Cracked Horizontal Front Tooth? (photo)

The best thing to do is to see your dentist soon. Cracks aren't predictable, it may break sooner or later but I think it will break. It's better for your dentist to remove the cracked tooth structure and repair the tooth with composite bonding than to wait for it to break on it's own. This can reduce the chances of the crack exposing the pulp and the need for a root canal.

The tooth is obviously cracked and will eventually break off.  I would be proactive and have your dentist repair it before it breaks away.

Eventually, that cracked portion will break off. You can have the piece removed and replaced with bonding, by your dentist prior to that happening, so you will not be caught somewhere in an emergency situation in the future.