|Year : 2012 | Volume
| Issue : 3 | Page : 187-191
An unusual occurrence of geminated primary tooth with talon's cusp
S. V. S. G. Nirmala, Lalitha Velpula, Sivakumar Nuvvula, Sreekanth K Mallineni
Department of Pedodontics and Preventive Dentistry, Narayana Dental College, Nellore, Andhra Pradesh, India
|Date of Web Publication||15-Oct-2012|
S. V. S. G. Nirmala
Department of Pedodontics and Preventive Dentistry, Narayana Dental College and Hospital, Nellore, Andhra Pradesh - 524 003
Source of Support: None, Conflict of Interest: None
Gemination and talon's cusps are rare developmental dental anomalies affecting both primary and permanent dentitions. Talon's cusps normally occur on the palatal surface of permanent maxillary incisors, whereas gemination is more common in the primary dentition. The purpose of this article is to report an uncommon case of talon's cusp on a geminated primary maxillary lateral incisor, including details of the clinical and radiographic findings and treatment in an 8-year-old girl.
Keywords: Double tooth, gemination, primary dentition, talon′s cusp
|How to cite this article:|
Nirmala S, Velpula L, Nuvvula S, Mallineni SK. An unusual occurrence of geminated primary tooth with talon's cusp. J NTR Univ Health Sci 2012;1:187-91
|How to cite this URL:|
Nirmala S, Velpula L, Nuvvula S, Mallineni SK. An unusual occurrence of geminated primary tooth with talon's cusp. J NTR Univ Health Sci [serial online] 2012 [cited 2020 Apr 6];1:187-91. Available from: http://www.jdrntruhs.org/text.asp?2012/1/3/187/102451
| Introduction|| |
Developmental and morphological variations of the dentition are frequently observed during a routine dental examination in children. These include variation in number, size, and form. However, developmental disturbances of the teeth are more common in the permanent dentition than in the primary dentition. Gemination is the formation of two teeth from the same follicle,  and there is one common pulp chamber  which results in the embryological persistence of dental lamina. In gemination, the normal number of teeth is usually present for a given dental age, but one is geminated.  It is extremely difficult, if not impossible, to distinguish between fusion and gemination. The normal number of teeth present in the mouth is of little or no importance as fusion may occur between a normal tooth and a supernumerary tooth or between two supernumerary teeth. It is more prevalent in the anterior maxillary region, whereas fusion is more commonly found in the anterior mandibular dentition.  Incidence is approximately 0.1% in the permanent and 1% in the primary dentition with tendency to maxillary primary incisors and canine. 
Mellor and Ripa  originally proposed the term talon's cusp because they considered that the shape of the anomaly resembled an eagle's talon  but it could also present as pyramidal, conical, or teat-like.  The talon's cusp of anterior teeth is a relatively rare developmental anomaly characterized by the presence of an accessory cusp-like structure projecting from the cingulum area or cement-enamel junction of the maxillary or mandibular anterior teeth in both the primary and permanent dentition.  This anomalous construction is composed of normal enamel and dentin and either has varying extensions of pulp tissue into it or is devoid of a pulp horn. ,, The prevalence of talon's cusp varies considerably among populations, ranging from 0.06% to 7.7%.  The permanent dentition is affected more frequently than the primary dentition, and the anomaly is more common in males than in females. The lateral incisors being the most frequently involved followed by the central incisors and the canines. ,, The etiology of talon's cusp is not well known, however, it appears to have both genetic and environmental components. Similar to other abnormalities of tooth shape, talon's cusp originates during the morpho-differentiation stage of tooth development. It may occur as a result of outward folding of inner enamel epithelial cells and transient focal hyperplasia of the peripheral cells of mesenchymal dental papilla. , The rare occurrence of talon's cusp on a geminated tooth in permanent dentition has been published in the literature [Table 1]. The concurrent talon's cusp on a geminated tooth is an extremely rare finding or may be a coincidental finding in the case of primary dentition. The purpose of this paper is to report a case of a geminated tooth with talon's cusp in an 8-year-old girl in primary dentition which serves as first case report in the literature.
|Table 1: Published Case Reports of Geminated Tooth with Talon's Cusp and The Present Case|
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| Case Report|| |
An 8-year-old Asian girl presented with a chief complaint of decayed teeth to the Department of Paedodontics and Preventive Dentistry, Narayana Dental College and Hospital, Nellore, Andhra Pradesh, India. Her medical history was unremarkable and family history did not reveal any evidence of hereditary dental anomalies. The extra-oral examination showed normal facial appearance. On intra-oral examination, patient was at mixed dentition stage with adequate oral hygiene. She brushed her teeth daily with fluoridated toothpaste. On examination of soft tissue, findings were normal. Teeth present were (FDI Notation) 16, 55, 54, 53, 52, 11, 21, 62, 63, 64, 65, 26, 36, 75, 74, 73, 32, 31, 41, 42, 83, 84, 85, 46. Maxillary right first and second primary molar, left second primary molar, mandibular left primary second molar, and right primary first molar were decayed. Maxillary left first primary molar and mandibular right second primary molars were grossly decayed. The child was in the mixed dentition stage with Angle's class I molar relationship. The maxillary right primary lateral incisor had a large, bifid crown with talon's cusp on the palatal aspect. The crown of the geminated tooth was partially split with a notch on the incisal edge that extended labio-lingually to the middle of the crown [Figure 1]. On the palatal aspect, the crown exhibited a pronounced, well-defined accessory cusp extending from the cemento-enamel junction to within 1.8 mm of the incisal edge. The talon's cusp was pyramidal in shape and located on the mesial half of the crown, with the tip of the cusp attached to the crown [Figure 2]. The tooth showed pre-shedding mobility.
|Figure 1: Intraoral picture showing a bifid crown (arrow) with palatal talon's cusp (dashed arrow)|
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|Figure 2: (a) Anterior occlusal radiograph showing palatal talon's cusp (arrow). (b) Intraoral periapical radiograph showing the presence of underlying erupting permanent maxillary right lateral incisor|
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Further investigations included periapical radiograph of the maxillary anterior region and occlusal view of the maxilla [Figure 3]a and b, revealed a 'V'-shaped radio-opaque structure superimposed on the image of the affected crown, with the point of the 'V' towards the incisal edge. Radiographically, geminated taloned tooth had a single enlarged pulp chamber.
|Figure 3: (a) Intraoral periapical radiograph showing a single enlarged pulp chamber and one root appearance. (b) The occlusal radiograph revealed the presence of right lateral incisor, with the affected tooth impeding the eruption of the adjacent lateral incisor|
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Based on the clinical and radiographic findings the diagnosis of geminated tooth with talon's cusp was confirmed.
Maxillary right first and second primary molar, left second primary molar, mandibular left primary second molar, and right primary first molar were restored with GC Gold label IX™ (GC Corporation, Tokyo, Japan). Grossly decayed maxillary left first primary molar and mandibular right second primary molars were extracted followed by placement of a band and loop space maintainers. The treatment plan was aimed at the removal of the offending tooth under local anesthesia [Figure 4] a and b, after 1-week review was performed.
|Figure 4: Illustrating groove (arrow) and palatal talon's cusp of the extracted geminated tooth (dashed arrow)|
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Digital radiography of the extracted tooth revealed that two halves of the geminated tooth was mirror images of each other with a single large pulp chamber [Figure 5].
| Discussion|| |
Gemination or fusion of teeth is developmental anomalies with inherently peculiar anatomy. These anomalies may develop during the morphodifferentiation of the tooth bud as a result of a developmental aberration of both the ectoderm and mesoderm. However, it has been the difficulty of deciding whether a tooth is fused or geminated  and proposed that these anomalies be referred to in a common term, such as double teeth.  'Double teeth' is a term recommended by Brook and Winter  for teeth resulting from fusion, gemination, or concrescence. 'Double teeth' is an uncommon but by no means rare condition. Definite categorization of joined teeth as either gemination or fusion however is often difficult.  Both clinical and radiographic criteria are used to distinguish fusion from gemination. Fusion is the incomplete attempt of two tooth buds to fuse into one; on the other hand, gemination is the incomplete attempt of one tooth bud to divide into two.  Clinically when the joined teeth are counted as one, a full complement of teeth usually means that the phenomenon represents germination and less than full complement of teeth usually indicates fusion. A radiographic deliberation is the difference in the root configuration often seen between fusion and gemination. In the case of fusion there are usually two separate canals, whereas in gemination there is usually one large common root canal. The occurrence can be unilateral or bilateral.  In the present case, the single large pulp chamber with confluent enamel and dentine was present so this can be considered as a case of gemination unilaterally, was diagnosed by clinical and radiographic examination, and confirmed by digital radiography.
A more detailed classification of talon cusps was proposed by Hattab et al., who classified talon's cusps into three types according to its formation and extent: types I, II, and III. Classification includes type I (talon), characterized by an additional cusp projecting from the palatal aspect of an anterior tooth and extending for half the distance between the cemento-enamel junction and the incisal edge; type II (semi-talon) is characterized by an additional cusp 1 mm in extent or more, extending from the cemento-enamel junction for less than half the distance to the incisal edge; and type III (trace talon) manifests as a prominent cingulum and its variations. Due to the reporting of facial talon cusps, the classification was modified to include the facial talon cusp. Recently, a few reports have described the occurrence of both facial and palatal talon cusps on the same tooth,  which has led to a slight refinement of the definition. The present case of talon's cusp was diagnosed as type I (talon) accordingly. Dental fusion and gemination are usually asymptomatic, but both can result in a number of dental difficulties including tooth reduction in the permanent successors, increased susceptibility to subgingival bacterial plaque, aplasia, or malformation of the permanent successors and dental impaction. The possible complications with geminated tooth commonly exhibit labial and lingual vertical grooves on the crown surface. These grooves are pronounced in cases of incomplete fusion. Since these grooves are difficult to clean, caries may result. Placement of a sealant or composite material into these grooves decreases the caries risk.  Similarly, clinical problems may also arise from a talon's cusp. These include compromised esthetics, occlusal interferences, displacement and rotation of teeth, accidental cusp fracture with pulpal involvement, and therefore complications, periodontal problems, and temporomandibular joint pain resulting from excessive occlusal forces, tongue and lip irritation during speech and mastication, and caries susceptibility because of the developmental groove. ,,,,,, The presence of these accessory cusps may prevent proper bonding of brackets for orthodontic treatment and complicate the wearing of a mouth guard for sporting activities. However, talon's cusp with geminated tooth is a combination of dental anomalies, and few case reports had have been reported in the literature regarding this type of anomaly. It is important for clinicians to be aware of the potential complications that may occur with gemination and talon's cusp, especially in a single tooth. However, in the present case, the tooth was mobile and hence, was planned for extraction. Talon's cusp is a rare entity dental anomaly and more common permanent dentition than primary dentition, whilst gemination is more common in primary dentition. The occurrence of gemination with talon's cusp may be a coincidental.
| Conclusion|| |
Early diagnosis of these anomalies in the tooth by the pediatric dentist can thus improve the prognosis of treatment and minimize future complications. The concomitant occurrence of germination and talon's cusp in a single tooth is extremely rare, and a comprehensive clinical and radiographic examination is beneficial in identifying such defects.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]