| Abstract|| |
Amelogenesis imperfecta is a hereditary disorder with diverse clinical presentation, where enamel is the tissue that is primarily affected either quantitatively or qualitatively. Hypomaturation/hypoplastic amelogenesis imperfecta with taurodontism is a rare variant of amelogenesis imperfecta which is often confused with trichodentoosseous syndrome. We report a rare case of hereditary enamel defect with taurodontism associated with interradicular dentin dysplasia.
Keywords: Amelogenesis imperfecta, dentin dysplasia, enamel hypoplasia, hereditary enamel defect trichodentoosseous syndrome, taurodontism
|How to cite this article:|
Hegde V, Srikanth K. Interradicular dentin dysplasia associated with amelogenesis imperfecta with taurodontism or trichodentoosseous syndrome: A diagnostic dilemma. Indian J Dent Res 2014;25:269-71
|How to cite this URL:|
Hegde V, Srikanth K. Interradicular dentin dysplasia associated with amelogenesis imperfecta with taurodontism or trichodentoosseous syndrome: A diagnostic dilemma. Indian J Dent Res [serial online] 2014 [cited 2020 Jan 21];25:269-71. Available from: http://www.ijdr.in/text.asp?2014/25/2/269/135942
| Case report|| |
A 22-year-old male came with a chief complaint of forwardly placed tooth. On examination, it was noted that there was generalized brownish discolouration of the tooth associated with pitting up to the cervical third of the tooth. The enamel was present only in some areas of the tooth and absent in some. Generalized attrition was observed on the incisal and occlusal surfaces with open contacts. The oral hygiene status of the patient was poor with generalized gingival enlargement. Gingival bleeding was seen on probing. The first and the second molars of both the upper and lower arch was grossly decayed. The family history was strongly conclusive of a hereditary disorder. Every generation showed defective enamel. The patient's maternal grandfather, mother, and his brother have similar enamel defect. On probing, the enamel chipped on pressure of an explorer. Systemic examination revealed brittle nails. Radiographic examination revealed a thin rim of enamel with radiodensity greater than that of dentin. This was more evident in most of the proximal surface and in certain areas in the occlusal aspect. Periapical radiolucency was evident in relation to the upper and lower first molars and taurodontism in relation to permanent mandibular first and second molars bilaterally. Extraction of the right permanent first molar was carried out and ground section of the extracted specimen was performed. On histopathological examination, ground section revealed enamel and dentin to be in normal relation to each other. Enamel was evident in the proximal area and in some areas on the occlusal aspect. This loss of enamel in many areas on the occlusal aspect was probably due to attrition. In areas where the enamel was present, the enamel rod morphology was lost in the outer portions of the enamel. In the radicular dentin in the interradicular area, dysplastic dentin was seen. This dysplastic dentin lacked the normal morphology of dentin. There was no evidence of dentinal tubules within them. The dentinal tubules terminated in peripheral portions of the dysplastic dentin.
| Discussion|| |
Amelogenesis imperfecta is a hereditary disorder in which enamel is affected.  Amelogenesis imperfecta was first described in 1890, but it is Finn who classified it as a distinct entity from dentinogenesis imperfecta in the year 1938.  The prevalence of this condition is estimated to be 11 in 718 to 11 in 14,000 depending on the population.  Hypoplastic/hypomaturation amelogenesis imperfecta with taurodontism has been described as a rare autosomal variant of amelogenesis imperfecta. As the dental findings in trichodentoosseous syndrome are similar to those of the Witkop's type four; confusion often exists as whether an affected patient has amelogenesis imperfecta/trichodentoosseous syndrome. This is true when there is clinical variability in the expression of defects in trichodentoosseous syndrome.  While our case presented with a definite hereditary enamel defect with taurodontism, in addition to these dental findings there were nail changes as well. The patient presented with brittle nails. According to Crawford and Aldred if trichodentoosseous syndrome is inherited with complete expression, the affected individual in successive generations will show the typical hair, bone, and teeth changes. The kinky hair seen in children is lost in adults and the bone changes are not seen in all cases of trichodentoosseous syndrome. According to Leisti and Sjobhom and Shapiro et al., variable expression explain the nail changes seen in some patients of trichodentoosseous syndrome.  We could not elicit hair and bone change in our case. In relation to the enamel defect, the enamel was soft, chipped-chipped-off in many areas and produced open contacts [Figure 1]. The radiodensity of enamel was different from that of the enamel. The enamel was more radio-opaque than dentin. This made us toto categorize this defect as a hypomaturation/hypoplastic type of amelogenesis imperfecta. The outer two thirds of the enamel showed abscence of enamel rods, which blended with the normal appearing enamel beneath it [Figure 2]. In a localized area of dentin adjacent to the bifurcation of the root, a mass of dysplastic dentin was observed. This dysplastic dentin was devoid of any dentinal tubules. The peripheral normal dentin terminated in this mass of dysplastic dentin [Figure 3]. Whether this mass of dysplastic dentin is responsible for the taurodontism seen in this particular case is not known. However, it is logical to assume as this dysplastic dentin is seen very close to the root bifurcation and may have influence on the taurodontic appearance of the tooth. Nakata et al. also described a similar dentinal change in a ground section of a patient with amelogenesis imperfect however; there was no associated taurodontism.  Clinically, trichodentoosseous syndrome affected individuals have enamel hypoplasia, taurodontism, bone, hair, and nail changes. The hair, bone changes in trichodentoosseous syndrome are highly variable, age dependent and not observed in all patients with DLX3 gene mutation responsible for trichodentoosseous syndrome. In trichodentoosseous syndrome, the dental finding of enamel hypoplasia and taurodontism are the most penetrant finding observed in 100% of cases.  Seow in her study found that taurodontism of the molars including mandibular first molar was consistently present in a severe form in trichodentoosseous syndrome, while in amelogenesis imperfecta, including hypomaturation/hypoplastic variant, the taurodontic defects were no different from matched healthy controls and thus she concluded that this feature helps to differentiate between trichodentoosseous syndrome and amelogenesis imperfect.  Our case showed obvious radiographic evidence of taurodontism in relation to the lower right and left permanent first and second molars [Figure 1].
|Figure 1: OPG reveals enamel only in certain areas of the tooth; open contacts between teeth; taurodontism and periodontal abscess in relation to the lower molars|
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|Figure 2: Microphotograph of the ground section shows structure less enamel in the outer two thirds of the enamel and normal appearing enamel beneath it. The dentin appears normal; 10×|
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|Figure 3: Microphotograph of the ground section reveals an area of dysplastic dentin with the dentinal tubules terminating into it; 40×|
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To conclude, whether the present case represents a rare variant of amelogenesis imperfecta or an incomplete expression of trichodentoosseous syndrome remains a diagnostic challenge. Therefore, it becomes very important for dental practitioners to systemically evaluate the patient even though the clinical presentation is very similar to amelogenesis imperfecta. To the best of our knowledge, we categorize this case clinically and radiographically as a mild form of trichodentoosseous syndrome.
| References|| |
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|4.||Seow WK. Taurodontism of the mandibular first permanent molar distinguishes between Trichodentoosseous syndrome and amelogenesis imperfecta. Clin Genet 1993;43:240-6. |
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|7.||Price JA, Wright JT, Walker SJ, Crawford PJM, Aldred MJ, Hart TC. Trichodentoosseous syndrome and amelogenesis imperfecta are genetically distinct conditions. Clin Genet 1999;56:35-50. |
Department of Oral Pathology, SDM College of Dental Sciences and Hospital, Dharwad, Karnataka
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3]