NIH Rare Diseases

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.Orpha Number: 99789Disease definitionDentin dysplasia type I (DD-I) is a rare form of dentin dysplasia (DD, see this term) characterized by sharp conical short roots or rootless teeth.EpidemiologyPrevalence of DD-I is reported to be 1/100,000.Clinical descriptionThe condition affects both primary and permanent dentition. Signs of the condition are variable. In patients with DD-I, the teeth are generally unremarkable clinically with a normal shape and color. However, the roots appear sharp with conical, apical constrictions on radiography. The teeth are generally mobile, with frequent abscess formation and can be lost prematurely. Aberrant dentin formation can lead to partial or total pulp obliteration.EtiologyDD-I is caused by mutations in the DSPP gene (4q21.3) coding for dentin sialophosphoprotein, a precursor for dentin sialoprotein and dentin phosphoprotein which are involved in dentinogenesis.Diagnostic methodsSince teeth in DD-I appear clinically normal, diagnosis is based on radiographic features (abnormal roots, pulp obliteration, partially obliterated crescent shaped pulp chamber and occasionally pulp stones). Molecular genetic testing can be used to confirm the diagnosis.Differential diagnosisDifferential diagnoses include conditions that have overlapping clinical or radiographic features with DD such as those leading to early tooth loss: Kostmann syndrome, cyclic neutropenia, Chediak-Hegashi syndrome, Langerhans cell histiocytosis, Papillon-Lefèvre syndrome, hypophosphatasia, and vitamin D-resistant rickets (see these terms).Genetic counselingDD-I follows an autosomal dominant pattern of inheritance. There is therefore a 50% chance that a child born to an affected parent will have the condition.Management and treatmentAppropriate care makes it possible to achieve good esthetic appearance and functional performance.PrognosisPrognosis depends primarily on the age of diagnosis and the quality of management.Visit the Orphanet disease page for more resources. Last updated: 9/1/2012

MalaCards based summary

Dentin Dysplasia, Type I, also known as radicular dentin dysplasia, is related to dentin dysplasia and dentin dysplasia, type ii, and has symptoms including microdontia, taurodontia and periapical bone loss. An important gene associated with Dentin Dysplasia, Type I is SMOC2 (SPARC Related Modular Calcium Binding 2). Affiliated tissues include bone and testes.

OMIM

In dentin dysplasia type I, both primary and secondary dentitions are affected. The color and general morphology of the teeth are usually normal, although they may be slightly opalescent and blue or brown. Teeth may be very mobile and exfoliate spontaneously because of inadequate root formation. On radiographs, the roots are short and may be more pointed than normal. Pulp chambers are usually absent except for a chevron-shaped remnant in the crown (Witkop, 1975). Root canals are usually absent. Periapical radiolucencies may be present at the apices of affected teeth, for reasons unknown. On light microscopic examination of the permanent teeth, the coronal dentin is normal, but further apically becomes irregular, fills the pulp chamber, and has a 'sand-dune' morphology. Scanning electron microscopic studies of the deciduous and permanent teeth have been reported (Sauk et al., 1972; Melnick et al., 1980). (125400)

UniProtKB/Swiss-Prot

Dentin dysplasia 1: A dental defect in which both primary and secondary dentitions are affected. The clinical crowns of both permanent and deciduous teeth are of normal shape, form and color in most cases, although they may be slightly opalescent and blue or brown. Teeth may be very mobile and exfoliate spontaneously because of inadequate root formation. On radiographs, the roots are short and may be more pointed than normal. Pulp chambers are usually absent except for a chevron-shaped remnant in the crown. Root canals are usually absent. Dentin dysplasia 1, with extreme microdontia and misshapen teeth: A complex dental malformation characterized by extreme microdontia, oligodontia, dental shape anomalies affecting both primary and permanent teeth, double permanent-tooth formation, thin enamel, and very short roots with a thin associated alveolar bone, as seen in the spectrum of dentin dysplasia type 1.