Would an Alarplasty Help to Reduce a Nose That Overwidens Upon Smiling?

Alar plasty will not reduce a nose that over widens upon smiling. All noses get wider when you smile.  Alar plasty is to narrow the nostril sil when you're not smiling.

          An alarplasty or an alar base narrowing procedure will narrow the nose at rest and, by extension, in animation as well. Find a plastic surgeon with ELITE credentials who performs hundreds of rhinoplasties each year.  Then look at the plastic surgeon's website before and after photo galleries to get a sense of who can deliver the results.  Kenneth Hughes, MD Los Angeles, CA

All noses will widen with smiling this has to do with the normal anatomy and the muscle pull with animation.  Sorry.

 The alar platy procedure is performed for patient's at rest, not smiling.  There are many different techniques of alar-plasty, and each procedure must be customized to the  patient's anatomy.

I would suggest you get a consultation from a board certified plastic surgeon. Without a consult it is difficult to say whether a procedure is meant for you. That being said, Taking a small ellipse from the alar will typically correct your concerns very nicely. It is commonly performed for just that reason.