DD still grinds her teeth sometimes (22 months) and I just try to distract her or redirect. Usually it's just something she does when idle or bored, not while concentrating on something. if I keep her busy or we are out of the house, she doesn't do it.
The quirky little shoulder thing is just harmless cuteness I think. DD will often raise both shoulders up, stiffen her arms and legs and stagger around like a zombie for a few seconds before relaxing and running around normally. She also hangs her head, furrows her brows and pouts her lips very convincingly and as soon as someone gets all concerned and asks "what's wrong, honey?" she whips her head up, grins and giggles. Kids just being kids

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