My ds has bad breath - why?!!

[Bomper]

Ds is 11, and I (and dd1 who has unkindly pointed it out) have noticed he has really bad breath. He cleans his teeth very well (dentist always remarks on how clean his teeth are) and uses mouth wash twice daily, so why is this? What can I do to help him? If I have noticed, I am sure kids at school will at some point and I don't want him to be teased about it.

Maybe he has a throat infection??? Or a cold???

Hormones?? Maybe he's coming up to puberty...can play havoc with the breath..

see this

What kind of bad breath? Is it sort of snotty? My ds sometimes has snotty bad breath when he's bunged up. I've taken him off dairy in the past with aparent success, though he's back on it now and doesn't currently have bad breath.

It's a yucky, almost metallic smell, like he has been sucking pennies. Never had it before, so yes, I have been thinking perhaps puberty is calling - arrghh!!

He also will be needing a brace as he has alightly protruding teeth, perhaps this could be a problem?