The evaluation of nasolacrimal duct injury in Le Fort I osteotomy patients.

Background: Although Le Fort I surgeries are safe and successful procedures; nasolacrimal duct injuries may be observed due to these surgeries. The study aimed to investigate the prevalence of nasolacrimal duct injury in Le Fort I osteotomy patients.

Material and methods: The authors conducted a retrospective cohort study consisting of patients who underwent Le Fort I osteotomies between 2017 and 2021 in the Erciyes University Faculty of Dentistry. The primary predictor variables were the distance of the nasolacrimal canal to the outer cortex of the maxilla and the nasal floor, as well as the superior-inferior level of the superiorly positioned screw inserted in the maxilla aperture region relative to the nasolacrimal canal. The outcome variable was the presence of a nasolacrimal duct injury. Mann Whitney U test was used for quantitative variables between the two groups. A Pearson chi-squared analysis was used to compare categorical data. A p-value <0.05 was considered statistically significant.

Results: A total of 290 nasolacrimal canals were evaluated in 145 patients, 87 females, and 58 males. The mean age was 23.47± 6.67. There was a statistically significant relationship between screw level and nasolacrimal canal perforation (p<0,001). The distance between the most anterior border of the nasolacrimal canal and the outer cortical of the maxilla was significantly less in the perforation group (p<0,001). The fixation screw was significantly closer to the nasolacrimal canal in the perforation group (p<0,001).

Conclusions: In Le Fort I surgery, nasolacrimal duct injury may occur during screw fixation to the aperture region. Superiorly positioned fixation screws in the aperture region may damage the nasolacrimal canal. In patients where the nasolacrimal canal is close to the outer cortex, care should be taken when applying the fixation screws to the aperture region to avoid damaging the canal.