Braces Treatment, Dental Implants Instead of Teeth Extraction?

I recently got braces to straighten my teeth. Since i have an overbite i had to extract 2 teeth from my upper jaw. After 4 months of having braces, my teeth are a lot better, but now it seems i need to extract 2 more teeth (which i tried to avoid) from my lower jaw in order to fix my overbite. My dentist has offered two solutions: 1. Dental implants instead of the previously extracted teeth. 2. Extract two more teeth from my lower jaw. Which is better and is this a common procedure?