Orthodontics
Orthodontics is a specialty of dentistry that deals with the diagnosis, prevention and correction of malpositioned teeth and jaws. It can also focus on modifying facial growth, known as dentofacial orthopedics.
Abnormal alignment of the teeth and jaws is common. Nearly 50% of the population, according to the American Association of Orthodontics, has malocclusions severe enough to benefit from orthodontic treatment.: although this figure decreases to less than 10% according to the same AAO statement when referring to medically necessary orthodontics. There is a lack of strong scientific evidence for the health benefits of orthodontic treatment - the fact the academic journals and professional associations in the field of orthodontics were slow to admit. Treatment can take several months to a few years, it involves the use of dental braces and other appliances to slowly move the teeth and jaws around. If the malocclusion is very severe, jaw surgery may be used. Treatment is usually started before a person reaches adulthood since bones can more easily be moved around in children.
History
Orthodontics as a modern science dates back to the mid 1800s. Influential contributors to the field include Norman William Kingsley and Edward Angle. Angle created the first simple system for classifying malocclusions, a system which is still used today.Until the mid 1970s, braces were made by wrapping metal around each tooth. With advancements in adhesives it became possible to bond metal brackets to the teeth instead.
Methods
A typical treatment for incorrectly positioned teeth takes about 1 to 3 years to complete, with braces being altered slightly every 4 to 10 weeks by the specialists called orthodontists. Orthodontists are dental specialists who are University-trained in the prevention, diagnosis and treatment of dental and facial irregularities. They provide a wide range of treatment options to straighten crooked teeth, fix bad bites and align the jaws correctly. Multiple methods exist for adjusting malocclusion. In growing patients there are more options for treating skeletal discrepancies, either promoting or restricting growth using functional appliances, orthodontic headgear or a reverse pull facemask. Most orthodontic work is started during the early permanent dentition stage before skeletal growth is completed. If skeletal growth has completed, jaw surgery can be an option. Sometimes teeth are extracted to aid the orthodontic treatment.Orthodontic therapy can include the use of fixed or removable appliances. The majority of orthodontic therapy is delivered using appliances that are fixed in place, for example with braces that are bonded to the teeth with adhesives. Fixed appliances can have a greater mechanical control of the teeth and the treatment outcome is greater with the use of fixed appliances.
Fixed appliances are, for example, used to rotate teeth that don't fit the arch shape of the other teeth, to move multiple teeth to different places, to change the angle of teeth, or to change the position of the root of the tooth. It is not preferable if the patient has poor oral hygiene, if the patient isn't motivated, or if the malocclusions are mild.
Braces
are usually placed on the front side of the teeth, but may also be placed on the side facing the tongue. Brackets made out of stainless steel or porcelain are bonded to the center of the teeth using an adhesive. Wires are placed in a slot in the brackets which allows for controlled movement in all three dimensions.Apart from wires, forces can be applied using elastic bands, and springs may be used to push teeth apart or to close a gap. Several teeth may be tied together with ligatures and different kinds of hooks can be placed to allow for connecting an elastic band.
Clear aligners are an alternative to braces, but insufficient evidence exists to determine their effectiveness.
Treatment Duration
The time required for braces varies from person to person, depending on the severity of the problem; the amount of room available; the distance the teeth must travel; the health of the teeth, gums, and supporting bone; and how closely the patient follows instructions. On average, however, once the braces are put on, they usually remain in place for one to three years. After braces are removed, most patients will need to wear a retainer all the time for the first six months, then only during sleep for many years.Headgear
Orthodontic headgear—sometimes referred to as an "extra-oral appliance"—is a treatment approach that requires the patient to have a device strapped onto his or her head to help correct malocclusion—typically used when the teeth do not align properly. Headgear is most often used along with braces or other orthodontic appliances. While braces correct the position of teeth, orthodontic headgear—which as the name suggests is worn on or is strapped onto the patient's head—is most often added to orthodontic treatment to help alter the alignment of the jaw, although there are some situations in which such an appliance can help move teeth, particularly molars.Whatever the purpose, orthodontic headgear works by exerting tension on the braces via hooks, a facebow, coils, elastic bands, metal orthodontic bands, and other attachable appliances directly into the patient's mouth. It is most effective for children and teenagers because their jaws are still developing and can be easily manipulated. Thus Headgear is typically used to treat a number of jaw alignment or bite problems such as overbite and underbite.
Palatal expansion
can be achieved using either fixed or removable appliances.Jaw surgery
may be required to fix severe malocclusions. The bone is broken during surgery and is stabilised with titanium plates and screws to allow for healing to take place. After surgery, regular orthodontic treatment is used to move the teeth into their final position.During treatment
To reduce pain during the orthodontic treatment, low level laser therapy, vibratory devices, chewing adjuncts, brainwave musics or cognitive behavioral therapy can be used. However, the supporting evidence is of low quality and the results are inconclusive.Post treatment
After orthodontic treatment has completed, there is a tendency for teeth to return, or relapse, back to their pre-treatment positions. Over 50% of patients have some reversion to pre-treatment positions within 10 years following treatment. To prevent relapse, the majority of patients will be offered a retainer once treatment has completed, and will benefit from wearing their retainers. Retainers can be either fixed or removable.Removable retainers
Removable retainers are made from a clear plastic, and they are custom-fitted for the patient's mouth. It has a tight fit and holds all of the teeth in position. There are many types of brands for clear retainers including, Zendura Retainer, Essix Retainer and Vivera Retainer. Hawley retainer is also a removable orthodontic appliance made from a combination of plastic and metal that is molded custom to fit the patient's mouth. Removable retainers will be worn for different periods of time depending on patient need to stabilise the dentition.Fixed retainers
Fixed retainers are a simple wire fixed to the tongue-facing part of the incisors using dental adhesive and can be specifically useful to prevent rotation in incisors. Other types of fixed retainers can include labial or lingual braces, with brackets fixed to the teeth.Training
There are several speciality areas in dentistry, but the speciality of orthodontics was the first to be recognized within dentistry. Specifically, the American Dental Association recognized orthodontics as a speciality in the 1950s. Each country has their own system for training and registering orthodontic specialists.Canada
In Canada, obtaining a dental degree, such as a Doctor of Dental Surgery or Doctor of Medical Dentistry, would be required before being accepted by a school for orthodontic training. Currently, there are 10 schools in the country offering the orthodontic specialty. Candidates should contact the individual school directly to obtain the most recent pre-requisites before entry. The Canadian Dental Association expects orthodontists to complete at least two years of post-doctoral, specialty training in orthodontics in an accredited program, after graduating from their dental degree.United States
Similar to Canada, there are several colleges and universities in the United States that offer orthodontic programs. Every school has a different enrollment process, but every applicant is required to have graduated with a DDS or DMD from an accredited dental school. Entrance into an accredited orthodontics program is extremely competitive, and begins by passing a national or state licensing exam.The program generally lasts for two to three years, and by the final year, graduates are to complete the written American Board of Orthodontics exam. This exam is also broken down into two components: a written exam and a clinical exam. The written exam is a comprehensive exam that tests for the applicant's knowledge of basic sciences and clinical concepts. The clinical exam, however, consists of a Board Case Oral Examination, a Case Report Examination, and a Case Report Oral Examination. Once certified, certification must then be renewed every ten years. Orthodontic programs can award the Master of Science degree, Doctor of Science degree, or Doctor of Philosophy degree depending on the school and individual research requirements.