The Nasopalatine Canal in Adults on Cone Beam Computed Tomograms-A Clinical Study and Review of the Literature

AIM: The aims of this study were to assess the location, morphology and anatomical dimensions of the nasopalatine canal (NPC) on cone beam computed tomographic (CBCT) images and to compare our findings with recent reports on this matter. A detailed knowledge of anatomical variations is mandatory in skeletal surgery of the anterior maxilla.

PATIENTS AND METHODS: Two hundred CBCT scans of the mid-facial region were analyzed from adult patients at the Outpatient Clinic of the Department of Oral and Craniomaxillofacial Surgery, University of Hamburg, Germany. Patients were scanned using standard exposure time at normal patient positioning inside the CBCT device. Three-dimensional (3D) CBCT images were carefully analyzed regarding NPC location, morphology and anatomical dimensions, and variations of radiological morphology, with respect to age and gender.

RESULTS: In the sagittal plane, the NPC typically appeared as a canal with a mean length±standard deviation (SD) of 11.15±2.87 mm. The oral cavity opening of the canal is the incisive foramen, with a mean diameter of 4.49±1.71 mm. At the entrance to the nasal floor, in most cases, two apertures were found (Y-canal morphology), but also three or four openings were observed. In particular cases, the canal presented a cylindrical aperture with only one exit to the nasal floor. The average width of the NPC at the level of the nasal floor was 3.43±1.54 mm. The labiopalatal width of the NPC measured perpendicular to the long axis of the canal on sagittal plane was 2.48±1.33 mm. Interpretation of NPC morphology was significantly different when analyzing the images in the sagittal plane only, but the technique allowed demonstration of all aspects using the combined 2D/3D interpretation.

CONCLUSION: The NPC may exhibit important anatomical variations, both with regard to morphology and its dimensions. To avoid any potential complications during dentoalveolar surgery, careful preoperative evaluation is required. 3D imaging is recommended to determine canal topography and dimensions, and to assess the individual anterior maxilla's dimensions prior to surgical procedures, such as dental implant insertion or bone augmentation.