Morphometric evaluation and surgical implications of the infraorbital groove, canal and foramen on cone-beam computed tomography and a review of literature

Background: The purpose of this study is to evaluate the anatomy, morphometry, and variations of infraorbital groove (lOG), infraorbital canal (IOC) and infraorbital foramen (IOF) on the cone-beam computed tomography (CBCT) images and to investigate their relations with surrounding structures. Methods: IOG, IOC and IOF were evaluated retrospectively in CBCT images of 75 female (F) and 75 male (M) cases with a range of 18-65 years (F: 37.62 +/- +/- 13.55, M: 37.53 +/- 15.87) by Planmeca Romexis programme. IOG, IOC and IOF were examined bilaterally (300 sides) in the cases. The 13 parameters were measured on these images in axial, sagittal and coronal planes. Results: There was a very weak positive correlation between the age and the angle between IOC and IOG (p = 0.015, r = 0.198), there was a weak positive correlation between the age and skin thickness (p = 0.001, r = 0.281), and there was no correlation between the age and other parameters. A total of 21 (7%) IOCs were detected in maxillary sinus, bilaterally in 6 cases and unilaterally in 9 cases (5 on the left, 4 on the right). In 1 case, bilaterally, IOC was separated 2 canals while running anteriorly in the maxillary sinus. The larger one was directed to IOF in its normal course and the smaller one was directed to lateral wall of nasal cavity and opened to the inferior nasal meatus in front of the opening of nasolacrimal duct. Conclusions: We suggest that the parameters found in the present study may facilitate prediction of the location of the infraorbital nerve. Knowledge of this exact position in relation to easily measurable parameters may decrease the risk of infraorbital nerve injury during surgical approaches directed to this region and might serve as a guide during local anaesthetic interventions for dentistry, ophthalmology, plastic surgery, rhinology, neurosurgery and dermatology.