The osteogenic potential of short durations of low-level mechanical stimuli was examined in children with disabling conditions. The mean change in tibia vTBMD was ؉6.3% in the intervention group compared with ؊11.9% in the control group. This pilot randomized controlled trial provides preliminary evidence that low-level mechanical stimuli represent a noninvasive, non-pharmacological treatment of low BMD in children with disabling conditions. Introduction: Recent animal studies have demonstrated the anabolic potential of low-magnitude, high-frequency mechanical stimuli to the trabecular bone of weight-bearing regions of the skeleton. The main aim of this prospective, double-blind, randomized placebo-controlled pilot trial (RCT) was to examine whether these signals could effectively increase tibial and spinal volumetric trabecular BMD (vTBMD; mg/ml) in children with disabling conditions. Materials and Methods: Twenty pre-or postpubertal disabled, ambulant, children (14 males, 6 females; mean age, 9.1 Ϯ 4.3 years; range, 4 -19 years) were randomized to standing on active (n ϭ 10; 0.3g, 90 Hz) or placebo (n ϭ 10) devices for 10 minutes/day, 5 days/week for 6 months. The primary outcomes of the trial were proximal tibial and spinal (L 2 ) vTBMD (mg/ml), measured using 3-D QCT. Posthoc analyses were performed to determine whether the treatment had an effect on diaphyseal cortical bone and muscle parameters. Results and Conclusions: Compliance was 44% (4.4 minutes per day), as determined by mean time on treatment (567.9 minutes) compared with expected time on treatment over the 6 months (1300 minutes). After 6 months, the mean change in proximal tibial vTBMD in children who stood on active devices was 6.27 mg/ml (ϩ6.3%); in children who stood on placebo devices, vTBMD decreased by Ϫ9.45 mg/ml (Ϫ11.9%). Thus, the net benefit of treatment was ϩ15.72 mg/ml (17.7%; p ϭ 0.0033). In the spine, the net benefit of treatment, compared with placebo, was ϩ6.72 mg/ml, (p ϭ 0.14). Diaphyseal bone and muscle parameters did not show a response to treatment. The results of this pilot RCT have shown for the first time that low-magnitude, high-frequency mechanical stimuli are anabolic to trabecular bone in children, possibly by providing a surrogate for suppressed muscular activity in the disabled. Over the course of a longer treatment period, harnessing bone's sensitivity to these stimuli may provide a non-pharmacological treatment for bone fragility in children.

A considerable amount of work has been performed on methods of detecting individuals with low bone mass at an early stage. Some researchers have considered if dental radiographs could have a role in the detection of individuals with osteoporosis. A basic requirement for this would be that bone mass in the jaw relates significantly to that of other skeletal sites in which osteoporosis is a significant problem. The first aim of this study was to investigate the relationship between mandibular bone mineral density (BMD) and that of other skeletal sites commonly used for bone densitometry in the detection of osteoporosis. The second aim was to assess the validity of mandibular BMD as a predictor of BMD in these other sites. 40 edentulous females underwent dual energy X-ray absorptiometry (DXA) of the lumbar spine (L2–L4), DXA of the right femoral neck, single photon absorptiometry (SPA) of the proximal and distal forearm and DXA of the mandible. Significant correlations were observed between BMD in the mandibular body, ramus and symphysis and all other skeletal sites (p<0.02). Five patients (12.5%) had age matched Z-scores of −1.0 or lower in all three non-mandibular sites (lumbar spine, femoral neck and forearm). Using these patients as the proportion of the population with a positive finding of “low bone mass”, the sensitivity and specificity of mandibular BMD in predicting low bone mass for these patients was determined. Where a diagnostic threshold for low mandibular BMD was set at one standard deviation below the mean, the mandibular body BMD measurement gave high sensitivity (0.8) and specificity (0.97), the symphysis BMD low sensitivity (0.4) but a high specificity (0.77), while the ramus BMD had a moderate level of sensitivity (0.6) and high specificity (0.91). It is concluded that mandibular BMD assessed by DXA correlates significantly with BMD measurements of other important skeletal sites. The higher correlation coefficients and the greater sensitivity and specificity for the body of mandible suggest that this site should be used for any potential clinical application of dental radiographs in detection of osteoporosis.

Background: Severely disabled children with cerebral palsy (CP) are prone to low trauma fractures, which are associated with reduced bone mineral density. Aims: To determine whether participation in 50% longer periods of standing (in either upright or semiprone standing frames) would lead to an increase in the vertebral and proximal tibial volumetric trabecular bone mineral density (vTBMD) of non-ambulant children with CP. Methods: A heterogeneous group of 26 pre-pubertal children with CP (14 boys, 12 girls; age 4.3-10.8 years) participated in this randomised controlled trial. Subjects were matched into pairs using baseline vertebral vTBMD standard deviation scores. Children within the pairs were randomly allocated to either intervention (50% increase in the regular standing duration) or control (no increase in the regular standing duration) groups. Pre-and post-trial vertebral and proximal tibial vTBMD was measured by quantitative computed tomography (QCT). Results: The median standing duration was 80.5% (9.5-102%) and 140.6% (108.7-152.2%) of the baseline standing duration in the control group and intervention group respectively. The mean vertebral vTBMD in the intervention group showed an increase of 8.16 mg/cm 3 representing a 6% mean increase in vertebral vTBMD. No change was observed in the mean proximal tibial vTBMD. Conclusion: A longer period of standing in non-ambulant children with CP improves vertebral but not proximal tibial vTBMD. Such an intervention might reduce the risk of vertebral fractures but is unlikely to reduce the risk of lower limb fractures in children with CP.

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