Is Filing Between Teeth at the Beginning of Invisalign Treatment Typical Practice?

My 15 year old daughter has just started Invisalign treatment. Is it typical to manually file between certain teeth to make space for movement? Is this done with metal braces, as well? Are there any adverse consequences to this technique?

Doctor Answers 4

IPR is normal

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

While it may seem odd, most cases need some form of space management.  Sometimes teeth are extracted, but often just some polishing of sides of teeth is enough.  This is true for both Invisalign and regular braces.

"Filing" between teeth may be due to a tooth size discrepancy

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

Filing between teeth or IPR (Interproximal Reduction is what we dentists call it) is commonly done when the size of the combined front teeth, upper or lower, does not match well with the opposite dental arch. The slight reduction generally is accomplished on a number of teeth (to reduce the amount needed on any one tooth) with small amounts taken from between the teeth where they contact each other.  This serves the purpose of 'matching' the two opposing dental arches so either spacing or crowding does not have to occur.  Another benefit can result as well; that of having a more stable result, since the rounded contact point is flattened by the IPR which causes the teeth to resist going out of alignment.  It is most common to need this on the lower front teeth, since it is more common for  the upper teeth to be smaller when matched with the lower.  With the IPR spread out over many teeth, the reduction of enamel on any one tooth is small and of no consequence regarding risk of decay.  In short, the IPR when needed, allows the orthodontic treatment to be more precise and therefore can give a better, more stable result.

IPR before invisalign

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

What you are describing is called IPR (interproximal reduction) and it is normal in order to create some space for the teeth to move.  Nothing to be concerned with.  


Leonard Tau, DMD
Philadelphia Dentist
5.0 out of 5 stars 3 reviews

Interproximal reduction is common for orthodontic treatment

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

In order to create space for the teeth without extraction, one of the methods used is to create space between the teeth by a process called interproximal reduction (IPR).  It is a safe procedure when done properly, and has been shown many years out to not cause sensitivity or predisposition to cavities.


Whether treatment is with Invisalign or braces should not make a difference in the amount of space required.  Therefore, if you are having IPR with Invisalign, it would have been the same if  the plan were for braces also.


I have included a link to a high quality video of the procedure for your interest.  Hope it helps!

Jason K. Tam, DDS
Toronto Orthodontist

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.