Cristina Jardelino de Lima1,2, Saulo Gabriel Moreira Falci3,4, Danillo Costa Rodrigues1,5, Érica Cristina Marchiori1, Roger Willian Fernandes Moreira1. 1. Oral and Maxillofacial Surgery Section, Oral Diagnosis Department, Piracicaba Dental School, University of Campinas (UNICAMP), Tiradentes, 195, Diamantina, MG, 39100-000, Brazil. 2. Oral and Maxillofacial Surgery Section, Oral Diagnosis Department, Brazilian Navy, Brasilia, Brazil. 3. Oral and Maxillofacial Surgery Section, Oral Diagnosis Department, Piracicaba Dental School, University of Campinas (UNICAMP), Tiradentes, 195, Diamantina, MG, 39100-000, Brazil. saulofalci@hotmail.com. 4. Hospital Santa Casa de Caridade de Diamantina, Diamantina, Brazil. saulofalci@hotmail.com. 5. Hospital Santa Casa de Montes Claros, Montes Claros, Brazil.
Abstract
PURPOSE: The aim of the present study was to use mechanical and photoelastic tests to compare the performance of cannulated screws with solid-core screws in sagittal split osteotomy fixation. METHODS: Ten polyurethane mandibles, with a prefabricated sagittal split ramus osteotomy, were fixed with an L inverted technique and allocated to each group as follows: cannulated screw group (CSG), fixed with three 2.3-cannulated screws; and solid-core screw group (SCSG), fixed with three 2.3-solid-core screws. Vertical linear loading tests were performed. The differences between mean values were analyzed through T test for independent samples. The photoelastic test was carried out using a polariscope. RESULTS: The results revealed differences between the two groups only at 1 mm of displacement, in which the cannulated-screw revealed more resistance. Photoelastic test showed higher stress concentration close to mandibular branch in the solid-core group. CONCLUSIONS: Cannulated screws performed better than solid-core ones in a mechanical test at 1-mm displacement and photoelastic tests.
PURPOSE: The aim of the present study was to use mechanical and photoelastic tests to compare the performance of cannulated screws with solid-core screws in sagittal split osteotomy fixation. METHODS: Ten polyurethane mandibles, with a prefabricated sagittal split ramus osteotomy, were fixed with an L inverted technique and allocated to each group as follows: cannulated screw group (CSG), fixed with three 2.3-cannulated screws; and solid-core screw group (SCSG), fixed with three 2.3-solid-core screws. Vertical linear loading tests were performed. The differences between mean values were analyzed through T test for independent samples. The photoelastic test was carried out using a polariscope. RESULTS: The results revealed differences between the two groups only at 1 mm of displacement, in which the cannulated-screw revealed more resistance. Photoelastic test showed higher stress concentration close to mandibular branch in the solid-core group. CONCLUSIONS: Cannulated screws performed better than solid-core ones in a mechanical test at 1-mm displacement and photoelastic tests.