Supernumerary teeth imply the presence of additional teeth apart from the normal number and distribution and may occur during both deciduous and permanent dentition. It may appear at any site in the oral cavity either as single or multiple units, at one or more locations simultaneously. They are associated with numerous genetic conditions and are frequently an incidental finding, but they may cause complications which necessitate their removal, which is the primary treatment strategy.
Patients may not present with any complaints, and the finding of additional teeth may be incidentally discovered during physical examination . However, in patients with symptomatic development, inspection of the oral cavity will reveal the presence of additional teeth. Sometimes they may be asymptomatic; however, they may be often accompanied by local swelling, redness, and sometimes local tissue destruction, which may result in pain. However, close inspection of the oral cavity may not initially reveal the presence of supernumerary teeth, particularly if the tooth did not erupt, which further challenges the physician to make the diagnosis. However, signs such as the ectopic eruption of otherwise normal teeth, rotation of teeth for an unknown reason, or a wide diastema observed on physical examination should alert the physician to investigate the cause of such events. If the supernumerary tooth is visible in the mouth, then the patient may complain of food lodgement, bad breath or difficulty in cleaning that area. Most of the times, patient complain of aesthetic issues in the presence of supernumerary teeth like mesiodens.
The diagnosis of supernumerary teeth is achieved through the use of X-rays of the oral cavity, where additional teeth may be clearly observed. OPG provides a good view of all teeth and is the initial radiographic procedure of choice. Alternative methods include the use of 3D-CT scan, which is somewhat more expensive, but perhaps more efficient in diagnosing additional teeth. In any case, a detailed radiographic workup is necessary to confirm the diagnosis.
When supernumerary teeth are observed in patients, a detailed family history should be obtained, since it has been hypothesized that various genetic diseases are in connection with the development of additional teeth .
Before definite treatment is established, the localization and identification of all supernumerary teeth should be determined (whenever one additional tooth appears, the occurrence of more should be excluded before starting treatment) , as well as the status of the surrounding tissue should be accessed. If the additional teeth cause no complications and no discomfort to the patient, treatment may be postponed, and regular monitoring is sufficient. However, if potential complications such as the formation of cysts, migration to other sites such as the nasal cavity, and subsequent bone destruction are present, then surgical treatment should be initiated as soon as possible . A series of radiographs may be required to assess the location of the supernumerary impacted tooth and for deciding the surgical approach.
Extraction of additional teeth is usually indicated, and early extraction is proven to be of benefit, as it prevents the potential injury to the surrounding tissue. More importantly, tooth extraction in early stages may lead to auto-correction of rotated and displaced teeth, although an increased risk of interfering with adjacent roots of other teeth is present with early tooth extraction. Another indication for early surgery is the normal tooth eruption limited by the presence of an additional tooth. It is established that up to 90% of impacted permanent incisors erupt within 18 months after additional tooth removal, which provides sufficient proof to indicate early surgery.
Post-operative care is equally important in the treatment process, including regular follow-up of patients and observation of the behavior of teeth after extraction of supernumerary teeth.
Supernumerary teeth usually present as aesthetic, but sometimes as a functional issue, and may be debilitating for the patient. However, surgical treatment is effective in resolving the issue of additional teeth, but the surgical approach to this condition must be conducted carefully, to determine how to remove additional teeth without causing post-operative complications.
The exact mechanism of occurrence of supernumerary teeth is not yet understood, and several theories have been proposed, while a combination of environmental and genetic factors has been suggested to play a key role in the development of this condition   . Several genetic syndromes have been associated with this occurrence, including cleft lip and palate, Cleidocranial dysplasia, Gardener syndrome (also known as familial colorectal polyposis), Fabry disease, and many other, implying a genetic component in the pathogenesis  .
Supernumerary teeth can be classified according to chronology, location, morphology and their orientation . Chronologically, they are classified into pre-deciduous, similar to permanent teeth, and post permanent or complementary teeth; in terms of morphological classification, they are divided into conical, supplemental, tuberculate, and odontoma; topographic distribution divides supernumerary teeth into paramolars, mesiodens, distomolars, and parapremolars. Orientation implies whether teeth are vertical, transverse, or inverted, and these guidelines enable somewhat easier classification of supernumerary teeth .
Prevalence rates of supernumerary teeth are established to be between 0.8% and 3.6% , and this disorder is encountered in males more commonly, with a 2:1 ratio, for reasons that are not yet understood. Supernumerary teeth much more frequently occur during the permanent dentition period rather than in the deciduous period .
The appearance of supernumerary teeth occurs for unknown reasons, but when they do appear, they can potentially cause significant damage to the surrounding structures . In a certain number of cases, they may remain unerupted, and cause minimal damage, but in some cases, they may also induce displacement and rotation of adjacent teeth, as well as crowding, and eruption into the floor of the nasal cavity, which may result in tissue destruction and the development of follicular cysts.
Prevention of this condition cannot be performed at the moment, as the cause and the mechanism of occurrence have not been identified.
Supernumerary teeth are defined as those that appear in addition to the fixed number of teeth that are present during deciduous or permanent dentition. Their location can be anywhere in the oral cavity and may appear either as single or multiple teeth, both unilaterally and bilaterally. They are a rare occurrence  and are associated with several genetic syndromes, such as cleft lip and palate, Fabry disease, and many others, which links the development of this disorder to a genetic cause. A substantial number of cases are undiagnosed, because they may not erupt and be not visible, and are often an incidental finding on X-rays. It is more prevalent among males because of unknown reasons. The appearance of supernumerary teeth more commonly occurs during the process of permanent dentition . The presence of extra teeth can be asymptomatic, but patients often report misalignment or rotation of their teeth, and depending on the level of the eruption, they can cause damage to the surrounding structures, or they can cause extensive focal swelling and necrosis . The diagnosis is confirmed by radiographic techniques, such as X-ray techniques including the orthopantomogram (OPG), and three-dimensional computed tomography (3D-CT). Treatment primarily involves surgical removal of additional teeth. However, surgical treatment follows certain guidelines in terms of optimal timing and initiation of treatment, guided by imaging results.
Supernumerary teeth is the term for the presence of an increased number of teeth than regular, and they may appear during both deciduous and permanent dentition. Most patients have one additional tooth, but two or more teeth may appear as well, and they can appear in different locations simultaneously. It is still not understood why supernumerary teeth appear. A combination of genetic and environmental factors has been proposed in the pathogenesis model of supernumerary teeth. Between 0.5 and 3% of children in certain studies have been established to have additional teeth, and it has been noted that this syndrome develops more commonly among males. Patients with supernumerary teeth are usually asymptomatic, as the additional teeth may not cause any complaints, but the majority of patients report some degree of discomfort, and most common symptoms include pain, swelling, as well as rotation of regular teeth. Depending on the level of tooth eruption, the patient may have minimal changes in the oral cavity, or sometimes, local redness, swelling, and tissue destruction may occur. In addition to the discomfort, the supernumerary teeth may cause aesthetic problems that may be prominent as well, which can be a sole indication for treatment in some patients. Physical examination of the oral cavity may reveal an additional tooth, but this may be difficult if the tooth eruption has not occurred yet. For these reasons, a definite diagnosis of supernumerary teeth is confirmed by performing an X-ray of the entire oral cavity, usually called the orthopantomogram, which gives a clear view of all the teeth, and physicians may easily identify the additional tooth. Another technique which might be used is three-dimensional computed tomography, which is more expensive but provides a better view of the oral cavity and the soft tissues.
Treatment of supernumerary teeth is primarily surgical, but surgical treatment should be carefully evaluated through a full workup, and evaluation of adjacent tissue, since these teeth may cause local tissue injury, and sometimes even protrude to adjacent structures and cause bone destruction. However, surgical treatment provides maximal efficacy in resolving this condition.