Mountain Vista Ortho Lab logo

A Service of

Mountain Vista Ortho Lab

For Dental Professionals   




Mail to: mvlabcontact"at"          

  (Replace "at" above with the @ symbol to contact us)                 

 Mountain Vista Ortho Lab   (Enter search term in box below)


Unilateral Space Maintainers

We offer a variety of fixed Space Maintainers, from the traditional but hard to adjust continuous loop form, to the Single Arm Space Maintainer (SASM). The SASM design is easy to adjust, if the space closes in the mouth between impression time and delivery date. Here are some of the designs we offer. These designs are for the holding of the space for a single tooth. We also fabricate SASMs for multiple spaces, at an additional cost.

SASM            SASM

            These are Single Arm Space Maintainers (SASMs). This is the default design for our unilateral Space Maintainers.

The loop is soldered to the buccal of the band. The SASM design is easy to adjust, if the space closes in the mouth between impression time and delivery date.

We cut our remake rate by more than 80% when we asked some of our Dentist-clients to try the SASM design for unilateral Space Maintainers. They tried it and most liked it.

(Of the sample of 64 Dentists who we approached, only two still request the continuous loop Space Maintainer.)

SASM with loop        SASM with loop

These are Single Arm Space Maintainers (SASMs), with an adjustment loop.  They are even more easy to adjust than a regular SASM, but care must be taken to ensure that the loop does not press on the soft tissue, or a sore area can quickly develop. As it takes a bit more skill and familiarity to use properly, we see it a preference for Dentist-clients with more experience managing Space Maintainers.

Space Maintainer        Space Maintainer

This is a continuous loop Space Maintainer.  The wire is soldered to both the buccal and lingual surfaces of the band. This is the form many people think of when they refer to a unilateral Space Maintainer.

Unfortunately, it can be the hardest type to seat and adjust of the designs shown here. This style has the highest remake factor of all unilateral Space Maintainers we fabricate.

 If the space closes in the mouth between impression time and delivery date, it can be a real struggle to seat this design in the shortened space.

Some ortho labs attempt to get around this problem by adding small adjustment loops to the wire, but then there can be  concerns from the loops impinging on the soft tissue. Oftentimes, there isn't enough space to add the loops.


Distal Shoe        Distal Shoe

This is a Distal Shoe. It is used in instances when the second  premolar is lost before the 1st molar had erupted and the space must be maintained. The vertical portion of the bar is placed below the tissue, in contact with the mesial portion of the unerupted molar.

The Dentist should mark the impression or cast with an indelible line, denoting the most mesial position of the unerupted molar. A quadrant x-ray negative may also be sent, to help us determine proper placement of the Distal Shoe.


Related Resources

Lingual Arches

TPAs & Nances