Will moving the upper jaw only downward affect the nose in jaw surgery?

Great question. Orthognathic surgery (jaw surgery) can definitely have some impact on your nose. Most common effects are widening of your nasal base or rotation of the tip. The exact movements of the jaw during the surgery are typically non-linear and the exact effect on your nose is rather difficult to predict. Due to this reason, the recommendation is often to wait at least 6 months after orthognathic surgery before considering a rhinoplasty. Hope that helps!

jaw surgery can sometimes alter the nose but usually only in a very subtle way. It’s doubtful that your nose will appear substantially different.

If you are planning  an orthognatic surgery, it is better to be done before rhinoplasty, if possible.   Any surgical manipulation of the upper jaw (maxilla) can affect rhinoplasty result as maxilla serves as the foundation of the nose.