ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Hearing loss affects 30 million people in the United States; of these, 21 million are over the age of 65 years. This disorder may have several causes: heredity, noise, aging, and disease. Hearing loss from noise has been recognized for centuries but was generally ignored until some time after the Industrial Revolution. Hearing loss from occupational exposure to hazardous noise was identified as a compensable disability by the United States courts in 1948 to 1959. Development of noisy jet engines and supersonic aircraft created additional claims for personal and property damage in the 1950s and 1960s. These conditions led to legislation for noise control in the form of the Occupational Safety and Health Act of 1970 and the Noise Control Act of 1972. Protection of the noise-exposed employee was also an objective of the Hearing Conservation Act of 1971. Subsequent studies have confirmed the benefits of periodic hearing tests for workers exposed to hazardous noise and of otologic evaluation as part of the hearing conservation process.Research studies in laboratory animals, using scanning electron microscopical techniques, have demonstrated that damage to the inner ear and organ of hearing can occur even though subjective (conditioned) response to sound stimuli remains unaffected. Some investigators have employed an epidemiologic approach to identify risk factors and to develop profiles to susceptibility to noise-induced hearing loss. The need for joint involvement of workers and employers in the reduction and control of occupational noise hazards is evident.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Fifty-six patients were treated surgically for middle ear cholesteatoma using the combined approach tympanoplasty technique. One year later a second-look procedure was performed in all the patients, which permitted the anatomic effects of the combined technique to be mapped out before ossicular reconstruction was performed. At three, six, and twelve months after the first operation the development of retraction pockets was also studied. Recurrent cholesteatoma was found in twelve cases (21.4%), and residual cholesteatoma in fourteen (25%). The posterior tympanotomy. was closed in 31 cases (55.4%), whereas the mastoidectomy cavity was overgrown and closed in 22 (39.4%). Twelve months after the first operation (just before the second look), a retraction pocket was found in twenty-one cases (37.5%), and at the second-look operation twelve of these were proven to be a manifest recurrent cholesteatoma. The formation of new retraction pockets was found to be time-dependent, that is, to increase almost linearly during the control interval between the operations. The investigation shows the necessity for standardizing the presentation of results after cholesteatoma operations and the importance of determining a convenient postoperative time for reporting the incidence of cholesteatoma recurrences.

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Supported by funds from the House Ear Institute, Los Angeles, an affiliate of the University of Southern California School of Medicine

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID

ISSN:0192-9763    

出版商:OVID    

年代:1986

数据来源: OVID