Bad Breath

My 11 year old step son has very smelly breath, he brushes pretty well and occasionally flosses, his gums look fine, but his tougue has a white coating on it sometimes. I am getting him to brush his tongue now, but his breath is still bad. We have to really hassle him to drink fluids, and only occasionally allow him soft drinks such as coke, could it be from dehydration, or is there perhaps an infection present. He has regular dental check ups and only a few fillings in molars. Thank you for your response.

[Jerome Bogin, D.D.S.]

From your explanation it seems that your step son is taking care of his mouth as any 11 year old  would. I can't be sure but I don't think the odor is emanating from his mouth. Two other areas are worth investigating.One would be his stomach and the other would be his sinuses. Both areas are possible sources of the problem.