Talon cusp, first described by Mitchell in 1892, is a debatable and an interesting developmental anomaly [
The prevalence rate of talon cusp varies from 0.04% to 10% in the English literature [
Hattab et al. classified talon cusp into three types according to degree of the cusp formation and extension [
A cross-sectional prevalence study for various types of talon cusp was conducted for 3 months from February to April 2011 in outpatient department of S.R. Dental College, Haryana, India. The study sample consisted of 5200 patients (2714 males and 2486 females), seeking dental treatment, who were selected randomly. Their age ranged from 14 to 75 years. Exclusion criteria included pediatric age group below 14 years, patients having cleft lip/palate, medically compromised patients, and completely edentulous patients. The patient was examined with professional illumination by a single examiner (G.S) trained in oral diagnosis. The sociodemographic and clinical findings were recorded. The diagnostic criterion of Hattab [
Twelve cases of talon cusp (prevalence: 0.02%) in 10 patients were documented (2 bilateral cases and 8 unilateral). In this cross-sectional study, twelve cases of talon cusp (11 maxillary teeth (91.6%) and one mandibular tooth (8.4%)) were observed in ten patients (6 males and 4 females). Six cases (50%) were recorded in permanent maxillary central incisor, four (33.3%) in permanent maxillary lateral incisor, one (8.4%) in permanent maxillary canine, and one (8.4%) in fused mandibular incisor tooth. No specific preference for side was documented. Type I talon cusp and type II talon cusp were present in five cases each (40.1%) and type III talon cusp was presented in two (16.2%) cases (Table
Distribution of talon cusps in study according to age, sex predilection, site, and type.
Cases | Age (in years) | Sex predilection | Site (tooth) involved | Type of talon cusp | Side |
---|---|---|---|---|---|
1 | 22 | M | Anterior right mandibular incisor (fused tooth) | I | Unilateral |
2 | 51 | F | 21 | I | Unilateral |
3 | 21 | M | 22 | III | Unilateral |
4 | 34 | F | 11, 21 | II | Bilateral |
5 | 27 | F | 12 | II | Unilateral |
6 | 36 | M | 12, 22 | I | Bilateral |
7 | 23 | M | 13 | II | Unilateral |
8 | 31 | M | 11 | III | Unilateral |
9 | 25 | F | 11 | I | Unilateral |
10 | 43 | M | 21 | II | Unilateral |
M: male; F: female.
Summary of the observed talon cusp cases according to individual tooth.
Tooth number | Total number of individual teeth observed in patients examined ( |
Number of teeth in which talon cusp was observed | Observed frequency toothwise |
---|---|---|---|
Maxillary right central incisor (11) | 5200 | 3 | .0005% |
Maxillary left central incisor (21) | 5200 | 3 | .0005% |
Maxillary right lateral incisor (12) | 5200 | 2 | .0003% |
Maxillary left lateral incisor (22) | 5200 | 2 | .0003% |
Maxillary right canine (13) | 5200 | 1 | .0001% |
Maxillary left canine (23) | 5200 | — | — |
Mandibular canines (33 and 43) | 5200 | — | — |
Mandibular Incisors (31, 32, 41, 42) | 5200 | 1* | — |
During the study, a rare case of talon cusp on a fused mandibular incisor was also observed. This finding (talon cusp on fused tooth) was the only finding observed among the coexisting dental anomalies. To the best of our knowledge, only four cases of talon cusp associated with fusion have been reported in the English literature [
A 22-year-old male reported to Department of Oral Medicine and Radiology with the chief complaint of missing teeth in the anterior maxillary region. The patient revealed history of trauma resulting in avulsion of teeth 2 years back. The patient had been wearing a removable partial prosthesis since one and a half years and now wanted fixed prosthesis instead of removable partial denture. There was no remarkable medical history. General examination was normal. Intraoral examination revealed presence of three mandibular incisors. A double tooth was observed in the right mandibular incisor region (Figure
Intraoral photograph showing the presence of double tooth in place of mandibular right central and lateral incisors.
Occlusal clinical view showing the presence of talon cusp on the double tooth.
Intraoral periapical radiograph of the double tooth showed the presence of single large crown and root with a single canal instead of two right mandibular central and lateral incisors (Figure
Intraoral periapical radiograph showing the presence of single root of double tooth.
Panoramic radiograph revealing absence of other dental anomalies.
On the basis of the clinical and radiographic examination, a diagnosis of talon cusp on fused mandibular incisor was given. The patient was informed about the condition and was advised grinding of the talon cusp. Since the patient was asymptomatic and was also not concerned about the esthetics, he refused treatment of grinding of talon cusp on fused tooth. The patient was referred for fixed prosthesis of the maxillary right central and lateral incisors. The patient was advised regular follow-ups.
The prevalence of talon cusp in our study (12/5200; 0.02%; 1 in around 430 cases) was found to be comparable to that in the study conducted by Hegde in 1999 [
The reported prevalence of talon cusp in the literature is most commonly seen in maxillary lateral incisors (56.2%) followed by maxillary central incisor (35.4%) and maxillary canine (8.3%) [
A slight male predilection (60%) was also observed in our study, whereas no sex predilection was observed by Gunduz and Celenk [
Talon cusp has been reported in patients with Sturge-weber syndrome [
A fused tooth is a rare developmental disorder characterized by the union of two adjacent teeth. The occurrence of the fusion is more in primary dentition (0.5%) as compared to permanent dentition (0.1%) [
The etiology of fusion is still unknown. Environmental factors like hypervitaminosis A, thalidomide embryopathy, and viral infection during pregnancy have been postulated but not proved [
Fusion is often misdiagnosed as gemination. Gemination is a developmental anomaly of shape, which is considered as an effort by a single tooth germ to divide ensuing in a large single tooth with bifid crown, with the coronal halves having mirror images. Several clinical and radiographic criteria like morphology of crown and root chamber and number of teeth are used to differentiate fusion from gemination. In case of fusion, when the anomalous tooth is counted as one, teeth count reveals a missing tooth, whereas in gemination there is normal teeth count. However, distinguishing fusion and gemination by tooth count alone is not a parameter in all cases because fusion can occur between supernumerary and normal teeth [
A summary of documented cases of fusion with talon cusp.
Authors | Involved arch | Fused teeth involved | Age/gender | Other dental anomalies |
---|---|---|---|---|
Danesh et al. (2007) [ |
Maxilla | Central incisor and supernumerary tooth | 9/M | — |
Ekambaram et al. (2008) [ |
Mandible | Central incisor and lateral incisor | 14/M | — |
Rao and Hedge (2010) [ |
Mandible | Central and lateral incisors | 11/M | — |
Present authors (2012) | Mandible | Central and lateral incisors | 22/M | — |
The documentation of very few cases of talon cusp with fusion on same tooth prevents the authors from doing a significant analysis. Talon cusp has also been associated with various dental anomalies like mesiodens, microdontia, odontomas, shovel-shaped incisors, germination, and dens invaginatus [
The different types of talon cusp represent varying complications. Type III talon cusp is likely to cause an esthetic problem to patient, whereas type I talon cusp is more likely to be endodontically challenging. Type II talon cusp is a greater risk factor for trauma from occlusion and occlusal interference leading to periodontal problems. All types of talon cusp can present varying degrees of operative difficulty during various dental procedures like periodontal splinting, extractions, and endodontic procedures. However, data on the complications caused by talon cusp and their types is not existent in the English literature. Studies should be conducted to describe the various complications associated with these types of talon cusp.
Asymptomatic cases of talon cusp should be left untreated. However treatment options vary for symptomatic cases from simple grinding to orthodontic, endodontic, and prosthetic procedures depending on the extent of complications and size of talon cusp [
The prevalence of talon cusp in our study was extremely low (0.02%; 1 in 430 cases) and infrequent in mandibular arch. Type I talon cusp and type II talon cusp were the most prevalent types observed in our study and overall there was a slight male predilection (60%). Clinicians should be alert in diagnosing this unique entity that can help in early treatment of the condition and thereby preventing any potential complications. A larger sample size for the prevalence of types of talon cusp should be conducted. Talon cusp associated with fusion on a same tooth is an extremely rare entity.
The authors declare that there is no conflict of interests regarding the publication of this paper.