Protrusion of the infraorbital canal into the maxillary sinus: A cross-sectional study in Cairo, Egypt

Purpose: The aim of this study was to investigate the prevalence of infraorbital canal protrusion in an Egyptian sub-population using cone-beam computed tomography and to describe its radiographic representation. Materials and Methods: This retrospective cross-sectional study was conducted using the records of 77 patients and 123 maxillary sinuses. The full lengths of the sinuses were visible for the detection of infraorbital canal protrusion. The infraorbital canals were classified into 3 types based on their relation to the sinus. If the septum was present, its length and its distance from the sinus floor were measured. Qualitative and quantitative variables were described as percentages and means with standard deviations, respectively. Results: The infraorbital canal most commonly presented as the normal confined type (detected in 78.1% of sinuses), whereas the suspended (or protruded) variant was found in 14.6% of the examined sinuses. The septal length ranged from 0.9 to 5.1 mm, with a mean of 2.8 +/- 1.1 mm. The distance to the sinus floor ranged from 5.2 to 29.6 mm depending on the sinus shape and size. Conclusion: The present study indicates that protrusion of the infraorbital canal is not rare, and surgeons that use the maxillary sinuses as corridors for their procedures must be more cautious, especially in the upper lateral confines of the sinus. (Imaging Sci Dent 2022; 52: 359-64)