Introduction
Having an extra tooth, also known as a supernumerary tooth, is a relatively common dental condition that affects around 2-3% of the population. An extra tooth can grow in many different areas of the mouth and can cause various problems if left untreated. This article will provide an overview of supernumerary teeth, their causes, potential issues, and the treatment options available.
What is a Supernumerary Tooth?
A supernumerary tooth is an extra tooth that grows in addition to the normal set of teeth. Humans normally have 20 primary teeth and 32 permanent teeth. Supernumerary teeth are teeth that form outside of this typical formula. They are sometimes referred to as extra, supplementary, or accessory teeth.
Supernumerary teeth can grow on the upper or lower jaw and may erupt into the mouth fully or remain impacted below the gumline. They can form singly, multiply, unilaterally, or bilaterally in the maxilla or mandible. The most common extra teeth are mesiodens, which erupt between the upper central incisors. Other common locations include between the upper lateral incisor and canine (distomolar), distally behind the third molars (fourth molars), and premolars.
Prevalence and Occurrence
Supernumerary teeth occur more frequently in males than females, at a ratio of roughly 2:1. The prevalence of supernumerary teeth ranges from 0.1-3.6% in the general population, with permanent extra teeth being more common than primary.
Supernumerary teeth occur more often in certain disorders, including:
| Disorder | Prevalence |
|---|---|
| Cleidocranial dysplasia | 90% |
| Gardner’s syndrome | 20-30% |
| Fabry disease | 24% |
| Ellis-van Creveld syndrome | 50-60% |
| Ehlers-Danlos syndrome | 12-14% |
| Incontinentia pigmenti | 28% |
| Trichorhinophalangeal syndrome | 14% |
Etiology
The exact causes of supernumerary teeth are not fully understood but are likely multifactorial. Some of the possible contributing factors include:
– Hyperactivity or disturbances of the dental lamina during tooth development
– Splitting of tooth buds or a third tooth germ
– Genetic and environmental factors
– Excess growth factors or inadequate growth inhibitors during odontogenesis
– Syndromes like cleidocranial dysplasia and Gardner’s syndrome
Supernumerary teeth tend to have a strong genetic component and often run in families. Environmental factors like radiation exposure may also play a role in some cases. Ultimately, the presence of extra teeth represents developmental alterations or hyperactivity of the cells responsible for tooth production.
Complications and Effects
In many cases, supernumerary teeth remain impacted and do not erupt into the mouth or cause any issues. However, they can lead to a variety of complications, including:
– Failure or delayed eruption of permanent incisors
– Crowding, displacement, or rotation of adjacent teeth
– Abnormal eruption sequence
– Tooth impaction
– Crowding or stressing of the alveolar bone
– Aesthetic or functional problems like malocclusion
– Increased predisposition to dental caries
– Cyst formation or root resorption of nearby teeth
– Crowding that causes an increased overjet or overbite
– Interference with orthodontic alignment
– Nasal cavity growth disturbances
The effects range from mild cosmetic irregularities to severe functional impairments and disruption of permanent dentition. That is why early diagnosis and treatment of supernumeraries is crucial.
Types of Supernumerary Teeth
Supernumerary teeth can be classified into two types based on shape:
1. Supplemental Teeth: Resemble normal teeth in size and shape.
2. Rudimentary Teeth: Dysmorphic and smaller in size. Common examples are conical teeth and tuberculate teeth.
Some other unique types of supernumeraries include:
– Paramolars: Extra molars distal to the third molars
– Distomolars: Extra molars distal to third molars
– Parapremolars: Additional premolars not associated with a complementing premolar
– Mesiodens: Extra tooth in the maxillary central incisor region
– Odontoma: Non-functional mass of dental tissue
Identification of the type of supernumerary can help determine the appropriate treatment approach.
Diagnosis of Supernumerary Teeth
There are several ways that extra teeth may be discovered in a patient:
– Clinical examination – Unexpected teeth or abnormalities noticed during routine dental exam.
– Radiographs – Supernumeraries often detected by panoramic radiograph, cone beam CT, or periapical radiographs.
– Delayed tooth eruption – Failure of permanent teeth to erupt may indicate an underlying supernumerary blocking it.
– Incidental finding – Supernumerary discovered when evaluating or treating another condition.
If an extra tooth is suspected, imaging and possibly three-dimensional scanning will be used to confirm the diagnosis and visualize the orientation and location of the tooth/teeth. Important factors include whether the tooth is erupted or impacted, single or multiple, and how it is positioned relative to adjacent teeth.
Treatment Options
If no pathologic conditions or complications are present, no treatment may be required beyond monitoring. However, surgical removal is often recommended to prevent or resolve issues from the supernumerary tooth. The optimal time for removal is disputed, but options include:
– Early removal between ages 6-10 if space is needed for permanent incisors
– Postponement until root development of adjacent teeth is mostly complete
– Removal whenever complications or problems from the extra tooth arise
The surgical extraction technique will depend on the tooth position. Common approaches include:
| Technique | Description |
|---|---|
| Simple extraction | For supernumeraries that have erupted into the mouth |
| Surgical exposure | When tooth is impacted with partial eruption |
| Surgical flap | Open flap provides access to deeply embedded teeth |
Non-surgical space management may be needed after removal to prevent migration of adjacent teeth into the empty space. Follow-up X-rays are also important to verify complete removal and normal healing.
Prevention
There are no evidence-based preventive measures known for supernumerary teeth, given that the causes are not well established. Prompt removal soon after development is probably the best approach for preventing complications.
Genetic counseling may be indicated for some syndromes where supernumeraries are common. Further research is still needed to determine if there are ways to prevent their occurrence altogether.
Outcomes and Prognosis
The majority of cases involving supernumerary teeth have positive outcomes when managed properly. Early diagnosis and treatment lead to better prognosis by minimizing their potential effects on permanent dentition.
With appropriate surgical extraction and follow-up care, most functional and aesthetic issues can be prevented or corrected. However, supernumeraries that go untreated for prolonged periods have higher risks of causing permanent impacts on occlusion and alignment.
Regular dental monitoring is important even after removal to ensure normal tooth eruption and watch for any residual effects. Overall outlook is good in most patients when supernumerary teeth are removed in a timely, careful manner.
Conclusion
Supernumerary teeth are extra teeth that exceed the normal dental formula, although they may not always erupt into the mouth. These extra teeth can develop as single or multiple teeth in various locations in the maxilla and mandible. Supernumeraries may be classified as supplemental or rudimentary based on morphology.
While supernumerary teeth are relatively common dental anomalies, their causes are multifactorial and not fully understood. They tend to develop most often in males and can be associated with certain genetic syndromes. Although supernumeraries may not always cause complications, they can lead to crowding, displacement, cysts, and other functional problems in some cases.
Therefore, early diagnosis with proper radiographic imaging is recommended, followed by careful surgical extraction and monitoring to prevent permanent effects on occlusion and dental alignment. With prompt management, most patients with supernumerary teeth have excellent long-term outlook and normal dentition.