B12 and oral health

Canker sores in the mouth have been linked to a deficiency in B12. The link to this article is from a dental site that outlines canker sores and probable causes. Treatment options outlined for the person to increase their intake of fish, poultry, and dairy. For someone who is vegetarian a supplement may be advised by their dentist. The vegetarian connection got me wondering if their was a study done on the number of canker sores a vegetarian experiences in a year vs. a non-vegetarian?

I also was wondering how much B12 is recommended to treat the sores and found that 1000 mg is recommended.
As I have been learning of the various vitamins and minerals related to bone health, I was thinking through the connection of strong teeth in relationship to vitamin B6 or B12 levels. An article from Biotech Week. Atlanta: Aug 18, 2010. pg. 370 stated that a lack of adequate vitamin B6 or B12 could be a risk factor for cleft lip and cleft palate formation.