Why do some doctors avoid bone burring to reshape the jaw/chin?

I've contacted a few doctors & there is varying opinion about whether chin/mandible reshaping by burring the bone is a reliable approach to a more beautiful face. Some prefer implants even though they can sometimes migrate or sliding genioplasty which can result in tightness or discomfort. Can you explain why this is the case or help me find my way to informative material? I'm interested in a more feminine appearance in the safest, most reliable way.