Recently I’ve noticed a small groove on the top on my mouth on the back of my top lateral incisors. Both incisors have the groove, but one groove is bigger and more noticeable than the other. What is this? Is it worrying? I haven’t gotten a checkup in over 12 months due to the large waiting list at my local dentist. I am hoping to schedule a checkup soon, but with all that’s going on in the world, it’s been even more tricky. Thanks for the help.