Anatomical evaluation of nasopalatine canal on cone beam computed tomography images

Nasopalatine canal (NPC) (incisive canal) morphology is important for oral surgery techniques carried out on the maxilla, in the treatment of naso- palatine cyst, palatal pathologies that require a surgical intervention.

The morphology of NPC was classified in sagittal, coronal and axial planes on the cone beam computed tomography (CBCT). The length of NPC was found by measuring the distance between the mid-points of nasopalatine foramen and incisive foramen. The numbers, shapes and diameters of incisive and nasopalatine foramina were examined. Nasopalatine angle present between the NPC and the palate and anterior to the NPC was measured.

In the sagittal plane, the shape of NPC was classified in six groups: 26.7% hourglass, 14.7% cone, 13.3% funnel, 16.0% banana, 28.7% cylindrical and 0.7% reverse-cone-shaped. In the coronal plane, shape of NPC was classified in three groups: 63.3% Y-shaped, 36.0% single canal, 0.7% double canal and external border of NPC was classified in four groups: 26.7% U, 28.7% Y, 44.0% V and 0.7% reverse-V-shaped. In the axial plane, the shape of nasopalatine foramen, incisive foramen and NPC at the mid-level was evaluated. The shape of the canal was detected as four types at three evaluated levels: round, oval, heart- and triangle-shaped. It was seen in every three axial planes that the round group is more than the others.

The morphological properties and variations of NPC should be con- sidered with a correct radiological evaluation so as to prevent the complications and improper practices in local anaesthesia, maxillary surgery and implant surgery practices. Especially dentists, otolaryngologist and plastic surgeons need to know the anatomy and variations of NPC.