Hypophosphatasia: Evaluation of Size and Mineral Density of Exfoliated Teeth.

OBJECTIVE: Most cases of hypophosphatasia (HPP) exhibit early loss of primary teeth. Results of micro-computed tomography (micro-CT) analysis of teeth with HPP have not yet been reported. The purpose of the present study was to describe the size and mineral density distribution and mapping of exfoliated teeth with HPP using micro CT. STUDY DESIGN: Seven exfoliated teeth were obtained from a patient with HPP. Exfoliated teeth sizes were measured on micro CT images and mineral densities of the mandibular primary central incisors were determined. RESULTS: Partial dentures were fabricated for the patient to replace the eight primary teeth which had exfoliated. Most primary teeth sizes were within the normal range. The mean values of enamel and dentin mineral densities in teeth with HPP were 1.35 and 0.88 g/cm3, respectively, in the mandibular primary central incisors. CONCLUSION: Mineral density distribution and mapping revealed that the values in teeth with HPP were lower than the homonymous teeth controls in all regions from the crown to apex. Furthermore, it was demonstrated that the differences between HPP and controls were larger on the crown side and the differences tended to converge on the apex side. These results suggested that the present patient showed mild hypomineralization in the primary dentition.

Self-Esteem and Oral Condition of Institutionalized Abused Children in Japan.

OBJECTIVE: Abused children have been reported to have low self-esteem. The aim of this study was to investigate the effects of dental intervention on self-esteem, oral condition, and concern for oral health in abused children admitted to a child protection service facility. STUDY DESIGN: We examined the oral condition of 65 children (34 boys, 31 girls; aged 2-15 years), instructed them in tooth-brushing. Self-esteem was examined using Pope's five-scale test for children. Before discharge, the children completed questionnaires on concern about their oral health. RESULTS: The findings revealed the reasons for admission were child abuse and neglect (n=45), domestic violence against the mother (n= 20), special needs (n=11), delinquency (n=7), school refusal (n=2), and other reasons (n=3). Thirty-five of the 65 residents (54%) needed treatment for caries. Of these, 24 (69%) were abused children and 11 (31%) were admitted due to other reasons. Mean self-esteem score differed significantly between the resident children (n=43) and an outpatient control group (n=102) (59.16±14.54 vs 73.92±16.81, respectively; p<0.01). CONCLUSION: Although the abused children had low self-esteem, after dental intervention, positive answers regarding oral health were obtained. The findings suggest that dental interventions might be effective for helping to improve the self-esteem of abused children.

Effect of the antineoplastic agent busulfan on rat molar root development.

OBJECTIVE: The antineoplastic bifunctional-alkylating agent busulfan (Bu) induces developmental anomalies. We examined histopathological changes in the molar roots of rats that received Bu at different stages of root formation. DESIGN: At different developmental stages, i.e., on postnatal days (P) 13, 15, and 19, rats were administered 7.5 mg/kg of Bu dissolved in dimethyl sulfoxide (DMSO) and then killed on P 30. After micro-computed tomography analysis, the maxillary first molars underwent immunohistochemical analysis for cytokeratin 14 (CK14), nestin, and dentin sialoprotein (Dsp). This was followed by histomorphometric analysis. RESULTS: The rats receiving Bu at an early stage (i.e., P 13 and P 15) showed osteodentin formation and complete destruction of the Hertwig's epithelial root sheath (HERS). Cells around osteodentin showed nestin and Dsp immunoreactivity. The root lengths in rats treated with Bu at P 13 (1228.44 ± 62.17 µm) and P 15 (1536.08 ± 109.71 µm) were lower than that in the control rats (1674.10 ± 40 µm). A narrowed apical foramen and an increased amount of osteodentin were also present, depending on the rat's age at the time of treatment (P < 0.05). CONCLUSION: Busulfan treatment in juvenile rats resulted in abnormal root development, depending on the stage at which Bu was administered. This abnormal development may result from the destruction of the HERS. The administration of Bu caused a shortage of HERS cells, which are required for normal root development. This disturbs root formation, resulting in osteodentin formation and a narrowed apex foramen.