Table 3.

The association of type of oral health professional and demographic/environmental variables with NIHL

	Studies assessing the risk variablea (n)	Direct association with hearing loss, n (%)	No association with hearing loss, n (%)
Type of oral health professional
Dentist	11	9 (82)	2 (18)
Dental specialists	5	5 (100)	0 (0)
Dental assistants	4	2 (50)	2 (50)
Demographic and environmental variables
Difference between ears	14	10 (71)	4 (29)
Years of clinical experience	11	9 (82)	2 (18)
Age	8	6 (75)	2 (25)
Gender	5	1 (20) (males)	4 (80)
Hours of exposure per day	4	1 (25)	3 (75)

^aCalculations were only performed if four or more of the included studies (n = 17) reported on the variable.