Tooth Agenesis

What is tooth agenesis?

Tooth agenesis is a condition in which a person is born without some of their teeth. In other words, certain teeth never developed. Tooth agenesis can involve both primary (baby) and permanent (adult) teeth. But it most commonly affects permanent teeth.

There are three main types of dental agenesis: anodontia, hypodontia and oligodontia.

Anodontia vs. hypodontia vs. oligodontia: What’s the difference?

• Anodontia: The complete absence of teeth.
• Hypodontia: The absence of one to six teeth.
• Oligodontia: The absence of six or more teeth.

How common is tooth agenesis?

Tooth agenesis affects between 3% and 10% of the U.S. population. It’s slightly more common in women and people assigned female at birth.

How does tooth agenesis affect my appearance?

Dental agenesis can occur in any area of your mouth. But the teeth most commonly missing in people with tooth agenesis include the:

• Lower second premolars (the teeth just in front of your molars on the bottom).
• Upper second premolars (the teeth just in front of your molars on the top).
• Upper lateral incisors (the smaller teeth on either side of your top two front teeth).

How does tooth agenesis affect my oral health?

If you’re missing teeth, it can make eating and speaking more difficult. It can also lead to inadequate bone growth, which may make your jaw look smaller than it should be.

What are the symptoms of tooth agenesis?

The main symptom of tooth agenesis is missing teeth. People with this condition also sometimes have:

• Small, peg-shaped teeth.
• Gaps and spaces between their teeth.
• Taurodontic teeth (large, rectangular teeth that have extremely large pulp chambers).

Tooth agenesis is also a symptom of some genetic disorders, like ectodermal dysplasia. People with ectodermal dysplasia might have:

• Thinning hair.
• Nail abnormalities.
• A lack of sweat glands.
• Poor vision.
• Hearing loss.

What causes tooth agenesis?

An abnormality of the dental lamina usually causes tooth agenesis. The dental lamina is a band of tissue under your gums where your teeth form. Statistically, family history is responsible for most cases of dental agenesis. But other factors can cause it, too.

Tooth agenesis and family history

Parents have the potential to pass dental agenesis down to their biological children. There are several genes involved in tooth formation, including:

• EDA.
• EDAR.
• EDARADD.
• WNT1OB.

Depending on the responsible gene, inheritance can follow different modes. Healthcare providers determine genetic disorders by looking at two copies of a gene — one from each biological parent.

People inherit tooth agenesis in one of four ways:

• Autosomal dominant: Only one copy of an abnormal gene (from either biological parent) is necessary for dental agenesis to develop.
• Autosomal recessive: Two copies of an abnormal gene (one from each biological parent) are necessary for tooth agenesis to develop.
• X-linked dominant: There’s one dominant abnormal gene on the X chromosome. So, a person assigned male at birth who has X-linked dental agenesis will pass that gene to all of their daughters.
• X-linked recessive: There are one or two recessive abnormal genes on the X chromosomes. Therefore, a person assigned female at birth has a 50% chance of having a child with tooth agenesis.

Tooth agenesis and other health conditions

Dental agenesis can occur in combination with other health conditions, including:

• Cleft lip or cleft palate.
• Genetic disorders, such as ectodermal dysplasia or Down syndrome.
• Low birth weight.
• Infectious diseases, like rubella or candida.

Tooth agenesis and medical treatments

Dental agenesis may develop following childhood cancer treatments, such as:

• Chemotherapy.
• Radiation therapy.

How is tooth agenesis diagnosed?

A dentist or other healthcare provider typically diagnoses tooth agenesis during a routine examination. If they suspect dental agenesis, they’ll take dental X-rays to confirm the diagnosis.

How is tooth agenesis treated?

Dentists treat dental agenesis with orthodontics or teeth replacement treatments. These options might include:

• Dentures.
• Dental bridges.
• Dental implants.
• Orthodontic treatment, such as braces.

Children with tooth agenesis usually wear partial dentures until they’re old enough for other treatments.

Can I prevent tooth agenesis?

Tooth agenesis often runs in families, so there’s nothing you can do to prevent it. It’s important to note that even if you have dental agenesis, it doesn’t necessarily mean you’ll pass it on to your children.

What can I expect if I have tooth agenesis?

Tooth agenesis isn’t life-threatening. But it can certainly interfere with daily routines such as eating and speaking. This can have a negative impact on your quality of life.

Talk to your dentist if you decide to seek treatment for tooth agenesis. They can discuss your options with you in detail and find a solution that fits your unique needs and personal preferences.

If your child has dental agenesis, talk to your dentist about treatment options. Many children wear partial dentures until their bones are fully developed. Once they stop growing, they can benefit from dental implants or other more permanent options.

When should I talk to my dentist?

If you’re concerned about missing teeth or spaces in your smile, talk to a dentist about treatment options. There are many different teeth replacement solutions, and they can help find one that works best for you.

What questions should I ask my dentist?

If you have tooth agenesis, here are some questions you might want to ask a dentist or healthcare provider:

• How many teeth are missing?
• What are my treatment options?
• How long can I expect treatment to take?
• Is tooth agenesis affecting my nutrition or digestion?
• Should my child or I have genetic testing for other congenital disorders?

A note from Cleveland Clinic

Tooth agenesis is a condition characterized by congenitally missing teeth. (This means that people with the condition never developed certain teeth.) Without treatment, dental agenesis can interfere with eating, speaking and your overall quality of life. If you or your child has tooth agenesis, talk to your dentist about treatments to restore your appearance and oral health.