History: 50 year old man with headache.
This is a case of odontogenic sinusitis, which is inflammation in a sinus adjacent to odontogenic infeciton or sinusitis as a result of sinus entry during dental surgery. The differential diagnosis includes sinus disease of other origins such as fungal sinusitis or bacterial superinfection after a viral URI, or mutliple mucous retention cysts.
Odontogenic sinusitis is diagnosed on CT when there is mucosal thickening in a sinus adjacent to an inflamed tooth, whether there is a dental carie, or in this case, a periapical lucency suggestive of a periapical abscess. It is treated with tooth extraction and antibiotics.