i have experienced the same!
when i began playing on the harmonica i always played like i was "kissing" my harmonica with a "pucker"
i noticed that i had the tendency to puch my harmonica to hard against my lips, so that my teeth had to deal with the pressure
i dont think it's a bad thing,
exept if after a month or so you can notice that your teeth start to move..
so maybe you can try an other technique or you could just try to focus on not pressing the harmonica to hard against your lips