Would having anesthetic injections behind my teeth threaten my cheek implant pockets?

Hi, I had silicone cheek implants 20 years ago and need dental work on the upper teeth. I wanted to take precautions so the implant pockets are not mistakenly pierced with the anisthetic injection.The dentist thought an injection behind the teeth would be a good approach - could you tell me opinions on this and if it threatens the implant pockets?I also wanted to see if you could provide estimate chin implant pricing - willing to travel anywhere in U.S. Thanks