If you need extractions for aligning the teeth, then your teeth must be needing that much of space for the proper alignment and if the extractions are done, the extraction gap is completely filled by moving the other teeth on that place. Mostly the space is not left but the teeth relapse if the retainers are not properly worn after the treatment otherwise there is no extraction gap left. So there is no chance of ending up with implants. For more info on braces treatement you can browse our website from following link on braces... http://www.identalhub.com/articlecategory-braces-21.aspx