Can treatment with chondroitin and glucosamine sulphate prevent changes in the articular disc caused by temporomandibular joint osteoarthritis?

BACKGROUND: Chondroitin and glucosamine sulphates (CGS) are considered structure-modifying drugs and have been studied in the prevention, delay or reversal of structural morphological changes in joints caused by osteoarthritis. OBJECTIVE: The aim of the present study was to investigate the action of CGS on the progression of chemically induced osteoarthritis in the temporomandibular joint (TMJ) of rabbits by evaluating the serum levels of tumour necrosis factor (TNF-α) and collagen in the articular discs. MATERIALS AND METHODS: A sample of 36 male rabbits was divided into three groups: control (CG), osteoarthritis (OG) and treatment (TG). The disease was induced by intra-articular injection of sodium monoiodoacetate (10 mg/mL) in the OG and TG groups bilaterally. After 10 days, the TG animals received subcutaneous injection of chondroitin sulphates and glucosamine (7.5 mg/kg) and the OG and CG received saline solution (50 µL). Euthanasia times were subdivided into 40 and 100 days. Collagen quantification was performed by biochemical and histological analysis and for the quantification of serum levels of TNF-α, an enzyme immunoassay was used. RESULTS: The TG showed an increase in the collagen area of the articular disc when compared to the CG and the OG. The increase collagen concentration in the discs did not show a statistically significant difference between the groups. Post-treatment TNF-α levels were significantly lower in TG compared to OG. CONCLUSIONS: The results indicate that CGS treatment delayed the degeneration of the collagen in the TMJ articular disc and reduced serum TNF-α levels, indicating a preventive effect on OA progression.

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.

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.