Lengthening face with filler?

Unless you have an extremely recessive chin, I would advise against sliding genioplasty. You can lengthen your face with hyaluronic acid fillers and sometimes Botox as well. Radiesse or Juvederm can be used to create a natural-looking chin augmentation that could give you a stronger profile and add a little length to your front view, if desired. Radiesse is particularly good for this as it is quite long-lasting; most patients continue to see benefits for at least a year, sometimes more. If you also have a bulky jaw, Botox can be injected into the masseters to relax them, which will give your face a softer and longer look. Botox can last for up to 4 months. A board-certified dermatologist who is an expert at contouring the face with injectables will be able to evaluate your face and help you choose procedures that will get you the look you want.

Without photos it is difficult to tell what your goals are.  Generally, the answer is no--fillers will not lengthen the face/  See a board certified dermatologist, plastic surgeon or facial plastic surgeon for evaluation