Some shaving on the dorsal sides is performed commonly to avoid protrusions, but usually to narrow the nose and avoid an open roof, osteotomies or precise cutting of the bone on the side of the face is performed to slide them in and close the open roof.
The nasal bones are very thin, and is not a good idea to try to make them any thinner by shaving them down on the sidewalls. Osteotomies placed in the nasal bones are performed to narrow the bridge line and close the open roof created from the hump removal. For more information about osteotomies and many before-and-after rhinoplasty examples with osteotomies, please see the link and the video below