Angelo Luiz Freddo1, Caroline Comis Giongo2, Deise Ponzoni3, Adriana Corsetti4, Edela Puricelli5. 1. Professor, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre; Professor, Department of Oral and Maxillofacial Surgery, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil. Electronic address: angelofreddo@gmail.com. 2. Department of Oral and Maxillofacial Surgery, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. 3. Professor, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre; Professor, Department of Oral and Maxillofacial Surgery, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil. 4. Professor, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. 5. Professor, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre; Professor and Department Head, Department of Oral and Maxillofacial Surgery, Santa Casa de Misericórdia Dental Center, Porto Alegre, RS, Brazil.
Abstract
PURPOSE: This study evaluated the use of low-level laser therapy (LLLT) and exposure to a magnetic field (MF) during distraction osteogenesis. MATERIALS AND METHODS: The sample consisted of 18 rabbits divided into 3 groups of 6 animals each: control, MF exposure (briefly, magnetized gold-coated washers were placed next to the distractor device), and LLLT exposure (830 nm applied every 48 hours over 4 points [dose, 5 J/cm2] during the consolidation period). The same distraction osteogenesis protocol was used in all 3 groups (0.5 mm every 12 hours for 1 week). RESULTS: Quantitative microscopic analysis of sections stained with hematoxylin and eosin showed a statistically significant difference in the amount of newly formed bone in the MF group compared with the LLLT group (P = .006). The number of cells with more than 3 argyrophilic nucleolar organizer regions also was significantly different between the LLLT and control groups (P = .038). CONCLUSION: Distraction osteogenesis effectively promoted bone lengthening. The LLLT group exhibited a larger amount of newly formed bone and a larger number of osteoblasts in the cell division phase, but the difference was not statistically relevant compared with the control group.
PURPOSE: This study evaluated the use of low-level laser therapy (LLLT) and exposure to a magnetic field (MF) during distraction osteogenesis. MATERIALS AND METHODS: The sample consisted of 18 rabbits divided into 3 groups of 6 animals each: control, MF exposure (briefly, magnetized gold-coated washers were placed next to the distractor device), and LLLT exposure (830 nm applied every 48 hours over 4 points [dose, 5 J/cm2] during the consolidation period). The same distraction osteogenesis protocol was used in all 3 groups (0.5 mm every 12 hours for 1 week). RESULTS: Quantitative microscopic analysis of sections stained with hematoxylin and eosin showed a statistically significant difference in the amount of newly formed bone in the MF group compared with the LLLT group (P = .006). The number of cells with more than 3 argyrophilic nucleolar organizer regions also was significantly different between the LLLT and control groups (P = .038). CONCLUSION: Distraction osteogenesis effectively promoted bone lengthening. The LLLT group exhibited a larger amount of newly formed bone and a larger number of osteoblasts in the cell division phase, but the difference was not statistically relevant compared with the control group.