IADR Abstract Archives
Three-Dimensional Study of Orthodontic Tooth Movement in Hypercholesterolemic Rats.
Objectives: To study the dynamics of orthodontic tooth movement (OTM) in a three-dimensional model of rat jaws subjected to a hypercholesterolemic diet.
Methods: Eight recently weaned Wistar rats (60±5 grams) were divided into two groups and fed for 7 weeks with one of the following diets: A-Control Diet (CD n:4) B-Hypercholesterolemic Diet (HCD n:4). At t=5 weeks, both experimental groups underwent exodontia of the lower left second molar and installation of an orthodontic appliance for 2 weeks. At final time t:7 weeks, euthanasia was performed. Blood was obtained by cardiac puncture to evaluate lipid profile (mg/dL); total cholesterol (TC); C-HDL; C-non HDL and triglycerides. The right and left hemimandibles were resected. The contralateral side of the untreated mandible served as an internal non-force control and all measurements were performed on both sides of the mandible. Microtomographs of all jaws were performed with a Bruker Microtomograph (resolution: 26,6µm) and using 3D Slicer software, 3D models and morphometric point determination were performed to quantify the OTM. Points determination: M1: amelocemental border (ACB) per mesial 1 Molar (1M); D1: ACB per distal 1M; M3: LAC per mesial 3 Molar (M3); D3: ACB per distal 3M; point F: mandibular foramen. Different segments were determined. Non-parametric t-test and Mann Whitney test were used (p<0.05). The results are expressed as X±SD.
Results: Serum TC was higher in DHC (61±7.73mg/dL vs. 168.7± 39.92 mg/dL; p<0.0001). Regarding morphometric measurements we found that: M1-F: DC:0.14 ±0.01 vs DHC 0.09±0.02); D1-M3: 0.23±0.15 vs 0.26±0.05); D3-F: -0.42±0.1 vs -0.34±0.05), M1-D3: 0.38±0.5 vs 0.19±0.08).
Conclusions: The morphometric parameters evaluated in the three-dimensional reconstruction allow characterizing the orthodontic tooth movement in hypercholesterolemic rats, which is more abrupt and less predictable.
Methods: Eight recently weaned Wistar rats (60±5 grams) were divided into two groups and fed for 7 weeks with one of the following diets: A-Control Diet (CD n:4) B-Hypercholesterolemic Diet (HCD n:4). At t=5 weeks, both experimental groups underwent exodontia of the lower left second molar and installation of an orthodontic appliance for 2 weeks. At final time t:7 weeks, euthanasia was performed. Blood was obtained by cardiac puncture to evaluate lipid profile (mg/dL); total cholesterol (TC); C-HDL; C-non HDL and triglycerides. The right and left hemimandibles were resected. The contralateral side of the untreated mandible served as an internal non-force control and all measurements were performed on both sides of the mandible. Microtomographs of all jaws were performed with a Bruker Microtomograph (resolution: 26,6µm) and using 3D Slicer software, 3D models and morphometric point determination were performed to quantify the OTM. Points determination: M1: amelocemental border (ACB) per mesial 1 Molar (1M); D1: ACB per distal 1M; M3: LAC per mesial 3 Molar (M3); D3: ACB per distal 3M; point F: mandibular foramen. Different segments were determined. Non-parametric t-test and Mann Whitney test were used (p<0.05). The results are expressed as X±SD.
Results: Serum TC was higher in DHC (61±7.73mg/dL vs. 168.7± 39.92 mg/dL; p<0.0001). Regarding morphometric measurements we found that: M1-F: DC:0.14 ±0.01 vs DHC 0.09±0.02); D1-M3: 0.23±0.15 vs 0.26±0.05); D3-F: -0.42±0.1 vs -0.34±0.05), M1-D3: 0.38±0.5 vs 0.19±0.08).
Conclusions: The morphometric parameters evaluated in the three-dimensional reconstruction allow characterizing the orthodontic tooth movement in hypercholesterolemic rats, which is more abrupt and less predictable.