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Missing Teeth (Hypodontia)

Missing teeth, sometimes known as edentulism, occur when one or more teeth are absent from the mouth. Tooth loss can result from various factors, including dental decay, gum disease, trauma, or certain health conditions. Although tooth loss can significantly affect your overall dental health, it is crucial to identify and address it. The consequences can include changes in the alignment of other teeth, which can impact your ability to chew and your general well-being. It also affects speech, self-esteem, and nutrition.

By Able Health I Medically reviewed by Dr. Alireza Estedlal

Page last reviewed: February 2024 I Next review due: February 2026

What is Hypodontia?

Hypodontia is the medical term for the congenital absence of certain teeth. This condition is a type of dental agenesis, which refers to teeth that are congenitally absent, meaning you were born with the issue. An individual with hypodontia has between 1 and 6 missing teeth (excluding wisdom teeth). It typically affects between 2% and 8% of the population and can occur in anyone.

While hypodontia can affect any part of the mouth, the teeth most commonly missing in those with the condition include:

  • Top lateral incisors: Smaller teeth adjacent to the upper front teeth.
  • Top second premolars: Teeth located just in front of the upper molars.
  • Lower second premolars: Teeth located just in front of the lower molars.

Symptoms

The main sign of hypodontia is having between one and six congenitally missing teeth, which can occur anywhere in the mouth, except for wisdom teeth. This condition can affect both primary (baby) teeth and permanent (adult) teeth. Additionally, individuals with hypodontia may have teeth that are smaller than usual or peg-shaped. Gaps and spaces between existing teeth are also common.

On the other hand, hypodontia may be indicative of certain genetic conditions. For example, some individuals with missing teeth may exhibit symptoms of ectodermal dysplasia, which can also cause issues such as:

  • Abnormalities in the nails
  • Thinning hair
  • Hearing impairment
  • Poor eyesight
  • Absence of sweat glands

Is Hypodontia a Birth Defect?

Hypodontia is considered a birth defect, and children are likely to inherit the condition from their biological parents. In some cases, hypodontia may occur in infants and children who have experienced certain diseases and infections or undergone treatments such as chemotherapy or radiation therapy during critical stages of tooth development.

What Causes Hypodontia?

Typically, individuals with hypodontia have an irregularity in their dental lamina, a band of tissue beneath the gums where teeth develop. Most often, hypodontia is related to a family history of the condition. However, various factors can also contribute to missing teeth.

Hypodontia-Associated Syndromes

Hypodontia may occur alongside other disorders or conditions such as:

  • Low birth weight
  • Cleft lip or cleft palate
  • Genetic conditions, like Down syndrome or ectodermal dysplasia
  • Infectious disorders, like rubella or candida
  • Chemotherapy
  • Radiation therapy

How is Hypodontia Inherited?

Several genes play a role in the occurrence of hypodontia, including:

  • WNT1OB
  • EDA
  • EDAR
  • EDARADD

The inheritance of hypodontia can follow various patterns based on the specific gene involved. Like many genetic conditions, healthcare providers typically determine the inheritance pattern by examining the status of both sets of genes—one inherited from each biological parent.

Hypodontia can be inherited through one of four genetic inheritance patterns:

  • Autosomal recessive: Both sets of an abnormal gene (one from each biological parent) must be present for hypodontia to occur.
  • Autosomal dominant: Only one abnormal gene copy, inherited from either biological parent, is required to cause hypodontia.
  • X-linked dominant: A dominant abnormal gene is present on the X chromosome, meaning that an individual assigned male at birth (AMAB) with X-linked hypodontia will pass the defective gene to each of their female children.
  • X-linked recessive: One or two recessive abnormal genes are present on the X chromosome, meaning an individual assigned female at birth (AFAB) with X-linked hypodontia has:
    • 25% chance of having a daughter who carries the abnormal gene
    • 25% chance of having a daughter who does not carry the gene
    • 25% chance of having a son with hypodontia
    • 25% chance of having a son who is not affected by hypodontia

Diagnosis and Tests

How is Hypodontia Diagnosed?

Hypodontia is often diagnosed through dental X-rays, which can confirm the absence of teeth. During an examination, the dentist will also check for other symptoms of hypodontia, such as peg-shaped teeth, small teeth, and gaps between teeth.

Treatment and Management

How is Hypodontia Treated?

Treatment options for hypodontia can include:

Children with missing teeth can use partial dentures until they are old enough for alternative treatments.

Prevention

Is Hypodontia Preventable?

Since hypodontia is generally inherited, it cannot be prevented. However, having hypodontia does not necessarily mean you will pass it on to your children.

Living With

When Should I See a Doctor if My Child Has Hypodontia?

If your child primary teeth have not erupted or come through the gums by age 4, or if the permanent teeth have not emerged by age 14, it is important to see a dentist for evaluation. Consult your dentist during regular appointments if you have concerns about your child’s missing teeth.

A Note from MD.co.uk

Hypodontia is characterised by the congenital absence of one to six teeth. While this condition can cause difficulties with eating and speaking, it is highly treatable. Consult your dentist about treatment options to improve your smile, self-confidence, and overall quality of life if you or your child has missing teeth.