Orthodontic treatment is a way of straightening or moving teeth, to improve the appearance of the teeth and how they work. It can also help to look after the long-term health of your teeth, gums and jaw joints, by spreading the biting pressure over all your teeth. The role of an orthodontic therapist includes: fitting orthodontic headgear, facebows, tooth separators and bonded retainers. taking impressions. placing brackets and bands on teeth. giving advice on appliance care.