RESUMO
OBJECTIVE: Investigate the distribution of epidermal growth factor receptor (EGFR) in pericoronal follicles as a predictor of progression to odontogenic cysts and tumors. STUDY DESIGN: Immunohistochemical EGFR staining patterns (membrane-only, cytoplasm-only, or combined membrane and cytoplasmic staining) in the reduced enamel epithelium and nests of odontogenic epithelium associated with follicles of impacted molar teeth were evaluated. The staining pattern of 20 specimens of pericoronal follicle was compared with that of 16 normal oral mucosa samples and to squamous cell carcinoma samples. RESULTS: Combined membrane and cytoplasmic staining was observed for normal oral mucosa mostly in proliferating layers (basal and suprabasal), decreasing in intensity toward the surface. Seven epithelial nests presented membrane-only staining, and the majority presented either a cytoplasm-only or a combined staining pattern. The staining patterns observed in reduced enamel epithelium were cytoplasm-only and combined. CONCLUSION: EGFR membrane-only staining may be an indicator of increased potential for epithelial nests to become odontogenic cysts or tumors.
Assuntos
Receptores ErbB/análise , Cistos Odontogênicos/etiologia , Tumores Odontogênicos/etiologia , Dente Impactado/complicações , Adolescente , Adulto , Estudos de Casos e Controles , Membrana Celular/química , Transformação Celular Neoplásica , Citoplasma/química , Saco Dentário/química , Células Epiteliais/química , Feminino , Humanos , Masculino , Dente Serotino , Mucosa Bucal/citologia , Coloração e Rotulagem/métodos , Estatísticas não Paramétricas , Coroa do DenteRESUMO
The purpose of this study was to assess the tissue alterations in the temporomandibular joint (TMJ) of the New Zealand White rabbit (Oryctolagus cuniculus L.), after a unilateral occlusal interference insertion on the animal's right side back teeth. A total of 36 animals were used, thirty of which belonged to the experimental group and six to the control group. We established three experimental periods: 24 hours, three days and seven days. The control group animals were divided two by two; each pair followed the same experimental periods of the former one. The experimental group animals were submitted to the use of a 0.3 mm thick metallic cap with a visor. All animals were euthanized, and the TMJs were removed. Using a microscope for examination we observed, in all experimental periods, the presence of intra-articular hemorrhage in the supra- and infra-disk compartments as well as in the retro-disk zone. There were no inflammatory cells detected. The thickness of the condylar fibrocartilage presented significant alterations among the animals of the three experimental groups. In the left TMJs no inflammatory cells were detected. The results suggest that the insertion of a unilateral occlusal interference in rabbit back teeth does not cause any inflammatory intra-articular process within seven days; however, it does cause bilateral intra-articular hemorrhage and a larger compression of the condylar fibrocartilage in the joint opposite the side where the interference is placed. We also concluded that, in order to do research on the temporomandibular joint using animals, it is necessary have an independent (or separate) group of animals as controls.