|Year : 2016 | Volume
| Issue : 2 | Page : 54-56
Concomitant supernumerary tooth with partial anodontia in the mandibular anterior region: A nonsyndromic rare condition
Madhuri Alankar Sawai
Department of Periodontology, Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India
|Date of Web Publication||27-Jun-2016|
Madhuri Alankar Sawai
C-765, Ground floor, Rear Part, New Friends Colony, New Delhi - 110 065
Source of Support: None, Conflict of Interest: None
Partial anodontia is the failure of one or more teeth to develop. It is quite common in the permanent dentition. The third molars, mandibular second premolars, and maxillary lateral incisors are the most common teeth to be congenitally missing. However, it is rare in the mandibular arch. A combined occurrence of a supernumerary tooth with hypodontia is still rarer, especially when it occurs in the same dental arch and in a nonsyndromic situation. Only a few cases of this condition have been reported in the dental literature. The case reported here describes one such rare occurrence.
Keywords: Anodontia, congenital, mandibular incisors, nonsyndromic, supernumerary tooth
|How to cite this article:|
Sawai MA. Concomitant supernumerary tooth with partial anodontia in the mandibular anterior region: A nonsyndromic rare condition. Dent Med Res 2016;4:54-6
|How to cite this URL:|
Sawai MA. Concomitant supernumerary tooth with partial anodontia in the mandibular anterior region: A nonsyndromic rare condition. Dent Med Res [serial online] 2016 [cited 2020 Aug 4];4:54-6. Available from: http://www.dmrjournal.org/text.asp?2016/4/2/54/184736
| Introduction|| |
In humans, dental anomalies in terms of decreased or increased numbers are quite common. They are known as hypodontia (partial anodontia) or hyperdontia, respectively. The literature reports numerous cases of exclusive occurrence of these anomalies. They are usually associated with some syndromes such as Down's syndrome, cleidocranial dysplasia, and orodigitofacial dysostosis. The concomitant presence of partial anodontia with supernumerary teeth, i.e., hypo-hyperdontia or oligopleiodontia is a rare condition of the human dentition. Even rarer is the presence of such condition in the same area of the arch.
The etiopathogenesis of this simultaneous hypo-hyperdontia is obscure.  Disturbance in the migration, proliferation, and differentiation of the neural crest cells and interaction between the epithelial and mesenchymal cells during initiation stage of tooth development has been suspected as possible causes. 
The most commonly seen supernumerary tooth is the mesiodens seen in between the maxillary central incisors. A presence of mesiodens in the mandibular arch is a rare phenomenon. It is, even more, unusual to find a mesiodens with the agenesis of the central incisors in the mandibular arch. Only few similar cases have been reported in the dental literature. ,,,,
Presented here is one such rare case of simultaneous presence of a single, completely formed supernumerary tooth with missing permanent central incisors in the mandibular arch without any associated syndrome.
| Case report|| |
A 26-year-old female patient reported to the Department of Periodontology at Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India. She had visited the department with the desire of getting her teeth cleaned. The medical, dental, and family history was noncontributory. The extra-oral examination did not reveal any abnormality. Intraoral examination revealed the presence of all permanent teeth except the mandibular central incisors. All the permanent teeth were of normal morphology.
There was spacing between the mandibular lateral incisors, which was partially occupied by the conical supernumerary tooth [Figure 1]. The clinical examination revealed only mild calculus deposits. No history of trauma or dental extractions could be elicited. There were no associated signs or symptoms suggesting a syndrome.
|Figure 1: Clinical picture of the rare finding showing a single fully developed supernumerary tooth with the absence of mandibular central incisors|
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An intraoral periapical radiograph of the mandibular anterior region showed the absence of mandibular central incisors (tooth no 24 and 25). There was a conical shaped supernumerary tooth with complete root formation and no evidence of any associated pathology [Figure 2].
|Figure 2: Intraoral periapical view showing fully developed conical supernumerary tooth. Absence of both mandibular central incisors|
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Based on the history and clinical examination, a provisional diagnosis of hypo-hyperdontia and localized chronic gingivitis was made. The differential diagnosis of Cleidocranial dysplasia, Down's syndrome, orodigitofacial dysostosis, and Hallermanstreiff-Streiff syndrome was considered. However, as all the signs of the above said syndromes were negative, the final diagnosis of mandibular anterior hypo-hyperdontia was made.
The patient was not aware of her condition; hence, she was explained about the same. Her chief complaint was treated by doing full mouth scaling. She was given the option of esthetic correction by minor orthodontic treatment, followed by reshaping the supernumerary tooth and replacing the missing tooth in the residual space. However, the patient refused treatment due to financial and time constraint and also due to religious reasons. She was followed up for 6 months during which she denied further dental treatment.
| Discussion|| |
The incidence of hypodontia of the mandibular central incisors is 0.41-0.5% as observed by Graphen in 1956.  In a survey of 2070 individuals, he reported only three cases where both the mandibular central incisors were missing.  The literature shows the absence of permanent mandibular central incisors associated with the presence of over retained deciduous teeth. However, the occurrence of the concomitant supernumerary tooth with partial anodontia in the same segment of the dental arch is a rare anomaly in the human dentition. To the best of the author's knowledge, only five cases have been reported where a supernumerary tooth is present in the available space of the missing mandibular central incisors. Out of these, only two cases have been reported in the permanent dentition, while others in the mixed dentition (ages 6-8 years) [Table 1].
In this case report, the possibility of a microdont central incisor associated with the congenital absence of the contralateral mandibular central incisor cannot be excluded. However, the distinct conical shape of the tooth bears no resemblance to a central incisor. As reported by Luten, supernumerary teeth in the labial segment can be classified into three types: Conical, tuberculate, and supplemental types. The supplemental types of supernumerary teeth closely simulate the adjacent teeth.  Furthermore, Low reported that conical types of supernumerary teeth are located near the midline and have root formation chronologically matching the teeth of the region.  The distinct conical shape with no resemblance to the adjacent teeth and root formation matching the adjacent teeth suggest that the tooth is not a normal central incisor. Therefore, the diagnosis of mandibular midline supernumerary tooth associated with agenesis of mandibular central incisors was made.
The case presented here is similar to the cases reported by Marya et al.  and Verma et al.  as they both have reported this unusual occurrence in permanent dentition. All these three cases showed complete root formation of the conical supernumerary tooth. In addition, there was no associated syndrome in all these three reported cases. However, the only difference was that they were observed in male patients, which is contradictory with this case. ,
Though the exact role for the occurrence of this condition is unknown, there could be a possible role of genes and enzymatic defects. Mutations in genes PAX9, MSX1, and AXIN2 have been implicated as the likely cause of the agenesis in the nonsyndromic hypodontia.  The usual mode of inheritance of hypodontia is autosomal dominant, but occasionally autosomal recessive and x-linked and polygenic/multifactorial models of inheritance have been reported. 
The reported cases of hypo-hyperdontia in the mandibular anterior region do not reveal any systemic abnormality or syndrome. This may suggest that such cases are sporadic and may be due to gene mutation and is relatively harmless condition. However, such cases can provide more insight in genetic research which can give a better insight in their occurrence.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
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[Figure 1], [Figure 2]