Evaluation of Nasolacrimal Canal Morphology on CBCT in Patients Undergoing Le Fort I Osteotomy: Preliminary Results

Objective: Le Fort I osteotomy is a safe and successful surgical procedure that is widely usedto correct skeletal maxillary deformity. Although the procedure is generally safe, nasolacrimalcanal injury may occur in rare cases. Nasolacrimal canal anatomy and morphology should wellknown to reduce this complication risk. The aim of this retrospective study was to evaluate thenasolacrimal canal anatomical features and localization.Materials-Methods: 240 bony nasolacrimal canals analyzed on 120 patients who underwentLe Fort I osteotomy. The anteroposterior-transverse diameter of bony nasolacrimal canal, thedistance between maxillary buccal cortical bone and nasolacrimal canal were measured atlevel most superior and inferior of nasolacrimal canal in axial section. The distance betweennasal floor and most inferior of nasolacrimal canal were also measured in coronal section. Allmeasurements were performed by the same radiologist.Results: The anteroposterior diameter of the bony nasolacrimal canal was 5.88±1.12mm atmost superior level and 7.68±1.49mm at most inferior level. The transverse diameter was4.86±0.9mm at most superior level and 4.82±0.94mm at the most inferior level. The distancebetween maxillary buccal cortical bone and nasolacrimal canal was 3.49±1.78mm at mostsuperior level and 7.15±3.1mm at most inferior level. The most inferior point of nasolacrimalcanal was approximately 16.95±2.61mm above to the nasal floor.Conclusion: The inferior part of nasolacrimal canal may be at risk for injury during Le Fort Iosteotomy. Evaluation of the anatomical features of the nasolacrimal canal on preoperativeCBCT is important to minimize the risk of nasolacrimal canal injury.