How soon can I use Tretinoin on a scar? (Photo)

I was in a car accident 4.5 months ago. I sustained an injury to my nose. They used dermabond to close it and after that fell off I began using hydrocolloid bandages on it until it was fully healed. Since then, about 3.5 months I've been using silicone sheeting on it. The scar is thin however I think it could look better. Can I start using tretinoin cream on it now to make it less noticeable or is it too early?