1) Apical pathology lifting maxillary sinus floor and 2) Upper size limit of incisive canal
Asymptomatic chance finding on 74 year old male subject of a well defined unilocular apical lucency of #2 (see arrows in sagittal and coronal slices). There is a superior opaque cortical boundary which is the floor of the maxillary sinus which has been lifted up by the apical soft tissue. Since the floor of the sinus is lifted up, the disease is external to the sinus and is classified as extrinsic sinus disease as opposed to intrinsic disease originating from inside the sinus.
The diagnosis is most likely an apical granuloma or radicular cyst secondary to chronic apical periodontitis.
The first axial slice shows a large midline well defined unilocular lucency palatal to #8 and #9 which is the incisive canal. It measures 6 mm wide which is the upper limit of normal. No further investigation is required.”