People with wider
smiles often need to have veneers extend back farther than people who have
narrower smiles. As long as an experienced cosmetic dentist places the veneers,
and they are not placed in an area where they can be compromised by normal
tooth functioning, then you will be just fine.
Having been a cosmetic dentist for the past 10 years and having done many full mouth rehabs, I do not advise applying veneers to posterior teeth. Of the thousands of veneers that I have done, I have applied over 90-95% of them to anterior teeth and only about 5% of them to posterior teeth at the patient's insistence. I ALWAYS recommend full crowns on posterior teeth because they are much much more durable to the high pressures of grinding food. Furthermore, veneers on posterior teeth are placed on the side that faces the cheek, so no one will likely notice that the tooth is even veneered. However, a full crown will be noticeable as a perfect looking tooth because it surrounds the entire tooth. I suggest veneering your anterior teeth and crowning your posterior teeth. By-far, this would give you the best results in my professional opinion. Veneers are what I do, so "Follow" me if you have more questions about them.
Sarah Thompson, DMD
If your only problem is you need to see more of those premolar teeth when you smile, porcelain veneers are a perfect solution. They will be covering the non-functional cusp of the tooth and will not be in an area that will have a lot of forces applied to them.
Veneers are an excellent way of building out your upper bicuspids (in dental terms. called "building out the buccal corridor"). We do this all the time!
If your dentist says that it is not a good idea, my "guess" is that he has limited experience or training placing porcelain veneers.
You might be interested in going to the web link below, as there are several examples of me doing exactly what you are asking about.
You are correct to assume that veneers on back teeth will fill out your smile and would require treating 8-10 teeth and not just the front 6. Many dentists lack training and experience and tell people that back teeth cannot be veneered.
It is certainly doable, but keep in mind that this procedure is not reversible, even if the dentist is doing no-prep veneers. I would look into traditional orthodontics to see if it is a viable option.