Baby teeth (dentists call them primary or deciduous teeth) aren't just for chewing. Each one also acts as a guide for the permanent tooth that replaces it. If a primary tooth is lost too early, the permanent tooth loses its guide and can drift or erupt at an angle. Neighboring teeth also can move or tilt into the space so the permanent tooth can't come in.
Primary teeth can be lost prematurely in several ways:
- They can be knocked out in a fall or other accident.
- Extensive decay can require that a primary tooth be extracted.
- Primary teeth can be missing at birth.
- Some diseases or conditions, including hypophosphatasia (an inherited bone disease), diabetes and aggressive periodontitis (gum disease), which is unusual in children, can contribute to early tooth loss.
If your child loses a primary tooth before the permanent tooth is ready to come in, or if the permanent tooth is missing, your dentist may decide to use a space maintainer. The maintainer keeps the space open until the permanent tooth comes in.
A space maintainer is a small appliance made of metal or plastic. It can be removable, or your dentist can cement it in your child's mouth.
A removable space maintainer looks like a retainer or a flipper partial denture. It uses artificial teeth to fill in the space or spaces that need to be maintained. This type of space maintainer often is used for cosmetic reasons when the space is obvious to other people. Removable space maintainers work well in older children who can reliably follow directions about caring for this appliance.
There are several kinds of fixed space maintainers. A band-and-loop maintainer is made of stainless steel wire. The maintainer is held in place by an orthodontic-type band around an adjacent tooth or a crown on the tooth. A wire loop attached to the band or crown extends into the space and touches the tooth on the other side of the space to hold both teeth in place.
A lower lingual holding arch is used when teeth are lost on both sides of the lower jaw. Lingual refers to the inside or tongue side of the teeth. This type of space maintainer also uses bands wrapped around a tooth on either side of the mouth behind the missing teeth. A wire connected to the bands runs along the inside of the bottom teeth. It distributes the biting and chewing forces throughout the entire jaw, which makes a lower lingual holding arch more stable than two separate band-and-loop maintainers.
Another type of fixed space maintainer, called a distal shoe appliance, is inserted under the gum. It's used when a primary tooth is lost but there is no tooth behind it for the wire arm of a band-and-loop maintainer to touch. In this case, the end of the metal arm is inserted under the gum instead, and keeps the space from closing.
Distal shoe appliances are difficult to construct and often don't work the way they should. The incoming tooth can easily become stuck in the jawbone, or get pushed aside and come in crooked. As a result, most dentists will try to keep the primary tooth in the mouth until the permanent tooth underneath is ready to come in.
Children missing several teeth can have a partial denture made instead of a space maintainer. For example, children with ectodermal dysplasia (a congenital disease) often are missing multiple primary teeth, and there are no permanent teeth to replace them. A child with this condition will use a removable denture until his or her jaw stops growing. After that, the child can receive dental implants or a bridge, or continue to use a partial denture.
Not every tooth that is lost too early requires a space maintainer. If one of the four upper front teeth is lost early, the space will be maintained on its own until the permanent tooth comes in.
If you do not take your child to the dentist regularly - at least every six months - putting in a space maintainer can be detrimental, especially if your child does not brush well. The gum tissue in the space can grow over the wire arm, increasing the risk for infection. If that happens, your dentist may have to remove the gum tissue surgically.
If the permanent tooth is about to erupt, your child's dentist may not place a space maintainer unless space is a critical issue for orthodontic reasons.
Some children may not be able to cooperate during the process of making the space maintainer. Others may be at risk of injury if the space maintainer comes loose or breaks. These include children with diseases that affect how they breathe or swallow, and children who are very young. However, the ability to cooperate with the dentist is more important than a child's age. Young children can receive space maintainers if they are able to cooperate during the process.
Each space maintainer is custom-made by a dentist or orthodontist.
For a fixed space maintainer, a metal band is placed around one of the teeth next to the space, and impressions are made. The band is removed and sent to a dental laboratory with the impressions. The lab creates the space maintainer and sends it back to your dentist, who cements it in place at a second office visit. Sometimes, a space maintainer can be made in the office in a single visit without impressions.
To make a removable space maintainer, impressions are made and sent to a lab, which makes the appliance.
The space maintainer may feel unusual at first, but after a few days, your child probably will forget about it. A removable space maintainer with replacement teeth can affect speech until your child gets used to it.
It's important for your child to brush regularly to keep the gum tissue healthy. If your child has a fixed space maintainer, he or she needs to avoid chewy candy and gum, which can loosen the band or get caught in the wire arm.
Finally, your child shouldn't push on the space maintainer with his or her tongue or fingers because that could bend or loosen it.
Your dentist will follow the progress of the incoming permanent tooth by taking X-rays regularly. When the tooth is ready to erupt, the space maintainer is removed.
If there is no permanent tooth, the space maintainer will be used until your child's growth is completed (age 16 to 18), and then a bridge, implant or removable partial can be placed in the space.