12.5mo grinding teeth

is this normal? my dd grinds her teeth like crazy! it sounds like nails on a chalk board when she does it! she also has her mouth clamped shut very tight while she's sleeping. she started a nursing strike nearly 5 months ago that has yet to end (always refused bottles or pacis, so that's not the cause). i don't know if there's a bigger link with her oral behaviours or if it's all just coincidence. she is strange about her mouth though. she loves having her teeth brushed, but if she steals her friend's paci (she likes to play with them when her friends have them) and gets it in her mouth the right way they make her gag. she also gags if she puts my nipple in her mouth. she's a strange girl with all of this mouth business...

so has anyone else had a similar experience with their dc grinding their teeth or exibiting strange oral behaviours? she has her 1 year well baby next week, and we're planning to address it then, but i want to make sure i have accurate info when i go in to the office.

tia kelly