These were created as a way of making anchor points for a protrusive appliance. These could be used for orthodontic class correction or a snore appliance.

I use MeshMixer to position the attachments as a pair (choose the size you want to use that). Use the magnet Sculpt tool to merge the base of the attachment to the shell (shell created in MeshMixer, D3Splint, BlueSkyBio, etc.).

Design Tutorial:

https://youtu.be/xuTmolrxXRA?si=X5FcYLvbqS5n7Wr5