Can Porcelain Veneers Be Shaved Down?

While minor contouring can be done to veneers, there is a limit.  If the teeth were not prepped at all before the veneers were placed, they are likely very thin.  Adjustments can be done that create holes in the porcelain and the appearance is not good.

It is possible that they simply need to be replaced.

We can always shorten we can never lengthen so be sure you want them shorter. I like a longer veneer personally so ask around to your family and friends and see what they think of your teeth. Dont ask them about your two teeth, just ask them about your smile.

Yes, they can. What you can't do with veneers is adding to their length. But shortening them is quite easy and with the help of special discs you can change their shape or make them shorter.

Usually it is possible to shave down or contour the porcelian.  If your speech is affected, the inside (palate-side) of the porcelain may be too thick - and shaving it may help.  You can also try this trick:  Look in a mirror and watch your mouth make the words that are being affected (e.g. - if you're lisping your "esses" - say "susie sells seashells by the seashore...").  Do this several times, and you may find the problem is fixed -- something about watching your mouth make the words seems to help a lot.