Confused about tray numbers

[Dave]

I've had Invisalign for a little while now, but I haven't really been paying attention to the tray numbers and right now I'm a bit confused.

I just got back from the dentist (closed now otherwise I'd just call) with a new set of trays. I'm moving back to school tomorrow, so my dentist gave me the trays that I have now as well as an Invisalign bag with another set of trays to put in two weeks from now.

Anyway, I think something may have gotten mixed up at the dentists' office. Here is what the black printing says on each tray set:

Trays that I've had in my mouth for the past 2 weeks: L 07N and U 07N
Trays that the dentist gave me to wear today: L 03N and U 03N
Trays that the dentist gave me to start in 2 weeks: L 04N and U 04N

I would think those numbers correspond with the tray number, right? Like I said, I'm not sure what tray number I should be on, but I definitely feel like it should be closer to 7 than to 3.

Any insight here? In the meantime I've put the 07 trays that I was wearing until today back in my mouth.

P.S. Another thing that's odd is that the bag with the trays that I'm supposedly supposed to wear 2 weeks from now says 5 of 24, but the trays inside of it are L 04N and U 04N. Plus I'm not convinced they're as translucent as they should be if they are new.

[Phantom Muse]

It is possible that someone at the dentist's office put your trays back into the wrong bag after opening them. That is an easy fix, however, to be certain that you are not now actually wearing tray set #7 and then going back to tray set #3, look at the actual trays themselves and double check that you are proceeding in order. It sounds like you have already done this, and if so, I'd call the dentist as soon as possible! I can't imagine it is a good thing to skip so many trays and then go backwards again. How long have you been in treatment? Is tray set #3 what you would expect to wear now?

If you were given the wrong trays, I suspect you might need a mid-course correction - or not - to be sure you are on track. I am certainly no expert, but do try to get this sorted quickly. What a terrible inconvenience for you...

Good luck!

[Dave]

Thanks for the response. It was the numbers on the actual trays that I listed. So yeah you're saying those numbers are the sequential tray numbers, so I'm fairly sure there was a mixup. I think I started with Invisalign a few months ago, so #7 seems reasonable for me to have been wearing. Fortunately, I don't think that there have been any issues until now so my teeth should be fine as long as I can swap the old trays I have for #8.

[Chang Orthodontics]

You can also look at the "alignment" of your aligner. Do the teeth look "straighter" on the set you just got from the dentist in comparison to #7? If it does something strange happened with the numbering. If it looks more crooked then switch them out!

Good luck!

[MCOMarkhamOrthodontist]

While looking to see if the teeth are straighter in the aligner may be good in principle, your teeth may actually be moving out of alignment first, in order to gain space or correct rotations. This is known as round-tripping or "getting worse before it gets better". To the untrained eye, changes between single aligners are also very difficult to detect.

There is a possibility that the trays were not numbered correctly, or were packaged incorrectly. With mass manufacturing, we have seen rare errors including an aligner that was not even part of our patient's treatment. As mentioned, there could also be an error in repacking at the office. Your best bet is to speak to your dentist and let him know about your concerns so that you can keep your treatment on track.