Chronic maxillary rhinosinusitis of dental origin represents approximately 5 % of chronic maxillary rhinosinusitis. The diagnosis of this pathology is often delayed and mainly based on endoscopy and medical imaging. Its treatment is complex and requires the involvement of several teams. This article discusses two cases of chronic maxillary rhinosinusitis secondary to dental treatment. A literature review on the epidemiology, diagnosis, treatment and complications are also introduced.