Investigating the Morphology of the Nasolacrimal Canal in Cone Beam Computed Tomography Images and Its Relationship with Age and Gender.

Introduction: Nasal and paranasal anatomical structures are closely related to the nasolacrimal canal (NLC). As a result of this anatomical relationship, several studies have reported that nasal and paranasal sinus pathologies often play a major role in the etiology of nasolacrimal duct obstruction. The purpose of this study was to investigate the anteroposterior diameter, transverse diameter, length and angle of the bony NLC with nasal floor on the right and left by using cone beam computed tomography (CBCT) and to explore the influence of gender and age on the above-mentioned parameters.

Methods: The current study was conducted by examining the archive of primary CBCT images of patients who were referred for medical imaging to a private maxillofacial radiology clinic in Ahvaz, Iran, in 2020. In axial images, anteroposterior diameter and transverse diameter of the canal in the level of infraorbital were measured. In sagittal images, the length of the NLC was evaluated from the most proximal to the most distal part. Also, to examine the canal pathway, the angle between the canal and the floor of the nasal cavity was measured. Finally, all patient data, including age, gender and canal dimensions, diameter and path, was collected in the information form and referred to the statistics consultant for analysis.

Results: In the present study we included information of primary CBCT images of 126 patients who had been referred to a private maxillofacial radiology in Ahvaz, Iran, in 2020. Participants' average age was 28.22±8.13 years for women and 31.54±8.12 years for men, and a small age difference between sexes was seen. The average angle of the right canal with nasal floor was 108.29±7.96º for men and 113.70±7.57º for women, with a significant statistical difference by gender being observed. The mean values of the right channel length were 10.47±2.56 mm for women and 12.54±2.40 mm for men, and the difference between them was statistically significant. The mean values of the left canal length were 109.30±8.67 mm for women and 114.52±9.01 mm for men, and the difference between them was also statistically significant.

Conclusion: This study provides useful information on the morphometric properties of the bony nasal canal. Careful anatomical knowledge about the morphology of the bony nasal canal may help physicians to plan the treatment options. As the present study raises some concerns related to the age and gender differences in nasopalatine canal morphology that may affect patients' diagnosis and treatment, dentists are recommended to use CBCT images as well as additional techniques with this regard.