Once the braces are removed and the teeth/bite has been aligned, the patient will normally move into the retention phase of treatment. Retention is defined as that period of time where the braces have been removed and the teeth are still relatively unstable. The ligament fibre attachments from the roots of the teeth to the bone surrounding the teeth have been stretched and moved during the braces. These fibres have a tendency to pull the teeth back into the position they were in prior to treatment. Over time, the fibres will reorganize, and the teeth will become stable. It is during this reorganization time that permanent and removable retainer appliances are recommended to maintain the alignment of the teeth until they are stable.
Retainers are usually fitted within a week of the braces being removed. This time is needed for the lab to fabricate the retainers. Tooth movement is usually insignificant during this time period. If there is tooth movement, the retainer will provide a means to re-establish the alignment. A time period longer than a week runs an increased risk of additional tooth movement in some patients. The amount of movement will vary from patient to patient, and also depends on the original position of the teeth. If the teeth have shifted significantly, the retainers may not fit properly. It is therefore important to see the orthodontist within that one week time period.
When the braces have been removed, an impression or scan is taken of the teeth with alginate, similar to what was done at the records appointment for the plaster models. The retainers are then custom-made for each individual patient by the lab. When retainers are given to the patient, the orthodontist may need to perform some adjustment of the plastic or wires to make sure it has a proper fit. The retainers are designed to retain, and are therefore generally passive appliances. Normally retainers are not made to move the teeth, but to hold the teeth in their current positions (although some tooth movement can be done with retainers on a limited basis). It is not uncommon for a patient to feel some tightness, and later, soreness as a result of the retainers when first worn. This may be due to slight amounts of tooth movement since the braces were removed. If this occurs, the retainers should be worn more or even full-time until the fit improves.
Full time wear of the retainers is usually recommended initially for most patients, and then night wear following braces removal. Since every patient will have differing amounts of post-treatment tooth movement, this recommendation may be more or less than what is required for most patients. Wear of retainers needs to continue for as long as you want to guarantee straight teeth.
Only if the retainers are fitting well, will the teeth remain straight. It is important that if you lose or break the retainers, or feel that there is a problem that you come straight in to have them checked or replaced. It is your responsibility to maintain retainers. There is a treatment fee to replace lost, broken or damaged retainers, or retainers that have lost their fit.