The Anatomy of the Frontal Process of the Maxilla in the Medial Wall of the Lacrimal Drainage System in East Asians.

PURPOSE: To investigate the anatomical structure characteristics of the frontal process of the maxilla in the medial wall of the lacrimal drainage system for endoscopic dacryocystorhinostomy based on the cone-beam computed tomography images.

METHODS

One hundred eight sides of orbits were retrospectively evaluated in this study. The angulation and thickness of the frontal process of the maxilla in the medial wall of the lacrimal drainage system were measured and compared at 2 different levels: lacrimal sac level and nasolacrimal duct level. The vertical height between the 2 measurement levels was also measured. Data were compared between males and females.

RESULTS

The average angulation and thickness of the frontal process of the maxilla were found significantly larger at the lacrimal sac level than at the nasolacrimal duct level (83.1 ± 11.3° vs. 61.7 ± 10.9° and 2.7 ± 0.9 mm vs. 1.1 ± 0.4 mm) (p < 0.001). The vertical height between the 2 levels was significantly higher in males than in females (8.6 ± 1.8 mm vs. 7.8 ± 1.7 mm) (p = 0.015).

CONCLUSIONS

We found the angulation and thickness of the frontal process of the maxilla in the medial wall of the lacrimal drainage system decreased from the upper to the lower level. Starting the osteotomy during endoscopic dacryocystorhinostomy might be easier and safer at the midpoint level of the maxillary line.