The discoidin domain receptors, DDR1 and DDR2, are nonintegrin collagen receptors and tyrosine kinases. DDRs regulate cell functions, and their extracellular domains affect collagen fibrillogenesis and mineralization. Based on the collagenous nature of dentoalveolar tissues, we hypothesized that DDR1 plays an important role in dentoalveolar development and function. Radiography, micro–computed tomography (micro-CT), histology, histomorphometry, in situ hybridization (ISH), immunohistochemistry (IHC), and transmission electron microscopy (TEM) were used to analyze Ddr1 knockout ( Ddr1−/−) mice and wild-type (WT) controls at 1, 2, and 9 mo, and ISH and quantitative polymerase chain reaction (qPCR) were employed to assess Ddr1/ DDR1 messenger RNA expression in mouse and human tissues. Radiographic images showed normal molars but abnormal mandibular condyles, as well as alveolar bone loss in Ddr1−/− mice versus WT controls at 9 mo. Histological, histomorphometric, micro-CT, and TEM analyses indicated no differences in enamel or dentin Ddr1−/− versus WT molars. Total volumes (TVs) and bone volumes (BVs) of subchondral and ramus bone of Ddr1−/− versus WT condyles were increased and bone volume fraction (BV/TV) was reduced at 1 and 9 mo. There were no differences in alveolar bone volume at 1 mo, but at 9 mo, severe periodontal defects and significant alveolar bone loss (14%; P < 0.0001) were evident in Ddr1−/− versus WT mandibles. Histology, ISH, and IHC revealed disrupted junctional epithelium, connective tissue destruction, bacterial invasion, increased neutrophil infiltration, upregulation of cytokines including macrophage colony-stimulating factor, and 3-fold increased osteoclast numbers ( P < 0.05) in Ddr1−/− versus WT periodontia at 9 mo. In normal mouse tissues, ISH and qPCR revealed Ddr1 expression in basal cell layers of the oral epithelia and in immune cells. We confirmed a similar expression pattern in human oral epithelium by ISH and qPCR. We propose that DDR1 plays an important role in periodontal homeostasis and that absence of DDR1 predisposes mice to periodontal breakdown.
ResumoIntrodução: A Disfunção Temporomandibular (DTM) se manifesta clinicamente como diversos problemas envolvendo a musculatura mastigatória, as articulações temporomandibulares e/ou suas estruturas associadas. Atualmente, essas disfunções apresentam elevada prevalência na população e afetam a qualidade de vida de seus portadores. Objetivo: Descrever as principais características e os sinais e sintomas de pacientes atendidos em um serviço especializado de Dor Orofacial. Material e método: A pesquisa foi realizada no Ambulatório do Serviço de Controle da Dor Orofacial do Hospital Universitário de uma universidade federal, contendo uma amostra de 236 fichas de pacientes atendidos no período entre 2005 e 2011. Realizou-se a coleta de dados contidos na ficha clínica específica do serviço, elaborada pelos próprios pesquisadores com base no RDC/TMD e no Índice Anamnésico Simplificado de Fonseca. A ficha clínica foi elaborada de acordo com a realidade deste ambulatório e dos seus pacientes, para facilitar o diagnóstico destas desordens. Em seguida, foi procedida a análise descritiva dos dados. Resultado: Entre os pacientes atendidos, houve predomínio do gênero feminino, faixa etária entre 41 a 60 anos, grau de escolaridade Ensino Médio completo, vínculo empregatício e encaminhamento por cirurgiões-dentistas. A presença de dor diária com intensidade 5 e dor do tipo pulsátil, e o cansaço muscular foram as características mais prevalentes. Conclusão: De acordo com os resultados obtidos, pode-se concluir que as mulheres procuram mais o serviço especializado e que os pacientes com DTM normalmente possuem elevados níveis de tensão e dor, sendo necessário um tratamento multidisciplinar.Descritores: Epidemiologia; dor facial; articulação temporomandibular; músculos mastigatórios. AbstractIntroduction: The Temporomandibular Disorders (TMD) are manifested clinically as many problems involving the masticatory muscles, temporomandibular joints, and / or associated structures. Currently, these disorders have a high prevalence in the population and affect the quality of life of their bearers. Objective: Describe the main features, signs and symptoms of patients treated at a specialized service of Orofacial Pain. Material and method: The study was conducted in a Service of Orofacial Pain located at a University Hospital the sample consisted of 236 patients' records treated between 2005-2011. Data was collected in specific clinical record, developed by the researchers and based on the RDC/TMD and also Fonseca's Simplified Index. The clinical record was constructed in accordance to the clinic's reality and its patients, to facilitate the diagnosis. Then was performed a descriptive data analysis. Result: Among the patients treated most patients were female; aged 41-60 years; high school education level; with employment and most part was referred by dentists. The most prevalent characteristics were daily pain with intensity level 5, throbbing pain and muscle fatigue. Conclusion: According to the results, it can be concluded that, women ...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.