Introduction: Due to the close anatomic relationship between paranasal structures and NLC, the morphometric measure of the nasolacrimal canal (NLC) could be affected by the osteomeatal complex (OMC) anatomical variations. The present study aimed to assess the effect of OMC variations on the NLC morphometric features using cone-beam computed tomography (CBCT).
Materials and methods: This cross-sectional study consisted of CBCT images of 150 subjects in the case group with at least one OMC variation and 40 cases in the control group without any OMC variation within the age range of 18-50 years. The presence of the OMC variations, including agger nasi, nasal septum deviation, concha bullosa, Haller cells, paradoxical middle turbinate, and pneumatization of the uncinate process, was evaluated in each patient. The NLC morphometric measurements were performed and compared between the case and control groups.
Results: The middle anteroposterior diameter and middle sectional area of NCL were significantly higher in patients with OMC variations, as compared to that in the control group. The NLC volume was significantly higher in patients with agger nasi, nasal septum deviation, concha bullosa, and pneumatization of the uncinate process, as compared to that in the control group. Nonetheless, no significant difference in NLC angulation with the nasal floor or Frankfurt horizontal plane was observed in the presence of each OMC variation.
Conclusions: As evidenced by the obtained results, a higher volume of the canal was revealed in the presence of some of the OMC variations. Therefore, it can be suggested that OMC variations cannot be a predisposing factor in cases with primary acquired nasolacrimal duct obstruction.
Keywords: Cone-beam computed tomography; Morphometry; Nasolacrimal canal; Osteomeatal complex variation.