One of the first things we do with new patients is to tell them exactly how a bite should fit. That way, we can compare their situation to the ideal, which is our objective for every patient. We show the patient how a bite should fit together so that they understand what is wrong with their bite.
Ideally, the upper jaw accepts the lower jaw like a doorframe accepts a door. Additionally, the upper teeth should bite down on the outside of the lower teeth. When biting all the way down, the full length of the lower front teeth should be visible. Furthermore, you shouldn’t bite too deeply over the lower front teeth or have an opening in the front.
The way the bite fits together on the sides is the foundation of our bite. Just like the foundation of a house, it is the most important part of the bite. Even though it is the part nobody sees in the mirror when they smile. The front cusp of the upper molar should fit into the groove of the lower molar so that all the teeth fit together like bricks in a wall.
The most important relationship between the teeth is the fit of the upper canine tooth between the lower canine and the lower first premolar. This is because when you shift your jaw from side to side as you chew your food, and when you clench or grind at night, you glide off of those teeth and help protect your jaw joint. Not only does the fit matter for aesthetic reasons, but they are also important from a functional point of view.
When we compare our family members with ourselves as we try to figure out what might be going on, we can see certain recurring traits.
If the upper jaw is biting on the inside of the lower jaw, we call it a posterior crossbite. We might also see something called an overjet. This is when the upper jaw overlaps the lower jaw, and leaves a gap. An underbite, on the other hand, is when it is in the opposite direction. We may see crowding if the front teeth do not have enough space to be straight.