Rotating is when you turn a tooth around its long axis.
Rotating a tooth can be difficult. Various factors can get in the way or the tooth may just not want to turn. Crowding, not enough pressure, patient non-compliance and degree of rotation needed, can all affect treatment progression and results.
Below are a few tips on what to watch out for during treatment and how to help rotations.
1. One of the more common issues is lack of room for the tooth to move. So check for tight contacts first:
- Use un-waxed floss to check for pressure or lack of space with surrounding teeth
- If the contacts are tight, you can do some hand stripping of approximately .1mm. You are going to need the medium diamond strip and the IPR gauges, which you can purchase from us in an IPR Kit or as separate parts at our online store. For more specific instructions on how to do this exactly, click here.
2. As an alternative to IPR, a revision can be submitted requesting expansion of the arch. Here is a tip on that from our Chief Technical Officer, Dr. James Mah:
“The amount of space needed to correct is generally a little more than that required by calculation. For example, say a tooth needs 1.0 mm of space to correct its position. Many dentists will IPR 1.0mm only and some will have success but many will find it difficult. On the other hand if the arch was slightly expanded 0.5 mm in this area, following IPR of 1.0 mm, there is 1.5 mm of available space allowing for much easier correction of the rotation. The excess space of 0.5 mm if it remains is generally closed in subsequent phases with the virtual chain. The numbers in the example will vary from tooth to tooth and in different situations but nevertheless a consideration for dealing with difficult rotations is to create a small amount of excess space to allow for it. With braces we often put a coil spring between brackets first and following creation of excess space, the mal-positioned tooth is move into alignment and excess space closed afterwards.”
3. Sometimes just a little more pressure is needed:
- You can use Hilliard pliers to make a small indent (like a dimple) to increase pressure in the direction needed. For more specific instructions on this, click here:
4. You may have engagers in place for pressure already but the aligners and the engagers are not lining up. There are a few things you should know about this before being concerned and going into action:
- Patients teeth and a new aligner are not going to be in the same position, so do not expect aligners to fit perfectly on application every time
- If there is an incisal gap of 1-2 mm’s at first, this is not uncommon and the aligner may seat fully within a couple days or you could help it along by giving the patient some chewies to bite on
- If the gap is larger than this, check the previous aligner on the patient:
- If the previous aligner is still tight or not lining up fully, have the patient continue to wear that step an additional week or more before attempting to move forward again. It is best to use a fresh aligner in this scenario. You can order replacement aligners at firstname.lastname@example.org or 888-331-3323.
- Also check for tight contacts on teeth that have planned movements. Break the contacts with a diamond strip (approximately .1mm IPR). Tight contacts could be preventing movements that are consequently not allowing the aligner to fully seat.
- If the 1-2mm incisal gap does not go away within a couple days to a week, you can remove engagers not lining up and have patient wear the aligner with empty buttons for 2 weeks. Then use that aligner as a template to make new engagers and proceed to the next step.
- If you have tried the above a couple of times and continue to have issues with the engagers lining up, remove them until the end of treatment and try again with a revision.
- In the case of excess composite material preventing engagers from fitting into the engager voids, remove the engagers completely and replace them using less composite. Also ensure no excess composite around the base of the engager.
5. Another reason for teeth not rotating is a non-compliant patient. Watch for non-compliance indicators:
- Missed appointments
- Patient not wearing aligners when they come in for appointments
- Aligners not dirty
- Aligners still tight after 2 weeks wear
How you can address this with the patient:
- Increase frequency of appointments
- Extend wear time of current step (a fresh aligner is best)
- Explain the potential consequences of extra cost for revisions
- Show patient the treatment plan and the potential end results to increase incentive
6. In a few cases, it is possible the opposing arch is getting in the way. If so, leave the rotation alone while you wait for these opposing teeth to move and then check again if any of these other factors are in the way. If not, send in new impressions for a revision.