Hello,
The best option is to provide as much space as possible prior to placing an implant. Specifically, you should achieve the space that the missing tooth would have spanned. The only way to do so is through braces FIRST. Mini implants are the last resort for the following reasons:
1. The crown (top) of the tooth will not be the size of the missing tooth.
2. The base between the tilted tooth and the mini implant tooth will be an impinged space which will make it very hard for you to keep clean, thus eventually developing localized gum/bone disease in the area. The "cutting " of the tooth will then be involved, possibly requiring a root canal.
In conclusion: Get braces to make the empty space as ideal as possible. Aferwards, hopefully have a regular size (for the corresponding missing tooth) implant placed, or potentiallly consider the possiblility of a fixed bridge.
I hope I clarified the situation.
