Polarized light study of enamel and dentin dysplasia

Periodontal status of patients with dentin dysplasia type I: report of three cases within a family

BACKGROUND

Dentin dysplasia type I (DDI) is a rare hereditary disturbance of dentin formation. It is characterized by clinically normal-appearing crowns; obliteration of pulp chambers; and short, blunted and malformed roots that are commonly associated with periodontal attachment loss (PAL). In this context, we report three cases within a family with similar clinical and radiographic features of DDI but with differing microbiologic and periodontal conditions.

METHODS

A 42-year-old white female and her two daughters (25 and 10 years of age) presented with a diagnosis of DDI. Probing depth (PD), clinical attachment level (CAL), visible plaque, and bleeding on probing (BOP) were recorded. Subgingival biofilm samples were randomly collected and analyzed by checkerboard DNA-DNA hybridization.

RESULTS

The mother presented 34.9% of sites with PD > or =4 mm, 41.3% of sites with CAL > or =4 mm, and 57% of sites with BOP; both daughters presented no sites with PD or CAL >3 mm and <10% of sites with BOP. Microbiologic analysis detected Gemella morbillorum, Neisseria mucosa, and Staphylococcus aureus in > or =50% of the mother's samples. The daughters showed high levels (>10(4) bacterial cells) of some periodontopathic bacteria, including members of the red (Porphyromonas gingivalis) and orange (Fusobacterium periodonticum and F. nucleatum polymorphum) complexes and beneficial species of the yellow (Streptococcus gordonii) and purple (Veillonella parvula) complexes. The mother presented high mean levels only for four tested species (N. mucosa, Prevotella melaninogenica, Treponema denticola, and V. parvula).

CONCLUSION

A combination of radiographs, microbiologic analysis, and preventive professional monitoring care is important to avoid PAL and to provide oral health in patients with DDI.

Dentinogenesis imperfecta with dens in dente

An uncommon case of dentinogenesis imperfecta with dens in dente was studied by light microscopy, microradiography, and electron-microprobe analysis. Numerous canals and cellular inclusions were found in the coronal portion of the dentin where the tubules were sparse and irregularly distributed. In the radicular portion of the molar, large canals ran parallel to each other down to the apical region. The cementum was thinner and the Tomes granular layer greater in amount than usual. A dens in dente occurred in the radicular portion of the molar. It was located in a cavity and consisted of a mineralized cap of enamel, a spherical dentinal mass, and cellular cementum, located outside the cavity and in the "cervical" portion of the dens in dente.