CASE REPORT

Spectrumof dentin dysplasia in a family: case report and literature review

W. Kim Seow, BDS, MDSc, DDSc, PhD Stephen Shusterman, DMD Abstract The dentin dysplasias (DD),which maybe classified as type I (DD1)or type 2 (DD2),form a group of rare, inherited abnormalitiesthat are clinically distinct fromdentinogenesis imperfecta. Studies of affected families mayhelp to distinguish different types of DDand provide further insight into their etiology and clinical management.This report describes a family that showed characteristic dental features of DD1, including clinically normalcrowns in both primaryand permanentdentitions, and mobileteeth that maybe associated with prematureexfoliation. Radiographicfeatures included calcification of the with crescent-shaped, radiolucent pulp remnants, short, tapering, taurodontic roots, and manyperiapical pathoses that maybe q¢sts or .A spectrumof dentin dysplasia wasnoted within the family. Strategies to prevent pulp and periapical infections and early exfoliation of the teeth include meticulousoral hygieneand effective caries-preventivemeasures. ( P ed iatr Dent16:437-42,1994) Introduction and literature review Histologically, in DD1, most of the coronal and Dentin dysplasias (DD) form a group of rare dentin mantle dentin of the root is usually reported to be abnormalities that are clinically distinct from normal, and the dentin defect is confined mainly to the dentinogenesis imperfecta. 1-3 Since its recognition in root2, s, 10 The dysplastic dentin has been reported to 19203 as "rootless teeth" and as "dentin dysplasia" by consist of numerous denticles, containing whorls of Rushton in 1933,4 the clinical features of DDhave been osteodentin that block the normal course of the den- tinal tubules,s, 10,11 well described. However, to date, relatively little is 12 knownabout the pathogenesis of the dentin defects, or A recent suggestion to subclassify DD1into four their pathological and clinical implications. As over- subdivisions based on the radiographic appearance of lapping pathological features may be present in the the pulp chambersis not likely to be clinically feasible various types of DD, studies of affected families may due to the simultaneous presence of all varieties of the help to delineate different types and provide further pulp chambers in any particular patient. Simpler sub- 13 insight into the etiology and clinical managementof classifications into either mild or severe maybe more these conditions. clinically relevant. Classificationof dentindysplasias Dentindysplasia, type II (DD2) Generally, two main classes of DD are recognized The clinical features of DD2contrast sharply with based on clinical and radiographic appearance. Shields those of DD1, and consist classically of: primary teeth et al. 2 proposed the classifications -- type I, or "dentin that have a bluish or amber discoloration, and perma- dysplasia," and type II or "anomalous dysplasia of nent teeth that appear normal;14-17 and primary teeth dentin." Witkop1 later described type I as "radicular that show total pulp obliteration, and permanent teeth dentin dysplasia" and type II as "coronal dentin dys- that show thistle-tube pulp configuration and pulp plasia" to indicate the parts of the teeth that are prima- stones14-17 in pulp chambers. rily involved. A third type of dentin dysplasia, DD3or Histologically, the affected teeth in DD2typically focal odontoblastic dysplasia, also has been proposed.S show a thin layer of normal coronal dentin and a sud- den transition to dysplastic dentin, which is sclerotic Dentindysplasia, type I (DD1) and2,3, amorphous17 with few tubules. The classical features in DD1, which have been well documented by several case reports, 3-9 are: 1) normal- Modeof inheritance appearing clinical crowns in both dentitions; 2) short, In both types of DD, the modeof inheritance is auto- conical, or absent roots that may lead to mobility and somal dominanto1, a However, there is no information early exfoliation of the teeth; 3) total obliteration of the regarding the gene defects in any type of DD. pulps except for thin, crescent-shaped pulpal remnants parallel to the cementoenamel junctions; and 4) Etiology periapical radiolucent areas, which may be granulo- The etiology of DD1remains speculative. Logan et mas or cysts associated with noncarious teeth. al. is suggested that abnormalcalcification of the pulp is

Pediatric : November/December1994 - Volume 16, Number 6 437 related to degeneration of the dental papilla, whereas Differential diagnosis Sauk and coworkers 1° postulated that premature in- Differential diagnosis of DDfrom dentinogenesis vagination of the epithelial root sheath is associated imperfecta (DI) is important, since there are several with abnormal dentin deposition. An alternative hy- overlapping features in these conditions (Table 1). pothesis8 that has received greater attention is that the DI, the mode of inheritance is also autosomal domi- primary defect in DD1resides in the ectomesenchymally nant.a0, 21 However,in DI, there is amber-gray opales- derived odontoblasts, and that the abnormal root mor- cence associated with marked of both denti- phology is secondary to abnormal odontoblastic func- tions, 2°-21 whereas in DD2,the discoloration and attrition tion or differentiation. Supporting this hypothesis is a are limited to only the primary dentition, and in DD1, further suggestion that as the early formed mantle den- the teeth are clinically normal. Radiographically, DI tin is normal, and the later-formed dentin is abnormal, presents with bulbous crowns and short roots,2°-2~ the defect may be related to defective interaction of whereas DD1 shows , and DD2 usually odontoblasts9 with the ameloblastic layer2 shows normal crown and root outlines. In addition, As is the case with DD1, the etiology of the dentin while all three entities show pulp obliteration, only defects in DD2is enigmatic. As in DD1, the change to DD2shows typical thistle-shaped pulp chambers. the formation of abnormal dentin after a period of nor- In addition to local primary defects of dentin, a few mal dentin formation suggests a genetically based de- generalized, systemic conditions may show extensive fect of an enzymesystem involved in the normal induc- obliteration of the pulp resembling the dental defects tion of odontoblast function. of DD. These generalized conditions include tumoral 22 Table. Characteristic features of dentin dysplasia and dentinogenesis imperfecta calcinosis, which shows extensive calcification of Dentin Dysplasia Dentinogenesis joints and the pulps of the (DD) Imperfecta(DI) teeth, as well as the brachio- skeletogenital23 syndrome, Type I (DD1) Type 2 (DD2) which shows mental retar- Inheritance AD AD AD dation, abnormal ribs, bone sclerosis, and hypospadias. Clinical In addition, a possibly new Appearance Prim. & perm. Prim. teeth - discolored" Prim. & perm. syndrome of dentinal dys- teeth - normal Perm. teeth - normal teeth discolored° plasia occurring with gen- Mobility ++ - eral bone sclerosis also had been24 described. Attrition - + (Prim. teeth) ++ Radiographic Case report Bulbous crowns - ++ Proband Short roots ++ + Medical and dental Taurodontism ++ histories Periapical The proband was an 8- radiolucencies ++ + + year-old male who was re- ferred by his general den- Pulp obliteration ++ ++ ++ tist for further dental Pulp remnants Horizontal Thistle-shaped Minimal pulp management, his father line at CEJ pulp chambers remaining having been previously di- Histologic agnosed with dentin dys- Mantle dentin Normal Normal Normal plasia. The medical history was noncontributory. In Coronal dentin Irregular tubules, Prim. teeth - irregular Mainly atubular particular, there was no his- whorls of tubules dentin, laminations, tory of bone disease or un- osteodentin Perm. teeth - normal somedenticles. usual bone fractures. He Root dentin True denticles, was the product of a full- excessive dentin term, uncomplicated preg- remodelling nancy, birthweight 7 lbs. His dental history re- ¯ The discolored teeth in both cases usually appearopalescent and amberor gray. vealed that eruption of the AD= autosomal dominant. primary dentition was un-

438 Pediatric Dentistry: November/December1994 - Volume 16, Number6 Figs 1, 2.Buccal views of the left (left) and right (right) posterior teeth showing the loss of periodontal attachment of the mandibular second molars, and the buccal crossbites of the maxillary primary canines.

remarkable in timing and sequence. Mobil- ity of the teeth had been noticed by the par- ents. There was no history of dental infec- tion, and no restorations had been placed. General examination General examination revealed a healthy, intelligent 8-year-old of normal height (48 in.), and weight (65 lbs). His face was nor- mal, orthognathic, and symmetrical with Class 1 profile. Dental examination The patient had an early mixed denti- tion with all first permanent molars and mandibular central incisors partially erupted. The crowns of the primary teeth and erupting permanent teeth had normal shape and color, except that the cervical thirds appeared opaque. Mobility of the teeth was severe for all second primary Fig 3. Panoramic radiograph of proband showing calcification and obliteration molars and incisors, moderate in the first of all the dental pulps including those of the developing teeth. Note horizontal primary molars, and minimal in the pri- radiolucent lines approximately parallel to the cementoenamel junctions and the large periapical radiolucencies around the resorbed roots of the primary mary canines. molars. The occlusion was Angle's Class I with minimal overjet and overbite. The maxillary primary the cementoenamel junctions, probably representing canines were in buccal crossbite, resulting most likely remnants of the pulp, were noted. In addition, large from buccal migration of the mandibular primary ca- radiolucencies were observed apical to the roots of the nines. There was severe buccal displacement of the primary molars, which were severely resorbed. The mandibular second primary molars with exposure of left mandibular first permanent molar and the left max- the resorbed radicular borders of the these teeth (Figs 1 illary second primary molar both appeared taurodontic. and 2). Around these mobile teeth were gross accumu- It was difficult to assess the remaining teeth because of lations of plaque and severe periodontal inflammation. the significant amount of root resorption. In other teeth, plaque and was minimal. There was no periodontal pocketing greater than 2 mm. Histopathological examination A naturally exfoliated primary incisor tooth was Radiographic examination available for histological examination. A ground sec- A panoramic radiograph (Fig 3) showed the pres- tion (Fig 4) showed a normal outline of the tooth and ence of all permanent teeth except the third molars. normal enamel formation. The coronal dentin, imme- Positions of the developing permanent teeth were nor- diately subjacent to the enamel, appeared normal. There mal except for the maxillary right second premolar, was an abrupt transition of the dentin to an abnormal which was rotated. pattern in the deeper layers. The abnormal dentin ap- All teeth showed calcification and obliteration of the peared to contain multiple foci of calcification sur- pulp including those of the developing permanent teeth. rounded by whorls of irregular tubular dentin. These Horizontal radiolucent lines approximately parallel to calcified masses were separated by fine channels.

Pediatric Dentistry: November/December 1994 - Volume 16, Number 6 439 Fig 4. Ground section of permanent teeth were normal shape and size. Mild, a naturally exfoliated diffuse brown opacities were noted on the facial sur- primary incisor from the faces of all the incisors and first permanent molars. The proband. Note normal outline of the tooth and occlusion was Class I, with normal overjet and over- normal enamel. The bite. Except for a moderately mobile mandibular left coronal dentin appears first primary molar, all the other teeth exhibited nor- normal from the incisal mal mobility. edge to a level approx- imately parallel to the Radiographic examination cementoenamel junction, A panoramic radiograph (Fig 5) revealed all perma- after which there is nent teeth to be present, including the crypts of the an abrupt change to developing mandibular third molars. The radiographic dysmorphic dentin. The abnormal dentin consists appearance of the teeth was similar to those noted in of many foci of calci- the proband. Calcification of the pulp was noted in fication containing whorls both erupted and developing permanent teeth as well of irregular tubular as the remaining primary teeth. In both primary and dentin. Fine channels are permanent molars, horizontal radiolucent lines paral- present between the lel to the cementoenamel junctions were noted, repre- calcified masses. senting remnants of the pulp. In the developing premolars, these pulp chambers were larger and more triangular, with fine extensions communicating with the bone on the mesial and distal surfaces of the root. In addition, all the permanent and primary molars ap- peared taurodontic. Affected sibling Affected father Medical and dental histories General examination An affected 10-year-old brother was available for dental examination. His medical history was The affected father also had an unremarkable medi- noncontributory although he suffered from mild asthma cal history. He had no dysmorphic features and was for which he took prophylactic cromoglycate. At birth normal height (6 ft) and weight (170 lbs). he was full-term following an uncomplicated preg- Dental examination nancy, and weighed 7 lb 12 oz. At 9 weeks, he was Dental examination revealed very good oral hygiene treated for pyloric stenosis, and at 12 weeks, he under- with minimal gingivitis. The maxillary left first premolar went surgical correction for an inguinal hernia. and first molar, the mandibular left first molar, and the General examination At the initial dental visit, he was a healthy, intelligent boy of normal height (56 in.) and weight (65 lbs). His face was symmetrical, and his profile straight. Dental examination Dental examination revealed good oral hygiene and minimal plaque and gingivi- tis. There was no periodontal pocketing greater than 3 mm. The patient was in the mixed dentition appropriate for his age. The first perma- nent molars, all incisors, and the maxillary right first premolar were fully erupted. A well-fitting band-loop space maintainer had been placed on the maxillary right second primary molar. The maxillary right first primary molar had been ex- tracted approximately a year earlier Fig 5. Panoramic radiograph of proband's brother. Note severe calcification due to an "abscess." and obliteration of the pulps of the posterior teeth, but relatively normal pulp Like his brother, all the primary and chambers in the anterior teeth.

440 Pediatric Dentistry: November/December 1994 - Volume 16, Number 6 mild as the root lengths were not exces- sively short, and the father had been able to retain his teeth well into middle age. However, in addition to the typical fea- tures of DDI, the family also showed cer- tain features found in DD2. Of note were the fully erupted maxillary and mandibu- lar anterior teeth of the older child, which appeared to have radiographically patent radicular pulp chambers. This feature of uncalcified pulp chambers at the time of eruption is considered a characteristic fea- ture of DD2.9-15'16 Furthermore, in the fa- ther, narrow but patent pulp chambers were still discernible in the anterior and Fig 6. Panoramic radiograph of affected father of proband shows severe premolar teeth. calcification of the pulps of the molars. Fine, thread-like remnants of the pulps This family thus shows a spectrum of are discernible on those anterior teeth that had not had endodontic treatment. DD with features of both types 1 and 2, and 9 Note successful retrograde endodontic fillings on the mandibular right second resembles a previously reported family molar, and maxillary left second premolar. The roots of the mandibular canines that showed similar dental findings. In and the maxillary left first premolar appear dilacerated. this regard, this report supports the theory that a range of severity occurs in this mandibular right first and second molars had been condition, and that subclassifications of DDI into previously extracted due to infection. A five-unit left further divisions is not warranted based on currently maxillary and a three-unit left mandibular bridge re- available information. placed the missing teeth. The anterior teeth appeared One of the main clinical problems encountered in discolored, most likely secondary to endodontic DDI are short, tapering roots associated with tooth therapy. There was minimal tooth mobility. mobility and premature exfoliation.1'3 In this family, Radiographic examination however, the root lengths were not excessively short- ened, and mobility was observed in the primary denti- A panoramic radiograph (Fig 6) revealed successful tion only. Furthermore, the excellent oral hygiene prac- conventional in both maxillary ticed by the patients has prevented further attachment central and left lateral incisors, and the mandibular left loss from periodontal infections. In the father, the pres- central incisor. In addition, successful retrograde me- ence of a maxillary five-unit bridge that had lasted tallic restorations were noted in the root apices of the approximately 10 years further attests to the slow rate maxillary right second premolar and the mandibular of periodontal bone loss in this patient. As intrinsic left second molar. of the root was noted in abnormalities of the cementum are not consistent fea- both mandibular canines and the maxillary right first premolar. In addition, the maxillary molars were taurodontic. Significant periodontal bone loss was noted around most teeth. A periapical full-mouth radio- graphic survey confirmed these findings. In addition, •-T-O thread-like remnants of the pulp were noted on nonendodontically treated teeth. Family pedigree A family pedigree (Fig 7) showed that the most likely mode of inheritance is autosomal dominant with a high degree of penetrance. Discussion The family in this report has clear features of DDI c Normal female Normal male such as clinically normal crowns, mobility of the teeth, • Affected female Affected male pulp obliteration with horizontal crescent-shaped pulp remnants at cementoenamel junctions, multiple Fig 7. Pedigree of proband's family shows autosomal dominant radiolucencies, taurodontism and short, tapering roots. mode of transmission of condition, and high degree of penetrance The defect in this family may be considered relatively (arrow shows proband).

Pediatric Dentistry: November/December 1994 - Volume 16, Number 6 441 tures 8,17 of DD, it is likely that loss of periodontal at- type 1: report of a case. J AmDent Assoc119:721-23, 1989. tachment may be adequately prevented through effec- 7. Meirs DR,Herbert FL: Dentinal dysplasia type I: report of case. ASDCJ Dent Child 57: 299-302, 1990. tive oral hygiene. 8. MelnickM, Levin LS, BradyJ: Dentin dysplasia type I: a scan- Although not histologically identified in the present ning electron microscopic analysis of the primary dentition. family, periapical granulomas and apical cysts 1-~ present Oral Surg Oral MedOral Patho150:335-40,1980. another important management problem. These are 9. Ciola B, Bahn SL, Goviea GL: Radiographic manifestations of likely to have resulted from "spontaneous" pulp infec- an unusual combinationof TypeI and TypeII dentin dysplasia. Oral Surg Oral MedOral Pathol 45:317-22, 1978. tions associated with severe pulp obliteration. In addi- 10. Sauk JJ, LyonsHW, Trowbridge Ho, WitkopCJ: An electronoptic tion, abnormal extensions of the pulp occlusally may analysis and explanation for the etiology of dentin dysplasia. cause pulp exposures from minimal dental caries. 3 Thus, Oral Surg Oral MedOral Pathol 33:763-71, 1972. effective preventive measures for dental caries such as 11. Tidwell E, CunninghamCJ: Dentinal dysplasia: endodontic treatment, with case report. J Endodont5:372-76, 1979. fissure sealants and topical fluoride are important as- 12. O’Carroll MK,Duncan WK,Perkins TM:Dentin dysplasia: pects of patient management. Prophylactic stainless reviewof the literature and a proposedsubclassification based steel crowns may be considered for patients with ac- on radiographic findings. Oral Surg Oral MedOral Pathol companying , but care must be taken 72:119-25,1991. to prevent periodontal inflammation, which may exac- 13. Scola SM,Watts PG:Dentinal dysplasia Type1. A subclassifi- cation. Br J Orthod14:175-79, 1987. erbate the likelihood of early exfoliation. 14. RosenbergLR, Phelan JA: Dentin dysplasia type II: review of In the primary dentition, extraction of involved teeth the literature and report of a family. ASDCJ Dent Child 50:372- and space maintenance are the obvious treatments for 75, 1983. pulpal infections. However, in the permanent denti- 15. Bixler D: Heritable disorders affecting dentin. In: Oral Facial tion, both conventional and retrograde root fillings have Genetics, Stewart RE, Prescott GH,Eds. St Louis: CVMosby Co, 1976, pp 227-61. been successful, as demonstrated in the present and 16. Burkes EJ Jr, Aquilino SA, Bost ME:Dentin dysplasia II. J previous cases.", 25 Endodont5:277-81, 1979. In conclusion, DD is a rare, inherited abnormality of 17. JasminJR, Clergeau-Guerithault S: A scanning electron micro- dentin that may lead to early exfoliation of the teeth. scopic study of dentin dysplasia type II in primarydentition. Early diagnosis of the condition and application of Oral Surg Oral MedOral Pathol 58:57-63, 1984. 18. LoganJ, BecksH, SilvermanS Jr: Dentinal dysplasia. Oral Surg effective preventive strategies may help prevent or Oral MedOral Pathol 15:317-33, 1962. delay loss of the dentition. 19. Wesley RK, WysockiGP, Mintz SM, Jackson J: Dentin dyspla- sia type I: Clinical, morphologicand genetic studies of a case. Dr. Seowis associate professor, pediatric dentistry, University of Oral Surg Oral MedOral Pathol 41:516-24, 1976. QueenslandDental School, Brisbane, Australia, and visiting profes- 20. Bixler D, Conneally PM, Christen AG: Dentinogenesis sor, Harvard Schoolof Dental Medicineand the Children’s Hospital imperfecta: genetic variation in a six-generation family. J Dent and Dr. Shustermanis chief of dentistry, Children’s Hospital, Boston, Res 48:1196-99,1969. Massachusetts. 21. Levin LS: The dentition in the syn- 1. WitkopCJ Jr: Hereditary defects of dentin. Dent Clin North dromes. Clin Orthop 159:64-74, 1981. Am19:25-45, 1975. 22. Witcher SL Jr, Drinkard DW,Shapiro RD, SchowCE Jr: Tu- 2. Shields ED, Bixler D, E1 KafrawyAM: A proposed classifica- moral calcinosis with unusual dental radiographic findings. tion for heritable humandentine defects with a description of Oral Surg Oral MedOral Pathol 68: 104-7, 1989. a new entity. Arch Oral Biol 18:543-53,1973. 23. Gorlin RJ, CohenMM Jr, Levin LS: Syndromesof the Head and 3. Steidler NE, Radden BG, Reade PC: Dentinal dysplasia: a Neck, 3rd ed. Oxford: Oxford University Press, 1990, pp 801- clinicopathological study of eight cases and review of the lit- 10. erature. Br J Oral MaxillofacSurg 22:274-86,1984. 24. Morris ME,Augsburger RH: Dentine dysplasia with sclerotic 4. Rushton MA:A case of dentinal dysplasia. Guys Hosp Rep bone and skeletal anomalies inherited as an autosomal domi- 89:369-73,1931. nant trait: a new syndrome. Oral Surg Oral MedOral Pathol 5. EastmanJR, MelnickM, Goldblatt LI: Focal odontoblastic dys- 43:267-83,1977. plasia: dentin dysplasia TypeIII? Oral Surg 44:909-14,1977. 25. Coke JM, Del Rosso G, Remeikis N, Van Cura JE: Dentinal 6. Brenneise CV, Dwornik RM,Brenneise EE: Clinical radio- dysplasia, TypeI: report of a case with endodontic therapy. graphic, and histological manifestations of dentin dysplasia, Oral Surg Oral MedOral Pathol 48:262-68, 1979.

442 Pediatric Dentistry: November/December1994- Volume16, Number6