Bracket - an orthodontic appliance made of metal or ceramic that can be cemented to the tooth surface for holding orthodontic wires

Crowding - is the most common problem in orthodontics caused by insufficient space

Invisalign - a newly developed technique using a series of plastic trays to move the teeth.  The trays are manufacutred according to the computerized predicted teeth position.

Functional appliances - orthodontic devices (either fixed or removable) designed to correct mismatch of the jaw position by modifying the growth.  Work more favorably on growing patients.

Mandible, mandibular - lower jaw

Maxilla, maxillary - upper jaw

Occlusion - refers to the normal spatial relationship of the teeth when the jaws are closed

Overbite - refers to the amount of vertcial overlap between the upper and lower incisors

Overjet - refers to the horizontal distance between the upper and lower incisors

Prognathia, prognathic - protruding jaw bone

Protrusion, dental/skeletal - when teeth or jaws protrude outward

Retainer - a device that is used for keeping the teeth in position

Retention - a process that allows teeth to settle into a stable position after orthodontic treatment

Retrognathia, retrognathic - underdevelopment of jaw bone making it look recessive

Spacing - is due to a tooth-to-jaw size disharmony causing an excess space between teeth

Twin block - a pair of retainers worn on upper and lower arches, used for correcting the jaw discrepancy