Hearing Difficulties Among Experienced Dental Hygienists: A Survey

Assess prevalence of self-reported hearing difficulties among experienced dental hygienists who have been practicing for a minimum of 20 years and explore the relationship between hearing difficulties and occupational noise exposure from ultrasonic scalers.

A 19-item survey was mailed to a random sample of 1,067 dental hygienists who had obtained their California licenses between 1972 and 1992. To estimate the prevalence of hearing difficulty, binomial proportion and associated 95% confidence interval are presented. Logistic regression model of hearing difficulty was used to assess an association with ultrasonic scaler use.

Response rate was 35% (n=372/1,067). The prevalence of self-reported hearing difficulty was 40% (95% confidence interval, 35 to 44%). Of the 17% (95% confidence interval, 14 to 21%) of respondents that reported hearing difficulty due to ultrasonic scalers, most (91%) reported that their hearing difficulty was confirmed by an audiologist. Respondents with hearing difficulty due to scalers were 2-times (odds ratio: 2.0, 95% confidence interval, 1.1 to 3.6, p=0.03) more likely to report significantly higher scaler use than those who did not have hearing difficulty after adjusting for age and other potential causes of hearing difficulties.

The prevalence of hearing difficulty at 40% among dental hygienists with an average age of 56 years was considerably higher than the reported national average at 17% for adults 70 years or older. Long-term noise exposure to dental equipment, such as ultrasonic scalers, may contribute to hearing difficulties among experienced dental hygienists. Ear protection is suggested as a preventive measure while using noisy dental equipment.