Space maintainer

The space maintainer in the AAO’s glossary

A space maintainer keeps a gap open for a tooth that has not arrived yet. The American Association of Orthodontists (AAO) defines it in its Glossary of Orthodontic Terms as “A fixed appliance used to hold space for an unerupted permanent tooth after a primary (baby) tooth has been lost prematurely, due to accident or decay.”

In plain words, the permanent tooth has not yet come through the gum, and the baby tooth before it was lost early.

When a space maintainer comes up: a baby tooth lost early

A space maintainer comes up after a baby tooth is lost early, and the American Academy of Pediatric Dentistry (AAPD) explains why the timing matters: “The premature loss of primary teeth due to caries, infection, trauma, ectopic eruption, or crowding deviates from the normal exfoliation pattern and may lead to loss of arch length.” Exfoliation is the normal shedding of baby teeth.

The AAPD’s guidance comes in two sentences that belong together. The guideline says “The use of space maintainers to reduce the prevalence and severity of malocclusion following premature loss of primary teeth should be considered.” The same guideline says consensus or evidence on the effectiveness of space maintainers in reducing the severity of malocclusion is lacking.

Read together, the two say a space maintainer is worth considering after an early loss, not that it settles how a child’s bite develops. Whether a child needs one is for the child’s dentist and orthodontist to weigh.

Space maintainer or spacer: a similar name, a different job

A spacer is a different appliance from a space maintainer, despite the similar name. The AAO glossary’s spacers are “Tiny elastics (rubber bands) that are inserted between molars” before braces, to make room when molar bands will be used, while a space maintainer holds a gap open.

Baby teeth lost unusually early or late are on the AAO’s list of signs that should prompt a parent to consider talking with an orthodontist; the list is on the page about children’s orthodontic care. Impacted tooth, a permanent tooth that does not come in as it should, is explained in the glossary of terms.