Orthodontics

# Overview
Orthodontics is a specialty of dentistry that is concerned with the study and treatment of malocclusions (improper bites), which may be a result of tooth irregularity, disproportionate jaw relationships, or both. The word comes from the Greek words ortho meaning straight and odons meaning tooth.
Orthodontic treatment can focus on dental displacement only, or can deal with the control and modification of facial growth. In the latter case it is better defined as "dentofacial orthopedics".
Orthodontic treatment can be carried out for purely aesthetic reasonsimproving the general appearance of patients' teeth and face for cosmetic reasonsbut treatment is often prescribed for practical reasons, providing the patient with a functionally improved bite (occlusion).
The father of orthodontics is Dr. E. H. Angle.

# Methods
If the main goal of the treatment is the dental displacement, most commonly a fixed multibracket therapy is used. In this case orthodontic wires are inserted into dental braces, which can be made from stainless steel or a more esthetic ceramic material.
Also removable appliances, or "plates", headgear, expansion appliances, and many other devices can be used to move teeth. Functional and orthopaedics appliances are used in growing patients (age 5 to 13) with the aim to modify the jaw dimensions and relationship if these are altered. (See Prognathism.) This therapy is frequently followed by a fixed multibracket therapy to align the teeth and refine the occlusion.
After a course of active orthodontic treatment, patients will often wear retainers, which will maintain the teeth in their improved position while the surrounding bone reforms around them. The retainers are generally worn full-time for a short period, perhaps 6 months to a year, and then worn periodically (typically nightly during sleep) for as long as the orthodontist recommends. It is possible for the teeth to stay aligned without regular retainer wear. However, there are many reasons teeth will crowd as a person ages; thus there is no guarantee that teeth, orthodontically treated or otherwise, will stay aligned without retention. For this reason, many orthodontists recommend periodic retainer wear for many years (or indefinitely) after orthodontic treatment.
Appropriately trained doctors align the teeth with respect to the surrounding soft tissues, with or without movement of the underlying bones, which can be moved either through growth modification in children or jaw surgery (orthognathic surgery) in adults.
Several appliances are utilized for growth modification; including functional appliances, Headgear and Facemasks.
These "orthopedic appliances" may influence the development of an adolescent's profile and give an improved aesthetic and functional result.

# Conditions
The most common condition that the methods of orthodontics are used for is correcting anteroposterior discrepancies. Another common situation leading to orthodontic treatment is crowding of the teeth.

## Anteroposterior discrepancies
Anteroposterior discrepancies are deviations between the teeth of the upper and lower jaw in the anteroposterior direction. For instance, the top teeth can be too far forward relative to the lower teeth ("increased overjet".) The headgear is attached to the braces via metal hooks or a facebow and is anchored from the back of the head or neck with straps or a head-cap. Elastic bands are typically then used to apply pressure to the bow or hooks. Its purpose is to slow-down or stop the upper jaw from growing, hence preventing or correcting an overjet. For more details and photographs, see Headgear - Orthodontic.

## Crowding of teeth
Another common situation leading to orthodontic treatment is crowding of the teeth. In this situation, there is insufficient room for the normal complement of adult teeth, which can sometimes motivate tooth extraction|teeth being extracted in order to make enough room for the remaining teeth.

# Diagnosis and treatment planning
In diagnosis and treatment planning, the orthodontist must
- recognize the various characteristics of malocclusion and dentofacial deformity;
- define the nature of the problem, including the etiology if possible; and
- design a treatment strategy based on the specific needs and desires of the individual.
- present the treatment strategy to the patient in such a way that the patient fully understands the ramifications of his/her decision. 

# Image Gallery
- Hawley retainers are the most common type of retainers. This picture shows retainers for the top and bottom of the mouth.
- Dental braces, with a powerchain, removed after completion of treatment.
- Headgear & J-hooks for connection into the patients mouth.
- Unilateral Posterior Crossbite
- Crossbite
- Crossbite
- Crossbite  (Image courtesy of Berna Zorkun DMD and copylefted)
- Crossbite  (Image courtesy of Berna Zorkun DMD and copylefted)
- Crossbite  (Image courtesy of Berna Zorkun DMD and copylefted)
- Crossbite  (Image courtesy of Berna Zorkun DMD and copylefted)
- Crossbite  (Image courtesy of Berna Zorkun DMD and copylefted)
- Unilateral cross bite where the maxillary molar is lingual (towards the tongue) than the occluding mandibular molar.
- A cantilever is used to obtain the buccal displacement of tooth 1.4 which is in cross bite.
- Cantilever attached to a power arm . The power arm is applied on the lateral incisor bracket, whereby the force, delivered by the cantilever, generates a M/F ratio at the bracket equal to the length of the power arm (if this is perpendicular to the line of action of the force).
- TwoComposite Cantilevers. Two cantilevers made out of beta titanium 0.018" are welded to a beta titanium transpalatal arch.
- Palatal expander
- Rapid palatal expander
- Rapid palatal expander
- Rapid palatal expander
- 10-year-old boy with false maxillary prognathism
- Alveolar prognathism, caused by thumb sucking and tongue thrusting in a 7 yr old girl.
- Facemask or reverse-pull headgear with straps hooks for connection of elastic bands into the patients mouth, typically worn 12 to 22 hours a day depending on treatment plan.
- Essix retainer in the foreground (used on upper); illustration of an early Hawley retainer in the background.
- The bottom (as worn) of an upper Hawley retainer resting on top of a retainer case.

# Training
Various countries have their own systems for training and registering specialist orthodontists; generally a period of full-time post-graduate study is required for a dentist to qualify as an orthodontist. The orthodontic specialty is the earliest dental specialty.

## Europe
In the United Kingdom, this training period lasts three years, after completion of a membership from a Royal College. A further two years is then completed to train to consultant level, after which a fellowship examination from the Royal College is sat. In other parts of Europe, a similar pattern is followed. It is always worth contacting the professional body responsible for registering orthodontists to ensure that the orthodontist you wish to consult is a recognized specialist.

## United States
A number of medical and dental schools in the United States offer advanced education in the specialty of Orthodontics to dentists seeking postgraduate education. The courses range from two to three years of full-time classes and clinical work in the clinical and theoretical aspects of orthodontics. Generally, admission is based on an application process followed by an extensive interviewing process by the institution, in order to select the best candidate. Candidates usually have to contact the individual school directly for the application process. A list of orthodontic schools can be obtained from the American Association of Orthodontists.