There is a close anatomical relationship between the root apices of the molar and premolar teeth and the maxillary sinus floor. It is therefore possible that odontogenic diseases, dental treatment and the position of a dental implant affect the maxillary sinus. The authors exposed 3 case reports and a literature review of maxillary sinus pathology with an odontogenic origin.

Three clinical cases of unilateral odontogenic sinusitis are presented. The presenting symptoms, diagnostic procedures, treatment and follow-up of patients are exposed and discussed. A literature review is conducted.

The first case is an extensive radicular cyst, which caused important unilateral maxillary swelling; the treatment was a combination of endoscopic sinus surgery and a Caldwell-Luc operation. The second case reports an oroantral fistula of the alveolo-sinusal type after an upper premolar extraction; the patient remained with signs and symptoms of odontogenic sinusitis after medical treatment and consequently a surgical closure of the oroantral fistula was performed. The third case is a displaced dental implant in the maxillary sinus that was removed by endoscopic sinus surgery, thus avoiding a more aggressive external procedure.

Due to the relations and the anatomical structure of the upper jaw, a careful differential diagnosis of pathology of the maxillary sinus is needed. The dental origin of the maxillary sinus pathology remains overlooked, which leads to a delay in diagnosis and proper treatment. A correct diagnosis is based on a carefully taken clinical history, which should include the presence of dental pathology and/or instrumentation and reference to unilateral symptoms. The majority of the cases require endodontic treatment and medical treatment for sinusitis. In specific cases, surgery becomes the necessary treatment path for the resolution of dental pathology and inflammatory processes of the maxillary sinus.