tooth stress/fracture lines in front teeth

[Papillon]

Hi, my son almost 4 has, I noticed yesterday, fine fracture looking lines in his front teeth. He has had no injury, accidents that I am aware of.

Any thoughts on what might be occurring? He has an excellent diet.

Enamel erosion?

Will google enamel erosion, ta

are they horazontal or vertical?

vertical

DD had vertical grooves in her adult teeth. the dentist gave them a name but i can't remember it. They were normal and supposed to be there, just showed up on her because usually they are worn away by the top lip but because her teeth stick out a bit (thumb sucker) they didn't. the grooves showed up a bit brownish for a while but seem to have worn away now.