One Tooth, Many Layers: Dental Anatomy Explained
One Tooth, Many Layers
Imagine your teeth much like a candy apple: A hard outer shell protects the softer inner layers. Here is your dental anatomy explained, from outer to innermost tooth layers.
What it is: The outer layer of your tooth that has a white appearance.
What it’s made of: Composed mostly of calcium phosphate, this is the hardest substance in the human body.
What you should know: Like your hair, tooth enamel isn’t composed of living cells, which is why you can tap on it and chew with it without experiencing pain. Unlike your hair, however, tooth enamel can’t grow back. If you lose it, it’s gone for good.
What it is: The tissue just underneath your enamel that connects and binds your teeth to your gums and jawbone.
What it’s made of: Tough, connective tissue.
What you should know: Cementum can look different on everyone: 60 percent of teeth have cementum that overlaps enamel, 30 percent of teeth have cementum that meets enamel and the remaining 10 percent have a gap between their cementum and enamel, according to the University of Minnesota.
What it is: The tissue that makes up most of your tooth and lies under the enamel and cementum.
What it’s made of: Living cells that are harder than bone, but not as hard as dental enamel.
What you should know: Dentin’s cells release a hard, mineralized substance and are sensitive to temperature changes and pressure.
What it is: The more sensitive, inner layers of your teeth.
What it’s made of: Living cells that have blood vessels and nerves running through them, meaning this can be a sensitive, high-pain area if decay and bacteria reach into the pulp.
What you should know: Just like your body, pulp is made mostly of water — about 75 to 80 percent. As you age, the pulp can develop denticles or “pulp stones” that are small, stone-like objects made of calcium.
Do you know your incisors from your molars? Here’s what you should know about dental anatomy when it comes to the different tooth types.
Wisdom Teeth: Also known as your “third” molars, your wisdom teeth are the last teeth that will come in, usually between ages 17 and 25. Scientists theorize wisdom teeth are late to the dental party because our ancestors enjoyed a diet of leaves, roots, nuts and meats that required strong chewing power. Today, diets are much softer, and jaws also have become smaller through the years. Some people’s wisdom teeth never come in while others come in and crowd the mouth, cause headaches or other aches and pains. If you have your wisdom teeth removed at an earlier age when the teeth are softer, you are less likely to experience pain and post-surgery complications.
Molars: After your wisdom teeth, the molars are the backmost set of teeth. These teeth are flat on their crowns or tops, making them ideal for grinding your food. In total, you have eight molars. Studies of homo erectus and Neanderthal skeleton molars has revealed that cooking food has dated back to 1.9 million years ago, another evolutionary indicator that food became softer and easier to chew, according to Scientific American.
Premolars: You have eight premolars that bridge the gap between your front teeth and the back molars. They are smaller in size, but still retain chewing power.
Canines: Canine teeth are more than just fodder for vampire lore. You have four, and they are the longest and only teeth in your mouth with one cusp.
Incisors: Your incisors are the teeth you present to the world. You have four on your upper gum line and four on your lower. They are useful in cutting and tearing foods — dig in!