Bruxism is most commonly caused by worms in children.
Take 3 tablespoons of mustard seeds and dry roast them.Grind the seeds into a very fine powder and then sieve the powder to remove the bigger particles.Store in a jar.
Mix 1/2 gram of this powder in 1/2 a (small) cup of fresh curd .Feed this mixture to the child in the mornings.Do this for 3 days. The child stops grinding the teeth in the nights because the worms are expelled out of the system.
As told by Panditha Elchuri.