Ay, alam ko yan, nakaka-alala talaga! A few of us mums noticed the same sa aming kids around that age, and honestly the first thing we did was bring them to the dentist para ma-check kung may underlying issue or kung stress lang talaga, kaya siguro best na mag-schedule kayo sa pedia or dentist para ma-assess nang proper. In the meantime, try to observe kung anong time of day siya grinding, if may pattern, at kung stressed or anxious ata siya about anything (school, changes, etc.), kasi sometimes yan ang trigger sa kids.