Journal of Medicine, Radiology, Pathology & Surgery (2019), 6, 9–11 CASE REPORT Bilateral dens evaginatus in deciduous first molars: A rare finding D. B. Nandini1, N. B. Nagaveni2, B. S. Deepak3, P. Poornima2 1Department of Oral Pathology and Microbiology, Dental College, Regional Institute of Medical Sciences, Imphal, Manipur, India, 2Department of Pediatric Dentistry, College of Dental Sciences, Davangere, Karnataka, India, 3Department of Conservative Dentistry, Dental College, Regional Institute of Medical Sciences, Imphal, Manipur, India Keywords: Abstract Accessory cusp, deciduous dentition, dens Dens evaginatus is a developmental anomaly affecting the shape of the teeth. Although evaginatus, evaginated odontoma, occlusal many cases have been reported in permanent dentition, the occurrence in deciduous enamel pearl, primary mandibular molar, supernumerary cusp, talon’s cusp, tubercle dentition is rare. Although the condition does not cause serious consequences, sometimes it may result in problems necessitating professional treatment. This article reports a rare Correspondence: case of bilateral dens evaginatus in deciduous mandibular first molar. A brief review of Dr. D. B. Nandini, Department of Oral etiology, complications, preventive measures, and management has been discussed. Pathology and Microbiology, Dental College, Regional Institute of Medical Sciences, Imphal, Manipur, India. Phone: +91-9448404214. E-mail: [email protected] Received: 10 November 2018; Accepted: 15 December 2018 doi: 10.15713/ins.jmrps.154 Introduction lesions were noticed in 74, 75, 84, and 85 (Fédération Dentaire Internationale tooth notation). An incidental finding showed the Dens evaginatus (DE) is a developmental anomaly affecting the presence of DE in teeth 74 and 84 [Figure 1]. The cusp tips of tooth structure. DE was first described in a human tooth by Mitchell, the accessory cusps did not show attrition. Intraoral periapical in 1892.[1] This condition is named by different names in different radiographs revealed the presence of enamel, dentin in these teeth, namely talon’s cusp in anterior teeth, Leong’s premolar in accessory cusps [Figures 2a and b]. No depression in occlusal premolars, and cusp of Carabelli in maxillary molar. DE has been surface was noticed in the corresponding maxillary primary given various names such as odontome, odontoma (odontome) of axial core type, tuberculated cusp, accessory tubercle, occlusal molar. Composite resin restoration was done in the teeth tuberculated premolar, Leong’s premolar, evaginatus odontoma showing moderate carious lesions. No evidence of any carious (evaginated odontome), occlusal tubercle, tuberculum anomalous, lesions was observed during the follow-up. The patient is kept accessory cusp, supernumerary cusp, interstitial cusp, occlusal enamel under observation to access any associated complications and to pearl, and talon cusp.[2,3] The incidence varies according to the type know whether the permanent successors also show evidence of and tooth affected. The frequency of occurrence varies depending on DE later. the type, size, shape, location, and composition of the cusp. It is more common in permanent dentition, maxillary arch, anterior region, and Discussion incisor teeth. It is commonly found in females. Bilateral occurrence in deciduous mandibular molars is a rare phenomenon.[4] DE affects both the deciduous and permanent dentition; however, the incidence in deciduous dentition is quite rare. It may manifest unilaterally or bilaterally. It is most often reported Case Report on the premolars in the permanent dentition. There is typically a A 6-year-old female patient reported to the college with bilateral, symmetric distribution, with a slight sexual predilection complaint of carious teeth. On clinical examination, carious for female. It is thought to develop more often in persons of Journal of Medicine, Radiology, Pathology & Surgery ● Vol. 6:1 ● Jan-Feb 2019 9 Nandini, et al. Dens evaginatus Mongoloid ancestry: Chinese, Japanese, Filipinos, Eskimos, and American Indians.[4] DE prevalence in Indians has been reported to be 3–4%. The exact etiology is unknown, but a multifactorial inheritance combining the polygenetic and environmental factors has been suggested. It is believed that an abnormal proliferation and evagination of inner enamel epithelium and underlying ectomesenchyme into the enamel organ during the bell stage of tooth development lead to this condition.[5] The enamel knot plays an important role as transient signaling center in tooth morphogenesis. The primary knot influences the underlying ectomesenchyme by expressing fibroblast growth factors-4 and 9, transforming growth factor-β, and bone morphogenetic proteins-2, 4, and 7 and also induces formation of secondary knots. Molecular studies have revealed that the epithelial-mesenchymal interactions, especially the signaling between enamel knot and underlying ectomesenchyme, Figure 1: Clinical photograph showing bilateral dens evaginatus in determine the number of cusps in a tooth during odontogenesis. deciduous mandibular first molars A disturbance in this signaling mechanism is said to cause DE. PAX and MSX genes are said to be responsible for the abnormal shape of the teeth.[6] DE may be associated with other disorders such as shovel-shaped incisors, peg-shaped incisors, megadont, odontomas, bifid cingula, three rooted molars, and mesiodens[2] and may be a part of syndromes such as Rubinstein-Taybi syndrome,[7] Mohr syndrome (oral-facial-digital II syndrome),[8] Sturge-Weber syndrome (encephalotrigeminal angiomatosis), and Ellis-van Creveld syndrome.[9] DE is classified based on its location by Schulge [Table 1].[10] Five variations of DE have been classified based on the location of the tubercle: Cone-like enlargement of lingual or buccal cusp, tubercle on inclined plane of lingual or buccal cusp, or a tubercle a b arising from the central groove.[3] Lau further classified the tubercle according to its anatomical shape as smooth, grooved, Figure 2: Intraoral radiograph showing dens evaginatus in the right terraced, and ridged.[11] Oehler et al. identified the evagination (a) and left (b) deciduous mandibular first molars according to the pulp contents within the tubercle by examining the histological appearance of the pulp using the decalcified Table 1: Schulge’s classification of DE depending on its location[15] serial sections of extracted teeth with DE [Table 2].[5] Types Types description DE may contain enamel and dentin and sometimes encloses 1 A cone‑like enlargement from the lingual cusp the pulp tissue extending into it. This anomaly is associated with some complications. There is risk of caries since there is 2 A tubercle on the inclined plane of the lingual cusp invariably a deep groove or pit between this projection and other 3 A cone‑like enlargement of the buccal cusp [12] cusps. Most often, it causes occlusal interference resulting in 4 A tubercle on the inclined plane of the buccal cusp occlusal wear and fracture. This may lead to exposure of dentin 5 A tubercle arising from the occlusal surface obliterating the and pulp. It might even cause habitual posturing of mandible central groove with resultant temporomandibular joint problems in later life.[4] Reports of pulpitis with subsequent pulp necrosis have also been found in literature. Periodontal problems and irritation Table 2: Oehler’s classification of DE according to pulp content[7] to adjacent soft tissues such as gingiva and tongue may also be Types Types description seen. Clinicians must carefully evaluate and plan the treatment 1 Wide pulp horns (34%) according to the individual case. Occlusal grinding of the cusp for occlusal adjustment 2 Narrow pulp horn (22%) and the need of endodontic treatment in case of pulp 3 Constricted pulp horn (14%) involvement should be informed to the patient. Pulp capping 4 Isolated pulp horn remnants (20%) or partial pulpotomy has been suggested for treating vital 5 No pulp horns (10%) pulp. Preventive resin composite sealing of the dentin or 10 Journal of Medicine, Radiology, Pathology & Surgery ● Vol. 6:1 ● Jan-Feb 2019 Dens evaginatus Nandini, et al. Class I amalgam cavity preparation would be the treatment of pathophysiology, and comprehensive treatment regimen. choice if there is no pulp exposure. Pit and fissure sealants are J Endod 2006;32:1‑9. recommended as preventive measures, while composite resin 4. Nagarajan S, Sockalingam MP, Mahyuddin A. Bilateral accessory and amalgam restorations have also been advocated as DE is central cusp of 2nd deciduous molar: An unusual occurrence. prone to caries. Root canal therapy and extraction have been Arch Orofac Sci 2009;4:22‑4. suggested in selected cases. The treatment of DE includes pulp 5. Oehlers FA, Lee KW, Lee EC. Dens evaginatus (evaginated vitality preservation, caries prevention, elimination of tongue odontome). Its structure and responses to external stimuli. Dent Pract Dent Rec 1967;17:239‑44. irritation, and meeting esthetic and occlusal requirements. The 6. Thesleff I. Epithelial‑mesenchymal signalling regulating tooth most recent treatment approach for DE teeth with immature morphogenesis. J Cell Sci 2003;116:1647‑8. roots and necrotic pulp is to use regeneration (revascularization 7. Gardner DG, Girgis SS. Talon cusps: A dental anomaly in the of necrotic pulp space). Preventive measures such as oral rubinstein‑taybi syndrome. Oral Surg Oral Med Oral Pathol hygiene care, diet advice, and topical fluoride gel should also 1979;47:519‑21. [9,12]