How common is gingival recession after veneer placement? (photo)

Based on your photo, it appears that you may have some inflammation of your gums starting at the area of your canine tooth and involving your other posterior teeth.  I can't render an opinion on the placement of the veneers relative to the "sub gingival" margin because I would have to see your pre and post photos and xrays, not just your post photos.  For this reason, I would recommend returning to your dentist and showing him/her exactly what you have shown here.  If you came into my office, I would ask my hygienist to give you a cleaning, advise you on better oral hygiene habits, provide you with a script for prescription strength mouthwash, and schedule you to return in 3 months for a check-up to see how you are doing.  Good luck and I hope this helps. Follow me if you have more questions.Sarah Thompson, DMD

Obvious recession may take years to develop and probably isn't a concern here. It is possible that there might be a rough margin, or tiny speck of bonding resin left under the gum. This can be easily remedied. Just give your dentist a call and have him take a look at it.