Traditionally, dental hygienists worked in dental offices, clinics or other dental facilities. They examined teeth, took radiographs, and cleaned teeth.
As health care expenses have skyrocketed, there has been a movement to allow dental auxiliaries (including dental hygienenists, expanded-duty dental assistants, and so-called "dental therapists") to have a greater range of duties, either under various degrees of supervision by a licensed dentist, or in some cases independent of licensed dentists.
Understandably this has caused quite an outcry among dentists. But the continued lack of available and affordable dental care has prompted a move to allow a greater range of dental services to be provided by these so-called "mid-level" providers.
The rules governing the scope of dental hygiene practice vary from state to state. An outline of the various regulations concerning some of these expanded functions can be found here:
Hello! I am a Registered Dental Hygienist (RDH) in Detroit Michigan. While I do not practice currently, I work at a Dental School, actually the one I graduated from. If you have the slightest interested in becoming a Dental Hygienist I would first advise you to shadow a Hygienist for a few hours, or even an entire day, if you can. You will see a lot of different ways that an RDH works with their patients, the Dentist, and others in the office. You will get a viewpoint of the profession much better than when you are there for your own dental "cleaning".
To become an RDH (and you must be registered by the state you work in to be a Dental Hygienist!) you can go through Community or Junior College Program or to a four year college or university. I chose to attend a four year university as I wanted a Bachelor's Degree, but you can find the same jobs with a two-year, Associates, degree too! The same jobs are available to both a two year degree school or a four year degree school. The only difference is the degree that you will graduate with, either an Associates or a Bachelor's.
Mandatory pre-requisites are different for every school, but they are generally English (Composition and Literature), Math (Algebra), Psychology, Sociology, Speech, Biology, Microbiology, Chemistry, Nutrition, and Anatomy & Physiology. The DH programs are usually 2 years long and encompass a lot of the items that you have already been listed here, but are taught in relation to the oral cavity. Generally a DH degree will take four years, two years of pre-requisites and two years for the program itself.
I loved working as an RDH, but it can be difficult on the body, and I decided that I couldn't really do the work for very long (not 5 8 hour days a week!), so I now work as the Dental Student Rotation Scheduler for the Dental School that I graduated from with my DH BS degree.
I hope this answers your question!