Multiplepre-eruptive intracoronal radiolucent lesions in the permanentdentition: case report W.Kim Seow, MDSc, DDSc, PhD, FRACDS adiolucencies in the dentin of crowns of Medicalanddental histories unerupted teeth maybe observed incidentally The patient was healthy. After the fracture of the R on dental radiographs.1-17 These defects are premolar, her parents sent her for a full examination, usually initially located in the parts of dentin adjacent including blood chemistry, which yielded normal val- with the enamel on the occlusal parts of the dental ues. The patient had always attended regular dental crown.1Although the lesions resembledental decay and visits. Shehad a history of large "holes" in her primary have been referred to as "pre-eruptive caries",4-8 these molars, in spite of a putatively noncariogenicdiet, ex- radiolucencies in unerupted teeth are unlikely to have cellent oral hygiene, fluoride supplementation since resulted fromcaries as they are not exposedto the oral early infancy, and regular professional fluoride appli- microbialflora) Instead, they are likely idiopathic, de- cations. She had resided in a town with nonfluoridated velopmental,or resorptive lesions. In resorptive lesions, water since birth. histological examination of tissue removed from She had undergoneorthodontic therapy for correc- unerupted teeth often showthe presence ofosteoclasts tion of mild Class II malocclusion. Duringremoval of and Howship’slacunae within the dentin.5’ 14. 17 The an orthodontic band from the mandibularsecond pre- pathogenesis of such lesions is thought to be the in- molar using routine techniques, the crowncompletely gress of resorptive cells from tissues surroundingthe detached from the root. The patient had not experi- developing tooth through a small opening on the oc- enced pain or any other symptoms prior to the clusal1 surface or the cementoenameljunction (CEJ). incident. An endodontist and a prosthodontist were Although this phenomenoncan occur in any tooth, immediatelyconsulted regarding the prognosis of the previous cases were all of the permanentdentition ex- retained root. Endodonticsand restoration with a post cept for the first case in the primarydentition recently crown were suggested. 1 reported. From the literature, the most commonly Clinicalfindings affected teeth are the third molars, permanentsecond molars, and premolars.1 In addition, two other case On examination, the patient appeared healthy, reports have mentionedfirst permanentmolars, 9’ 10 and cheerful, and cooperative. Height, weight, and facial another two a permanentcanine. 2’ 11 features were all within normallimits. Dental exami- Nearly all previously reported cases note that most nation revealed a full permanentdentition except for lesions were relatively small and usually occurred in the third molars and the crownof the mandibularsec- only one or two affected teeth per individual.12-19 In ond premolar. Large occlusal amalgamrestorations contrast, this report showsmultiple affected teeth in were observed on all first permanentmolars. Smaller an otherwise healthy adolescent. Theaims of this case occlusal restorations were seen in the mandibularleft report were to illustrate the unusual occurrence of second molar and the maxillary right second premo- multiple lesions in a single individual, the severity of lar. A mandibularlingual arch retainer was present. the destruction without obvious clinical signs, as The gingiva and other soft tissues were within nor- well as the difficulty of diagnosis once the teeth have mal limits. At the site of the mandibularleft second fully emerged. premolar, the mucosa appeared to have almost com- pletely covered the decoronated tooth, except for a Casereport small linear fistula on the occlusal ridge (Fig 1). The 14-year-old Caucasian female was referred to Radiographicfindings the author for diagnosis regarding the fracture of an A Panorex radiograph confirmed the level of frac- apparently normal mandibular left second premolar ture to be at the CEJ(Fig 2). In addition, radiolucent crown approximately 6 weeks earlier during routine defects in dentin were clearly visible adjacent to the orthodontic debanding. The detached premolar crown enamelon the mesial aspects of the occlusal surfaces whichhad been stored dry wasbrought in by the patient. in the mandibular right second molar and the Pediatric Dentistry-20:3, 1998 AmericanAcademy of Pediatric Dentistry 195 unerupted man- dibular left third molar (Fig 2). Examination of bite-wing radio- graphs (Fig 3) exposed a month previously re- vealed a similar radiolucent le- Fig 1. Mandibular teeth of the patient sion on the max- depicting the large restorations on the illary right sec- mandibular first permanent molars. There was ond premolar, a linear fistula on the mucosa where the crown and confirmed of the mandibular left second premolar had Fig 2. Orthopantogram of the patient exposed at time of crown fracture. Note intracoronal radiolucent defect in dentin just beneath the that present on been detached. dentinoenamel junction on the mesial aspect of the occlusal, in the the mandibular mandibular left third molar and the mandibular right second molar. The right second permanent molar. round radiolucent area at the apical aspect of the mandibular left second To determine if the defects were evident on earlier premolar is not continuous with the periodontal membrane space, and is radiographs, orthopantograms and bite-wings exposed most likely the mental foramen. several years previously were reviewed. An orthopanto- gram exposed 3 and a half years earlier, at age 10, (Fig 4) indicated that the unerupted mandibular left sec- the soft tissue components could not be examined. Ex- ond premolar showed a radiolucent lesion in dentin amination of undecalcified sections of the tooth underneath the occlusal enamel. In addition, similar but revealed that the coronal dentin had almost completely smaller lesions were also observed in both mandibular resorbed from within (Fig 6). Small fragments of den- tin which were still adherent to the enamel showed second molars. Bite-wing radiographs exposed at age 7 (Fig 3) showed large occlusal amalgam restorations in evidence of resorption and possibly secondary bacte- the right mandibular first permanent molar and radiolu- rial destruction from within. The resorptive processes cencies in the dentin in the left maxillary first permanent appeared to have spread to the enamel at some sites, leading to scalloping of the enamel margins at the ad- molar and the left mandibular first permanent molar. Additionlly, both mandibular primary molars and the vancing front (Fig 7). left maxillary primary first molar had large amalgam restorations. Unrestored proximal caries were noted on the left maxillary first and second primary mo- lars (mesial) and both mandibular first primary molars (distal). Examination of the crown specimen The external surface of the crown of the fractured mandibular left pre- molar appeared normal in color and shape (Fig 5). The enamel appeared intact in the entire crown. Probing of the external enamel surface with a sharp explorer did not reveal any deep occlusal pits. The cervical margins of the detached crown were smooth and appeared to have separated cleanly from the root. Internally, there was a layer of intact enamel surrounding a mass of dry, friable material in the cen- Fig 3. Bite-wing radiographs of the patient. The upper set was exposed at age 7 and the lower ter of the crown. set at 14 years. Note from the upper set of bite-wings, radiolucent defects underneath the As the fractured tooth had been enamel on the left mandibular and maxillary first permanent molars, and from the lower set, kept in dry storage for several weeks, similar defects in the right mandibular second molar and the right maxillary second premolar. Also, in the upper set, proximal caries was noted on the mesial of the left maxillary first and second primary molars, and distal of both mandibular first primary molars. 196 American Academy ofPediatric Dentistry Pediatric Dentistry - 20:3, 1998 manent dentition2 1<; and the majority in the mandible. Furthermore, most previous cases have mentioned the involvement of only one or two affected teeth in each subject. This case differs from most previous ones in that more than two teeth were affected in one individual. There was direct radiographic evidence of defect presence during the pre-eruptive stages in both perma- nent mandibular second molars, mandibular left third molar, and mandibular left second premolar. In these teeth, the radiographic appearance and location of the defects strongly suggest that these represent classical intracoronal dentinal resorptive lesions which are ac- Fig 4. Orthopantogram of patient exposed at approximately 10 years of 1 age showed intracoronal radiolucent defects in dentin just beneath the quired pre-eruptively. dentinoenamel junction in both mandibular second molars and the In addition, similar radiolucent defects were noted mandibular left second premolar. on radiographs of the following permanent teeth after eruption: left maxillary first molar, left mandibular first Discussion molar, and maxillary right second premolar. However, Radiolucencies within the crowns of unerupted teeth as these radiographic defects were noted posteruptively, may represent large buccal pits, calcification abnormali- they were difficult to distinguish from caries. Decay is ties such as hypoplasia of enamel or dentin, or likely to superimpose on resorption lesions soon after