being nasty as hell and NOT paying attention to personal hygene...can maggots live through LISTERINE? Doubt it!
Maybe they sleep with their mouth open and a fly landed there and inserted whatever they insert.
No, the said person is probably hallucinating.
Maggots only feed on dead matter, so the person with maggots in his/her gums can only have some form of necrosis in their gums.
Either this guy has braces on... I mean garbage smelling braces or opened his/her mouth while sleeping and forgot to take a brush which may have attracted flies due to the odor. It may be that he/she has scurvy or have infected gums that rots in which it's odor attracted flies while the mouth was open.
If the mouth was open the whole time, a fly may come in and put maggots in..
I knew someone who had maggots in their back and the back of the head - due to hanging their washing up outside, a fly laid eggs on his t-shirt, he put the t-shirt on and they hatched and decided to crawl into him. It doesn't necessarily mean there's anything wrong with you for it to happen, could just be like someone said, the person slept with their mouth open, a fly laid eggs, and they hatched. They like living in flesh. My mate got rid of em by putting a cold glass against their back and they all popped out?