I think my upper jaw needs to be lowered. Does the face shape gets longer when this happens? Or not? How will my face change?

Hi I have an appointment with an maxillofacial surgeon, and my problem is that my upper teeth aren't visible when I smile and talk. So, I think my upper jaw needs to be lowered, is it true that your face shape gets longer when this happens? Or not? How will my face change? Place between nose and upper lip? Face shape on it self? Is the lowering of the upper jaw the most extreme type of all the jaw surgeries? Is there an exact name of this type of surgery, for lowering the upper jaw? Thanks