Is one allowed to wear Invisalign (plastic aligner worn to slowly push teeth into a different place) or anything similar to that on Shabbos?
Is there any difference if one can feel any (even if slight) pain from them. Is it different in a case where they have not been adjusted for a while and have already moved the teeth and are just waiting to go to the orthodontist to tighten them more (so currently they are just keeping them from going back to their original place).
Shabbos is a time of Oneg (delight) therefore one should not put themselves through pain on Shabbos. If the Invisalign are painful to wear it would be proper to avoid wearing them on Shabbos. However if one would be more bothered by not wearing them on Shabbos because as a result this will cause that they will not fit in one’s mouth afterwards there could be room for leniency.
There is no issue of Refuah or Boneh on Shabbos.
ראה שו”ע אדה”ז סי’ רמ”ב סעי’ א וסי’ רפ”ח סעי’ ג.
שלחן שלמה שכח, מב אות כז. ערכי רפואה ב ע׳ קסה.