Malocclusion or “bad bites” is one of the most common dental problems. When you have malocclusion, your upper and lower teeth don’t align when you close your mouth. Malocclusion typically happens when your teeth are crowded — meaning your teeth are too large for your mouth — or are crooked. But it can also happen if your upper and lower jaws aren’t aligned. Malocclusion is usually treated with orthodontics or braces. Some more serious malocclusion might require surgery.