Effect of obesity on bone tissue and periodontal structures during orthodontic movement: microtomographic, immunohystochemical and histological analysis

• Grant number: 17/03756-0
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2017
• End date: January 31, 2020
• Field of knowledge: Health Sciences - Dentistry - Orthodontics
• Principal Investigator: Mírian Aiko Nakane Matsumoto
• Grantee: Mírian Aiko Nakane Matsumoto
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated researchers: Francisco Wanderley Garcia de Paula e Silva ; Karla Orfelina Carpio Horta ; Maria Bernadete Sasso Stuani

Abstract

The objective of the present study was to evaluate the effect of obesity on orthodontic movement in Wistar rats, by means of computerized micro-tomography, histological and immunohistochemical analyzes. 40 rats of approximately 3 weeks of age randomly divided into 4 groups of 10 animals will be used: Group I - rats with one hemi-maxilla submitted to induced tooth movement (ITM) for 7 days; Group II- Obesity-induced rats and with one hemi-maxilla submitted to ITM for 7 days; Group III - rats with one hemi-maxilla submitted to ITM for 14 days; Group IV- Obesity-induced rats with one hemi-maxilla submitted to ITM for 14 days. The remaining hemi-maxilla of each rat will be used as control. After euthanasia, the hemi-maxillas will be submitted to chemical and biological processing in order to prepare the samples for microtomography examination. Next, the histotechnical and immunostaining procedures will be performed to evaluate the mediators that modulate the bone remodeling process by analyzing the protein expression of osteoclastogenesis markers (RANK, RANKL and OPG), matrix metalloproteinases (MMP-1, MMP -8 and MMP-13) and pro-and anti-inflammatory cytokines (IL-1beta, IL-6, IL-10 and TNF alfa); as well as the amount of osteoclasts, through staining of the enzyme tartrate-resistant acid phosphatase. Finally, the description of the radicular and peri-radicular regions and the morphological analysis in sections stained with Hematoxylin-Eosin under conventional microscopy will be performed. The analyzes will be executed by experienced and calibrated examiners, without prior knowledge of the group being evaluated. The data obtained will be submitted statistical analysis using the program Graph Pad Prism 5.0, with a significance level of 5%. (AU)