|Year : 2015 | Volume
| Issue : 2 | Page : 55-57
Gemination in primary central incisor
Indavara Eregowda Neena, Roopali Sharma, Parameshwarappa Poornima, Korishettar Basavaraj Roopa
Department of Pedodontics and Preventive Dentistry, College of Dental Sciences, Davangere, Karnataka, India
|Date of Web Publication||22-Dec-2015|
Indavara Eregowda Neena
Department of Pedodontics and Preventive Dentistry, College of Dental Sciences, Pavilion Road, Davangere - 577 004, Karnataka
Source of Support: None, Conflict of Interest: None
Geminated teeth are the consequences of developmental anomalies leading to the eruption of joined elements. According to the current definitions, gemination occurs when one tooth bud tries to divide, whereas fusion occurs if two tooth buds unite. This article presents one such case report of germination of a primary tooth which was endodontically treated due to deep carious involvement.
Keywords: Developmental anomaly, gemination, primary teeth
|How to cite this article:|
Neena IE, Sharma R, Poornima P, Roopa KB. Gemination in primary central incisor. J Oral Res Rev 2015;7:55-7
| Introduction|| |
Developmental dental disorders may be due to abnormalities in the differentiation of the dental lamina and the tooth germs that is anomalies in number, size, and shape, or due to abnormalities in the formation of the dental hard tissues, that is, anomalies in structure. However in some, both stages of differentiation are abnormal. Developmental dental disorders are not only congenital, but they may also be inherited, acquired, or idiopathic. 
Dental anomalies of number and forms may occur in the primary and permanent dentitions. The terms double teeth "double formations," "joined teeth," "fused teeth," or "dental twinning" are often used to describe fusion or gemination, both of which are primary development abnormalities of the teeth. 
In 1963, Tannenbaum and Alling, defined gemination as the formation of the equivalent of two teeth from the same follicle, with evidence of an attempt for teeth to be completely separate, this is indicated clinically by a groove or depression which could delineate two teeth. Radiographically, there appears to be only one pulp chamber.  Thus, in germination, if the bifid tooth is counted as one entity, the total number of teeth in the dental arch is otherwise normal.
Prevalence and incidence of dental anomalies in relation to maxillary lateral incisors in the Indian population indicate that gemination, and fusion (both unilateral and bilateral) accounted for 0.28% and 0.18%, respectively.  Data available for the primary dentition combined the prevalence of fused and germinated teeth, the conditions being relatively frequent, ranging from 0.5% to 2.5% according to the population surveyed. 
The etiology is unknown, but trauma has been suggested as a possible cause though a familial tendency has been suggested.  In the anterior region, this anomaly can cause unpleasant esthetic appearance due to irregular morphology. Furthermore, the deep groove present in these teeth may be susceptible to caries and periodontal disease and may require endodontic intervention in some cases.
| Case Report|| |
A 5-year-old girl visited the Department of Pedodontics and Preventive Dentistry, College of Dental Sciences, Davangere with a chief complaint of swelling and pain in the upper front teeth. The clinical examination showed the presence of sinus in relation to central incisor and also revealed the presence of geminated 51 [Figure 1]. The patient showed no other abnormalities in the oral structures showing the normal pattern. Radiographic examination revealed the presence of a single pulp chamber and root canal [Figure 2], which is one of the distinguishing features of geminated teeth from fusion.
| Discussion|| |
While the literature on the occurrence of double teeth is extensive, there is still much discussion concerning the nomenclature. Some authors have tried to differentiate them by counting the teeth or by observing the root morphology; others use fusion and gemination as synonyms.
Diagnosis based on counting the number of teeth present in the dental arch, is not, however, always possible. This is because nothing impairs the fusion between a "normal" and a supernumerary element while the contiguous "normal" tooth is congenitally absent, resembling clinical cases of germination.  Use of Levitas' classiﬁcation to distinguish between cases of fusion and gemination is very practical. 
Finally, some authors simply call the phenomenon "double teeth" or "connated teeth" to avoid confusion over terminology. 
Double teeth were classified into four morphological types by Aguilσ et al.  using both the clinical and radiographic appearance as criteria and guide [Table 1].
| Etiopathogenesis|| |
Although environmental factors such as trauma, vitamin deficiencies, systemic diseases, and certain genetic predisposition have been suggested as possible causes, the exact cause of gemination is unknown. Grover and Lorton claim that local metabolic interferences, which occur during morphodifferentiation of the tooth germ, maybe the cause. 
This condition has a familial tendency. It may be associated with syndromes such as achondrodysplasia, and chondroectodermal dysplasia, or can be found in nonsyndromic patients as in the present case.
Gemination is the result of "schizodontism" - the splitting of tooth germ during development or "synodontism" - fusion of a regular tooth bud with a supernumerary tooth bud.
| Clinical Considerations|| |
Gemination is seen more in the primary dentition than permanent dentition and this has an effect on the succedaneous dentition such as delayed exfoliation of the affected teeth due to greater root mass and increased root surface area. 
This anomaly presents a problem of unpleasant esthetics due to abnormal morphology. When deep grooves are present, there is a greater susceptibility to involvement with caries or periodontal disease. As in this case due to deep carious involvement, the tooth underwent chronic irreversible pulpitis leading to sinus formation and thus was pulp treated and obturated with zinc oxide eugenol.
The main periodontal complication in gemination cases occurs due to the presence of fissures or grooves in the union between the teeth involved. If these defects are very deep and extend subgingivally, the possibility of bacterial plaque accumulation in this area is quite high. Strict oral hygiene is imperative to maintain periodontal health. Furthermore, gemination may have an adverse effect on occlusion, causing deviation. 
| Conclusion|| |
Diagnosis and management of geminated teeth have always been challenging for the clinicians. Since exfoliation times are usually different for each tooth involved in the gemination, consideration should be given to the variations in root resorption. Geminated teeth may also contribute to esthetic concerns, space problems, and occlusal disturbances. Hence, careful monitoring of the condition is recommended.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]