooth 23. The following pairs of changes in maxillofacial system are frequently present: inflated body of bone or alveolus--increased mobility of teeth; the formed fistula--swelling at the mucofacial fold, swelling at the mucofacial fold--pain. The applied treatment of cysts was surgical--cystotomy or cystectomy.