Dental hygienists held about 167,000 jobs in 2006. Because multiple job
holding is common in this field, the number of jobs exceeds the number of
hygienists. Almost all jobs for dental hygienists were in offices of
dentists. A very small number worked for employment services, offices of
physicians, or other industries.
Source: Bureau of Labor Statistics, U.S. Department of Labor, Occupational Outlook Handbook, 2008-09 Edition