Dens Evaginatus of Anterior Teeth (Talon Cusp): Report of Five Cases

Dens evaginatus of anterior teeth (talon cusp): Report of five cases

Juan J. Segura-Egea, DDS, MD, PhD1/Alicia Jiménez-Rubio, DDS, MD, PhD2/ José V. Ríos-Santos, DDS, MD, PhD3/Eugenio Velasco-Ortega, DDS, MD, PhD3

The talon cusp, or Dens evaginatus of anterior teeth, is a relatively rare dental developmental anomaly characterized by the presence of an accessory cusplike structure projecting from the cingulum area or cementoenamel junction. This occurs in either maxillary or mandibular anterior teeth in both the primary and permanent dentition. This article reports five cases of talon cusp, two of them bilateral, affecting permanent maxillary central and lateral incisors and canines that caused clinical problems related to caries or occlusal interferences. (Quintessence Int 2003;34:xxxÐxxx)

Key words: dens evaginatus, dental anomalies, occlusal interference, talon cusp

ens evaginatus is a developmental anomaly char- volved (67%), followed by the central incisors (24%) Dacterized by the presence of an extra cusp, occur- and canines (9%).7,8 ring more frequently in mandibular premolars.1 In ca- Family histories of cases reported previously re- nines and incisors, Dens evaginatus originates usually vealed that sometimes talon cusp affected patients who in the palatal cingulus as a tubercle projecting from had consanguineous parents.6,9 Moreover, there are sev- the palatal surface; however, the anomaly also has af- eral dates [Au: What is meant by “dates?” Reports?] fected the labial surface of the tooth.2,3 Mitchell4 first in the literature that support the hereditary character of described this dental anomaly as a “process of horn- talon cusp: the anomaly has been described affecting like shape, curving from the base downward to the two siblings,10,11 two sets of female twins,12 and two cutting edge” on the lingual surface of an maxillary family members,9 and the prevalence of talon cusp is central incisor of a female patient. Mellor and Ripa5 high in some racial groups.13–16 The family involvement named the accessory cusp talon cusp because of its re- and the association of the talon cusp with other dental semblance in shape to an eagle’s talon. abnormalities, suggest that genetics may be a major Talon cusp occurs more frequently in the perma- causative factor. However, sporadic occurrences of this nent than in the primary dentition and shows a abnormality probably are induced by trauma or other predilection for the maxilla over the mandible.6 The localized insults affecting the tooth germ. Talon cusp af- maxillary lateral incisors are the most frequently in- fects both sexes and commonly is unilateral, but one fifth of the cases are bilateral.9 The anomalous talon cusp is composed of normal enamel and dentin with varying extensions of pulp 1Associate Professor, Dental Pathology and Therapeutics, Department of tissue. Shay17 reported that pulp tissue can extend to Stomatology, School of Dentistry, University of Seville, Seville, Spain. the center of the tubercle and, once fractured, the 2Associate Professor, Dental Anatomy, Department of Morphological Sciences, School of Medicine, University of Seville, Seville, Spain. pulp is exposed. When talon cusp interferes with the normal occlusion, an occlusal adjustment by grinding 3Professor of Comprehensive Dentistry, Department of Stomatology, School of Dentistry, University of Seville, Seville, Spain. the palatal projection must be performed, with the Reprint requests: Dr Juan J. Segura-Egea, C/ Cueva de Menga n¼ 1, por- possibility of exposure of the dentin-pulp complex tal 3, 6¼-C, 41020-Sevilla, Spain. E-mail: [email protected] and, consequently, pulp necrosis.18

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Fig 1 Case 1. Occlusal view showing a prominent accessory Fig 2 Case 1. Periapical radiograph. cusp on the palatal surface of the right canine. Darkly stained developmental grooves are evident.

The cases reported in the literature as talon cusp packed with dental plaque. A carious lesion was de- are very different since this anomaly varies widely in tected clinically in the distal groove. The affected tooth shape, size, structure, location, and site of origin.19 The was responsive to electric pulp testing. The cusp did tip of the cusp may stand away from the crown or may not irritate the tongue during speech and mastication be in close approximation to the lingual surface.6 and did not interfere with the occlusion. Radiographs Some cusps are quite sharp and spiked, while others showed the presence of enamel, dentin, but not pulp are teatlike and have rounded and smooth tips. Talon horn in the palatal accessory cusp (Fig 2) [Au: Edits cusps may be markedly enlarged or exaggerated cin- ok?]. The left canine did not show tahn cusp. gula on the maxillary incisors.20 Others have described them as hornlike, conical, or pyramidal.7,9 Davis and Case 2 Brook21 stated that talon cusp may represent the ex- treme of a continuous variation progressing from a A 28-year-old male was seen for oral prophylaxis. normal cingulum, to an enlarged cingulum, to a small Clinical examination disclosed prominent cusplike accessory cusp, to a talon cusp. structures on the palatal surfaces of both the left max- This article reports five cases of talon cusp, two of illary lateral incisor and the left maxillary canine (Fig them bilateral, affecting permanent maxillary central 3). The accessory cusp of the lateral incisor was pyra- and lateral incisors and canines that caused clinical midal in shape and extended from the cementoenamel problems related to caries or occlusal interferences. junction one third to the incisal edge. It was attached to the palatal surface and extended distally. The cusp tip was pointed and slightly sharp. The cusp measured CASE REPORTS 3.7 mm in length (incisocervically), 3.9 mm in width (mesiodistally), and 3.3 mm in thickness (labiolin- Case 1 gually). Noncarious, but stained, developmental grooves were observed laterally. A caries lesion was A healthy 21-year-old female was seen for a routine evident in the mesial surface of the tooth. dental examination. Her medical and dental history The accessory cusp of the canine also was pyrami- was unevenfful. The right maxillary canine exhibited a dal in shape and extended from the cementoenamel small prominent cusp on the palatal surface (Fig 1). junction one quarter to the incisal edge. It was at- The accessory cusp on the right canine, conical in tached to the palatal surface and extended perpendic- shape, was projected from the cementoenamel junction ular to the mesiodistal surface of the crown. and extended less than halfway to the incisal edge. The Noncarious developmental grooves were observed lat- cusp measured 3.3 mm in length (incisocervically), 4.3 erally. The cusp measured 2.9 mm in length (incisocer- mm in width (mesiodistally), and about 2.6 mm in vically), 2.7 mm in width (mesiodistally), and 2.4 mm thickness (labiolingually). A small bridge of enamel in thickness (labiolingually). connected the accessory cusp to the palatal surface of The talon cusps did not irritate the tongue during the tooth. The developmental grooves on the distal and speech and mastication, but, due to the reduced over- the mesial side of the cusp were darkly stained and bite, the taloned teeth, mainly the left lateral incisor,

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Fig 3 Case 2. Anomalous cusplike structures on the palatal as- Fig 4 Case 3. Talon cusps on maxillary lateral incisors (mirror pects of both maxillary left lateral incisor and canine. photograph).

interfered slightly with the occlusion. An occlusal adjustment by grinding the palatal projection of the lateral incisor was performed in one appointment.

Case 3

A 19-year-old male presented to the dental clinic for a routine dental examination at the end of an orthodon- tic treatment. The patient appeared healthy and of normal physical development for his age. There was no reported history of orofacial trauma. The occlusion was a Class I molar relationship. Both maxillary right and left lateral incisors showed an accessory cusp on Fig 5 Case 4. The talon cusp on right maxillary lateral incisor is the palatal aspect (Fig 4). The accessory cusp on the pointed and sharp and coincides with the midline (mirror photo- left maxillary lateral incisor measured 2.7 mm in graph). length (incisocervically), 3.9 mm in width (mesiodistally), and 2.2 mm in thickness (labiolingually). The talon cusp was pyramidal in shape and located on the Case 4 center of the crown, with the tip of the cusp attached to the crown. The accessory cusp extended from the A 10-year-old male presented for the treatment of sev- cementoenamel junction more than one third to the eral carious lesions. Clinical examination disclosed a incisal edge. Noncarious but slightly stained develop- prominent cusplike structure on the palatal surface of mental grooves were present at the junction of the the maxillary right lateral incisor (Fig 5). The talon talon cusp and the palatal surface of the tooth. The cusp was pyramidal in shape and extended from the anomalous cusp on the right maxillary lateral incisor cementoenamel junction halfway to the incisal edge. It measured 2.6 mm in length (incisocervically), 3.5 mm was attached to the palatal surface and extended per- in width (mesiodistally), and 2.0 mm in thickness pendicular to the mesiodistal surface of the crown. (labiolingually). The talon cusp was conical in shape The cusp tip was pointed and sharp and coincided and located in the distal half of the crown, with the tip with the midline of the long axis of the tooth, forming of the cusp attached to the crown. The accessory cusp a Y-shaped crown outline. The cusp measured 4.5 mm extended fiom the cementoenamel junction one third in length (incisocervically), 4.0 mm in width to the incisal edge. The mesial developmental groove (mesiodistally), and 3.5 mm in thickness (labiolin- was stained but noncarious. The affected tooth re- gually). Noncarious developmental grooves were ob- sponded normally to electric and thermal pulp tests. served laterally. The tooth appeared normal and re- Both maxillary canines showed a bifid cingulum. sponded to electric pulp testing. Due to the reduced Neither of the taloned teeth interfered with the nor- overbite, the talon cusp interfered with the occlusion; mal occlusion. wear facets were present on the cusp and the incisal

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Fig 6 Case 5. Abnormal palatal structures on both central in- Fig 7 Case 5. Periapical radiograph showing V-shaped ra- cisors. diopaque structures superimposed on the image of the affected crowns.

cisor had the same form, showing a similar enamel ridge pointing to the mesial side of the incisal edge. Both taloned teeth showed accentuated marginal ridges surrounding a deep lingual fossa taking a shovel-shaped form. In both teeth, noncarious but stained developmental grooves were observed laterally. A periapical radiograph (Fig 7) showed a V-shaped radiopaque structure superimposed on the image of the affected crowns, with the “V” pointing toward the incisal edge. Both talon cusps were outlined by two distinct white lines converging from the cervi- cal area of the affected tooth toward the incisal edge. Fig 8 Case 5. Occlusal view (mirror photograph). Pulp extension could be traced radiographically to the middle of the cusps. The lateral incisors and the canines also showed abnormal structures on their palatal surfaces (Fig 8). A small, sharp and pointed cusplike structure was evi- edge of the opposing tooth. No other dental variations dent in the cingulum of the right lateral incisor. The were detected. An occlusal adjustment by grinding anomalous structure was pyramidal in shape and lo- slightly the accessory cusp of the lateral incisor was cated on the center of the crown, with its tip attached performed in one appointment. to the crown and extending from the cementoenamel junction more than one third to the incisal edge. Case 5 Noncarious developmental grooves were present. The left lateral incisor and both canines showed bifid cin- A 20-year-old female presented to the dental clinic for gula. Both the lateral incisors and the canines showed an oral prophylaxis. Both maxillary right and left accentuated marginal ridges and shovel-shaped form. centraI incisors showed an anomalous anatomy on the palatal surface (Fig 6). Very prominent bifid cingula were apparent on the palatal aspects of both central DISCUSSION incisors. [Au: Edits to sentence ok?] Furthermore, cusplike structures extending from the cementoenamel Dens evaginatus is an anomaly of great clinical signifi- junction more than halfway to the incisal edge were cance, sometimes causing occlusal interference. The evident. The talon cusp on the left central incisor was cleaning of the area between the nodule and the tooth located in the center of the crown and was teatlike in is difficult, and caries are often found.18 shape, with an enamel ridge extending from the ce- Talon cusp originates during the morphodifferentia- mentoenamel junction more than one third to the in- tion stage of tooth development but the etiology of the cisal edge. The accessory cusp on the right central in- condition remains unknown.9 In the majority of cases

4 Volume 34, Number 4, 2003 Segura-Egea et al reported, the talon cusp is isolated rather than an inte- Anomalous palatal structures on the left lateral in- gral part of any disorder. Nevertheless, the anomaly has cisors and both canines in case 5, representing a varia- been reported in patients with Sturge-Weber syndrome tion of enlarged or prominent cingula and their varia- (encephalotrigeminal angiomatosis),8 Mohr syndrome tions, could be classified as type 3 or “trace talon.” (orofacialdigital II syndrome),20 Ellis-van Creveld syn- Large talon cusps may cause clinical problems in- drome,10 and Rubinstein-Taybi syndrome.22 None of the cluding occlusal interference, displacement of the af- cases reported here were associated with any known fected tooth, irritation of the tongue during speech abnormal systemic developmental syndrome. and mastication, carious lesion in the developmental Control of the complex processes of dental devel- grooves that delineate the cusp, pulpal necrosis, peri- opment appears to be multifactorial, that is, primary apical pathosis, attrition of the opposing tooth, and polygenetic with some environmental influence. Talon periodontal problems due to excessive occlusal cusp is usually associated with other dental variations: forces.26 bifid cingula, dens invaginatus, exaggerated cusps of Early diagnosis and management of talon cusp is Carabelli, and particularly with shovel-shaped maxil- important in order to prevent occlusal interference, lary incisors,6,9 a polygenic inheritable trait character- compromised esthetics, carious developmental ized by accentuated marginal ridges that surround a grooves, periodontal problems due to excessive oc- deep lingual fossa.23 In case 5, several of these dental clusal forces, or irritation of the tongue during speech anomalies were present. and mastication.9,19 In cases 2 and 3, an occlusal ad- As in the case of talon cusp, the maxillary lateral justment by grinding the palatal projection of the incisors are the most commonly affected with shovel- taloned tooth was performed to eliminate the prema- ing and dens invaginatus.24,25 The susceptibility of the ture contact. lateral incisors to abnormalities could partly be related The treatment of talon cusp implicates careful clini- to compression of the tooth germ of the lateral incisor cal decision. The aid of radiographs is essential to as- by the adjacent central incisor and canine, which de- sess whether the accessory cusp contains or is devoid velop about 7 months earlier than the lateral incisor. of a pulp horn. However, radiographic tracing of the Increased localized external pressure on a tooth germ pulpal configuration inside the talon cusp has inherent during the morphodifferentiation stage may result in difflculties because the cusp is superimposed over the either outfolding of the dental lamina (in the case of affected tooth crown.26 However, in case 5 the pulp talon cusp) and shoveling or infolding of the dental extensions inside the talon cusps were radiographi- lamina as in dens invaginatus.24 cally evident. Güngör et al27 reported a case of bilat- Hattab et al6 classified the anomaly based on the eral talon cusps on primary maxillary central incisors degree of their formation and extension into three whose histologic evaluation revealed the existence of types: type 1 (talon): additional cusp that projects pulpal tissue in the anomalous cusps. Thus, a previous from the palatal surface of an anterior tooth and ex- radiographic study must have been performed before tends at least half the distance from the cementoe- the removal of the cusp to avoid the pulp exposure namel junction to the incisal edge; type 2 (semitalon): that would require endodontic treatment.5 an additional cusp of a millimeter or more but extending less than half the distance from the cementoenamel junction to the incisal edge; and type 3 (trace REFERENCES talon): enlarged and prominent cingula and their variations. 1. Oehlers FA, Leek KW, Lee EC. Dens evaginatus (evaginated According to the classification by Hattab et al,6 the odontome): Its structure and responses to external stimuli. Dent Pract Dent Rec 1967;17:239–244. talon cusps described in the current cases classified as 2. Jowharji N, Noonan RG, Tylka JA. A unusual case of dental follows: anomaly: A “facial” talon cusp. ASDC J Dent Child 1992; The anomalous conical cusp on the left canine in 59:156–158. case 1, the accessory pyramidal cusps on the left max- 3. Abbott PV. Labial and palatal “talon cusps” on the same illary lateral incisor and the left maxillary canine in tooth. A case report. Oral Surg Oral Med Oral Pathol Oral case 2, the talon cusps presented in the case 3, and the Radiol Endod 1998;85:726–730. talon cusp evident on the palatal surface of both cen- 4. Mitchell WH. Case report. Dent Cosmos 1892;34:1036. tral incisors and the right lateral incisor in case 5 were 5. Mellor JK, Ripa LW. Talon cusp: A clinically significant classified as type 2 or “semitalon.” anomaly. Oral Surg Oral Med Oral Pathol 1970;29: 225–228. The talon cusp in case 4, pyramidal in shape and 6. Hattab FN, Yassin OM, al Nimri KS. Talon cusp in perma- extending from the cementoenamel junction more nent dentition associated with other dental anomalies: than halfway to the incisal edge was classified as type Review of literature and reports of seven cases. ASDC J 1 or “talon cusp.” Dent Child 1996;63:368–376.

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7. Hattab FN, Yassin OM, al Nimri KS. Talon cusp-clinical significance and management: Case reports. Quintessence Int 1995;26:115–120. 8. Chen R-J, Chen H-S. Talon cusp in primary dentition. Oral Surg Oral Med Oral Pathol 1986;62:67–72. 9. Segura JJ, Jiménez-Rubio A. Talon cusp affecting permanent maxillary lateral incisors in 2 family members. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;88:90–92. 10. Hattab FN, Yassim OM, Sasa IS. Oral manifestations of Ellis-van Creveld syndrome: Report of two siblings with unusual dental anomalies. J Clin Pediatr Dent 1998;22: 159–165. 11. Meon R Talon cusp in two siblings. N Z Dent J 1990;86: 42–44. 12. Liu JF, Chen LR. Talon cusp affecting the primary maxillary central incisors in two sets of female twins: Report of two cases. Pediatr Dent 1995;17:362–364. 13. Tsai SJ, King NM. A catalogue of anomalies and traits of the permanent dentition of southern Chinese. J Clin Pediatr Dent 1998;8:41–45. 14 . Harris EF, Owsley DW. Talon cusp: A review with three cases of native North America. J Tenn Dent Assoc 1991;71: 20–22. 15. Meon R. Talon cusp in Malaysia. Aust Dent J 1991;36: 11–14. 16. Chawla HS, Tewari A, Gopala krishnan NS. Talon cusp: A prevalence study. J Indian Soc Pedod Prev Dent 1983;1: 28–34. 17. Shay JC. Dens evaginatus—Case report of a successful treatment. J Endodon 1984;7:324–326. 18. Ferraz JAB, Carvalho Junior JR, Saquy PC, Pecora JD, Sousa-Neto MD. Dental anomaly: Dens evaginatus (Talon Cusp). Braz Dent J 2001;12:132–134. 19. Segura JJ, ‘Jiménez-Rubio A. La cúspide en garra: Origen embriológico, implicaciones clínicas y manejo terapéutico. Arch Odonto Estomatol 1998;14:429–436. 20. Goldstein E, Medina L. Mohr syndrome or oral-facial-digi- tal II: Report of two cases. J Am Dent Assoc 1974;89: 377–382. 21. Davis PJ, Brook AH. The presentation of talon cusp: Diagnosis, clinical features, association and possible aetiol- ogy. Br Dent J 1986;159:84–88. 22. Gardner DG, Girgis SS. Talon cusps: A dental anomaly in the Rubinstein-Taybi syndrome. Oral Surg Oral Med Oral Pathol 1979;47:519–521. 23. Brabant H. Dental Morphology and Evolution. Chicago: The University of Chicago Press, 1971:285–289. 24. Jiménez-Rubio A, Segura JJ. Bilateral dens invaginatus of maxillary lateral incisors associated with a supernumerary dens invaginatus. Endod Dent Traumatol 1997;13:196–198. 25. Jiménez-Rubio A, Segura JJ, Feito JJ. A case of combined dental development abnormalities: Importance of a thor- ough examination. Endod Dent Traumatol 1998;14:99–102. 26. Hattab FN, Hazza’a AM. An unusual case of talon cusp on geminated tooth. J Can Dent Assoc 2000; 67:263–266. 27. Güngor HC, Altay N, Kaymaz FF. Pulpal tissue in bilateral talon cusps of primary central incisors: Report of a case. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000; 89:231–235.

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