Why am i getting so many craze lines on my lower incisor teeth.i am 34, and i cannot grind on those teeth, because i have a overbite, they don't touch.

Usage: Daily usage when you bite into food (like a sandwich, or if you eat ribs, or peaches/nectarines and "hit" the pit) or traumatic injury (accident or fall) can cause this. Any harmful habits like biting your nails, chewing on pens or pencils? Plus, when you are sleeping, you may bring your lower jaw far enough forward to cause the teeth to contact. See you dentist for their recommendation.

Have dentist check: Your jaws border movements, remember you're not just simply in a constant static bite position all day. Yes, you do have a habitual centric occlusion, but you need to check with your dentist about your anterior guidance, and excursions, protrusions, and look into guards, splints, orthosis, etc. If necessary.

Jaw positions: Most people don't realize how much movement they get from their lower jaw. Craze lines typically develop as a result of excessive force being applied to teeth. Even though you may not be able to consciously move your teeth together, you may be doing it subconsciously at night and that's why you're getting the craze lines. Check with your dentist to let them help determine the cause.

Trauma: Craze lines usually caused by trauma, such as biting into ice or hard candy, or from pernicious habits, such as ginding your teeth at night when you sleep, chewing on pens/pencils, etc. Please see your Dentist. Good detective work is necessary to find out why, and what can then be done to reduce future damage.