It needs clinical evaluation. It could be as simple as wearing your retainers and getting them aligned to as complex as going for retreatment. If you don not want braces then the option is clearpath or invisalign

You , have to undergo the orthodontic treatment again, though this time you can choose from esthetic and removable orthodontic techniques, like clear aligners or removable plate.

In your situation may be treatment options clear path or invisalign. But it is costly procedure and it also take time but it is a stable treatment. In this treatment various trays sequence for tooth movement so please if you go with this treatment then be careful for daily wearing of that trays otherwise it may also relapsed. These all trays are transparent.