Reparational analysis of three-dimensional grafts printed in the "gap" created after modified osteotomy in rabbit maxilla

• Grant number: 23/16726-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2024
• End date: September 30, 2024
• Field of knowledge: Health Sciences - Dentistry - Oral and Maxillofacial Surgery
• Principal Investigator: Leonardo Perez Faverani
• Grantee: Gustavo Ribeiro Ferreira
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Lower jaw repositioning in orthognathic surgeries represents an unstable movement with higher recurrence rates. The use of grafts helps with bone stability and repair. Prefabricated grafts are subject to movement due to difficult fixation during surgery and this instability can lead to postoperative complications. The use of additive manufacturing allows the customization of grafts, facilitating their fixation. However, the literature is scarce regarding the biological characteristics of this treatment modality. The objective of this study will be to evaluate whether the use of hydroxyapatite (HA) bone grafts manufactured by additive manufacturing interferes with the bone repair of inferiorly positioned rabbit premaxillae compared to treatment with plates and screws alone. 12 male rabbits will undergo modified LeFort I osteotomy in the premaxilla region associated with a GAP osteotomy. The animals will then be divided into 2 groups. In the PLATES group (n=6), premaxilla fixation will be performed only with titanium L-shaped plates and 1.5mm system screws. And in the PLATES+GRAFTS group (n=6), the premaxilla will be fixed with L-shaped titanium plates and screws from the 1.5mm system associated with the fixation method with a personalized block graft based on hydroxyapatite (HA) made by additive manufacturing, and fixed with 1.5mm screws. After 6 weeks, euthanasia will be performed and biopsies will be collected from the central regions of the bone defects to perform histomorphometric and proteomic analysis. Quantitative data will be subjected to the Shapiro-Wilk test to determine the statistical test, considering a significance level of 5%.