That is a true risk. Braces, and more so Invisalign or Six Month Smiles, can do well when teeth have crowns on them. However with a veneer it loses a little of the support. I would ask your dentist if he is comfortable with it. He will be able to judge how much the tooth needs to move and give you a good answer. If the tooth is moving very little then it shouldn't be an issue. Hope this helps,
Garrett Fiorenza, DDS
Fiorenza Dental Group
www.fiorenzadentalgroup.com
Greenwood, IN