From September 2001. to February 2004. in the Institute for ENT and Maxillofacial Surgery were investigated 107 patients with the inflammatory diseases of the maxillary sinuses. Patients with sinusitis were separated into group of patients with rhinogenic (72) and patients with odontogenic maxillary sinusitis (35). We found that the etiology of odontogenic sinusitis was mostly artificial caused after some dental surgery (88%), what is totally opposite to the spontaneous etiology of rhinogenic sinusitis. Surgical treatment of rhinogenic sinusitis mostly was endonasal polypectomy with operation by Caldwell-Luc or FESS. Odontogenic sinusitises were mostly treated by FESS and surgical "closing" of oral-antral fistula by local mucogingival flap (51%).