Abstract: Objective: To analyze the affected tooth, the common causes, the treatments and the outcomes of odontogenic maxillary sinusitis. Methods: Cases about patients affected by odontogenic maxillary sinusitis in First Clinical Division of Peking University School and Hospital of Stomatology from January 2000 to December 2012 were collected and retrospectively analyzed. Results: 23 cases were collected. The diseases of maxillary first molars caused 47.7% of odontogenic maxillary sinusitis cases. Chronic periapical periodontitis caused 78.3% of odontogenic maxillary sinusitis cases. The treatments should combine treating dental diseases, medicine and sinus surgeries. The outcomes were satisfactory. Conclusion: Diseases of maxillary first molars were the most common to cause odontogenic maxillary sinusitis. Most of odontogenic maxillary sinusitis were caused by chronic periapical periodontitis. Combined treatments could get good results.

Key words: Maxillary sinusitis , Odontogenic, Maxillary molar