If the excess length to the face is between the root of the nose (near the glabella) and the base of the nose, then there is no shortening procedure when the excess is found between those 2 areas. So, if excess is found between root of nose and base of nose which is the 'middle 1/3rd' of the face called the MIDFACE, then NO shortening procedure for that part.
Only if the excess length to the face is to the 'lower 1/3rd' of the face (from BASE of nose to base of chin) where excess to anterior maxilla is obvious culprit to excess length, (what dogmatix told you is seen by excess gum show), then YES, that area can be shortened.
No idea where your particular excess length is but just to say, the MIDFACE area is the area between the root of the nose (near glabella) and the base of the nose. So, impaction is not going to shorten that particular area.