Hypodontia (Absent Teeth)

What is hypodontia?

The first human teeth erupt around 6 months of age and are known as the milk teeth or deciduous teeth. It is then replaced by the permanent teeth later on in childhood. Sometimes this normal process is impaired where the teeth do not erupt at all. Hypodontia is condition characterized by failure of the formation of teeth. The disorder is of developmental origin and more commonly affects the permanent teeth rather than the deciduous teeth.

Hypodontia Types

Hypodontia can involve single or multiple teeth and is also known as oligodontia when multiple teeth (more than 6 teeth except the wisdom tooth) are involved. If all teeth are absent the condition is called as anodontia. Generally missing third molars (wisdom tooth) are not classified as a part of hypodontia.

Hypodontia Symptoms

A tooth is termed as congenitally missing when it does not erupt in the mouth and cannot be seen present within the jaws bones upon examination with dental x-rays. The lower second premolar and upper lateral incisors are most commonly involved congenitally missing teeth. Usually upper central incisors are always present and the pattern of remaining missing and present teeth may vary.

Age of Complete Set of Permanent Teeth

Generally the permanent teeth completely erupt by the age of 13 years except for the third molars (wisdom teeth). The teeth erupt in a chronologic order and  absence of a particular tooth at the age of its eruption and lack of evidence of presence of teeth on a dental x-ray confirms hypodontia.

Small Cone Teeth

Majority of the cases hypodontia is associated with microdontia – a condition characterized by small size of the teeth. Microdontia may be generalized affecting all the teeth or may involve a single tooth. Generally the incisor teeth appear small and conical shaped in cases with microdontia.

Causes of Hypodontia

Females are more likely to experience hypodontia than males. The causes of oligodontia are related to a genetic mutation and transmitted as a dominant trait form parents to offspring. The disorder is almost always present in cases of cleft palate. Other associated disorders with hypodontia include hereditary ectodermal dysplasia and Downs’s syndrome.

Exposure to certain drugs and radiation during pregnancy increases the frequency of hypodontia. Hormonal defects leading to hyperparathyroidism (overactive parathyroid gland) are also involved in the absence of teeth. Rubella virus infection during pregnancy is also linked with development of hypodontia in the baby.

Other associated factors with hypodontia include low birth weight and increased age of the mother during pregnancy. Hypodontia is also more frequently observed in twins. Patients with genetically inherited oligodontia are more prone to develop epithelial ovarian cancer. Certain gene mutations leading to hypodontia may also be involved in development of polyps of the colon and colorectal cancer

Hypodontia Treatment

Treatment of hypodontia varies according to the extent of missing teeth and presence of microdontia.

  • Single tooth hypodontia generally leads to aesthetic problems. Associated with microdontia it may lead to generalized spacing of the teeth. Orthodontic treatment to close the extra space can be carried out in such cases. Spacing can lead to few periodontal problems and periodontal therapy is advised in these patients.
  • Prosthodontic replacement of missing teeth can also be advised in cases where orthodontic treatment is not desired. Single tooth dental implant is also a treatment option.
  • In cases with oligodontia, family history for carcinomas should be noted. Multiple missing teeth can be replaced by removable partial dentures or fixed prosthodontic replacements. Multiple teeth dental implants can be used for achieving aesthetics and functions.

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One Response to “Hypodontia (Absent Teeth)”

  1. stephanie z says:

    hello thank you for this… Will i transfer this disorder to my kids ??? i have many missing teeth about 12 ??? please answer … THANK YOU

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