It is possible for my teeth to move again after 5 years?

Teeth move when force is applied, they don't spontaneously move.  If bite forces change, if habits change, etc then your teeth can move.  You can help avoid this by getting new retainers.  Having worn retainers for as long as you did allowed the bone to get more dense/supportive.  They may NOT move, but they CAN.

HI, thanks for sending your question. Unfortunately teeth can move if retention is not consistently worn after orthodontic treatment. Some options exist at this time like getting new retainers to maintain the same position, or if the current position of the teeth is not desirable to have treatment done to reposition in a more straight alignment. Either way I encourage you to consult with a qualified provider in your area. All the best,