Difference between Dental Therapy and Dental Hygiene:
Dental therapists can only perform procedures on 4-17 year old. Basically carry out all procedures dentists can except for invasive treatments. E.g. charting and examinations, local anaesthetics, extractions of primary teeth, cavity prepping for primary and permanent teeth.
Dental hygienists can work on people of all ages and can track signs of periodontal disease, perform prophylaxis, remove sutures and perio-packs and perform orthodontic needs, along with many other tasks.