ABSTRACT
OBJECTIVE: The aim of this study was to evaluate whether altered occlusion affects both the condylar cartilage thickness and the cytokine levels of the TMJs of rats. DESIGN: Thirty adult-male rats (n=30) were randomly assigned to three experimental conditions: a control group that underwent sham operations with unaltered occlusion; an FPDM group that underwent functional posterior displacement of the mandible that was induced by an incisor guiding appliance; and an iOVD group in which the increased occlusal vertical dimension was induced in the molars. The rats were subjected to the FPDM or iOVD model for 14 days and then killed. Both the right and left TMJs were removed and randomly assigned to examination with staining or immunoassay techniques. Toluidine blue staining was used to measure the thicknesses of the four layers of the articular cartilage (i.e., the fibrous, proliferating, mature, and hypertrophic layers). ELISA assays were used to assess the concentrations of the pro-inflammatory cytokines IL-1α, IL-1ß, IL-6, and tumour necrosis factor (TNF-α). The measurements of the articular cartilage layers and cytokine concentrations were analyzed with ANOVA and Tukey's tests and Kruskal-Wallis and Dunn tests, respectively (α=5%). RESULTS: The thickness of articular cartilage in the FPDM group (0.3±0.03mm) was significantly greater than those of the control (0.2±0.01mm) and iOVD (0.25±0.03mm) groups. No significant difference was observed between the control and iOVD groups. The four articular cartilage layers were thicker in the FPDM group than in the control and iOVD groups, and the latter two groups did not differ one from each other. Both the FPDM and iOVD groups exhibited higher cytokine levels than did the control (p<0.05) group. Compared to the FPDM group, the iOVD group exhibited significantly higher levels of IL-1ß and TNF-α. CONCLUSION: Both models induced inflammation in the TMJ and caused significant structural changes in the TMJ and surrounding tissues.
Subject(s)
Cartilage, Articular/metabolism , Cartilage, Articular/physiopathology , Cytokines/metabolism , Dental Occlusion , Temporomandibular Joint/metabolism , Temporomandibular Joint/physiopathology , Animals , Enzyme-Linked Immunosorbent Assay , Male , Mandibular Condyle/metabolism , Mandibular Condyle/physiopathology , Random Allocation , RatsABSTRACT
Devido à rápida progressão da doença periodontal, a presença de defeitos periodontais infraósseos é um achado frequente nos pacientes portadores de periodontite agressiva. O objetivo deste trabalho foi relatar clínica e radiograficamente uma abordagem periodontal regenerativa em paciente com histórico de periodontite agressiva generalizada. A paciente apresentava persistência de bolsa periodontal associada a defeito infraósseo na mesial do dente 46 mesmo após abordagens periodontais não cirúrgicas. O sítio foi tratado por meio de terapia periodontal regenerativa utilizando-se proteínas derivadas da matriz do esmalte (PDME) associadas a substituto ósseo composto de beta-tricálcio-fosfato e hidroxiapatita (β-TCP-HA). Dez meses após a terapia regenerativa, observou-se redução da profundidade de sondagem e preenchimento radiográfico do defeito periodontal. Desta forma, pôde-se concluir que a terapia periodontal regenerativa foi capaz de promover melhoras clínicas, demonstrando que tal procedimento é viável, mesmo em pacientes com histórico de periodontite agressiva generalizada.
