RESUMO
ABSTRACT Purpose: to investigate the toxicity effects of major hydrocarbons present in gasoline on the auditory system and the related mechanisms of action. Methods: a literature review between 2005 and 2015 was conducted using LILACS, MEDLINE and SciELO, by combining descriptors and their respective terms in Portuguese, English and Spanish. Results: studies performed in humans and animals with hearing impairment, confirmed by morphological tests in rats, the influence of factors such as dose, duration, species and type of stimulus in hearing loss, and ineffective protection of workers by the threshold levels of exposure in the mixture of the compounds, were chosen. Conclusion: toluene is regarded as an ototoxic compound that damages outer hair cells in the middle region of the cochlea, with evidence of interaction with noise. Ethylbenzene and xylenes can be considered potentially ototoxic based on the results of animal studies. No sufficient data were found on benzene to form a conclusion.
RESUMO Objetivo: realizar levantamento sobre a toxicidade ao sistema auditivo e os respectivos mecanismos de ação provocados pelos principais hidrocarbonetos presentes na gasolina. Métodos: revisão bibliográfica, entre os anos de 2005 a 2015, realizada nas bases LILACS, MEDLINE e SciELO, por meio da combinação de descritores e seus respectivos termos em português, inglês e espanhol. Resultados: foram identificados estudos em animais e humanos com danos auditivos confirmados por exames morfológicos em ratos; influência de fatores como dose, duração, espécie e tipo de estímulo na perda auditiva; e insuficiência de proteção dos trabalhadores pelos níveis limites de exposição na mistura dos compostos. Conclusão: de acordo com os resultados, tolueno é considerado ototóxico, lesando células ciliadas externas em região média da cóclea, com evidências de interação com ruído; etilbenzeno e xilenos podem ser considerados potencialmente ototóxicos, devido a estudos com animais; e sobre o benzeno não foram encontrados dados suficientes para conclusões.
RESUMO
The periodontal plastic surgeries have been valued and sought by people who claim they want to correct "gummy smile", which happens when one has expose more gum than teeth when smiling. There are many causes for the gummy smile, this scientific article covers four cases of altered passive eruption of the teeth with excess keratinized gingiva. The harmonic smile disturbed aesthetic is a discomfort that troubles many people, especially women. Based what has been discussed so far, this paper has as main objective report clinical cases of esthetic periodontal surgeries osteoplasty made by undergraduate students of the dentistry program. Such techniques promote a more adequate dental exposure and create anharmonical smile on the patient. The cirurgical procedures were indicated based on the analysis of the smiles. After the procedures were made, we conclude the techniques used were suitable based on the satisfaction of the patient and that they were easy to execute in order to obtain an aesthetic smile.
RESUMO
The gummy smile is becoming one of the most frequent complaints reported by patients unhappy with your smile. According to the etiology, will be proposed various treatments. The purpose of this case report is to describe the lip repositioning technique, softening the gummy smile of the patient. It concludes that the lip repositioning technique is suitable for the correction of the gummy smile.