Dentin Dysplasia Type I

Dentin 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.

Epidemiology

Prevalence of DD-I is reported to be 1/100,000.

Clinical description

The 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.

Etiology

DD-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 methods

Since 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 diagnosis

Differential 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 counseling

DD-I follows an autosomal dominant pattern of inheritance. There is therefore a 50% risk that a child born to an affected parent will have the condition.

Management and treatment

Appropriate care makes it possible to achieve good esthetic appearance and functional performance.

Prognosis

Prognosis depends primarily on the age of diagnosis and the quality of management.