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 reasons—improving the general appearance of patients’ teeth and face for cosmetic reasons—but treatment is often prescribed for practical reasons, providing the patient with a functionally improved bite (occlusion).
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.
Dental braces, with a powerchain, removed after completion of treatment.
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. 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 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.
One of the most common situations 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 result in teeth being extracted. Crowding of teeth is recognized as an affliction that stems in part from a modern western lifestyle. We do not know for sure whether it is due to the consistency of western diets; a result of mouthbreathing; or the result of an early loss of deciduous (milk, baby) teeth due to decay. It is also possible that Homo sapiens have evolved smaller jaws without a reduction in the number of teeth they will house happening at the same time. Orthodontics is not always for aesthetic purposes. Braces may be prescribed in cases of so-called “overbite” to help prevent teeth being knocked out in an accident, for example, hockey or skating.
Much has been made in the media of links between tooth extraction and temporo-mandibular joint dysfunction (problems, including clicking and jamming, of the jaw joint). No research has shown a definitive link between orthodontic treatment, extraction of teeth and jaw joint problems. Most temporo-mandibular joint problems are multifactorial in origin (that is having a number of possible etiologic agents).
Diagnosis and treatment planning
In diagnosis and treatment planning, the orthodontist must (1) recognize the various characteristics of malocclusion and dentofacial deformity; (2) define the nature of the problem, including the etiology if possible; and (3) design a treatment strategy based on the specific needs and desires of the individual. (4) present the treatment strategy to the patient in such a way that the patient fully understands the ramifications of his/her decision.
[References: T. M. Graber, R.L. Vanarsdall, Orthodontics, Current Principles and Techniques, “Diagnosis and Treatment Planning in Orthodontics”, D. M. Sarver, W.R. Proffit, J. L. Ackerman, Mosby, 2000]