Hypodontia: Cause, Signs, Risks & Treatments

Hypodontia: Cause, Signs, Risks & Treatments

Oral health conditions are not always preventable. Hypodontia or congenitally missing teeth is an example of that. According to the NHS, 3-5% of the people in the UK are born with missing teeth. This not only causes aesthetic and functional problems but can also be financially burdensome. This is because treatment for hypodontia can take years, and still, it will remain with you for a lifetime.

Normally, a child will have a full set of primary teeth by the age of 3; between the ages of 12 and 14, all their permanent teeth come out. An abnormality in their interruption can be a sign of this problem. It is possible to detect it early on through preventative X-rays at an early age. 

What Is Hypodontia? 

Hypodontia is the most common dental anomaly that refers to the absence of 1 to 5 teeth. It results in the formation of gaps and spaces, which can result in the misalignment of the adjacent teeth and cause a deep bite and overjet, among other problems. 

Although it can affect both primary and permanent teeth, usually, it’s the latter that’s affected. There is a possibility that if a primary tooth is missing from birth, its permanent counterpart might be missing as well. 

It is common for hypodontia to coexist with other symptoms of genetic disorders. For instance, it can occur due to ectodermal dysplasias – a group of inherited disorders that affects the teeth, nails, hair, skin, and sweat glands. It may also exist in an isolated manner without being part of any syndrome. 

According to the American College of Prosthodontics, wisdom teeth, upper lateral incisors (right next to the centre teeth), and second premolars are more commonly missing. It’s unclear whether this condition affects the upper jaw more than the lower jaw or whether it’s more prevalent in front of the mouth than in the back.

Tooth Agenesis 

It should be noted that hypodontia is a type of tooth agenesis, a condition in which teeth are congenitally missing. Depending on the number of teeth that are missing, it has 3 broad classifications. 

  • Oligodontia – It refers to the congenital absence of 6 or more teeth (primary or secondary). It more commonly occurs as a result of a syndrome. 
  • Hypodontia – As mentioned above, it refers to the congenital absence of 1-5 teeth. 
  • Anodontia – It refers to the genetic condition in which all teeth are missing at birth. It is quite rare, and its incidence is less than that of hypodontia and oligodontia. 

Here, it should be noted that there may be slight variations in the definitions of these dental anomalies when it comes to the number of teeth. 

What Are The Signs & Symptoms of Hypodontia?

The following signs can be indicative of the presence of hypodontia: 

  • Microdontia – a condition in which a person has teeth that are smaller than normal. 
  • Abnormal Retention of Primary Teeth – In the case of hypodontia, the permanent counterpart of the primary tooth may be missing. This delays the resorption of the primary tooth’s root. This means that it doesn’t fall out and can stay in place for 40-50 years. 
  • Taurodontism – A dental anomaly that affects the shape of the tooth. The body of the tooth is enlarged, along with the pulp chamber, while the roots of the tooth are reduced in size as a result. 
  • Abnormal Eruption – The absence of adjacent teeth or the space for them to come out can result in the abnormal eruption of secondary teeth. 
  • Transposition of Permanent Teeth – It is also possible for adjacent teeth to interchange their positions with each other – which is known as transposition. 
  • Enamel Hypoplasia – It refers to a condition in which the enamel on the teeth is missing. As a result, the tooth becomes prone to breakage and decay. 

Keep in mind that hypodontia affects the natural shape of the teeth. Other than being small, they may also have a peg-shaped or conical appearance. 

What Causes Hypodontia? 

The exact cause of hypodontia is not known. However, there are some explanations: 

Genetics

Some evidence suggests that genetic factors may play a role in the development of hypodontia. For instance, hypodontia occurs more commonly in monozygotic twins (identical twins) than in dizygotic ones (fraternal twins), which indicates the influence of genes. 

Hundreds of genes are involved in tooth development, and an abnormality in them can result in this dental anomaly (including as a symptom of another syndrome). Because of the combination of the genes involved, the incidence of hypodontia is higher in females than males. 

Environmental Factors

Along with genetics, hypodontia is also believed to occur due to environmental factors. Exposure to toxic drugs, trauma, and infection can cause this dental anomaly.

For instance, research has found that hypodontia was more common in children who were exposed to thalidomide in utero (this drug is responsible for causing severe birth defects in many children in the 60s). Chemo and radiation therapy may also be responsible for hypodontia. Smoking may be another risk factor for congenitally missing teeth. 

Evolution

The size of the human jaw has shrunk significantly, and according to researchers at Stanford, it is due to the changes in our lifestyle. It has been suggested that hypodontia is a result of an evolutionary adaptation to this shrinking of the jaws, so it’s not exactly an anomaly. However, this view isn’t widely held.

What Are The Effects of Hypodontia? 

Hypodontia can cause severe cosmetic and functional problems. Missing teeth can affect the alignment of the adjacent teeth. They can shift into the empty space, which can cause problems with the bite. Other than that, hypodontia can also affect the speech and chewing ability of a person. 

The growth of their jawbone can also be negatively affected, which will change their overall facial structure. Gum disease is another hazard of this dental anomaly, and it can worsen oral health, impacting the health of the other teeth. All these factors can lower the overall quality of life of an individual (especially growing children) as they may avoid socialisation. 

What Is The Treatment For Hypodontia? 

The treatment for hypodontia is complicated because it requires a multidisciplinary approach. You may be required to get the help of a paediatric dentist, an orthodontist, a prosthodontist, and an oral and maxillofacial surgeon. That’s because different problems related to hypodontia need to be addressed. For instance, you may need the following: 

  • Braces – Since missing teeth will result in spaces and gaps, one way to avoid the misalignment of teeth is to close the gaps systematically. This is possible through the wearing of braces. 
  • Dental Coil Spring – This is a special spring placed between two teeth to create space between them. This can help in the placement of an artificial tooth missing due to hypodontia. 
  • Tooth Extraction – Another recommended treatment option may be tooth extraction. If the teeth are too crowded, the extraction of some teeth can help ensure a normal alignment. 
  • Dental Bridges – A dental bridge can help if a gap has been created by one or more missing teeth. It is made with dental crowns that are usually held in place by false teeth being cemented to the existing adjacent teeth. 
  • Dental Implant – For missing teeth, dental implants are more commonly used. They consist of titanium screws embedded into the jawbone; false teeth are placed on top of them. However, it should be noted that this treatment may not be recommended at an early age while the jawbone is still growing. 
  • Dentures – Dentures are fixed or removable dental appliances that can be worn if too many of your teeth are missing. These artificial teeth fit over the gums to restore functionality to your mouth. 

Children should start having their dental X-rays at an early age. This will help in the detection of any missing teeth. Missing teeth are easier to restore sooner rather than later when teeth have shifted a lot. Also, keep in mind that depending on the severity of the problem, the treatment can take years to complete. 

Concluding Remarks 

Hypodontia is a problematic dental anomaly that can cause significant oral health problems. The exact cause of this problem isn’t known, and since a person is born with it, it may not be possible to prevent it. However, different treatments are available to fix the different problems that can arise as a result of it. 

The treatment can be quite complicated and expensive, but without it, the quality of life of an individual can be badly affected. Early treatment can help make matters less complicated which is why dental X-rays at an early age can help. If you notice delayed or abnormal tooth development in your child, you should make sure to get in touch with a dentist.