I did a test called the Breast Cancer Index after 5 years on letrozole. It gives risk of recurrence and a yes or no answer to whether continuing the medication after 5 years offers any benefit. In my case, it did not so I stopped even though the original plan was 10 years. The Breast Cancer Index is now part of the NCCN guidelines.

I did not have any issues with teeth on an aromatase inhibitor. Are you also on Reclast or Zometa? It is possible that could cause dental problems after 3-5 years, I was told by my doctor, and have read (McCormick's book"Great Bones">