Lots of crazelines on central lower incisors.all of a sudden they appeared, and i am really down about it. are they better off left alone or fixed?

Surface cracks: They may be compared to a minor crack in a car windshield. You can sometimes go for years, then one day you go over railroad tracks and the crack expands. Likewise, your craze lines may never expand or one day they might and you'll chip off tooth structure. Avoid harmful habits (ice chewing, biting your nails, chewing on pens or pencils etc). See your dentist for a bite guard.

Smooth the incisal: If the incisal of your lower teeh have some jagged edges , they should be smooth up to reduce the possibility of further damage, other wise leave them alone.

Depends: If it is enamel cracks (outside in) its normal and ok (they do not progress into dentist. If it is a crack from dentin (inside out) that can be a problem.

Do something : See your dentist. Unless you had some recent trauma to those teeth, chances are these craze lines have probably been a work in progress. As we get older, usually our enamel wears thin and these lines become more obvious. A splint or guard will help reduce wear and tear. A veneer or crown may also help protect the tooth from cracking.

Bruxism and bite: Your stress, bruxism, occlusion, and diet/habits are all factors. You may have a pitch bite problem, or anterior class i interference, premature contact problem, or nocturnal bruxism, .. Check with your dentist, look into appliance therapy and/ or ortho..