Teeth: Anatomy and Common Diseases
- Medicine Community & Research
- Jan 12
- 4 min read
By: Sanjana Malkareddy
MCR Texas
Introduction
Your teeth play a vital role in digestion by physically breaking down food into smaller portions, making swallowing easier. Children typically have 20 baby teeth that develop between 4 months to 6 years old. Those baby teeth are temporary and will someday fall out leaving room for adult teeth. A normal adult mouth has 32 teeth, except for people with hypodontia (missing teeth) and hyperdontia (extra teeth). With your adult teeth being permanent and the important function teeth have, keeping your teeth healthy is crucial.
Anatomy
Types of teeth
The average adult mouth contains 32 teeth that can be further divided into four categories. These categories each have different functions and characteristics.
The incisors are the most noticeable teeth and include the first four teeth on the upper jaw and lower jaw. Incisors are necessary to bite into food.
One tooth is located in each quadrant, these four teeth make up the canines. The canines are the pointest teeth and help tear into foods.
The following two teeth next to the canines make up the premolars (also called bicuspids). There are eight premolar teeth in total. These teeth share similar characteristics to canines and molars, they aid in tearing and crushing food into s swallowable pieces.
Molar teeth are the last three teeth at the back of the mouth. Since there are three molars in each quadrant, there are twelve in total. If you have wisdom teeth, it can alter the total number of molars you have. The molars are responsible for the majority of the chewing and are beneficial for crushing up food.
Structure of a tooth
A tooth is composed of two primary parts, the crown and the root.
The crown is the part of the tooth that is visible (located above the gum) and is covered in enamel. The crown is composed of:
The anatomical crown is the upper part of the tooth that is visible.
Enamel, being the hardest tissue in the human body, is the outer layer of a tooth. It not only keeps your teeth safe from bacteria but also provides additional strength to protect them from the force that comes with chewing.
Dentin, located underneath the enamel, shields the teeth from hot and cold temperatures.
Making up the majority of the tooth, the root is not visible as the gums cover it. The root also extends into the jaw, holding the tooth in place. The root consists of:
The root canal is a passageway containing pulp.
The cementum covers the root and works with the periodontal tissues to hold your tooth in place.
The periodontal ligament, containing blood vessels and nerves, helps the teeth stay in place by connecting them to their sockets.
The blood vessels provide nutrients to the periodontal ligament, while the nerves control the amount of force you use while chewing.
Located around the roots and composed of tooth sockets, the jawbone secures the teeth in place.
Common Conditions
Tooth Decay
Also called cavities, tooth decay is characterized by small holes occurring when a buildup of acid and bacteria resides on the tooth’s surface. If untreated, the bacteria can continue to penetrate the tooth, eventually reaching the pulp. Cavities can cause pain, heat and cold sensitivity, and may result in tooth loss or infection.
Pulpitis
Pulpitis, or inflammation of the pulp, mainly occurs due to an untreated cavity. The primary symptoms include severe pain and sensitivity in the affected tooth. Pulpitis can result in an infection, leading to the formation of an abscess in the tooth’s root.
Periodontal disease
Periodontal disease is often referred to as gum disease and is an infection of the gums. Receding, bleeding, swollen, or red gums are common symptoms of this disease. It may also lead to foul breath, discomfort, sensitivity, and loosened teeth. Risk factors include smoking, specific medications, and poor dental hygiene.
Malocclusion
Malocclusion, the misalignment of teeth, can result in underbites, overbites, or crowding. It’s typically hereditary but can also occur due to thumb-sucking, prolonged use of pacifiers or bottles, impacted or missing teeth, and ill-fitting dental appliances. This condition is often treatable with braces.
Bruxism
Bruxism is the action of grinding and clenching teeth. People with this condition are typically unaware they have it, and the majority of people only do it while sleeping. Gradually, bruxism can erode tooth enamel, causing damage and tooth loss. It also causes pain in the tooth, jaw, and ear. In severe cases, it can damage your jaw, preventing it from opening and closing properly.
Abscess
An abscess is a pocket of pus that forms on a tooth, caused by a bacterial infection. Symptoms include tooth pain that radiates to the jaw, ear, or neck. Sensitivity in the tooth, fever, swelling or tenderness in the lymph nodes, and swelling of the face or cheeks are also associated with a tooth abscess. If left untreated, the infection can spread to other body parts such as the sinuses or brain.
Tooth Erosion
Tooth erosion is caused by acid or friction and results in the wearing away of enamel. Foods and drinks high in acidity, stomach acid from gastrointestinal conditions, and chronic dry mouth can also cause tooth erosion. Typical indications of tooth erosion include discomfort, sensitivity, and changes in color.
Tooth Impactation
Tooth impaction occurs when there isn’t sufficient space for a new tooth to come in, often caused by overcrowding. While it frequently occurs with wisdom teeth, it can also arise if a baby tooth is lost before the permanent tooth is ready to emerge.
Conclusion
Teeth are essential for everyday life and should be properly cared for. Understanding their anatomy and the common conditions that can affect them is key to maintaining good oral health and preserving these vital structures that contribute so much to our daily well-being.
Citations
professional, C. C. medical. (2024, June 25). Teeth: Types, Function & Care. Cleveland Clinic. https://my.clevelandclinic.org/health/body/24655-teeth
Santos-Longhurst, A. (2018, May 15). Tooth anatomy: Diagram, structure and function, related condition. Healthline. https://www.healthline.com/health/tooth-anatomy#Symptoms%20of%20a%20tooth%20condition
