Abstract: PURPOSE: To establish a Beagle model, which was used to explore a new surgical pathway of sinus augmentation and analyze the effect of implantation of artificial bone substitutes. METHODS: Eleven male Beagle dogs (17 months, weighing 12-14 kg) were chosen with 22 maxillary sinus. Bilateral cone-beam CT (CBCT)scans were taken under intravenous anesthesia, to locate the range of the maxillary sinus, analyze the anatomical structure of the maxillary sinus wall, so as to make a plan of teeth extraction and measure the height and anteroposterior diameter of the sinus. A second CBCT scan was performed 2 months after extraction, to measure the height and the anteroposterior diameter of the bilateral maxillary sinus, in order to determine the volume of the artificial bone substitute, measure the distance from the bottom of the sinus to the crest(hereinafter referred to as the distance from B to C), and analyze the pathway. Fenestration of the maxillary sinus wall was conducted under general anesthesia and tracheal intubation, and the subjects were divided into 3 groups by implanting 3 kinds of artificial bone substitutes as designed (BioCap coating group, BioCap group and Bio-Oss group). The animals were sacrificed after taking the third CBCT scan 3 months after operation to test the bilateral maxillary sinus and sampled for analysis. The differences were analyzed with SPSS 19.0 software package for LSD test. RESULTS: It was found that the presence rate of thick infraorbital nerve bundles outside the maxillary sinus on CBCT was 100%. The maxillary sinus was located above the maxillary canine and the mesial root of third molar. The height of sinus was (8.10±1.05) mm, the anteroposterior diameter was (20.87±1.51)mm before teeth extraction. The height was (8.15±1.01)mm, the anteroposterior diameter was (20.89±1.21)mm, the distance from B to C in the middle of the sinus was (4.16±0.85)mm 2 months after teeth extraction. 1.2 mL artificial bone substitute were implanted into each sinus. The anteroposterior diameter was (20.86±1.27) mm, the distance from B to C in the middle of the sinus was (7.16±0.76)mm, the osteogenesis percentage was 85.15%±6.76% in BioCap coating group, 35.14%±6.13% in BioCap group, and 33.16%±6.75% in Bio-Oss group, 3 months after windowing. Statistical analysis showed that the distance from B to C after surgery was significantly higher than that before surgery (P<0.01). Osteogenic percentage in BioCap coating group was significantly higher than that in BioCap group and Bio-Oss group (P<0.01). There was no significant difference between BioCap group and Bio-Oss group (P>0.05). CONCLUSIONS: There was a large infraorbital nerve vascular bundle outside the maxillary sinus of Beagle dog which needed to open two layers of bone window to get into the sinus. Implanting artificial bone substitutes by opening a window outside the maxillary sinus of Beagle dogs could significantly increase the distance from the bottom to the crest, and could be used as animal models for maxillary sinus surgery.

Key words: Beagle dog, Animal model, Sinus augmentation