Maxillary sinus-floor elevation: an animal model.

OBJECTIVES To find an animal model for modified Caldwell-Luc procedure training. The animal model should have (1) a proper cortical thickness in the lateral wall; (2) a similar morphology and resistance of the Schneiderian membrane in humans; and, finally, (3) an oral approach. MATERIALS AND METHODS Twelve fresh heads (four Merino sheep, four Murciano-Granadina goats and four Large-White pigs). Two skulls from each of these species were also used. Several three-dimensional imagings from the skulls of each species were acquired using a C-arm. Two fresh heads of each species were used to perform the modified Caldwell-Luc procedure. Two fresh heads of each species were firstly frozen at -30 degrees C for 48 h and then sawed in blocks containing only the target region of the maxillary sinus. RESULTS The average thickness was 2.03 mm in goat and sheep and 2.80 in pig. Releasing and elevation of the Schneiderian membrane from the sinus floor were easy in the three species. The approach of the maxillary sinus in sheep, goat and pig from the buccal vestibule required a previous surgical enlargement of the buccal vestibule. CONCLUSIONS In conclusion, the cortical bone thickness and Schneider membrane characteristics in Merina sheep and Murciano-Granadina goat allow a perfect training for the modified Caldwell-Luc procedure. However, the approach from the oral cavity needs, in these species, a previous enlargement of the buccal vestibule. The excessive thickness of the cortical bone restricts the use of pigs for this technique.