|Year : 2015 | Volume
| Issue : 2 | Page : 76-78
Concurrent occurrence of multiple developmental anomalies: A rare case report and review of literature
B Thayumanavan1, T Jeyanthikumari2, P Meghalapriya3
1 Department of Oral and Maxillofacial Pathology, Sathyabama University, Dental College and Hospital, Chennai, Tamil Nadu, India
2 Department of Prosthodontics, Tamil Nadu Government Dental College and Hospital, Chennai, Tamil Nadu, India
3 Department of Oral and Maxillofacial Pathology, D Care Multispecialty Dental Clinic, Chennai, Tamil Nadu, India
|Date of Web Publication||2-Mar-2016|
Department of Oral and Maxillofacial Pathology, Sathyabama University, Dental College and Hospital, Chennai, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Talon cusp and fusion are uncommon odontogenic anomalies comprising of both primary and permanent dentition, which occur on the palatal surface of permanent maxillary incisors, while fused teeth are more common in the primary anterior dentition. This article reports an unusual case of talon cusp presenting on the lingual surface of fused permanent right mandibular central and lateral incisor in the permanent dentition in association with impacted left mandibular third molar. Recognition of this condition and early diagnosis are important to provide prophylactic measures, thereby preventing complications.
Keywords: Accessory cusp, central and lateral incisors, fusion, impacted left mandibular third molar, talon cusp
|How to cite this article:|
Thayumanavan B, Jeyanthikumari T, Meghalapriya P. Concurrent occurrence of multiple developmental anomalies: A rare case report and review of literature. J Indian Acad Dent Spec Res 2015;2:76-8
|How to cite this URL:|
Thayumanavan B, Jeyanthikumari T, Meghalapriya P. Concurrent occurrence of multiple developmental anomalies: A rare case report and review of literature. J Indian Acad Dent Spec Res [serial online] 2015 [cited 2019 Mar 18];2:76-8. Available from: http://www.jiadsr.org/text.asp?2015/2/2/76/177933
| Case Report|| |
A 45-year-old man reported to the Department of Oral and Maxillofacial Pathology with complaint of unsightly lower anterior teeth, irritation to tongue, incising problems, and food impaction. The patient appeared healthy and revealed normal physical development for his age. There was no reported history of orofacial trauma.
Intraoral examination revealed that right permanent mandibular central incisor and lateral incisor were fused [Figure 1]a and exhibited a large prominent cusp on the lingual surface extending from cementoenamel junction to the incisal edge. The talon cusp was pyramidal in shape and was located on the center of the fused right mandibular central and lateral incisors [Figure 1]b.
|Figure 1: (a) Labial aspect of fused permanent right mandibular central and lateral incisor (b) A pyramidal-shaped talon cusp on the lingual surface of the fused permanent right mandibular central and lateral incisor|
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The fused mandibular right central and lateral incisors had a large crown. The mesiodistal crown diameter was less than that of the adjacent normal left central and lateral incisors.
Noncarious developmental grooves were present at the junction of the talon cusp and lingual surface of the fused teeth. The affected teeth clinically showed attrition, tongue interferences, spacing, food impaction, and gingival recession.
The talon cusp on fused teeth responded normally to electrical and thermal pulp tests.
Intraoral periapical (IOPA) radiograph showed enamel and dentin layers within the accessory cusps on bifid crown with a single root canal [Figure 2]a.
|Figure 2: (a) IOPA showing enamel and dentin within talon cusp on bifid crown with single root canal (b) OPG showing talon cusp on fused permanent right mandibular central and lateral incisor and impacted left mandibular third molar|
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Orthopantomography (OPG) showed accessory cusp on bifid crown of fused permanent right mandibular central and lateral incisor with a single root canal associated with impacted left mandibular third molar [Figure 2]b.
Labial aspect showed fused mandibular right central and lateral incisors associated with spacing, attrition, and mild root exposure [Figure 3]a.
|Figure 3: (a) Labial aspect of model showing fused permanent mandibular right central and lateral incisors associated with spacing, attrition, and mild root exposure (b) Lingual aspect of model showing accessory cusp on the fused mandibular right central and lateral incisors. This accessory cusp measured 6 mm cervicoincisally, 4 mm mesiodistally, and 3 mm labiolingually|
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Lingual aspect showed accessory cusp on fused mandibular right central and lateral incisors [Figure 3]b. This accessory cusp measured in mm as follows:
- 6 mm in length (cervicoincisally).
- 4 mm in width (mesiodistally).
- 3 mm in thickness (labiolingually).
Based upon clinical examination, model analysis, and radiographic findings, a diagnosis of talon cusp on fused mandibular right central and lateral incisor teeth was made.
| Discussion|| |
Odontogenesis is a very complex process, in which reciprocal and sequential interactions between epithelial and mesenchymal cells regulate numerous cell activities that lead to formation of a functional tooth organ. Any aberration among these will result in various craniofacial malformations. 
Talon cusp is a developmental anomaly of tooth shape that first was recognized by Mitchell in 1892. It is an accessory cusp like structure on crown of the maxillary and mandibular anterior teeth in both primary and permanent dentition. This anomalous structure consists of normal enamel and dentin and may have extensions of pulp tissue into it (or) may be devoid of a pulp horn. Typically, it resembles an eagle's talon, but it can also present as pyramidal, conical, or teat-like shape. ,
The incidence of talon cusp ranges from 0.06% to 8%.  Talon cusp can also occur in association with other dental manifestations such as peg-shaped lateral incisors, agenesis or impacted canines, mesiodens, complex odontoma, megadont, dens evaginatus of posterior teeth, shovel-shaped incisors, dens invaginatus, and exaggerated Carabelli cusp.  In the present case, it was associated with fusion and impacted left mandibular third molar.
Talon cusp occurs more frequently in permanent dentition than in primary dentition. Males are affected more commonly than females. Almost 92% of the affected teeth in the permanent dentition have been encountered in the maxilla with the lateral incisors being the most frequently involved teeth (55%) followed by the central incisors (36%) and the canine (9%).  But in our case, the talon cusp was found in the mandible that is an uncommon finding.
Large talon cusps are clinically significant as they cause occlusal interferences, irritation of the tongue during speech and mastication, displacement of the affected tooth, carious lesion in developmental grooves that delineate the cusp, attrition of the opposing tooth, pulpal necrosis, periapical pathosis, and periodontal problems due to excessive occlusal forces. ,
Fusion is recognized as the union of two normally separated tooth buds with the resultant formation of a joined tooth with confluence of dentin.  Fusion may be partial or total; it depends on the stage of tooth development at the time of fusion. Usually, a fused tooth has two separate root canals and a single, wide crown. A small groove may be present between the mesial and distal sections of the melded crowns of fused teeth. 
The prevalence of connated or double teeth (0.2%) in permanent dentition and it ranges from 0.4% to 0.9% in primary dentition. The prevalence of unilateral double teeth is 0.5% and 0.1% in the primary and permanent dentition, respectively. A normal count of teeth reveals a missing tooth when the fused tooth is counted as one. 
The mandibular talon cusp on fused teeth described in the present case report fulfilled Hattab criterion and belonged to type I. 
In our patient, an uncommon finding of talon cusp on fused mandibular right central and lateral incisors was present in which involved teeth had one crown, one talon cusp, one root canal causing clinical problems such as tooth malalignment, spacing problems, arch symmetry, unacceptable appearance, food impaction, and periodontal involvement.
The present case is unique as talon cusp occurring in association with fused teeth in permanent dentition is a very rare finding. A PubMed search of talon cusp on fused teeth presenting in permanent dentition revealed only very few previous reports [Table 1].
|Table 1: Review of literature (based on PubMed search) of talon cusp on fused teeth presenting in permanent dentition|
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| Conclusion|| |
It is important for dental professionals to be familiar with common dental development anomalies. The patients should be properly informed of the potential risk factors and problems associated with the anomalies. Early diagnosis is important to avoid complications and examinations of siblings and relatives could facilitate early diagnosis and can minimize possible complications.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]