Intranasal ectopic dentition is a rare clinical entity. It may be asymptomatic or can be associated with different symptoms. In 25% of the reported cases an association with rhinosinusitis is suspected. The possible pathophysiology, diagnosis and treatment are discussed. Teeth in the floor of both nasal cavities, associated with chronic rhinosinusitis, are reported for the first time, and a new treatment option of endonasal extraction under microscopic control is presented.