An orthodontic device is a type of dental appliance used to correct misaligned teeth and jaws. A spacer, which is a 6-letter word, is a type of orthodontic device that is used to create space between teeth in order to make room for other orthodontic appliances. A RETAINER, which is an 8-letter word, is another type of orthodontic device that is used to hold teeth in place after braces have been removed.