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Year : 2018  |  Volume : 29  |  Issue : 4  |  Page : 517-520
Enamel pearl diagnosed by cone beam computed tomography: A clinical case report

Department of Dentistry, Pontifical Catholic University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil

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Date of Web Publication20-Aug-2018


Little research has been performed on tomographic observations of the dental development anomaly known as enamel pearl. This article presents a clinical case report in which enamel pearl was detected through cone beam computed tomography (CBCT). In this study, a patient was referred to undergo a CBCT of the left maxillary molar region, due to the patient's pain symptoms in this region. The CBCT showed the existence of an enamel pearl in tooth 27. A precise diagnosis made it possible for the patient to begin the preventive treatment against periodontal disease in tooth 27.

Keywords: Cone beam computed tomography, dental enamel, dental radiography, periodontal diseases

How to cite this article:
Rocha BD, Andrade J, Valerio CS, Manzi FR. Enamel pearl diagnosed by cone beam computed tomography: A clinical case report. Indian J Dent Res 2018;29:517-20

How to cite this URL:
Rocha BD, Andrade J, Valerio CS, Manzi FR. Enamel pearl diagnosed by cone beam computed tomography: A clinical case report. Indian J Dent Res [serial online] 2018 [cited 2022 May 23];29:517-20. Available from:

   Introduction Top

Enamel pearls, described for the first time in 1841 as a “pin's head,”[1] are enamel deposits in the bifurcation areas or on the root surface near the cementoenamel junction.[2] The average diameter of an enamel pearl is 0.96 mm, varying from 0.3 to 0.4 mm.[3] Regarding the structure, the enamel pearl can be classified into three groups: true or simple, composite, and composite with pulp chamber.[1],[4] The first consists only of enamel; the second consists of dentine and enamel; and the third is a pearl consisting of enamel, dentine, and the pulp chamber, which can be an extension of the coronary or root pulp. The majority of the enamel pearls contain a tubular dentine core.[1]

The prevalence of the enamel pearls varies between 0.83% and 9.7% and are uncommon in single-rooted teeth.[1],[2],[5],[6] However, this prevalence can vary depending on the evaluated population, group of studied teeth, and method used in the diagnosis of these structures. Akgul et al.,[2] who investigated the prevalence of enamel pearls in cone beam computed tomography (CBCT) images of 768 individuals, found a prevalence of 4.69% (36 individuals). All of enamel pearls of the 36 individuals were detected in molar teeth. By contrast, when considering only the molars of the 768 individuals, the prevalence was of 0.83% (36 of 4334 molar teeth). These authors also observed that there was no statistically significant association between the prevalence of enamel pearls and the patient's gender.

In general, the enamel pearl is more frequently observed in molars, especially in the second and third maxillary molars.[2] In the maxillary molars, enamel pearls are more commonly located in the bifurcation area between the distobuccal and palatal roots.[5]

Few studies in prior literature have evaluated enamel pearls through CBCT examinations. Thus, the presentation of this clinical case seeks to describe the tomographic characteristics of enamel pearls in such a way as to contribute to correct diagnostic of this dental anomaly.

   Case Report Top

A 35 year old female patient searched for a dentist, complaining of pain in the maxillary posterior teeth on the left side. In the anamnesis, the patient reported having submitted to endodontic treatment in teeth 26 and 27. The extraoral examination showed no abnormality. The intraoral examination showed the presence of restoration in teeth 24, 25, 26, and 27, as well as the absence of tooth 28. No intraoral fistula was found. The dentition appeared to be in good condition, and the patient's medical history proved to be negative.

A periapical radiograph was requested to evaluate the affected region through symptomatology, where the presence of a round, radiopaque, well-defined image was observed in tooth 27 [Figure 1]. As the periapical radiograph showed no image that justified the presence of pain symptoms, a CBCT examination, with a more well-defined field of view, was requested to better evaluate the area and search for possible cracks or fractures. A CBCT of the region was therefore performed using a Kodak 9000C 3D Extraoral Imaging System (Eastman Kodak Company, Rochester, NY, USA), with the following exposure factors: 74 Kv, 10 mA, 10.8 s exposure time, and a resolution of 76 μm × 76 μm × 76 μm voxel size.
Figure 1: Periapical radiograph. White arrow shows a round structure, radiopaque on the outside and radiolucent in the center, projected over the furcation area of tooth 27. The borders of the sphere are well defined, and there is a thin radiolucent line at the periphery. This image does not show the adherence between the sphere and tooth

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In the CBCT, a hyperdense round structure on the outside and a hypodense structure on the inside were observed in the furcation area, adherent to the roots of tooth 27, between the mesiopalatal and distopalatal roots, measuring 0.2 mm, suggesting the diagnosis of an enamel pearl [Figure 2] and [Figure 3]. A hypodense line was observed at the apex of the mesiobuccal root of tooth 26, presenting an increase in the adjacent periodontal space, which is compatible with an inflammatory and infectious osteolytic lesion [Figure 4]. Also observed was a hypodense line in the palatal root of tooth 26, near the metallic nucleus, which is compatible with a crack [Figure 5].
Figure 2: Cone beam computed tomography reconstruction. White arrow shows the enamel pearl fusion with the root dentin of tooth 27, located in the furcation area, between mesiopalatal and distopalatal roots. (a) Axial view. (b) Buccopalatal sectional view. P = Palatal, MP = Mesiopalatal, DP = Distopalatal

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Figure 3: Three-dimensional volumetric view of enamel pearl. Palatal view. White arrow shows an enamel pearl between mesiopalatal and distopalatal roots of tooth 27. MP = Mesiopalatal, DP = Distopalatal

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Figure 4: Cone beam computed tomography reconstruction. (a) Buccopalatal sectional view. (b) Yellow arrow shows a hypodense line at the apex of the mesiobuccal root of tooth 26. MB = Mesiobuccal, DB = Distobuccal

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Figure 5: Cone beam computed tomography reconstruction. Buccopalatal sectional view. Red arrow shows a hypodense line at the palatal root of tooth 26 compatible with a crack. P = Palatal, MP = Mesiopalatal, DP = Distopalatal

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The treatment plan included the extraction of tooth 26 and the periodontal control of tooth 27, given that enamel pearls facilitate the progression of periodontal breakdown.[5],[7]

   Discussion Top

The majority of studies on enamel pearls were performed using either extracted teeth[4],[5],[8],[9] or conventional radiography.[7],[10] Few studies in prior literature have evaluated enamel pearls using CBCT,[2],[3] and only one study was carried out using a micro-CT.[6] Thus, this article seeks to describe the tomographic aspects of enamel pearls through the presentation of a clinical case study.

The etiology of enamel pearls has yet to be fully clarified. The more accepted theory affirms that its development is due to the adherence of Hertwig's epithelial root sheath cells to the tooth's root surface during root development, differentiating into functioning ameloblasts that are apical to the cementoenamel junction.[1],[3],[6],[9] What is still not understood are the necessary conditions through which this differentiation of the ameloblast can occur in an ectopic location.[9]

Microscopically, the enamel pearl located in tooth roots is similar to immature enamel, presenting irregular areas and enamel prisms that are generally twisted and wavy.[1],[9] By contrast, the dentine presented a normal morphology with aligned dentinal tubules. Many times, there is a thin layer of afibrillar cementum covering the enamel pearl.[1]

The existence of an enamel pearl requires careful treatment, given that an improper diagnosis can trigger or worsen preexisting periodontal diseases, leading the affected tooth to an unfavorable prognosis.[5],[7] This fact is due to the greater facility of accumulating biofilms in the regions in which enamel pearls are present. In this sense, there is a greater probability of the occurrence of clinical cases of gingivitis or periodontitis that can lead to tooth loss.[8] Because the enamel pearl is a predisposing factor for periodontal lesion, the patient described in this clinical case study was referred for periodontal control in tooth 27.

Enamel pearls may also be related to the lack of success in endodontic treatments. In an attempt to aid in the diagnosis of complications stemming from the presence of enamel pearls, it is essential for dentists to perform a complete examination, including radiographic examinations and pulp vitality tests, in order, in certain situations, to be able to drain the lesion through gingival sulcus and swelling, in turn simulating an endodontic-periodontal lesion.[6]

For the dental professional to make the correct diagnosis of a dental anomaly, knowledge about anatomical variations and the help of imagery examinations, such as radiographs and CBCTs, are imperative. Radiographically speaking, the enamel pearl, associated with the periodontal or periapical lesion, reveals an angular bone loss along the root surface.[6] This is depicted as a radiopaque, dense, smooth image, overlapping the crown or affected tooth root. However, in the radiographic examination, the enamel pearl is often confused with a dental calculus, hindering correct diagnosis.[7] Hence, the CBCT is useful in identifying these anatomic structures.[6]

When the enamel pearl is exposed to the oral environment, surgical treatment is recommended since its elimination facilitates the patient's access to oral hygiene, allowing for the control of biofilms. Other procedures are often commonly recommended, such as odontoplasty, tunneling, root separation, resection, or extraction.[6],[10]

In the clinical case presented in this study, it could be observed that the pain symptoms were caused by the presence of cracks in the root of tooth 26. Tooth 27, which presented an enamel pearl, proved to be asymptomatic. Thus, the extraction of tooth 26 was recommended in an attempt to resolve the pain symptoms. The patient was also advised to undergo periodontal follow-up of tooth 27 to prevent the appearance of periodontal disease due to the presence of an enamel pearl.

   Conclusion Top

In the literature, there are few studies demonstrating the use of CBCT in the diagnosis of enamel pearls. Hence, this clinical case describes the tomographic characteristics of enamel pearls and highlights the importance of CBCT examinations in attaining more precise diagnoses of lesions associated with this dental anomaly since conventional radiographs do not provide the information about surrounding structures. Through the proper diagnosis of enamel pearls, preventive measures can be adopted to preserve the affected tooth.


Dr C.S. Valerio's studies were supported by the Coordination for the Improvement of Higher Education Personnel (CAPES Foundation).

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Moskow BS, Canut PM. Studies on root enamel (2). Enamel pearls. A review of their morphology, localization, nomenclature, occurrence, classification, histogenesis and incidence. J Clin Periodontol 1990;17:275-81.  Back to cited text no. 1
Akgül N, Caglayan F, Durna N, Sümbüllü MA, Akgül HM, Durna D, et al. Evaluation of enamel pearls by cone-beam computed tomography (CBCT). Med Oral Patol Oral Cir Bucal 2012;17:e218-22.  Back to cited text no. 2
Saini T, Ogunleye A, Levering N, Norton NS, Edwards P. Multiple enamel pearls in two siblings detected by volumetric computed tomography. Dentomaxillofac Radiol 2008;37:240-4.  Back to cited text no. 3
Cavanha AO. Enamel pearls. Oral Surg Oral Med Oral Pathol 1965;19:373-82.  Back to cited text no. 4
Chrcanovic BR, Abreu MH, Custódio AL. Prevalence of enamel pearls in teeth from a human teeth bank. J Oral Sci 2010;52:257-60.  Back to cited text no. 5
Versiani MA, Cristescu RC, Saquy PC, Pécora JD, de Sousa-Neto MD. Enamel pearls in permanent dentition: Case report and micro-CT evaluation. Dentomaxillofac Radiol 2013;42:20120332.  Back to cited text no. 6
Zenóbio EG, Vieira TR, Bustamante RP, Gomes HE, Shibli JA, Soares RV, et al. Enamel pearls implications on periodontal disease. Case Rep Dent 2015;2015:236462.  Back to cited text no. 7
Kaminagakura E, Salmon CR, Fonseca DC, Lopes MC, Tango RN. Prevalence and microscopic features of enamel pearls from permanent human molars. Braz J Oral Sci 2011;10:268-71.  Back to cited text no. 8
Risnes S. Ectopic tooth enamel. An SEM study of the structure of enamel in enamel pearls. Adv Dent Res 1989;3:258-64.  Back to cited text no. 9
Romeo U, Palaia G, Botti R, Nardi A, Del Vecchio A, Tenore G, et al. Enamel pearls as a predisposing factor to localized periodontitis. Quintessence Int 2011;42:69-71.  Back to cited text no. 10

Correspondence Address:
Dr. Flávio Ricardo Manzi
Pontifícia Universidade Católica De Minas Gerais, Av. Dom José Gaspar, 500 - Coração Eucarístico, CEP 30535610, Belo Horizonte, Minas Gerais
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijdr.IJDR_751_16

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  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]


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