Orthodontics is a branch of dentistry that specializes in treating patients with improper positioning of teeth when the mouth is closed (malocclusion), which results in an improper bite.

Orthodontics also includes treating and controlling various aspects of facial growth (dentofacial orthopedics) and the shape and development of the jaw. An orthodontics specialist is called an orthodontist.

Orthodontics used to be called orthodontia - the word comes from the Greek orthos, meaning "straight, perfect or proper", and dontos, which means "teeth".

Orthodontics also includes cosmetic dentistry; when the patient's aim is to improve his/her appearance.

An orthodontist uses a range of medical dental devices, including headgears, plates, braces, etc. to help in:

Closing wide gaps between the teeth
Making sure the tips of the teeth are aligned
Straightening crooked teeth
To improve speech or eating (oral function)
To improve the long-term health of gums and teeth
To prevent long-term excessive wear or trauma (of the teeth)
Treating an improper bite.