Proposal #00-08

"The Effects of Occupational Ultrasonic Noise Exposure on Hearing Deficits in Dental Hygienists"

The purpose of this case-control study is to determine whether long term ultrasonic noise exposure via the dental office environment has an effect on dental hygienists' hearing status. The sample will consist of 30 dental hygienists who have a high frequency of ultrasonic use and a matched group of 30 dental hygienists who have a low frequency of ultrasonic use. Registered dental hygienists who live in the Hampton Roads area will be mailed a Dental Hygiene Work History Questionnaire to determine those meeting the inclusion criteria and willing to participate in the study. Consenting subjects will be categorized according to employment history into one of two groups, and matched on age and familial hearing loss problems. Once the groups are formed, their hearing status will be measured by a certified audiologist via a standard audiometer. Audiometric data will be analyzed using the Wilcoxin MatchedPairs Sign Rank and a multicorrelational procedure to determine if longevity and frequency of ultrasonic noise exposure in the dental office environment is significantly related to hearing status in dental hygienists. Hypotheses will be tested at the .05 level of significance.