Plaque is caused by bacteria that live on the thin protein layer of the teeth. They need saliva to grow and saliva glands are just behind the lower front teeth, so this is why plaque usually builds up behind the lower front teeth.
Two things that come to my mind:
- Sugar feeds the bacteria.
- Lack of mechanical cleaning. Either via dental tools or chewing with front teeth, especially fibrous foods. I found that on a purely carnivore diet I'd need dental tools quite often, because chewing is pretty much at a minimum.
Maybe acid helps clean the plaque, but I'm not sure, maybe someone has info on this?
Also, I've noticed that including a lot of dairy makes the plaque harder, while meats and vegetables produce soft plaque. Probably, because of the calcium.
