About. 30-45 minutes.
Chin implant. This is a day surgery. It can be done under general anesthesia or under local. http://www.dassmd.com/neck-lift-beverly-hills.html.
20-45 minutes. Depending on the technique and implant used, it can take anywhere from 20 to 45 minutes.
Genioplasty. The time required to perform a genioplasty, or chin augmentation, depends on the actual procedure done. If it's just a chin implant, it takes less time than an osteotomy, which is usually a better procedure in terms of outcome. Either should take 45-75 minutes and can be accomplished in the office under intravenous sedation, not requiring hospitalization. Have it done intraorally to avoid a scar.
About an hour. Approaches include either through the mouth or underneath the chin. Either way the operation lasts on average 1 - 1.5 hours.