The Big Picture

Let’s start by having a big-picture look at the mouth, starting with your teeth themselves.Most people don’t spend much time thinking about their teeth, chewing, swallowing, or speaking.  However, your teeth play a critical role in all those functions, and are highly specialized to do so.  Notice how your lower lip intersects perfectly with your upper front teeth to make the “F” sound, or how your upper and lower front teeth almost touch to make an “S” sound.  Further, our mouth represents the very beginning of our digestive tract, and has the important role of beginning the process of digestion by breaking food down into more easily digestible pieces.   As such, your teeth can be thought of as units in a grinding apparatus.  When your teeth are healthy and solidly anchored, they are capable of creating incredible forces to break up hard foods.  Adults can generally create  about 250 pounds per square inch of force between their back teeth, with some Northern Inuit populations able to create up to 500 PSI due to their very chewy diet of seal and whale meat!Did you know?

The ability to chew hard foods is critical to the health of the rest of your body.  Whole grains, nuts, meat, fibrous vegetables like celery, and other whole foods generally require a healthy chewing system to be ingested efficiently.  Because critical menu items like dietary fiber and nutrient-dense foods are typically harder to chew, people who can’t chew well due to dental disease or tooth loss often show lower blood levels of important vitamins and minerals.  One interesting scientific study looked at blood nutrient levels in patients before and after they had their teeth extracted and complete dentures made.  It was discovered that the patient’s ability to exert chewing pressure on the food dropped to 20% of its prior (real teeth) level, and the blood levels of key nutrients dropped over the following months due to dietary changes as patients began to avoid harder-to-chew (nutrient rich) whole foods.

Teeth are the hardest tissue in the entire body, and are composed of a few different components.  The enamel, or hardest part, is the bright white layer that covers most or all of the part of the tooth that you can see in your mouth.  The dentin forms the core of the tooth, and most of its bulk.  While it’s less mineralized (and thus softer) than enamel, dentin’s relative porosity creates space for tiny nerve endings to extend throughout the tooth, giving it sensation.  These nerve endings originate in the center of the tooth, where a soft tissue mass known as the “pulp” resides, running up the center much like the lead in the center of a pencil.  The nerves and blood vessels in the pulp provide the ability for individual teeth to have sensation to temperature, sweet, spicy, and pressure.  This sensation is protective insofar as it serves to warn us when we bite into or chew something potentially harmful, like ice or a pebble in our food.

Fast Fact:  The mouth is the only place in the body where a rigid structure breaches the skin or mucous membrane.  Teeth, anchored in bony sockets, emerge through the gums during growth.  The fact that the gums are not pushed away by eating is due to an anatomical “wonder of the world” known as the periodontal attachment (more on that later).