A study of the high-frequency hearing thresholds of dentistry professionals

Int. Arch. Otorhinolaryngol. 2012;16(2):226-231. DOI: 10.7162/S1809-97772012000200012 Original Article A study of the high-frequency hearing thresholds of dentistry professionals Estudo dos limiares de audibilidade nas altas frequências em trabalhadores da área odontológica Andréa Cintra Lopes1, Ana Dolores Passarelli de Melo2, Cibele Carmelo Santos3. 1) Doctor. Professor Doctor. 2) Master of Human Communication Science by Faculty of Odontology of USP - Bauru, São Paulo. Speech Therapy Clinics of Spazio Fonoaudiológico, Lima - Peru. 3) Master of Human Communication Science by Faculty of Odontology of USP - Bauru, São Paulo. Speech Therapist of AMA - Hearing Aids and CPAP. Institution: Faculty of Odontology of Bauru - University de São Paulo Bauru / SP - Brazil. Mailing address: Andréa Cintra Lopes - Alameda Dr. Octávio Pinheiro Brizolla, 9-75 - Departamento de Fonoaudiologia - Vila Universitária - Bauru / SP - Brazil - Zipcode: 17012-901 - E-mail: Financial sponsorship: FAPESP, process n. 2007/01074-7. Article received in September 30, 2011. Article Approved in October 26, 2011. SUMMARY RESUMO Introduction: In the dentistry practice, dentists are exposed to harmful effects caused by several factors, such as the noise produced by their work instruments. In 1959, the American Dental Association recommended periodical hearing assessments and the use of ear protectors. Aquiring more information regarding dentists’, dental nurses’, and prosthodontists’ hearing abilities is necessary to propose prevention measures and early treatment strategies. Objective: To investigate the auditory thresholds of dentists, dental nurses, and prosthodontists. Method: In this clinical and experimental study, 44 dentists (Group I; GI), 36 dental nurses (Group II; GII), and 28 prosthodontists (Group III; GIII) were included, , with a total of 108 professionals. The procedures that were performed included a specific interview, ear canal inspection, conventional and high-frequency threshold audiometry, a speech reception threshold test, and an acoustic impedance test. Results: In the 3 groups that were tested, the comparison between the mean hearing thresholds provided evidence of worsened hearing ability relative to the increase in frequency. For the tritonal mean at 500 to 2,000 Hz and 3,000 to 6,000 Hz, GIII presented the worst thresholds. For the mean of the high frequencies (9,000 and 16,000 Hz), GII presented the worst thresholds. Conclusion: The conventional hearing threshold evaluation did not demonstrate alterations in the 3 groups that were tested; however, the complementary tests such as high-frequency audiometry provided greater efficacy in the early detection of hearing problems, since this population’s hearing loss impaired hearing ability at frequencies that are not tested by the conventional tests. Therefore, we emphasize the need of utilizing high-frequency threshold audiometry in the hearing assessment routine in combination with other audiological tests. Keywords: audiometry, hearing loss, high-frequency, hearing loss, noise-induced, dentistry. Introdução: Na prática odontológica, o Cirurgião-Dentista está sujeito aos efeitos nocivos provocados por diversos agentes, como pelo ruído emitido por seus instrumentos de trabalho. Em 1959, a American Dental Association recomendava avaliações audiométricas periódicas e uso de proteção auditiva. São necessárias maiores informações sobre o comportamento auditivo dessa população: Cirurgiões-Dentistas, Auxiliares e Protéticos para se propor medidas de prevenção e tratamento precoce. Objetivo: Investigar os limiares de audibilidade em Cirurgiões-Dentistas, Auxiliares e Protéticos. Método: Forma de estudo: Estudo Clínico.Participaram 108 profissionais, sendo 44 Cirurgiões-Dentistas (GI), 36 Auxiliares (G II) e 28 Protéticos (GIII). Foram realizadas: entrevista específica, meatoscopia, audiometria tonal convencional e de altas frequências, logoaudiometria, imitanciometria. Resultados: A comparação entre as médias dos limiares evidenciaram piora com o aumento da frequência para os 3 grupos testados; para a média tritonal de 500 a 2000Hz, e 3000 a 6000 Hz, o GIII apresentou os piores limiares, já para a média das altas frequências (9000 a 16.000Hz) o GII apresentou os piores limiares. Conclusão: A avaliação audiológica convencional não identificou exames alterados para os três grupos testados, no entanto, o exame da avaliação audiológica complementar como a audiometria de altas frequências indicou maior sensibilidade na detecção precoce de alterações auditivas uma vez que a perda auditiva dessa população acomete as frequências que não são testadas nos exames convencionais. Dessa maneira enfatizamos nesse trabalho a necessidade de inserir na rotina de exames a audiometria de altas frequências juntamente com os outros exames audiológicos. Palavras-chave: audiometria, perda auditiva de alta frequência, ruído, odontologia geral. Int. Arch. Otorhinolaryngol., São Paulo - Brazil, v.16, n.2, p. 226-231, Apr/May/June - 2012. 226 A study of the high-frequency hearing thresholds of dentistry professionals. Lopes et al. INTRODUCTION Noise is one of the most harmful agents for health, primarily for hearing, and it is often unavoidable at workplaces and entertainment venues. Noise-induced hearing loss (NIHL), which is hearing loss that is induced by high levels of sound pressure, is one of the most common occupational diseases. Currently, noise is a constant part of people’s daily activities, as it is present in traffic, leisure, and work; therefore, NIHL may become one of the main chronic diseases in the future (FIORINI, 2000). NIHL is defined as sensorineural hearing loss that occurs due to systematic occupational exposure to high levels of sound pressure, thus causing damage to the hair cells of the organ of Corti. Generally, this hearing loss is bilateral and symmetrical, insidious and irreversible, and is directly related to the period of exposure and individual susceptibility (BRAZILIAN NATIONAL NOISE AND HEARING PRESERVATION COMMITTEE, 1999; RABINOWITZ, 2000). This hearing disturbance is initially manifested at the frequencies of 6,000 Hz, 4,000 Hz, and 3,000 Hz, and broadens progressively to the frequencies of 8,000 Hz, 2,000 Hz, 1,000 Hz, 500 Hz, and 250 Hz. Noise rarely leads to profound hearing loss, which generally does not exceed 75 dB for high frequencies and 40 dB for low frequencies, and reaching its upper limit in the first 10 to 15 years of exposure (LUXON, 1998; HANGER, BARBOSA-BRANCO, 2004; GATTO et al., 2005). Generally, professionals only notice a hearing difficulty when the lesion is at an advanced stage, as the hearing symptoms are insidious and manifest late (SAVA, 2005). Continuous exposure to high levels of sounds may not only result in hearing damage, but also in a few secondary alterations, such as tinnitus, stress, physiological alterations to the heart rhythm and to blood pressure, as well as difficulty in discr (...truncated)