Why does my child have two rows of teeth?

Quick Answers

Some children are born with extra teeth, a condition called hyperdontia. The most common cause is the presence of supernumerary teeth, which are extra teeth that develop in addition to the normal set of 20 deciduous (baby) teeth. This can result in a child having two rows of teeth in the same location. Other causes include cleft lip and palate, dental lamina cysts, and certain genetic conditions like cleidocranial dysplasia. Treatment usually involves removal of the extra teeth.

What are supernumerary teeth?

Supernumerary teeth are extra teeth that develop in addition to the normal set of teeth. While most people have 20 deciduous (baby) teeth, those with supernumerary teeth develop more than this number. Supernumerary teeth are the most common cause of hyperdontia, which is defined as having more than the normal number of teeth.

Supernumerary teeth can develop in both deciduous and permanent dentition, but they are more common in permanent teeth. They may be found in any region of the dental arch, but most commonly occur in the upper incisor region. The prevalence of supernumerary teeth ranges from less than 1% to 3%. They are more common in males than females.

Supernumerary teeth can be classified into several types based on shape and location:

  • Conical – These have a cone shape and are the most common type of supernumerary tooth.
  • Tuberculate – These have multiple cusps or tubercles and are barrel shaped.
  • Supplemental – These resemble normal teeth and are located beside a normal tooth.
  • Odontomas – These are benign tumors made up of enamel, dentin, cementum and pulp tissue.

The specific cause of supernumerary teeth is not known, but they are thought to arise due to disruptions during tooth development. Genetic factors may play a role along with environmental factors like toxins or radiation. Hyperactivity of dental lamina is often cited as a potential cause.

How do supernumerary teeth cause two rows of teeth?

When supernumerary teeth develop, they can erupt into the mouth along with the normal set of teeth. If enough supernumerary teeth form, this can result in a double row of teeth in a segment of the dental arch or throughout the entire arch in some cases.

For example, a child may develop an extra incisor or premolar beside the normal ones that have already erupted. This could result in two rows of teeth in the front or back areas of the mouth.

In other cases, a less organized pattern of multiple supernumerary teeth erupting throughout the dental arch can lead to a double row of teeth both anteriorly and posteriorly. Eruption of odontomas near normal teeth can also contribute to a double row.

How are supernumerary teeth diagnosed?

Supernumerary teeth are most commonly diagnosed by visual oral examination by a pediatric dentist or orthodontist. The presence of additional teeth alongside or between the normal teeth will be visible. However, some supernumerary teeth remain impacted below the gums and are not visible on an oral exam.

In cases where supernumerary teeth are not visible, they may be detected through dental x-rays. Panoramic x-rays and periapical x-rays can reveal teeth hidden below the gums that have not yet erupted. Supernumerary teeth usually appear similar in density to normal teeth on x-rays.

To confirm a diagnosis of supernumerary teeth, a dentist will perform a clinical exam looking at the teeth already erupted, palpate the gums to feel for unerupted teeth, and take dental radiographs to visualize below the gums. The location and morphology of the extra teeth helps categorize the supernumerary teeth.

Should supernumerary teeth be removed?

Removal of supernumerary teeth is usually recommended, especially if they are causing any complications. Potential complications include:

  • Crowding or displacement of normal teeth
  • Delayed or failure of eruption of normal teeth
  • Diastema or spacing between teeth
  • Formation of cysts due to impacted teeth
  • Tooth decay in supernumerary or normal teeth
  • Root resorption of adjacent teeth

Supernumerary teeth that do not cause any apparent issues can be monitored by a dentist over time. Removal may be pursued if problems develop or are anticipated in the future.

The optimal timing for removal depends on the child’s stage of development. Early removal is ideal in the mixed dentition stage before the permanent teeth have fully erupted. Removal may be recommended later into adolescence or even adulthood if abnormalities are detected at a later stage.

Removal procedures

Supernumerary teeth can be removed by several methods depending on the location and development of the tooth. These include:

  • Extraction – The tooth is simply pulled out if it is visible and has erupted into the mouth.
  • Exposure and extraction – If the tooth is unerupted but near the surface, the gums are opened to expose it for removal.
  • Surgical extraction – Impacted teeth require surgical extraction, involving cutting into the bone to access and remove the tooth.

Dentists will utilize the least invasive extraction method appropriate for the tooth. General anesthesia is sometimes used for involved surgical extractions. Orthodontic braces may also be needed to create space before removal or close gaps after removal.

What is dental lamina cyst?

A dental lamina cyst, also known as a gingival cyst of the newborn, arises from remnants of the dental lamina. The dental lamina is a band of epithelial tissue that develops in the fetus and eventually forms the enamel organs that direct tooth development.

Normally the dental lamina regresses and disappears after all the tooth buds have formed. But remnants may persist and later proliferate into cysts. Dental lamina cysts often present as bluish raised nodules along the alveolar ridge in newborns or young infants.

They are believed to form due to proliferation of epithelial cells from dental lamina remnants stimulated by maternal hormones that crossed the placenta. These cysts are benign and usually regress spontaneously within the first few weeks to months after birth. No treatment is required unless the cyst grows excessively large or causes feeding problems.

How dental lamina cysts relate to extra teeth

While dental lamina cysts arise from remnants of the dental lamina, they are distinct from supernumerary teeth which are extra teeth that develop from tooth buds. However, the persistent dental lamina associated with dental cysts may also lead to additional tooth formation.

This means children with dental lamina cysts have a somewhat higher incidence of supernumerary teeth compared to the general population. So the presence of these cysts at birth can be a warning sign to watch closely for development of extra teeth later on.

Is cleft lip/palate related to extra teeth?

Cleft lip and cleft palate are birth defects that result from failure of the lip and palate to fuse properly during fetal development. Children born with these oral clefts have an opening or split in the upper lip and/or roof of the mouth.

Studies have found that children with cleft lip and/or cleft palate have a higher prevalence of supernumerary teeth compared to the general population. The reported rates of supernumerary teeth range from 4.5% to 10% in cleft lip/palate patients, higher than the less than 1% to 3% prevalence in the general population.

The supernumerary teeth commonly associated with cleft lip and palate include supplemental incisor-like teeth termed mesiodens. The excess tooth development is believed to result from the failure of fusion of facial processes that also caused the cleft anomaly.


In children with cleft lip/palate, supernumerary teeth can complicate orthodontic treatment needed to repair the cleft and properly align the teeth. The presence of extra teeth can limit space or create crowding.

Therefore, early diagnosis and removal of supernumerary teeth soon after detection is often recommended in these patients to facilitate orthodontic treatment.

Is there a genetic syndrome related to extra teeth?

Cleidocranial dysplasia is a rare congenital disorder that can cause abnormal development of the teeth, including the presence of supernumerary teeth. It is an autosomal dominant genetic condition caused by mutations in the RUNX2 gene.

Common dental abnormalities in cleidocranial dysplasia include:

  • Delayed loss of primary teeth and delayed eruption of permanent teeth
  • Prolonged retention of primary teeth, sometimes along with permanent teeth
  • Presence of multiple supernumerary teeth, often many more than normal
  • Failure of some permanent teeth to develop

The supernumerary teeth commonly seen with this condition are supplemental premolars and molars, though extra incisors and canines can also occur. In severe cases, over 20 supernumerary teeth have been reported.

Individuals with cleidocranial dysplasia require thorough dental monitoring and management. Extraction of supernumerary teeth is often needed to allow proper eruption and alignment of the permanent dentition.

When does hyperdontia need to be treated?

The presence of hyperdontia or extra teeth does not always require removal or treatment. Mild forms with only one or two supernumerary teeth that are not causing any apparent problems may only need periodic monitoring.

However, removal is often pursued in the following situations:

  • Supernumerary teeth are negatively impacting normal teeth due to crowding, displacement, or failure of eruption
  • Orthodontic treatment is planned and supernumerary teeth will impede this process
  • Supernumerary teeth increase risk of tooth decay due to crowding
  • Cysts or other pathology develops associated with the extra teeth
  • The teeth are causing a significant double row deformity

Early removal of problematic supernumerary teeth provides the best outcome as it prevents future complications. But even later removal may still be warranted if issues arise.

What is the process for surgical removal?

Surgical removal is necessary for supernumerary teeth that are impacted or unerupted. This involves making an incision in the gums to access and take out the tooth. Removal of visible erupted teeth can usually be done simply by extraction without surgery.

The basic surgical process includes:

  1. Anesthetizing the area – Local anesthetic is used, sometimes along with general anesthesia for young children
  2. Making an incision and flap – An incision is made in the gums to expose the tooth and surrounding bone
  3. Removing bone and tooth – Some bone is removed with a drill/bur to reveal the entire tooth, which is then extracted
  4. Closing the site – The gums are closed with sutures and the site left to heal over several weeks

Impacted supernumerary teeth or complex cases may require an oral surgeon to perform the extraction. Orthodontic treatment before and after extraction is sometimes needed. Regular follow up is necessary to monitor healing and bone growth.

Are there risks with removal?

Surgical removal of teeth does pose some risks and potential complications including:

  • Damage to adjacent teeth
  • Tooth fragments left in the bone
  • Injury to nerves
  • Excessive bleeding
  • Infection
  • Sinus involvement with upper teeth

However, these risks can be minimized by having the procedure done by an experienced oral surgeon. Proper surgical techniques help avoid complications. Meticulous follow-up care promotes normal healing and reduces chances of infection.

What is the recovery like after surgery?

Recovery after surgical extraction of a tooth usually takes around 1-2 weeks. Immediately after the surgery, there may be some bleeding and pain or discomfort at the site. This typically subsides within a few days with proper care.

Some things that can help with recovery include:

  • Using an ice pack on the area initially to minimize swelling
  • Taking over-the-counter pain medication as directed
  • Eating soft foods for a few days
  • Rinsing the mouth gently with salt water
  • Avoiding strenuous activity for 24 hours

The oral surgeon will provide detailed post-op care instructions. Returning for follow-up and suture removal is important. Most of the healing usually occurs within two weeks, but the bone may take several months to fully remodel at the extraction site.

Are there alternative treatment options?

Extracting supernumerary teeth is generally the standard treatment approach. However, not all teeth require removal if they are asymptomatic and not causing any problems.

Other management options may include:

  • Monitoring – Leave the supernumerary teeth in place and check periodically for any changes.
  • Reshaping – Reducing or smoothing the shape of extra teeth to prevent impacts on nearby teeth.
  • Orthodontic space management – Use braces to create space for the supernumerary teeth.

These conservative approaches may be appropriate in select cases where the teeth are well-positioned or Developing a specific treatment plan requires input from an orthodontist and oral surgeon evaluating the child’s condition.

What is the long-term prognosis?

The prognosis is generally positive if supernumerary teeth are properly managed. Early diagnosis and timely removal of problematic extra teeth can prevent complications and allow for normal eruption of the other permanent teeth.

With no treatment, outcomes tend to be poorer with higher rates of:

  • Malocclusion – misalignment and crowding of teeth
  • Tooth impaction
  • Cysts or gum disease
  • Tooth loss

Regular dental monitoring enables early intervention when needed. After removal, there is a chance of recurrence or development of additional supernumerary teeth. Continued follow up throughout childhood can detect any further problems.

With appropriate treatment and proper oral care, children with supernumerary teeth can have positive long-term dental health and proper function.


The presence of extra teeth or hyperdontia in a child often arises due to supernumerary teeth, which are additional teeth that develop alongside the normal dentition. This can result in a double row of teeth if multiple supernumerary teeth erupt.

Early diagnosis, monitoring for complications, and timely removal of any problematic extra teeth is key to managing this condition. Extraction is a common treatment, which may require surgery for unerupted teeth. Prompt evaluation and proper intervention can prevent many future complications.

While hyperdontia may be concerning to parents, the outlook is good with the proper treatment plan. Ongoing dental care and orthodontic treatment as needed can address this issue and allow for healthy dental development.

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