A supernumerary tooth is an additional tooth to the normal set of teeth. It may closely resemble the teeth of the group to which it belongs, i.e, molars, premolars or anterior teeth, or it may bear little resemblance in size or shape to the teeth with which it is associated.

It is also called as ‘hyperdontia’. It is defined as any tooth or tooth substance in the excess of the usual configuration of twenty deciduous or thirty two permanent teeth.

Pathogenesis and etiology

• The various factors which are responsible for formation of supernumerary teeth as follows:
• Phylogenetic reversion theory—this theory is nowadaysdiscarded.
• Dichotomy theory—this theory states that tooth bud issplit to form two different tooth,
• Hyperactivity of dental lamina—a supernumerary toothdevelops from 3rd tooth bud arising from dental lamina near the permanent tooth bud.
• Hereditary—it is inherited as an autosomal dominant trait, when associated with syndromes. It is inherited as an autosomal recessive trait when associated with only supernumerary teeth. Supernumerary teeth are most commonly found in relative of affected children than in general population.

Four different morphological types of supernumerary teeth have been described:

• Conical
• Tuberculate
• Supplemental
• Odontome

Conical. This small peg-shaped conical supernumerary tooth is most commonly found in the permanent dentition. It develops with root formation ahead of or at an equivalent stage to that of permanent incisors and usually presents as a mesiodens. The conical supernumerary can result in rotation or displacement of the permanent incisor, but rarely delays eruption.

Tuberculate. The tuberculate type of supernumerary possesses have more than one cusp or tubercle. It is frequently described as barrel-shaped and may be invaginated. Root formation is delayed compared to that of the permanent incisors. Tuberculate supernu- meraries are often paired and are commonly located on the palatal aspect of the central incisors. They rarely erupt and are frequently associated with delayed eruption of the incisors.

Supplemental. The supplemental supernumerary refers to a duplication of teeth in the normal series and is found at the end of a tooth series. The most common supplemental tooth is the permanent maxillary lateral incisor, but supplemental premolars and molars also occur. The majority of supernumeraries found in the primary dentition are of the supplemental type and seldom remain impacted.

Odontome. The term ‘odontoma’ refers to any tumour of odontogenic origin. Odontoma represents a hamartomatous malformation rather than a neoplasm. The lesion is composed of more than one type of tissue and consequently has been called a composite odontoma. Two separate types have been described, the diffuse mass of dental tissue which is totally disorganized is known as a complex composite odontoma; whereas, the malformation which bears some superficial anatomical similarity to a normal tooth is referred to as a compound composite odontoma.

According to location
• Mesiodens—it is located at or near the midline in the incisal region of maxilla between central incisors . It is a small tooth with cone shaped crown and short root. It may cause retarded eruption, displacement or resorption of adjacent root. It frequently causes improper alignment.

• Distomolar—it is found in molar region frequently located distal to 3rd molar. Generally, these teeth are smaller than normal 2nd and 3rd molar, crown morphology is highly abnormal.

• Paramolar—it is supernumerary molar, usually small and rudimentary and is situated buccally or lingually to one of the maxillary molars or interproximally between 1st, 2nd and 3rd maxillary molars.

• Peridens—supernumerary teeth that erupt ectopically, either buccally or lingually to the normal arch are referred as peridens.

Radiographic features

When it is needed—if abnormal clinical signs are present you can go for OPG examination, IOPA, occlusal radiographic examination.

Significance—radiograph will aid in determining the location and number of unerupted teeth. It can also used to see if there is any cyst formation.

Appearance—theirradiographicpictureischaracteristic of teeth.

Management

• Surgical extraction—it depends on potential effect on normal dentition, their position, number and complications that may result from surgical removal. If required, they should be extracted.

REFERENCE- SHAFER’S TEXTBOOK OF ORAL PATHOLOGY 8TH ED AND ANIL GHOM TEXTBOOK OF ORAL MEDICINE TEXTBOOK OF ORAL MEDICINE