Infraorbital canal bilaterally replaced by a lateroantral canal.

The infraorbital canal (IOC) normally courses above the maxillary sinus in the orbit floor. During a retrospective study of cone beam computed tomography (CBCT) scans, we found a previously unknown variant of the IOC. The IOCs were absent, being replaced by lateroantral canals coursing around and not above the maxillary sinus to open at infraorbital foramina which were located above the second upper premolar teeth. On coronal multiplanar reconstructions, the lateroantral canals were located anatomically at the outer limit of the zygomatic recess of each maxillary sinus, while the upper wall of the sinus was devoid of any canal. Such rare variant should be kept in mind by dental practitioners and surgeons, as it can determine modifications of common procedures. In this regard, the anatomy of maxilla, as well as mandible, should be evaluated in CBCT on a case-by-case basis.