Analysis of mandibular bone mineral density of senile osteoporosis patients / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the mandibular bone mineral density (BMD) change of senile osteoporosis patients and the relationship between the mandible bone loss and systemic bone loss.</p><p><b>METHODS</b>Forty senile osteoporotic patients (group A), 40 non-osteoporosis control elders (group B) and 40 healthy youths (group C) were included in this study. Standard digital panoramic tomography (SDPTG) was taken for each participant. Cortical width (CW), panoramic mandibular index (PMI), alveolar bone density and alveolar bone height were measured on the SDPTG. Lumbar and hip BMD were measured with dual energy X-ray absorptiometry (DXA).</p><p><b>RESULTS</b>Close relationship was found between CW (3.57 +/- 0.82) and systemic BMD for osteoporosis patients (P < 0.05). All the SDPTG indices including CW, PMI, alveolar bone density and alveolar bone height were different for osteoporosis patients from the healthy youths (P < 0.05). The osteoporosis patients had thinner CW (3.57 +/- 0.82) and smaller PMI (0.29 +/- 0.06) than non-osteoporosis control elders (CW: 4.07 +/- 0.75, PMI: 0.32 +/- 0.07, P < 0.05). The alveolar bone density (105.40 +/- 20.48) and alveolar bone height (10.42 +/- 1.82) of the non-osteoporosis control elders reduced compared with the healthy youths (alveolar bone density: 117.10 +/- 22.23, alveolar bone height: 11.69 +/- 1.63, P < 0.05).</p><p><b>CONCLUSIONS</b>The senile osteoporotic patients had significant mandibular cortical bone loss.</p>

Evaluation of mandibule bone loss of periodontitis with standard digital panoramic tomogram / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To compare the mandibular indices differences between periodontitis and non-periodontitis subjects by digital panoramic tomograms in order to find a simple and effective method to evaluate the density of alveolar bone and study the relativity between local bone loss and systemic bone loss.</p><p><b>METHODS</b>Standard digital panoramic tomograms of sixty periodontitis subjects and sixty non-periodontitis subjects were taken. Density and height cortical width (CW) and panoramic mandibular index (PMI) of alveolar bone were measured on the digital panoramic tomograms. SPSS 12.0 was used for statistics analyses.</p><p><b>RESULTS</b>The periodontitis subjects had lower height of alveolar bone (8.76 mm vs. 11.85 mm, P=0.000), lower density of alveolar bone (106.08 vs. 113.33, P=0.034), thinner cortical width (3.80 mm vs. 4.27 mm, P=0.008), while the difference of PMI between the two groups was not significant (P>0.05). The relativity between both density and height of alveolar bone with CW was significant (P<0.05), but not significant with PMI (P>0.05).</p><p><b>CONCLUSION</b>The optical method is a simple and effective method to measure the density of the alveolar bone. Compared with the non-periodontitis subjects, the periodontitis subjects not only have alveolar bone changed significantly but also have thinner cortical width.</p>

Bone density changes in the apical area after rapid orthodontic extrusion of subgingivally fractured tooth / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the bone density changes in the apical area of subgingivally fractured tooth after rapid orthodontic extrusion.</p><p><b>METHODS</b>Twelve fractured incisors in 11 patients extended 2 - 5 mm below the gingival line were selected. Two weeks after root canal therapy, the subgingival fragment was lifted up and the fracture line was brought 1.5 - 2.0 mm above the level of the gingival line by means of edgewise fixed appliance. After the extrusion completed, the tooth had been stabilized and held for 6 months. The CT Analyser software was used to measure the bone density changes in the apical area on radiographs once a month. Changes of relative value in bone density was quantitatively analyzed.</p><p><b>RESULTS</b>The average period of extrusion was 11 days. The relative value of bone density in the apical region was -39.6% immediately after extrusion and continuously increased afterwards. In the third month, the value (18.5%) changed most rapidly (P < 0.01).</p><p><b>CONCLUSIONS</b>Under the continuous and proper tooth axial extrusion force, the tooth moved rapidly and steadily. The bone density in the apical area approached normal value within 3 months after treatment.</p>