This clinical study used cone beam computerized tomography (CBCT) to locate the position of the anastomosis canal in lateral wall of maxillary sinuses, and to evaluate the thickness of lateral sinus wall and the distance from the lower border of the canal to the sinus floor, which could provide surgeon with information about this anastomosis. Two hundred and forty-two (242) volumes of CBCT scans were included in this study. The distances from the lower border of the anastomosis canal to the sinus floor and from the maxillary alveolar crest to the sinus floor were evaluated in transversal plane, and the thickness of the lateral sinus wall was measured at the distance of 3, 6, 9 mm from the sinus floor and at the level of the lower border of the canal at the same plane. The canal was identified in 87.6% (424/484) of the sinus. Most canals were intraosseous, or beneath the sinus membrane. The mean distance was 9.2 ± 3.5 mm from the lower border of the canal to the sinus floor, and 10.8 ± 4.0 mm from the alveolar crest to the sinus floor. The thickness of the lateral sinus wall was 2.4 ± 0.9 mm, 1.8 ± 0.8 mm, 1.7 ± 0.7 mm, 1.8 ± 0.8 mm at the distance of 3, 6, 9 mm from the sinus floor and at the level of the lower border of the canal. The location of the anastomosis canals varied from each patient, but the distance from the sinus floor was similar in different teeth sites. The sinus floor could be an anatomic landmark of sinus floor augmentation. In order not to interrupt this canal, great care must be taken by the implant surgeon to identify this canal.
Keywords: anastomosis canal; cone-beam computed tomography; maxillary sinus; sinus floor augmentation.