dental instruments and oral health

What are Space Maintainers?

Space maintainers are orthodontic appliances that manage premature primary tooth loss. Maintainers also help prevent malocclusions (misalignment of teeth), overcrowding, and other orthodontic conditions. If a child loses a tooth prematurely, space maintainers ensure permanent teeth do not erupt into the empty space. Tooth loss can be due to trauma, disease, overcrowding, or decay.

Early loss of baby teeth can also result in abnormal development of the upper and lower jaws. Monitoring the shedding of the primary teeth and the eruption of permanent teeth, called the “mixed dentition phase,” is crucial since teeth misalignment has a high chance of developing during this process.

Causes for Treatment

Children may need space maintainers if they have over-retained baby teeth, early childhood caries that result in tooth loss, or tooth loss that occurs due to trauma:

tooth with cavity graphic
Early Tooth Loss or Extraction Due to Primary Tooth Decay

Primary teeth easily fall victim to tooth decay, which typically results in extractions. Cavities commonly form on a child’s molars because primary tooth enamel is more fragile than permanent teeth. Even though baby teeth fall out, it is still crucial to take care of them. If one tooth becomes infected and isn’t treated quickly, the cavity-causing bacteria can spread to other teeth. If a child develops a cavity in his or her primary tooth, a dental restoration is necessary to prevent the spread of cavities, early tooth loss, overcrowding, and misalignment. Restorative options for primary teeth include amalgam fillings, composite fillings, or stainless steel crowns. Although, if a tooth must be extracted due to severe decay, space maintainers are placed to prevent misalignment or overcrowding as permanent teeth grow in.

three teeth with one being extracted graphic
Over-Retained Baby Teeth

Space maintainers also prevent orthodontic issues associated with over-retained baby teeth. Over-retained teeth refer to baby teeth that have loosened but then tighten back into the gums, preventing the eruption of permanent teeth. If the primary teeth are not extracted, dental crowding commonly develops, which is a condition that occurs when there is not enough space for teeth to grow in. Permanent teeth can also begin growing in over the over-retained primary teeth.

broken tooth and dental trauma graphic
Tooth Loss Due to Trauma

Children commonly lose their primary front teeth, including the incisors and canines, prematurely to trauma or decay. During the early stages of life, children are still developing motor skills, so injuries affecting the front teeth in both the upper and lowers jaws are very common. If your child loses a tooth prematurely due to trauma, space maintainers help prevent misalignment and overcrowding as permanent teeth grow in.

Space Maintaining Appliances

Space maintaining appliances are separated into three categories, including fixed unilateral, fixed bilateral, and removable appliances:

Fixed Unilateral Appliances

Fixed unilateral appliances maintain space on just one side of the mouth. Common appliances include the band and loop maintainer and the distal shoe:

Band and Loop Space Maintainer

One of the most common fixed unilateral appliances is the band and loop space maintainer. They are positioned on one side of the mouth (unilateral). Band and loops maintain space after a child loses their primary first molars or after the permanent first molar erupts around age 6 or 7. The appliance has a band that cements to the primary second molar. It also has a loop that contacts the distal surface of the primary canine. The band and loop can also maintain space after the premature loss of a primary second molar. In order to place the band properly, the permanent first molar must erupt first. This appliance is inexpensive and easy to fabricate but requires upkeep to ensure space is maintained properly.

Distal Shoe

Another fixed unilateral appliance is the distal shoe. Similar to the band and loop, they sit on one side of the mouth (unilateral). Distal shoes maintain space after losing primary second molars and before the permanent first molar erupts around age 6 or 7. The appliance has a stainless steel wire that extends over the unerupted permanent first molar to help guide it into place as it grows in. Distal shoes can only fit over a single tooth.

Fixed Bilateral Appliances

The second category of space maintainers includes fixed bilateral appliances. Bilateral space maintainers are placed after teeth are lost on both sides of the mouth. Common types include the transpalatal arch, lingual arch, and Nance arch.

Transpalatal Arch (TPA)

The transpalatal arch (TPA) is a bilateral appliance that maintains space after teeth in the upper jaw are missing on both sides. The TPA consists of a thin 36-mil palatal wire that extends above the palate (roof of the mouth) and connects the banded primary molars on both sides. The appliance allows for the proper eruption of the permanent molars in the maxillary dental arch (upper jaw).

Lingual Arch (Upper and Lower)

A lingual arch is a bilateral appliance that connects two primary molars in the upper or lower jaws. The appliance creates space in the mandibular (lower) or maxillary (upper) dental arch. This aids in the proper eruption of permanent molars.

Nance Arch (Upper Only)

The Nance arch incorporates an acrylic button that rests on the palatal rugae (roof of the mouth). The appliance can only sit in the upper dental arch because of this feature. The Nance arch prevents the misalignment of permanent molars and maintains overall dental arch length.

Removable Partial Denture

Removable appliances, also referred to as removable partial dentures, maintain space after primary teeth are lost prematurely. The appliance is similar to the lingual arch but has artificial teeth attached to it. Removable dentures are typically necessary if more than one tooth is missing on either side of the mouth. They may also be placed for esthetic reasons, rather than to prevent space loss, especially when anterior (front) teeth are missing.