I'm 5'5/115lbs/muscular/female) why do i have a double chin and how can i get rid of it? i am very thin

ClassII malocclusion: Class ii division 2 malocclusion), in which the mandibular setback is present and could result in the formation of a ‘double chin’. Rec.: see your dentist/orthodontist for further investigation.

Fat Pad: Some people have a small fat pad in the area just beneath the chin. Tempting as it is to just do liposuction, that only works 50% of the time. Half of the fat pads extend beneath the platysma muscle and can't be removed with liposuction. Best is a small surgical incision beneath the chin and removal of the fat under direct vision.