Abstract: Objective： To provide anatomical evidence for frontal sinus surgery through the agger nasi cell approach and the uncinate process approach by using the lamellar sectional anatomy image. Methods： The computerized cryomilling technique was used to obtain the continuous sectional data of the nasal parts. The frontal sinus′s anatomical boundary and the drainage path were observed. The relationship among the agger nasi cells, the uncinate process and the frontal recess was found. The distance of the center of the agger nasi cell′s anterior wall to the anterior extremity of the middle nasal concha′s root, the thickness of the agger nasi cell′s anterior wall, of the uncinate process′s root, and of the nasolacrimal canal′s medial wall connecting with the uncinate process′s root were determined. Results： The distance of the center of the agger nasi cell′s anterior wall to the anterior extremity of the middle nasal concha′s root was (7.12±0.74) mm. The thickness of the agger nasi cell′s anterior wall was (0.47±0.09)mm, of the uncinate process′s root was (1.27±0.22)mm, and of the nasolacrimal canal′s medial wall connecting with the uncinate process′s root was (1.71±0.08) mm. Conclusion： A precise data of the agger nasi cell′s anterior wall and the uncinate process can be found by the lamellar sectional anatomy image of the frontal sinus.

Key words: Frontal sinus, Dissection, Microtomy, Frontal recess, Agger nasi cell, Uncinate process