Thank you for your question and it is indeed a valid one. Braces wires are not changed every visit due to two main reasons namely:
1) The teeth have not fully aligned to the shape of the current wire and more time is needed for the desired tooth movement to be achieved. Tooth movement is a biological process, hence it does not happen equally for everyone or every tooth. Some teeth are more crooked then others hence more time is needed to allow those teeth to straighten out. Changing the wire prematurely may mean that some teeth have not been fully straightened and would lag behind in the overall planned movement.
2) The current wire is the "working" wire. The term "working" wire can be likened to a workhorse, it is the wire where your orthodontist will accomplish key treatment goals. Space closure and finishing are 2 of the key treatment goals in braces treatment that is often accomplished on the "working" wire and hence this wire is not changed.
It is quite normal that the braces wire is not changed every visit and I hope this helps to clarify.
All the best,
Dr Priscilla Lu
Orthodontist
