Orthodontics for children

The Canadian Association of Orthodontics recommends an orthodontic evaluation by the age of 7. Some conditions can benefit from an examination even earlier at the age of 5 or 6 years old. At 7 years of age, the child has a mix of baby and adult teeth. Orthodontists are trained to spot subtle problems with jaw growth and emerging teeth while some baby teeth are still present. The advantage for patients of early detection of orthodontic problems is that some problems may be easier to correct if they are found and treated early. Waiting until all the permanent teeth have come in, or until facial growth is nearly complete, may make correction of some problems more difficult. These conditions include, but are not limited to, certain jaw relationship problems, tooth eruption problems, supernumary teeth (extra teeth), premature loss of baby teeth, correction of bad habits (thumb or finger sucking or tongue thrusting), dental protrusion (teeth sticking out), severe dental crowding or excessive spaces between the teeth. Most of these conditions are recognizable by the dentist (who may refer the patient to an orthodontist) or even parents. But some of these conditions are more difficult to detect and necessitate the expertise of an orthodontist. The duration of early treatment usually varies from 6 to 24 months. This first phase of treatment must often be followed by a second phase, usually during the adolescence, once all the permanent teeth have erupted, to obtain an ideal occlusion.

Examples of problems requiring preventive or interceptive treatment in the mixed dentition

Upper jaw too narrow (posterior crossbite)
When the upper jaw is too narrow, the upper posterior teeth will be positioned inside of the lower teeth, the opposite of a normal relationship. This problem can present itself on one side or both sides and may be associated with a shift of the lower jaw. This problem can easily and predictably be corrected at an early age with an appliance to widen the upper jaw. This appliance can be either removable or fixed. The correction usually requires about 9 months of treatment and is followed by a retention period with a removable appliance to maintain the achieved correction.

Bad habit (digit sucking or tongue thrust)
Thumb sucking is usually not harmful at a young age. But if it persists and is left unadressed, especially when the adult teeth start to erupt (age 6-7), it can have detrimental effects on the position of the teeth and growth of the jaws. Children with a thumb sucking habit often present with a narrow palate (resulting from the pressure of the digit), protruding upper teeth and open spaces between the upper and the lower front teeth. A similar clinical presentation is observed in patients with a tongue thrusting habit (seen when the tongue pushes the front teeth during swallowing and at rest). A fixed appliance anchored to the upper teeth, worn for a period of 6 to 12 months, is very effective in eliminating the habit.

Protruded upper teeth
Studies have demonstrated a correlation between how far the upper front teeth stick out (protrusion) and the risk of dental trauma. Occasionally, the problem is so severe that the child cannot close his or her lips at rest, and the lower lip is blocked behind the upper teeth. This condition can be the result of a problem with the position of the teeth only, the position of the jaws (the upper jaw being too far forward in relation to the lower jaw or the opposite) or a combination of the two. An interceptive treatment aiming at the correction of the jaw or teeth at fault is recommended using a removable functional appliance and/or a few braces on the upper teeth. The duration of treatment depends on the severity of the condition and usually takes between 12 and 24 months to complete.

Lower teeth positioned too far forward in relation to the upper teeth (anterior crossbite)
Upper front teeth can occasionally be positioned behind the lower front teeth when the patient bites down. This condition can also be the result of either a problem limited to the position of the teeth only, the relationship of the jaws or a combination of both. Treatment will vary based on the diagnosis from the use of a few braces or a simple removable appliance in the case of tooth-related problems, to an orthopedic traction appliance (face-mask) for correction of discrepancies in the position of the jaws. Severe jaw-related problems are best treated with a combination of orthodontic treatment and orthognathic surgery (jaw surgery) once growth is completed.

Ectopically erupting teeth (teeth erupting in the wrong place)
Permanent teeth can erupt in the wrong place or direction, or become blocked behind baby teeth. If the situation is not addressed immediately, the baby tooth may be loss prematurely resulting in a lack of space for the eruption of the permanent tooth. In selected situations, early removal of a baby tooth can help redirect the eruption of the adult tooth replacing it.

Space maintainer following the early loss of a primary tooth
The early loss of a primary (baby) tooth, usually as a result of extensive decay, can lead to the adjacent teeth drifting into the space and blocking the eruption of the permanent tooth underneath. A fixed appliance to hold the space and prevent the drifting of the adjacent teeth is sometimes required. The appliance is left in place until the permanent tooth erupts.

Extraction of a primary tooth/teeth to allow eruption of permanent teeth when there is a lack of space
Some patients have severe lack of space in the mixed dentition. When certain criterias are met, the selective extraction of primary teeth and, occasionally, of some permanent teeth at very specific times in the child's dental development, may be recommended. As with most early interventions, this will be followed by full braces during adolescence.