Orthodontics is a branch of dentistry dealing with the relationship of teeth to each other, how they form the dental arch, how they bite together and their appearance.
Adult teeth start forming soon after birth; they grow and erupt into the mouth to replace the primary or milk teeth from the age of about six years onwards. During growth a number of developmental conditions may cause problems; if the teeth do not fit and align together correctly when the jaws are closed, the result is called malocclusion. In European countries the most common cause of malocclusion is overcrowding. Overcrowding occurs when there is an abnormal tooth arch size (such as large teeth in a small jaw). The usual treatment involves extraction and, if carried out at timely intervals, can produce good results. The most commonly extracted teeth are the premolars. Sometimes overcrowding causes poorly aligned or crooked teeth which have to be corrected by orthodontic braces. These can be removable or fixed. Removable braces have the wires and springs attached to an acrylic plate which is clipped into the mouth each morning and removed at night. Fixed braces are bonded with brackets directly to the teeth. These can provide more accurate and individual tooth movements than a removable brace. Orthodontic appliances are normally worn between 8 and 16 years of age, when growth is rapid and lateral pressure on a tooth can move it slowly through the relatively soft jawbone. Appliances must be regularly checked (about every three weeks) to ensure the desired movements are being achieved and to allow adjustments to be made. The average treatment period is around 18 months, and afterwards retaining braces may be advised in some cases to minimize relapse of the teeth position. After a brace has been fitted there may be an initial few days of discomfort; this may recur when the brace is adjusted or tightened. Small ulcerations may appear if the wires rub on the tissues. Meticulous attention must be paid to oral hygiene to prevent plaque and food accumulating around the brace and teeth.
Parents often think of orthodontic braces and other appliances as presenting an enormous problem to their children. In fact, children are usually more adaptable than adults and after an initial period of self-consciousness most cope exceedingly well with orthodontic treatment.
Malalignment of the jawbones can result in pronounced facial deformity. A classic example is the prognathism (protruding lower jaw) of the Hapsburg family. Mild skeletal abnormalities can be corrected using removable appliances which push on and guide the developing skeleton into a new shape. They are very successful in treating a retrognathic (receeding) lower jaw, and their use is timed to coincide with developmental growth spurts. Severe skeletal abnormalities usually need to be corrected surgically. Unlike routine orthodontic treatment, surgery begins after the final growth phase at about 18 years of age. Under a general anaesthetic, the lower jaw can be carefully fractured and realigned into a new, more desirable position. The bones are held by wires and pinned until they are healed. Following surgical correction, feeding is carried out through a straw using liquid foods until the splints can be finally removed.
This type of orthodontic correction requires great co-operation between the patient, oral surgeon and orthodontist.
There has never been more dental research conducted than at the present time. The enormous advances in knowledge made in the last thirty years or so are likely to be build upon with just as spectacular results in the next thirty years. Areas of study include better methods of preventing decay and periodontal disease, new materials for crowns and fillings and more rifined dental and surgical techniques. Future dentistry may involve coating the teeth with a special substance that is impervious to decay or perhaps introducing an anti-decay agent into the mouth. The completely pain-free administration of local anaesthetic is another possibility, and a routine visit to the dentist may entail absolutely no anxiety or apprehension on the part of the patient. What is certain, however, is that because people are keeping their teeth for longer as a result of improved dental practice and education in oral hygiene, they will continue to demand a dental service that will help them preserve their teeth in the best possible condition.