Reduction of osteoarthritis severity in the temporomandibular joint of rabbits treated with chondroitin sulfate and glucosamine.

Osteoarthritis is a degenerative disease that causes substantial changes in joint tissues, such as cartilage degeneration and subchondral bone sclerosis. Chondroitin sulfate and glucosamine are commonly used products for the symptomatic treatment of osteoarthritis. The aim of the present study was to investigate the effects of these products when used as structure-modifying drugs on the progression of osteoarthritis in the rabbit temporomandibular joint. Thirty-six New Zealand rabbits were divided into 3 groups (n = 12/group): control (no disease); osteoarthritis (disease induction); and treatment (disease induction and administration of chondroitin sulfate and glucosamine). Osteoarthritis was induced by intra-articular injection of monosodium iodoacetate. Animals were killed at 30 and 90 days after initiation of therapy. The treatment was effective in reducing disease severity, with late effects and changes in the concentration of glycosaminoglycans in the articular disc. The results indicate that chondroitin sulfate and glucosamine may have a structure-modifying effect on the tissues of rabbit temporomandibular joints altered by osteoarthritis.

Condylotomy to Reverse Temporomandibular Joint Osteoarthritis in Rabbits.

PURPOSE: Osteoarthritis (OA) of the temporomandibular joint (TMJ) is characterized by local tissue degeneration and pain. Treatments have been aimed at reducing symptoms, and only some can interfere with the progression of pathophysiologic changes caused by OA. Condylotomy is an alternative treatment for patients with OA refractory to conventional treatment. The aim of the present animal study was to investigate the influence of condylotomy on TMJ OA in New Zealand rabbits. MATERIALS AND METHODS: The 36 rabbits were divided into 3 groups: the osteoarthritis group (OG; induced OA), treatment group (TG; induced OA plus condylotomy), and control group (CG; neither OA nor surgery). OA was induced using intra-articular monosodium iodoacetate injection for 40 days. The rabbits in the TG underwent condylotomy and were killed 20, 40, and 60 days after treatment. The rabbits in the CG and OG were killed at the same points. RESULTS: The articular joint condition was better in the TG 60 days after surgery (P = .032). A direct comparison revealed regression of TMJ OA over time among the treated rabbits (P = .008). Surgical treatment promoted mandibular condylar remodeling in the TG, reversing the tissue degeneration caused by OA. CONCLUSIONS: Our findings suggest that condylotomy could be an option for the treatment of OA and prevent damage to TMJ structures. This could be of particular importance for patients without satisfactory responses to more conservative treatment.

Effects of a buried magnetic field on cranial bone reconstruction in rats.

The understanding of bone repair phenomena is a fundamental part of dentistry and maxillofacial surgery. Objective The present study aimed to evaluate the influence of buried magnetic field stimulation on bone repair in rat calvaria after reconstruction with autogenous bone grafts, synthetic powdered hydroxyapatite, or allogeneic cartilage grafts, with or without exposure to magnetic stimulation. Material and Methods Ninety male Wistar rats were divided into 18 groups of five animals each. Critical bone defects were created in the rats' calvaria and immediately reconstructed with autogenous bone, powdered synthetic hydroxyapatite or allogeneic cartilage. Magnetic implants were also placed in half the animals. Rats were euthanized for analysis at 15, 30, and 60 postoperative days. Histomorphometric analyses of the quantity of bone repair were performed at all times. Results These analyses showed significant group by postoperative time interactions (p=0.008). Among the rats subjected to autogenous bone reconstruction, those exposed to magnetic stimulation had higher bone fill percentages than those without magnetic implants. Results also showed that the quality of bone repair remained higher in the former group as compared to the latter at 60 postoperative days. Conclusions After 60 postoperative days, bone repair was greater in the group treated with autogenous bone grafts and exposed to a magnetic field, and bone repair was most pronounced in animals treated with autogenous bone grafts, followed by those treated with powdered synthetic hydroxyapatite and allogeneic cartilage grafts.

Effects of a buried magnetic field on cranial bone reconstruction in rats

ABSTRACT The understanding of bone repair phenomena is a fundamental part of dentistry and maxillofacial surgery. Objective The present study aimed to evaluate the influence of buried magnetic field stimulation on bone repair in rat calvaria after reconstruction with autogenous bone grafts, synthetic powdered hydroxyapatite, or allogeneic cartilage grafts, with or without exposure to magnetic stimulation. Material and Methods Ninety male Wistar rats were divided into 18 groups of five animals each. Critical bone defects were created in the rats’ calvaria and immediately reconstructed with autogenous bone, powdered synthetic hydroxyapatite or allogeneic cartilage. Magnetic implants were also placed in half the animals. Rats were euthanized for analysis at 15, 30, and 60 postoperative days. Histomorphometric analyses of the quantity of bone repair were performed at all times. Results These analyses showed significant group by postoperative time interactions (p=0.008). Among the rats subjected to autogenous bone reconstruction, those exposed to magnetic stimulation had higher bone fill percentages than those without magnetic implants. Results also showed that the quality of bone repair remained higher in the former group as compared to the latter at 60 postoperative days. Conclusions After 60 postoperative days, bone repair was greater in the group treated with autogenous bone grafts and exposed to a magnetic field, and bone repair was most pronounced in animals treated with autogenous bone grafts, followed by those treated with powdered synthetic hydroxyapatite and allogeneic cartilage grafts.

Rabbit model for osteoarthrosis of the temporomandibular joint as a basis for assessment of outcomes after intervention.

Osteoarthritis can be induced in the temporomandibular joint (TMJ) by primary or secondary trauma, or overloading of the joint. We have therefore systematically evaluated the histological progression of experimental osteoarthritis induced by a high concentration of monosodium iodoacetate into the rabbit TMJ. These findings may contribute to the establishment of a protocol to investigate the benefits of treatment of osteoarthritis of the TMJ. We used 21 male New Zealand rabbits; the 15 in the test group were given an intra-articular injection of monosodium iodoacetate 10mg/ml into the right TMJ and were killed after 60 (n=5), 80 (n=5), and 100 days (n=5). The six in the control group were given an injection of saline into the right TMJ. The assessment system for osteoarthritis based on six grades was used for the histological analysis of severity. The model was effective in producing histological changes in the cartilage consistent with those found in osteoarthritis at all time points. The within-group analysis indicated that the disease did not progress after 60 days. The successful induction of osteoarthritis in this way, its stabilisation after 60 days, and the appropriate size of the animal suggest that this experimental model is ideal for future studies of the effectiveness of treatment in osteoarthritis of the TMJ.

Influência da condilotomia sobre a articulação temporomandibular de coelhos com osteoartrite quimicamente induzida / Influence of condylotomy on temporomandibular joint osteoarthritis of chemically induced rabbits

Introdução: A osteoartrite (OA) é caracterizada como sendo uma doença degenerativa das articulações, apresentando uma reação inflamatória de baixo grau. Dependendo da severidade da osteoartrite, os tratamentos podem ser cirúrgicos ou não cirúrgicos. A condilotomia é uma opção de técnica cirúrgica sem interposição articular, em que se realiza uma fratura guiada, a partir de uma osteotomia oblíqua no processo condilar da mandíbula. Após a cirurgia, o côndilo assume uma posição mais anterior e inferior, com recaptura do disco, possibilitando funcionalidade articular e processo de reparo. Proposição: O objetivo do presente trabalho foi avaliar os efeitos da condilotomia nas estruturas teciduais do côndilo da articulação temporomandibular de coelhos portadores de osteoartrite quimicamente induzida. Materiais e métodos: Foram utilizados dois grupos de animais com degeneração de articulação temporomandibular (ATM) quimicamente induzida. O grupo controle (n=15) acompanhou o grupo teste conforme os tempos de morte dos animais. O grupo teste (n=15) foi submetido à fratura cirúrgica guiada do côndilo mandibular, após 40 dias a partir da indução da doença. A análise histológica da superfície do côndilo mandibular foi realizada considerando-se a severidade da osteoartrite, por meio do escore proposto por Pritzker et al. (2006). Realizou-se a quantificação de colágeno tipo I na camada da cartilagem articular por meio da coloração de Picrossírius, sob efeito de luz polarizada. Os animais foram mortos nos tempos de 20, 40 e 60 dias após a cirurgia. Resultados: A severidade da osteoartrite observada na articulação temporomandibular dos animais do grupo teste no tempo de 60 dias foi comparativamente menor em relação ao grupo teste no tempo de 20 dias e ao grupo controle no tempo de 60 dias. Observou-se um grau maior na severidade da OA no grupo teste de 20 dias em comparação ao grupo controle no mesmo tempo avaliado. A quantidade de colágeno tipo I na camada de cartilagem de...

Background: Osteoarthritis (OA) is a degenerative joint disease, associated with low-grade inflammation. Treatment involves non-surgical and surgical options, depending on the severity of OA. Condylotomy is an alternative procedure that does not require articular interposition, in which an oblique osteotomy of the mandibular condyle is performed to guide the fracture. After surgery, the condyle shifts to an anterior-inferior position, with disk recapture, allowing joint functionality and repair process. Purpose: This study aimed to evaluate the effects of condylotomy on tissue structures of the temporomandibular joint (TMJ) condyle in rabbits with chemically induced OA. Materials and methods: Animals with chemically induced temporomandibular joint (TMJ) degeneration were divided into two groups: control group (n=15), which followed the experimental group as for the time points when deaths occurred; and experimental group (n=15), which underwent surgical fracture guided by osteotomy of the mandibular condyle 40 days after disease induction. Histological analysis of the articular surface of the mandibular condyle was performed considering the severity of OA, using the grading system proposed by Pritzker et al. (2006). The Picrosirius-polarization method was used to quantify type I collagen in the articular cartilage. The animals were killed 20, 40 and 60 days after surgery. Results: The severity of OA in the TMJ of experimental animals at day 60 was comparatively lower than that of experimental animals at day 20 and controls at day 60. Experimental animals showed a higher OA severity grade than controls at day 20. The amount of type I collagen in the articular cartilage of control animals was lower than that of experimental animals, especially in the anterior region of the mandibular condyle of controls at day 60. Conclusion: Condylotomy is an effective surgical technique for reducing the severity of chemically induced OA in the condylar surface of the rabbit...

Acidentes pérfuro-cortantes na Faculdade de Odontologia da Universidade Federal do Rio Grande do Sul / Puncher-cutting accidents in the College of Dentistry of the Federal University of Rio Grande do Sul

O presente trabalho estudou os acidentes pérfuro-cortantes ocorridos entre alunos, professores e funcionários da Faculdade de Odontologia da Universidade Federal do Rio Grande do Sul. Foram identificados os instrumentos causadores, os locais atingidos, a condição de saúde geral do indivíduo envolvido no acidente pérfuro-cortante e, também, as principais circunstâncias. Os dados analisados foram obtidos a partir do Formulário de Acidente e Incidente de Serviço (FAIS), instituído pela Faculdade com a finalidade de registrar as ocorrências. Foram notificados 25 acidentes pérfuro-cortantes entre os anos de 2004 a 2006, com uma média de 8,33 casos ao ano. Os momentos de atendimento de pacientes e manipulação do instrumental foram os mais citados. As disciplinas ou setores mais relacionados foram a Periodontia e a Odontogeriatria. Os instrumentos mais envolvidos foram curetas periodontais e agulhas anestésicas. Em 24% dos casos os indivíduos não utilizavam nenhum tipo de Equipamento de Proteção Individual (EPI); em 2 casos notificou-se a falta de orientação para atendimento médico ou de enfermagem. Dos 21 alunos envolvidos nos acidentes, 1 não havia feito a vacina contra a Hepatite B e 5 deles notificaram a ausência de vacinação contra o Tétano. Em 3 dos 25 casos estudados os pacientes relataram ser portadores de doenças ou patógenos transmissíveis. Após o estudo, verificou-se que a instituição necessita aperfeiçoar seus métodos de controle de biossegurança.

The present work studied the puncher-cutting accidents occurred among students, professors and employees of the College of Dentistry of the Federal University of Rio Grande do Sul. The dental instruments, the places affected, the condition of general health of the person involved in the puncher-cutting accidents and also the main circumstances were identified. The data analyzed were obtained from the Formulário de Acidente e Incidente de Serviço (FAIS), made by the college with the purpose of register the incidents. Twenty-five puncher-cutting accidents were reported between 2004 to 2006, with an average of 8,33 cases per year. The moments of appointment of patients and manipulation of dental instruments were the most mentioned. The most related subjects or departments were Periodontics and Geriatric Dentistry. The most involved instruments were periodontal curettes and injection dental needles. In 24% of the cases the individuals did not use any kind of Individual Protection Equipment (IPE), in two cases were reported the lack of orientation for medical appointment or nursing. From the 21 students involved in the accidents, one had not made the vaccine against the Hepatitis B and 5 of them reported the absence of vaccination against the Tetanus. From the 25 cases studied only three of the patients said that they have transmitted diseases or pathogens. After study, found that institution needs improve their methods of biosafety control.