Clinical and radiographic findings and usefulness of computed tomographic assessment in two children with regional odontodysplasia.

Regional odontodysplasia is a rare, severe, and nonhereditary developmental disorder in tooth formation and involves epithelial and mesenchymal-derived dental tissue. On radiographs, affected teeth have an abnormal morphology, a hypoplastic crown, and only a faint outline of hard tissue, a condition termed "ghost teeth." We report clinical and radiographic findings from two children with regional odontodysplasia. Using computed tomography (CT), we calculated attenuation coefficients (i.e., Hounsfield units) for affected teeth and assessed the condition of dental follicles. To measure density, regions of interest were delimited and CT values were calculated. In our two patients, the CT values for enamel were lower in affected teeth than in sound teeth, while CT values for dentin were similar for affected and sound teeth. The average CT value for dental follicles in affected teeth was about 65 to 120, which suggests that dense fibrous connective tissues or hard tissue-like structures might be present in dental follicles. Analysis of CT values may be quite useful in the diagnosis and treatment of regional odontodysplasia.

Congenital defect of maxillary primary central incisor associated with exposed pulp and gingival [fibrosis]: case report.

This report describes a rare case of hypoplastic primary incisor in which the pulp was exposed at the crown portion and covered by the gingiva in a 1-year-11-month-old boy. The patient was referred to us due to swelling of his labial cervical gingiva of the maxillary right primary central incisor, and on examination, extended to the hypoplastic labial surface. Radiographically, there was a round radiolucent area on the crown including the edge. Surgical removal of the swollen gingiva revealed a large defect of the labial aspect of the incisor, showing pulpal tissue inside. The tooth was treated by vital pulpotomy. Histopathologically, the removed gingival tissue contained many pieces of dysplastic tooth elements in the lamina propria portion which should have been connected to the exposed pulp. The findings suggested that pulp exposure resulted from focal dental hypoplasia not from resorption of the tooth.