Variations in adult cortical bone mass as measured by a panoramic mandibular index

The measurement of mandibular cortical bone height in osteoporotic vs. non-osteoporotic postmenopausal women

The asymptomatic progression of osteoporosis, in conjunction with the possibility of catastrophic disability, makes this disorder a major public health priority. Various body sites, including the mandible, have shown susceptibility to decreasing bone density. In 1986, Benson et al. proposed a radiomorphometric technique called the Panoramic Mandibular Index (PMI) as an inexpensive noninvasive dental technique for osteoporosis screening, although no osteoporotic subjects were included in their study. The purpose of our study was to determine whether osteoporotic postmenopausal women would show a decrease in mandibular cortical bone height, as measured by the PMI index, when compared with nonosteoporotic postmenopausal women. Seventy-two Caucasian females (33 cases/39 controls), aged 54-71 years old, were selected through records and screening via a dual-energy x-ray absorptiometry scan (LUNAR-DEXA). ANOVA analysis indicated no differences in the mean PMI between case and control groups (0.37 +/- 0.15 and 0.38 +/- 0.13, respectively; p = 0.69). Other techniques, such as computer digitized radiography should be explored to test the validity of the PMI.

Tooth loss and mandibular osteopenia

The relationship between mandibular bone mass and tooth loss was studied in 269 patients who had neither metabolic disease nor local lesions affecting the mandibular cortex. In all of the subjects, the outline of the mental foramen was distinctly disclosed on unilateral or bilateral panoramic radiographs. Mandibular bone mass was evaluated by determining the mandibular cortical width in the mental region with the use of panoramic radiographs. The relationships of mandibular cortical width to patient age and sex and the number of teeth present were also investigated. In male subjects, there was no significant correlation between the number of teeth present and the mandibular cortical width. Among women in their seventh decade, those with 15 or more teeth showed significantly greater mandibular cortical width than those with fewer teeth. Decrease of mandibular bone mass was positively correlated with tooth loss in female subjects.

Correlates of bone mineral density in the postmenopausal estrogen/progestin interventions trial

We assessed the cross-sectional relationship of age, menopausal years, body mass, previous estrogen use, and ethnic background to bone mineral status in a sample of 875 healthy postmenopausal women at the time they were recruited from the community to participate in a multicenter clinical trial. The women were 1-10 years postmenopause, 45-64 years of age, and had not received estrogen replacement therapy within 3 months of enrollment. Of the participants, 89% were white, 69% had a spontaneous menopause, and 53% had a history of previous estrogen replacement therapy. Bone mineral density (BMD) of the lumbar spine (L2-4) and proximal femur was measured by dual-energy x-ray absorptiometry. Results were consistent with a significant negative linear regression of BMD on age or years from menopause. Body mass index (BMI) correlated significantly with BMD at all sites (L 2-4 r = 0.28; femoral neck r = 0.34, p < 0.0001). BMD adjusted for age and BMI were higher at both sites in women who had taken estrogen versus those who had not (L2-4 0.976 +/- 0.009 versus 0.932 +/- 0.01; femoral neck 0.740 +/- 0.006 versus 0.708 +/- 0.008, p < 0.05). Adjusted BMD also increased with duration of ERT. Parity was negatively associated with L2-4 BMD (p = 0.03) but did not correlate significantly with BMD at the femoral neck. Black women had the highest L2-4 BMD, and Hispanic women had the highest femoral neck BMD, even when results were adjusted for age and BMI. When data were corrected for differences in bone size, these interethnic differences were no longer significant. We conclude that increased body mass is positively correlated with BMD, and this may confer a degree of skeletal protection to heavier postmenopausal women. Exposure for 5 years to exogenous estrogen is associated with significantly increased age- and BMI-adjusted BMD.

Pantomography in assessment of the osteoporosis risk group

The diagnostic efficacies of three panoramic-based indices were compared with classification of bone mineral density by dual-energy x-ray absorptiometry. The panoramic indices were 1) cortical bone height, 2) an ordinal classification, and 3) the Panoramic Mandibular Index. The results indicate that panoramic dental radiographs should not be used to assess the patient's status regarding osteoporosis, although the means of the variables in different mineral density groups of skeleton may differ significantly.

Panoramic mandibular index and bone mineral densities in postmenopausal women

The panoramic mandibular index was used in a group of postmenopausal women to determine whether it correlates with bone mineral densities of the femoral neck, lumbar area, and the trabecular and cortical parts of the mandible. The bone mineral density values were measured by dual-energy x-ray absorptiometry of the femoral neck and lumbar area and by quantitative computed tomography of the mandible. Linear correlation of the panoramic mandibular index with all bone mineral density values was weak. However, the low and high index subgroup means were clearly dependent on the bone mineral density variables.

Oral radiographs in the detection of early signs of osteoporosis

A study was conducted to determine whether radiographic changes could be detected in the mandible of patients with mild-to-moderate postmenopausal osteoporosis and whether these changes could be used as a diagnostic tool to differentiate normal from osteoporotic patients. Subjects were classified as either osteoporotic (21) or normal (14) on the basis of bone density measurements of the lumbar spine and femoral neck, as determined by dual-photon absorptiometry. Mandibular bone density measurements were made on panoramic and periapical radiographs and expressed in terms of millimeters of aluminum equivalent. Thickness of the cortex at the angle of the mandible, sinus floor, and lamina dura of the tooth socket was also measured. There were no significant differences in any of the mandibular measurements between the normal and osteoporotic subjects. Whereas the skeletal bone measurements were correlated with each other, there was no correlation between skeletal and mandibular bone measurements. Women with mild-to-moderate osteoporosis could not be distinguished from women with normal bone density with the method described in this article.