Foreign bodies may be displaced into the maxillary sinus as a result of trauma or during dental interventions. They commonly cause chronic sinusitis and/or fungal infections. This paper presents the case of a foreign body lodged in the right maxillary sinus ostium of a 31-year-old female patient. The foreign body was observed incidentally during radiological examination. After careful clinical and radiological examination, it was concluded that the foreign body was a piece of amalgam displaced into the maxillary sinus during a traumatic extraction. It is an uncommon finding to observe an asymptomatic dental foreign body in a position so close to the natural ostium of the maxillary sinus for so many years without any oro-antral fistula formation and/or sinusitis attacks. We describe the non-surgical approach to the case and the need for surgical management will be questioned. The importance of consultation between otolaryngologists and oral and maxillofacial surgeons will also be emphasised.