An Illustrated Guide to Oral Histology. Группа авторов

by DI are weak and prone to breakage and wear.

      1.7.2 Key Identifying Features

      On histological sections, teeth affected by DI show irregular dentinal tubules. In some areas, dentinal tubules can be completely absent. The dentin present can be quite irregular and haphazard and the pulp chamber can be quite small or completely obliterated.

      1.7.3 Clinical Considerations

DI affects both dentitions and has an incidence of 1 in 6000 people [12]. The teeth have an amber color that ranges from yellow to brown or from blue to gray [13]. The normal scalloped interdigitation of dentin with enamel does not exist, and the flat enamel dentin junction leads to cracking of enamel followed by attrition of dentin [14]. The diagnosis is usually based on family history and the radiographical and clinical appearance of the teeth. Radiographically, the teeth usually have bulbous crowns with obliterated pulp chambers [12]. Clinically, the teeth are discolored with visible clinical defects and fractured enamel [5]. Treatment modalities include prosthetic crowns, over‐dentures, orthodontic treatment (depending upon the severity), and dental implants (when all other conservative approaches have failed [12, 15]).

1.8 Dentin Dysplasia (DD)

      Figure 1.15 H and E stained decalcified section showing DD with haphazard coalescent globules of dentin and pulpal obliteration.

Figure 1.16 H and E stained decalcified section showing DD with the typical “water around the boulders” appearance.

      1.8.1 Description

      Dentin dysplasia (DD) is a rare genetic disorder that affects the development of dentin, mostly in radicular area. It can affect both dentitions, where the teeth have normal enamel but abnormal dentin with atypical pulp morphology. The first classification of DD was put forward by Witkop in the 1970s with DD divided into two types: DD‐1 (radicular type) and DD‐2 (coronal type) [16]. The teeth affected by DD‐1 present with short, blunt roots with obliterated pulp chambers. In DD‐2, teeth present with discoloration (brown to blue, amber colored, or opalescent), normal roots but enlarged pulp chambers (thistle tube appearance). The pulp chambers of primary teeth in DD‐2 are almost completely obliterated whereas in permanent teeth, they may be partially obliterated.

      1.8.2 Key Identifying Features

      Histologically, irregular dentin with a disturbed tubular pattern, atubular areas, and globular atypical dentin masses inside pulp chambers can be seen.

      1.8.3 Clinical Considerations

      The etiology of this disease is still unclear. Wesley et al. previously proposed that it could be due to a problem with ameloblasts which leads to an abnormal differentiation of odontoblasts, leading to DD [17]. It was also proposed earlier that due to a problem with dental papilla (foci within it becoming calcified), DD develops as a result of less growth and/or obliteration of pulp chambers [18]. The diagnosis is based on clinical examination and radiographs. The teeth affected by DD have esthetic and functional abnormalities [19]. In addition, they are more prone to be mobile and are exfoliated prematurely [19]. The treatment options include stainless‐steel crowns, endodontic therapy (although difficult due to obliteration of pulp chambers), removable dentures, and dental implants [20–22].

References

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