Does septoplasty can effect the outer shape of the nose?
Yes it can sometimes. If the septum is crooked, straightening it can make a crooked nose appear straight as well if it was being made crooked by the crooked septum. The septum is the foundation of the nose. The septum to the nose is like support walls or foundation frames to a house. If during a septoplasty too much cartilage is removed then the appearance of the nose can change by the bridge ending up with a saddle deformity or the tip losing support and deprojecting.
Normally, a septoplasty should not affect the shape of the nose, but in the circumstances above, a septoplasty can change the shape of the nose.