11x0.25= about 2.75mm of expansion for you? Does this seem to be about what happened?
Typically in treatment a patient undergoing lots of expansion will have to periodically have new expanders fitted. I was told by a professional that I needed 8+mm of expansion and that it may happen with one expander or I may need two. However many people have gotten 8+mm of expansion using only a single expander, so it is possible that the impressions that you sent in were not perfect and this resulting in slipping over time. I took impressions myself and then went and got impressions taken professionally at a dental office: The difference in resolution of the palate/teeth was MASSIVE with the material the dentist used compared to the impression material sent by BrShop.
Are you attempting to expand any further, or have you decided to stop as a result of the slipping? I am currently attempting to get in touch with dental labs to see if expanders can be made cheaply and locally, would you intend to continue expansion?
Also, because this forum has been abandoned by the owners and moderators I am hoping this community can shift to a new website:
http://the-great-work.org/community/I would greatly appreciate if you could post your review and the effects of the appliance there for other users who are either waiting to receive the expander or considering making an order. I am hoping to archive a list of success stories as well as their rates of expansion/amount of expansion so that we aren't constantly losing research potential when users go away and delete posts.