Effect of anterior maxillary wall shape on ease of prelacrimal recess approach among Asians and Westerners.

PURPOSE: Endoscopic sinus surgery has been widely used in the treatment of most maxillary diseases, although the inability to access lesions in the anterior and inferior maxillary sinus walls is a major disadvantage. In few cases, the prelacrimal recess (PLR) approach can be used, which secures an overall view within the maxillary sinus. The distance between the anterior maxillary wall and lacrimal duct is related to the ease of the PLR approach. First we measured the distance between the anterior maxillary wall and lacrimal duct using anatomical image analysis to classify the types and then evaluated whether anatomical factors were related to the results.

METHODS

Both sides of the sinuses were evaluated in 272 participants (544 sides). After marking a tangent line (line 1 [L1]) through the posterior surface of the anterior maxillary sinus wall and a parallel line (line 2 [L2]) to the anterior surface of the lacrimal duct, the vertical distance between L1 and L2 was measured. Vertical distances of < 3 mm, 3-7 mm, and > 7 mm were classified as PLR approach types I, II, and III, respectively. In the axial plane image, line 3 (L3) (a horizontal line starting from the inner anterior maxillary sinus wall) was drawn and the angle with L1 (L1-L3A) was measured.

RESULTS

The proportions of types I, II, and III were 23.2% (126), 55.0% (299), and 21.8% (119), respectively. The mean L1-L3As for types I, II, and III were 12.87 ± 4.92°, 11.20 ± 5.08°, and 10.40 ± 4.47°, respectively, showing a significant difference in mean values (p < 0.001). The L1-L3A and vertical distance between L1 and L2 showed a significant negative correlation (r = - 0.201, p < 0.001).

CONCLUSIONS

We observed a correlation between the distance from the anterior maxillary wall to the lacrimal duct and L1-L3A. The L1-L3A indicates the degree of curvature of the anterior maxillary wall; therefore, the smaller the L1-L3A, the easier it may be to access the PLR.