Despite their small size and bone-like appearance, your teeth are made up of several different components. Understanding the anatomy of a tooth can help you care for your teeth and make sense of various dental procedures. There are four basic parts of a tooth – the enamel, the dentin, the pulp, and the cementum – and each has a specific location, composition, and function. To better understand this quartet, as well as the other elements that make up the anatomy of a tooth, please scroll down.
Anatomy of a Tooth
Formation of Teeth
Believe it or not, your teeth begin to form before you are born. Although they won’t show up right away, your twenty primary teeth (also known as “baby teeth”) begin to form during your sixth week and eighth week in utero. Permanent teeth develop during the twentieth week in the womb. If teeth do not develop at this time (or near it), they won’t form at all.
The Crown, the Neck, and the Root
Before we dig into specific components, it is important to note the difference between the top and the bottom of the tooth. The crown, which is the portion of the tooth above the cementoenamel junction (a.k.a., the neck of the tooth), is covered in enamel and composed largely of dentin. After it “erupts,” it is almost always visible. The root, which is located below the cementoenamel junction, is covered in cementum and located inside the bone socket. Although it is also mostly composed of dentin, it has pulp canals as well. Different teeth have different numbers of roots, typically varying between one and three (though molars sometimes have four or more).
The Complex Anatomy of a Tooth
All of your teeth, from the incisors and canines to the molars and wisdom teeth, contain several important parts. The following distinct components make up the anatomy of a tooth:
- Enamel: Enamel covers the outermost layer of the top of the tooth (the crown). It is the hardest and most mineralized tissue in the body, which is why it can be relied upon to crush up our food. However, enamel is also susceptible to tooth decay, so you must protect it through good dental hygiene practices. Enamel is not composed of living cells, so if it becomes damaged, only a dentist can repair the tooth. It varies in thickness over the surface of the tooth and is thinnest at its border. Minerals make up 96% of enamel’s content, with water and organic material composing the remainder.
- Dentin: Dentin is the layer of the tooth under the enamel. Although it is also a hard tissue, it is not as tough as enamel, so if decay reaches it, the bacteria can reach your dental pulp through millions of tiny tubules (hollow tubes or canals) in the dentin. If this happens, your tooth will quickly become infected and painful if it is not treated by a dentist. Dentin that is not covered in enamel will also be sensitive to heat, cold, acidity, sticky foods, etc. It is composed of 70% inorganic material, 20% organic material, and 10% water.
- Pulp: Pulp is found at the core of the tooth, within an area known as the pulp chamber. It contains nerve tissue, blood vessels, and connective tissue, which make it quite sensitive. If tooth decay reaches your pulp, you will experience pain and will likely need to have a root canal performed to remove the infected pulp and replace it with an inert material.
- Nerves and Blood Vessels: Nerves and blood vessels supply each tooth with nutrients through the pulp.
- Cementum: The root of your tooth is not covered by enamel. Instead, it is coated with cementum, a hard, calcified substance that attaches the tooth to the periodontal ligament (connective tissue that joins a tooth’s root to its socket). Cementum is much softer than enamel and slightly softer than dentin. If it is exposed through gum recession, it quickly wears away due to its thin structure and low mineral content. Cementum is composed of 45% inorganic material, 33% organic material (mostly collagen), and 22% water, and it has a yellowish color.
The components listed above are surrounded by other structures for protection and support. Although they aren’t officially part of the teeth, these structures’ existence and health is crucial in keeping the teeth in good condition.
- Gingiva: More commonly known as “gums,” gingiva is a mucosal tissue that covers your jaws. Some of it is visible in the mouth, and some of it is not. Some of it attaches to the tooth, some touches the tooth, and some doesn’t make contact with the tooth at all. Without proper and gentle oral hygiene, you can cause gum recession or gingivitis (i.e., gum disease).
- Periodontal Ligament: A fibrous tissue, the periodontal ligament attaches the cementum of the tooth to the alveolar bone. Its size decreases over time, and it performs many important functions including attachment, support, formation of bone, resorption of bone, sensation, and eruption. When you chew or bite, you place pressure on your periodontal ligaments and the sensation is interpreted by the nerve fibers.
- Alveolar Bone: The alveolar bone, which is a part of the jawbone, features small pits or hollows (also known as tooth sockets or dental alveoli) that contain the teeth. It is a thickened ridge and without it, the teeth would not stay in place.
Although your teeth are strong, they rely on you for care. Without regular brushing and flossing, a healthy diet (limiting sugary and acidic foods/beverages), and routine visits to your dentist, your enamel will waste away. And as you now know, this can affect the dentin and pulp, placing the entire tooth at risk. Luckily, you can easily protect your teeth using some basic dental hygiene.
Your teeth were meant to last a lifetime, so take care of them! If you’re looking for an experienced, reliable, and friendly dentist in or near Springfield, Missouri, contact Wilkinson Dental. Dr. Wilkinson and his team will give you the personalized treatment you deserve using state-of-the-art technology. Schedule your first appointment today by calling 417-708-0556 or requesting an appointment online. We look forward to hearing from you!