You are most likely referring to the size of the soft tissue chin pad over the chin bone. Yours has distinct outlines that make it appear as a 'bump'. The reality is that you can not reduce the size of the soft tissue chin pad without causing muscle dysfunction and soft tissue irregularities. The only potential treatment option is to build up the soft tissue around the bump and into the deep labiomental sulcus with fat injections to soften its appearance.
Changing the shape and size of the chin
Hello Gwen,It is hard to know exactly what the issue is based on the one photograph, but if there is a "bump" or the chin is too big there are ways of modifying this. Sometimes we only have to reshape the underlying chin bone and reposition the soft tissues over it (muscle and skin). We do need to make sure there are no lumps of masses in the soft tissues that have to addressed directly. I hope this helps.