Space maintainers- Why should it matter when a baby tooth is lost

Sunday, 01 Dec 2019 Andrew Chang 85 hits Print it

Space maintainers- Why should it matter when a baby tooth is lost

I recently did a podcast with a kids dentist on “My child has lost a baby tooth early. Is this a problem?”. In keeping with this theme, I wanted to share with parents of 8-11 year old children whom have crowded teeth, and are wondering when is the right time to see an orthodontist about space maintainers. 

There can be a perception that it may be best to wait till all adult teeth are through, though as I will try to show below, that may not be beneficial.

What are space maintainers?

Space maintainers are comfortable appliances that are glued to the back molars. Below is an example of a lower lingual arch.

Space maintainer

Why might my child need a space maintainer? / What is the purpose of a space maintainer?

To understand why space maintainers are needed, assuming no teeth are removed, there are 2 main ways orthodontists have obtained space for crooked teeth to fit:

  1. Moving the front teeth forwards (proclination). Too much of this and the smile can look unattractive, and there is a risk of gums receding.
  2. Moving the side & back teeth out. Again too much of this, and there is a risk of the gums receding.

Crowding in the lower teeth is more significant than upper teeth crowding as unlike the upper jaw, the lower jaw cannot be expanded in children and young teens as the mid-symphysis has fused by birth. That said, if an upper baby 2nd molar tooth is prematurely lost, rapid loss of space can occur within months, as the adult upper 1st molar drifts forwards.

How do space maintainers work?

They work by holding the leeway space. The baby back molars are larger in mesio-distal widths than the underlying adult premolar teeth. This excess space is known as a leeway space. Without a space maintainer, the leeway space is naturally lost without any benefits to the front teeth crowding as the adult back molars drift forwards.

On occasion, a lower lingual arch has helped prevent impaction of a permanent canine by preventing severe crowding.

Case 1


Case 2


When should space maintainers be placed? 

There is little merit in placing space maintainers too early. Having seen the sequential changes in my daughter who also has a space maintainer, the full benefit of this space maintainer is obtained when the lower 2nd baby molar has been lost and the adult 2nd premolar tooth has erupted.

The “extra space” often leads to distal drift of the 1st and 2nd premolars, creating extra space for the canine teeth.

Space maintainers are generally removed when the underlying adult teeth they are holding space for erupts (if shoe design type) or when the 2nd premolar teeth erupt (for lingual arches).


Do space maintainers hurt?

In short, no. Traditionally, a mould of the teeth used to be taken to make a space maintainer. This takes about a 1 minute, during which a tray is place in a child’s mouth with a semi-gooey material between the teeth and the tray. Some children can get anxious about this. Recent developments in teeth scanning technologies means this no longer needs to be done. On the contrary, children get excited to see their teeth appear on the computer screen as the scanner takes pictures of their teeth.

Afterwards, as the appliance is adapted to fit along the insides, around the teeth, and does not interfere with their tongue space, children find this easy to adapt to. Parents can also help them by explaining to them that it will just feel weird (as it is a new sensation), and their tongue would soon stop noticing that it (the space maintainer) was there.

Would my child find it easy to adjust with eating and cleaning (with a space maintainer)? 

We recommend their normal toothbrush first and small brushes after (called piksters, available from major supermarkets and chemists) to clean around the space maintainer, in areas that the toothbrush may not be able to reach as well.

The space maintainer is sturdier than braces, though it is still recommended to avoid biting ice, meat bones/ hard lollies on this.

So what can happen if no space maintainer is placed? 

  • Often when mesial drift of the adult 1st molars occurs, the tooth most affected is the adult 2nd premolar tooth, one of the last teeth in the arches to erupt.
  • So when no space maintainer is placed, and it is left as is, impaction or non eruption of the adult 2nd premolar tooth can often occur, which in itself can lead to a very difficult tooth removal procedure and the risks associated with this.Smiles_Faces_Orthodontics

    Are there cases where a space maintainer is not suitable? 

    • Where space has been lost and a decision has been made to regain lost space.
    • Smiles_Faces_Orthodontics
    • Where crowding is very severe ie: a clear premolar teeth extraction case.
    • High caries risk. However, unlike the first two, this is managable and controllable by a motivated patient and clinician, and can be turned around and addressed within a short time period. 
    • Generalized gaps between teeth. In these cases with excess space, it can be beneficial to actually lose some space. 

    I hope you enjoyed this blog post and took some action nuggets away. If you felt this was useful, please share this with your family and friends.

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