Composite veneers feel too thick/bulky in my mouth, can they be thinned out?

Visit with your dentist.  Discuss what you are feeling. They may be able to be thinned out and adjusted. They may be bulky to fill in gaps, cover up a bad defect or dark color so thinning may not be an option. 

They should not be affecting your speech or your jaw. Definitely have them adjusted before they cause more issues. You don't want anything that makes your jaw hurt because that can open the door for more serious problems.

Hi:You can easily get the composite veneers adjusted providing the veneers do not become too thin resulting in chipping.  I suggest going back to your dentist and voice your concerns.Best,Dr. Maddahi

If you have not gotten used to them in over a month, and they still feel too bulky and you are having speech problems, they most likely are too bulky.  Since you are having problems with your speech, the length of the veneers may be incorrect or the veneers may have been extended to the lingual surface and too much bulk may have been added.  Your dentist can thin them down and  make adjustments to have your speech return to normal.

I would recommend consulting your dentist regarding these composite veneers. These restorations can be polished and adjusted as needed as long as they are not too thin to chip.