JDC
case report
Unusual Dens Evaginatus on Maxillary Premolars: A Case Report M. Priya, BDS J. Jeevarathan, MDS M.S. Muthu, MDS, PhD V. Rathnaprabhu, MDS ABSTRACT Dens evaginatus is a developmental anomaly that can be defined as a tubercle from the surface of an affected tooth. It is composed of enamel and dentin usually enclosing pulp tissue. It is a rare dental anomaly commonly seen on premolars. A 12-yearold boy reported for the management of dental caries. He had bilateral occurrence of dens evaginatus on maxillary second premolars. The tubercle on the right side was unusually long without occlusal interference with the opposing primary mandibular second molar. Carious teeth were restored and the tubercle was left untreated. Management of dens evaginatus is determined by various factors which are discussed in decision-support system. Pulpal complication due to caries or fracture of tubercle can occur; hence it should be periodically monitored. (J Dent Child 2011;78:71-5) Received October 11, 2009; Last Revision January 1, 2010; Revision Accepted January 2, 2010. Keywords: dens evaginatus, maxillary premolar, classification
D
ens evaginatus is an anomaly of odontogenesis in which a tubercle composed of enamel, dentin, and usually enclosing pulp tissue is produced on the crown’s occlusal surface.1-6 The exact etiology of dens evaginatus (DE) is not clear, but several investigators have reported the occurrence in siblings, suggesting a familial or hereditary pattern.6-8 DE is a result of abnormal proliferation of the inner enamel epithelium into the stellate reticulum of the enamel organ during the morphodifferentiation stage of tooth development.3,4,9,10 It is most commonly seen in premolars, 1-6 and it occurs 5 times more frequently in the mandible than in the maxilla.11 Merrill and Curzon et al., however, have reported many cases of DE in Dr. Priya is tutor, Department of Pediatric Dentistry, Meenakshi Ammal Dental College & Hospital, Maduravoyal, Tamil Nadu, India Dr. Jeevarathan is a reader, Department of Pediatric Dentistry, Sree Balaji Dental College & Hospital, Narayanapuram, Chennai, Tamil Nadu, India, Dr. Muthu is professor & head, Department of Pediatric Dentistry, Saveetha Dental College & Hospital, Velappanchavadi, Chennai, Tamil Nadu, India, and Dr. Prabhu is professor and Head, Department of Pediatric Dentistry, Meenakshi Ammal Dental College & Hospital, Maduravoyal, Tamil Nadu, India. Correspond with Dr. Jeevarathan at dr_rathan@rediffmail.com Journal of Dentistry for Children-78:1, 2011
maxillary premolars. 6,12 DE varies with race and is more commonly seen among Mongoloids, 11,13 Chinese, Thai, and Caucasians,13 and the prevalence varies from approximately 1% to 4%.2,6,12,14-17 In Malaysia and Singapore, it is referred to as Leong’s premolar—named after M.O. Leong in 1946, who first drew attention to this anomaly at a meeting of the Malayan Dental Association. 18 Leong did not realize that the premolars were not the only teeth affected, but that the anomaly has been observed in molars, 14 canines, and incisors. 3 DE in the anterior teeth is referred to as talon cusp, as it resembles an eagle’s talon.19 Uyeno and Lugo,20 however, proposed that DE and talon cusp are the same dental anomaly. Other terms used interchangeably with DE include: tuberculated cusp; accessory tubercle; occlusal tuber-culated premolar; evaginatus odontoma; occlusal pearl11; interstitial cusp2; odontome of the axial core type3; and central cusp.21 DE is often bilateral,3 but even multiple evaginated teeth involving as many as 8 teeth are reported in the literature.2,3,5,6,9,12,22-24 The other dental anomalies that can occur concurrently with DE are mesiodens,2 dens invaginatus, 2,4 gemination, 4 macrodontia, multiple
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unerupted teeth, 25 and supernumerary mandibular premolar.26,27 The common problems associated with the evaginated tooth are occlusal interferences, caries around the fissure, and attrition of the opposing tooth. DE also has been reported to cause incomplete eruption, displacement of teeth, and traumatic occlusion because of the size and location of the tubercle.24 Rotation and tilting of teeth with DE also can occur as a sequelae of traumatic occlusion.4-6,9 Oehlers reported that abnormal occlusal forces on the crown can produce subluxation, leading to dilaceration of the root at the apical one third level.4 The end result of an evaginated tooth is pulpal infection, either by direct exposure due to cusp fracture or indirectly through patent dentinal tubules exposed due to wearing and attrition of the tubercle.4,6,24 Yip reported that 82% and approximately 26% of 57 premolars exhibited cuspal wear and pulpal involvement, respectively. 2 The possible sequelae following pulpal exposure are apical periodontitis, loss of vitality, facial infection, osteomyelitis,2,22,28 root cyst, and pericementitis.26 The prevalence of these complications was studied by many authors, who found that periapical abscess varied from 18% to 40%.4,14,29 The purpose of this article was to report a case of an unusually long and slender dens evaginatus in a maxillary right second premolar which did not interfere with the occlusion.
dibular right and left first molars. The maxillary right second premolar’s occlusal surface featured a prominent, rounded, very long projection from the central groove (Figure 1), and on the contralateral tooth there was a very mild elevation (Figure 2). There was no obvious sign of wear or fracture in the tubercle. An intraoral periapical radiograph of the maxillary right second premolar revealed the following features: a projection on the occlusal aspect; pulpal extension into the projection; complete root formation without any periapical pathology (Figure 3). The periapical radiograph of the maxillary left second premolar was unremarkable (Figure 4). Mandibular and maxillary impressions were made using alginate (ZelganŽ 2002, Dentsply, Gurgaon, Haryana, , India), and study models were prepared. Since the tubercle was extra long, a K file (Mani Inc, Tochigi, Japan) was used to measure its length (Figure 5) and was read on an endobloc (Dentsply, Maillefer, Swiss; Figure 6). The tubercle measured approximately 3 mm from the central fissure. Oral prophylaxis was administered and preventive resin restorations (A2 shade, Filtek Z 350, 3M ESPE, St. Paul, Minn) were performed on the permanent mandibular right and left first molars. As there was no
CASE DESCRIPTION
A 12-year-old male reported to the Department of Pediatric Dentistry, Meenakshi Ammal Dental College and Hospital, Maduravoyal, Tamil Nadu, India, with a chief complaint of decay in his tooth. The medical and past dental histories were noncontributory. On clinical examination, the patient was in the late mixed dentition period. The mandibular right and left second molars were the only primary teeth in the dentition. Dental caries was found in the permanent man-
Figure 1. Intraoral photograph showing the unusually long dens evaginatus from the maxillary right second premolar.
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Figure 2. Occlusal view of maxillary teeth with dens evaginatus on both second premolars (mirror view).
Figure 3. Intraoral periapical radiograph showing pulpal extension into dens evaginatus on the maxillary right second premolar.
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Figure 4. Intraoral periapical radiograph of the maxillary left second premolar.
occlusal discrepancy or interference of the tubercle, no specific treatment for the DE was administered. Preventive measures, however, as elaborated in the decisionsupport system (Figure 7), were planned and explained to the parents. The parents were not willing to engage in any preventive management of the sound tooth even after it was explained that the tubercle may experience future complications.
DISCUSSION
DE is also known as tuberculum anomalous, which is a developmental anomaly described as an enamel elevation similar to talon cusp, generally located in the main grooves of molars and premolars.28,30 The teeth commonly involved are mandibular premolars,1-6,9,23,25,31 but in our case it was seen bilaterally on the maxillary second premolar in varying clinical presentations. A complete search of the scientific literature did not reveal any classification for DE. Hence, we suggest the following classification in line with modified talons cusp classification, which was proposed by Jeevarathan et al., in 2005.32 1. Major DE—a cusp-like projection from a posterior tooth’s occlusal surface extending more than 2 mm from the central fissure/pit; 2. Minor DE—a cusp-like projection from a posterior tooth’s occlusal surface extending more than 1 mm but less than 2 mm from the central fissure/pit; and 3. Trace DE—a small elevation from a posterior tooth’s occlusal surface extending less than 1 mm from the central fissure/pit. In our case, the DE in the maxillary right second premolar is considered a major DE, whereas on the contralateral side it is considered a trace DE. The previously published reports had not measured the tubercle’s size. The proposed classification will be helpful in categorizing future DE reports. The authors initially considered the tip of a functional/nonfunctional cusp from the central fissures/pits of posterior teeth as a reference point Journal of Dentistry for Children-78:1, 2011
Figure 5. Measuring the length of dens evaginatus using a K file.
to classify DE similar to the cementoenamel junction and incisal edge in talon cusp classification. Due to the possibility of morphological variations of cuspal patterns, however, the functional or non functional cusps could not be considered. The most common problem in an evaginated tooth is occlusal interference when the tooth comes into contact with the opposing tooth. In our case, even though the tubercle on the maxillary right second premolar was unusually long, it did not interfere with the opposing tooth in occlusion or with the lateral excursion of the jaws (Figure 8). This could be due to the presence of the primary mandibular second molar, which is not the perfect antagonist to the maxillary second premolar. The patient and his parents were informed about potential problems with the eruption of the opposing premolar, and the need for regular monitoring was emphasized. If there is no occlusal interference, preventive measures based on depth of the fissures around the tubercle should be considered. When the fissures around the tubercle are not deep, application of fluoride can be done. If the fissures are deep, application of sealants is the treatment of choice to prevent caries and to
Figure 6. Tubercle length being read on an endobloc.
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Figure 7. A decision support system for the management of dens evaginatus.
reinforce the tubercle from fracture. 21,33-35 If there is occlusal interference, then management of DE is determined by the pulp horn extension within it. The pulp extension in an evaginated tooth could be wide, narrow, constricted pulpally, isolated, or even absent.11,13,24 In our case, the pulp horn extension in the maxillary right second premolar was wide, whereas on the contralateral side it was absent. When the pulp horn does not extend into the tubercle, grinding of the tubercle followed by composite restoration is the treatment of choice. If the pulp horn extends into the tubercle, then its height of penetration determines the treatment. When there is mild extension of the pulp, intermittent grinding of the cusp is advised to allow the repa-
Figure 8. Lack of Occlusal interference in lateral excursion.
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rative dentin formation followed by fluoride application to diminish sensitivity. 17,36,37 If there is accidental exposure of the pulp, direct pulp capping is recommended to maintain vitality. When there is severe extension of the pulp, complete removal of the tubercle with the necessary pulpal procedures based on vitality and status of root development is the treatment option for DE. Extraction is the treatment of choice when any orthodontic treatment is necessary for the patient, which demands removal of the premolar.31
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