All children should undergo an orthodontic examination at the age of nine years in order to identify problems of tooth development which can be simply corrected at this early stage. Common problems encountered include:
- Crowding of the incisor teeth
- Narrowness of the upper jaw leading to a poor biting relationship of the molar teeth (a crossbite)
- A reverse incisor bite
- Upper incisor protrusion and digit sucking
- Malposition of the upper canine teeth
- Poor quality first permanent molar teeth
- Missing teeth
Some of these problems can be managed with removable appliance treatment, simple fixed appliances or extractions which can help to greatly simplify later treatment.
Before and after upper removable appliance treatment for crossbite correction.
Fixed appliance treatment is the most precise way to control tooth movement to achieve the perfect smile. There are three main components to such appliances including the brackets (which are attached to the teeth), archwires (the wires placed into the brackets) and auxiliaries such as elastics. The bracket helps to determine the final tooth position. The archwire acts as the motor and places the necessary forces to initiate and sustain tooth movement. The brackets can be made of metal or tooth coloured ceramic materials.
Sometimes dental extractions have to be undertaken by the general dentist before starting fixed appliance treatment if space is required to correct tooth positions. The placement of fixed appliances is pain free and does not involve dental injections. Adjustments are typically undertaken at six weekly intervals. Sometimes breakages can occur and appointments have to scheduled between the main visits. The duration of fixed appliance treatment can vary between 6–18 months depending on the complexity of the case. There is some discomfort for 3–4 days following placement of fixed appliances which can be controlled by mild pain killers (e.g. paracetamol). The risks of fixed appliance treatment include dental decay (if there is excessive sugar within the diet and if tooth brushing is poor) and slight root shortening which is frequently minimal.
The wires used to align teeth are commonly termed 'archwires'. These are made of metal (stainless steel or nickel–titanium) materials. They can be covered with tooth coloured coatings to make them less obvious. However, these coatings do have a tendency to decay between visits and may slow tooth movement.
Self–Ligating Brackets (Damon, In–Ovation C)
Unlike conventional fixed appliances, self–ligating appliances utilise an integral clip mechanism within the bracket in order to secure the archwire. Manufacturers have claimed many advantages to using these mechanisms, however, few of these have been scientifically proven to this day. In our opinion the principal advantages of self–ligation include more secure attachment between the archwire and bracket, less discolouration of appliances in–between visits and greater efficiency in appliance adjustments.
Many types of self–ligating appliances are available but two that have dominated the market include the Damon appliance and the In–Ovation appliance. These differ in having a different clip mechanism to secure the archwire. To date, there is no scientific evidence that one type of appliance is better than the other..
The In–Ovation C Appliance pictured right.
Functional appliances are typically removable appliances that are designed to hold the lower jaw forwards for the correction of upper incisor protrusion in growing patients. The ideal time to use a functional appliance is during the pubertal growth spurt to help take advantage of the normal facial growth that is already occurring.
The Twin Block functional appliance pictured right.
Functional appliances are constructed after taking a dental impression of the teeth and can consist of a single component or an upper and lower component fitting over the teeth. They can produce spectacular results by reducing upper incisor protrusion and work by a number of mechanisms including retraction of the upper incisors, advancement of the lower incisors and a small degree of forward growth of the lower jaw. They are designed to be worn at all times, apart from sleeping, and typically produce the desired result within 9-12 months if compliance is good. Functional appliance treatment will often lead to a correction of the bite and is often followed by a course of fixed appliance treatment to fine tune tooth positions.
Before and after functional appliance treatment. Note the large reduction in upper incisor protrusion.
Invisalign is a virtually invisible was to straighten teeth and improve the smile. It can be used for those conscious about the appearance of fixed appliances where simpler tooth movements are required. Invisalign uses a series of clear removable aligners that gradually move teeth to their desired position. A major advantage of Invisalign, apart from being almost invisible, is that the appliance can be removed for eating, tooth brushing and important social engagements.
Invisalign Teen has all the above advantages but has also been adapted to be used in teenagers with the following modifications:
- It is tailored to young adults whose permanent teeth are still growing and forming
- Free replacement of lost or damaged aligners
- Each aligner also includes a colour indicator which fade the more it is worn. This helps parents to monitor if the aligners are being worn.