Computed tomography demonstrating left‐sided odontogenic sinusitis with maxillary and ethmoid sinus opacification, but no overt maxillary molar pathology. However, the periapical bone around the palatal molar root was remodeled or absent (yellow arrow). Due to an odontogenic sinusitis suspicion, the patient was referred to an endodontist who confirmed pulpal necrosis and apical periodontitis