Teeth alignment is maintained using retainers.
There are 2 types of retainers:
1. Fixed retainers
Fixed retainers are small lengths of wire glued to the back of the upper and lower front teeth separately to prevent them from moving.
These can be custom made (for better access for cleaning) or made directly in the mouth. Fixed retainers are meant to stay on the teeth as long as the patient desires straight teeth. Fixed retainers should be inspected regularly for signs of damage.
Issues with fixed retainers include fracture of the wire itself or fracture of the glue that holds the retainer on to the tooth surface. Retainer fractures tend to happen when a patient bites into something hard (like a nut) that gets wedged between the retainer wire and the tooth.
When a fixed retainer is damaged, it may need to be repaired or replaced. This should be done as soon as possible to prevent the unretained tooth from moving from its position.
2. Removable retainers
Removable retainers can be made out of clear plastic that covers all the teeth (Essix style) or with a wire loop and plastic backing (Hawley style). These are usually worn at night and the patient removes them during the day.
Removable retainers can be combined with fixed retainers for extra security. Removable retainers depend greatly on patient cooperation and compliance for success. Most patients stop wearing removable retainers within a year of completing orthodontic treatment due to a variety of reasons (forgetting to wear it, losing the retainer etc).
If no fixed retainer has been provided to complement the removable retainer, then relapse (where the teeth start to move) will occur. Removable retainers can also be used as bite guards for patients who grind their teeth in their sleep.
