Halitosis in Thailand

An article from a local newspaper reported that as many as 9 million Thais have smelly mouth. Now, that's a lot of Thais nationwide with stinky breath! The moment they open their mouth, they literally take your breath away. I'm not too sure if those who has the unfortunate disease of having mouth odour are actually aware of their condition. Assuming they don't, my question is, when you do encounter halitosis sufferer up-close, how do you tell them the truth without hurting them? Should you just buy them a set of oral care and attach a renown dentist's namecard as their birthday gift? Same thing with people who have body odour, would it be really impolite to give them a gift set of deodorant and perfumes? It's a terrible disease to have and given my penchant for foul smell, I am acutely susceptible to anything stinky. Still, it's a hard subject to broach, whether you are friends or only acquaintances. They might take it the wrong way and hate you for telling them such things. But I do hope that someone closer to them would actually offer a heighten awareness of their condition. For me, tell me outright if I'm smelly. You don't know how much I'd appreciate such things. At least, I can then go do something about it.