retainer, consideration (noun)
a fee charged in advance to retain the services of someone
servant, retainer (noun)
a person working in the service of another (especially in the household)
a dental appliance that holds teeth (or a prosthesis) in position after orthodontic treatment
A dependent or follower of someone of rank.
A paid servant, especially one who has been employed for many years.
Any thing or person that retains.
A fee one pays to reserve the other's time for services.
A device that holds teeth in position after orthodontic treatment.
Orthodontic retainers are custom-made devices, made usually of wires or clear plastic, that hold teeth in position after surgery or any method of realigning teeth. They are most often used before or after dental braces to hold teeth in position while assisting the adjustment of the surrounding gums to changes in the bone. Most patients are required to wear their retainer every night at first, with many also being directed to wear them during the day - at least initially. There are four types of retainers typically prescribed by orthodontists and dentists: Hawley, Essix, Zendura, and Bonded retainers.