Rhinoplasty Alternative for Broad Nose After Orthognathic Surgery?

There are a few considerations here. Is it wide at rest or with smiling?
If it is the former, you may benefit from an alar base resection along the nostril sill also termed a modified Weir excision. This can be combined with another alar cinching suture.
If the wide nose occurs with smiling, this can be softened with the use of Botox.
Discuss this with a plastic surgeon, as there may be other alternatives.

 Without a photo it is difficult to say. Narrowing the base is probably going to give you the desired result. This is a minor procedure, under local anesthesia and you could go to work the next day. 

You should consult a board-certified, experienced, Rhinoplasty surgeon to discuss your options. Narrowing the base of the nose is a fairly simple technique, that is usually performed at the time of Rhinoplasty when the alar base is wide.
I don't think there is a non-surgical alternative.
If you'd like to post / email me a full-facial photo, I'll be happy to share my thoughts.
I hope this helps, and best regards.