RESUMEN
The relation between orthodontic forces applied to deciduous teeth and the occurrence of root resorption, as a possible outcome of these forces, has not been studied to date. The aim of this work was to study root resorption in deciduous teeth of patients receiving orthodontic treatment. Twenty-four deciduous molars extracted for therapeutic purposes were studied: nineteen molars treated with light orthodontic forces and five untreated molars that served as control. Histological and histomorphome tric studies were performed to determine the magnitude of root resorption. Location of root resorption in treated deciduous teeth was different from that of physiological root resorption. Extent and volume of root resorption were more extensive and deeper in treated than in untreated teeth. These results suggest that radiographic follow-up of deciduous teeth subjected to orthodontic forces would be useful to prevent root fractures.
Asunto(s)
Diente Molar , Ortodoncia Correctiva/efectos adversos , Resorción Radicular/etiología , Diente Primario , Estudios de Casos y Controles , Niño , Humanos , Resorción Radicular/patologíaAsunto(s)
Antibacterianos/sangre , Quemaduras/sangre , Vancomicina/sangre , Quemaduras/patología , Niño , Monitoreo de Drogas/métodos , Humanos , MasculinoRESUMEN
OBJECTIVE: To evaluate the possible presence of vancomycin-resistant Staphylococcus aureus (VRSA) in a Brazilian hospital. DESIGN: Epidemiological and laboratory investigation of nosocomial VRSA. METHODS: 140 methicillin-resistant S aureus strains isolated between November 1998 and October 1999 were screened for susceptibility to vancomycin. The screening was carried out by using brain-heart infusion agar (BHIA) supplemented with 4, 6, and 8 microg/mL of vancomycin. The minimum inhibitory concentration (MIC) determination was carried out as standardized by the National Committee for Clinical Laboratory Standards using the broth macrodilution, agar-plate dilution, and E-test methods. PATIENTS: Hospitalized patients exposed to vancomycin. RESULTS: 5 of the 140 isolates had a vancomycin MIC of 8 microg/mL by broth macrodilution, agar plate dilution, and E-test methods. Four VRSA strains were isolated from patients in a burn unit who had been treated with vancomycin for more than 30 days, and one from an orthopedic unit patient who had received vancomycin treatment for 7 days. Pulsed-field gel electrophoresis characterized four of the VRSA strains as belonging to the Brazilian endemic clone. All five strains were negative for vanA, vanB, and vanC genes by polymerase chain reaction. Transmission electron microscopy of the five strains revealed significantly thickened cell walls. One patient died due to infection caused by the VRSA strain. CONCLUSIONS: This is the first report of isolation of VRSA in Brazil and the first report of isolation of multiple VRSA strains from one facility over a relatively short period of time. This alerts us to the possibility that VRSA may be capable of nosocomial transfer if adequate hospital infection control measures are not taken.