Last time we covered the teeth themselves….this time I’ll go into how teeth are anchored in place…and just how unique that anchorage is.As I mentioned last time, teeth are the only organs in our body that are anchored in bone AND are exposed to the outside environment.  You can imagine this is pretty tricky to make work…and it is!  Our bodies are excellent at keeping bacteria and foreign matter out, while keeping the inside perfectly clean.  To have a part of our body that breaches the “Seal” of skin or mucous membrane is unique.

Your teeth are anchored in the bone of your upper or lower jaw via a tiny network of millions of short ligaments, collectively known as the periodontal ligament.  These little ligaments, while only a fraction of a millimeter long, are associated with equally tiny nerves that sense any stretching of the ligament.  Thus, an intact periodontal ligament allows us to have proprioception, or sensation of position.  Imagine trying to chew an almond with no sense of how hard you were biting!

As we move toward the “crown” of the tooth, or the part that sticks out in your mouth, we see a different type of fibers become predominant.  These collagen fibers (13 different types) are woven in a complex web that interconnect tooth to tooth, gum to tooth and gum to bone like a very busy, tangled, taut set of guywires.  Imagine burying a few broomsticks in a row in the dirt and wrapping yarn every which way around them….you get the idea!    These “dentogingival” fibers are incredibly important, as they reinforce the attachment of your gums to your teeth and supporting bone.  Without these fibers, your gums would get pushed around by food and hang loosely around your teeth like worn-out turtleneck sweaters.  Instead, healthy gums hug the teeth and bone, shedding food and thus avoiding trauma and bacterial invasion.

Why is this Important?


OK, here’s where the rubber hits the road.  You’ve heard of gum disease, also known as pyorrhea or periodontal disease.  In this disease, bacteria live between the gum and tooth and induce your body to initiate an immune response.  Your body wants those bugs out of there!  Problem is, in the process of attempting to destroy the bacteria, the collagen fibers discussed above, as well as the anchoring bone, also get destroyed.  These slow, painless changes lead to boggy, red, limp gums that aren’t tough insulators and seal poorly.  Additionally, the bone loss that occurs makes the teeth looser and looser…until they are lost.  More on that later.

Did you know?

The root surfaces of teeth, normally covered by gum and / or bone, have nine times the nerve density of the crown of the tooth (the top that sticks out).  If the root surfaces are exposed due to loss of collagen fibers, the gums don’t hug the teeth as tightly, and thus the root surfaces are exposed to whatever you put into your  mouth…leading to sensitive teeth!