• Journal of Korean Dental Science
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• v.8 no.2
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• pp.65-73
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• 2015

Purpose: Parathyroid hormone (PTH) therapy has drawn attention, as an alternative to anti-resorptive drugs since PTH accelerates bone density by anabolic action. The purpose of this study was to identify the effect of intermittent PTH administration on jaw bones of rat undergone bilateral ovariectomy. Materials and Methods: Nine female Sprague-Dawley rats were divided into three groups. PTH group was ovariectomized (OVX) to induce osteoporosis and PTH $30{\mu}g/kg$ was administered 1 week after the surgery. In OVX group, ovariectomy was performed and only vehicle was administered by subcutaneous injection 3 times per week. Control group was subjected to sham surgery. The animals were sacrificed 8 weeks after the surgery and specimens were obtained from ilium and upper and lower jaw bones. Histological investigation was carried out by using an optical microscope and micro-computed tomography was taken to examine structural property changes in each bone sample. Result: In the ilium, the bone volume ratio (bone volume/total volume, BV/TV) of PTH, OVX and control groups was $53.75%{\pm}7.57%$, $50.61%{\pm}12.89%$, $76.20%{\pm}5.92%$ (P=0.061) and bone mineral density (BMD) was $1.12{\pm}0.09$, $0.88{\pm}0.48$, $1.38{\pm}0.07g/cm^3$ (P=0.061). In the mandible, BV/TV of PTH, OVX and control groups was $64.60%{\pm}12.17%$, $58.26%{\pm}9.63%$, $67.54%{\pm}14.74%$(P=0.670) and BMD was $1.21{\pm}0.17$, $1.19{\pm}0.13$, $1.27{\pm}0.18g/cm^3$ (P=0.587). In the maxilla, BV/TV of PTH, OVX and control groups was $61.19%{\pm}8.92%$, $52.50%{\pm}11.22%$, $64.60%{\pm}12.17%$ (P=0.430) and BMD was $1.20{\pm}0.11$, $1.11{\pm}0.16$, $1.21{\pm}0.17g/cm^3$ (P=0.561). No statistically significant difference was found in any variables in all groups. Histological observation revealed that the ilium in OVX group demonstrated sparsely formed trabecular bones compared with other groups. However, upper and lower trabecular bones did not present significant differences. Conclusion: Intermittent administration of PTH appears to affect the microstructure of rat jaw bones, but statistical significance was not found. However, the measurements in this study partly implicated the possible anabolic effect of PTH in vivo.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.11
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• pp.1081-1090
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• 2012

This study aims to track the longitudinal alteration pattern on the trabecular bone microarchitecture at tibial epiphysis induced by T-OA over time using in vivo micro computed tomography (${\mu}CT$). Ten SD rats were divided into control (n = 5) and T-OA (n = 5) groups. Anterior cruciate ligament transaction was performed for the T-OA group. The results showed that the alteration pattern on the trabecular bone microarchitecture at tibial epiphysis in the T.OA group was definitely different compared with that in the CON group from 0 to 8 weeks (approximately 4-16%, P > 0.05). In particular, a difference was observed in the bone formation and density distributions over time (from 0 or 4 to 8 weeks; approximately 5.15%, P < 0.05). An improved understanding of the alteration pattern on the trabecular bone microarchitecture at tibial epiphysis may assist in developing more targeted treatment interventions for T-OA.