Vliv mechanické stimulace osteoklastů u čelisti myší: kostní histomorfometrie a analýza metodou konečných prvků

The influence of mechanical stimulation on osteoclast localization in the mouse maxilla: bone histomorphometry and finite element analysis

journal article - other

en

The mechanism of traumatic bone resorption in the denture-bearing bone has not yet been established with regard to the osteoclastic activity in relation to the mechanical stimulus. The purpose of this studywas to clarify whether osteoclast appearance in maxilla depends on the strain intensity, using themurine loading model. The maxillary palate of thirteen-week-old male C57BL/6 mice was subjected to continuous pressure of 2 kPa (low stimulation, n = 4) or 7 kPa (high stimulation, n = 4) for 30min/day for 7 consecutive days, and the mice were sacrificed after the last loading. The control group underwent the same protocol without load (n = 4). An animal-specific finite element model was constructed based on morphology and characteristics obtained from the micro-CT data and used to calculate the strain intensity of the bone. The bone histomorphometric technique revealed significant reduction of cortical bone volume and significant increase of bone resorption parameters such as osteoclast number in the bone tissue under the loading contact in comparison to the control (p < 0.05). The osteoclasts were observed in the subsurface region adjacent to the loading contact and the peripheral region of the marrow space in the intracortical region of the cortical bone in the mouse maxilla in both stimulation groups. An average of more than 90% of the osteoclasts was observed in the areas with strain intensity higher than 85.0 micro strain for the high stimulation group. The result suggests that the osteoclastic resorption is location-dependent and is also sensitive to the local strain intensity.

Mechanismus traumatické kostní resorpce v kosti nebyla dosud stanovena s ohledem na aktivity osteoklastů ve vztahu k mechanickému namáhání. Účelem této studie je upřesnit, zda osteoklasty v horní čelisti, závisí na intenzitě deformace, pomocí výpočtového modelování. Horní čelist třináct týdnů starých samců myší C57BL / 6 byla vystavena kontinuální tlaku 2 kPa (nízká stimulace, n = 4) nebo 7 kPa (vysoká stimulace, n = 4) po 30 min/denně po dobu 7 po sobě následujících dnů. Kontrolní skupina bez zatížení (n = 4). Z mikro-CT snímků byl vytvořen výpočtový model. S histologických řezů provedena histomorfometrické analýza. Bylo zjištěno významné snížení objemu kortikální kosti a výraznému zvýšení kostních parametrů resorpce (osteoklastů). Průměr o více než 90% ze osteoklastů byla pozorována v oblastech s kmenem intenzitou vyšší než 85.0 u/um pro vysokou stimulační skupiny. Výsledek naznačuje, že resorpci resorpce je místně závislá a je také citlivá na intenzitě namáhání.

The mechanism of traumatic bone resorption in the denture-bearing bone has not yet been established with regard to the osteoclastic activity in relation to the mechanical stimulus. The purpose of this studywas to clarify whether osteoclast appearance in maxilla depends on the strain intensity, using themurine loading model. The maxillary palate of thirteen-week-old male C57BL/6 mice was subjected to continuous pressure of 2 kPa (low stimulation, n = 4) or 7 kPa (high stimulation, n = 4) for 30min/day for 7 consecutive days, and the mice were sacrificed after the last loading. The control group underwent the same protocol without load (n = 4). An animal-specific finite element model was constructed based on morphology and characteristics obtained from the micro-CT data and used to calculate the strain intensity of the bone. The bone histomorphometric technique revealed significant reduction of cortical bone volume and significant increase of bone resorption parameters such as osteoclast number in the bone tissue under the loading contact in comparison to the control (p < 0.05). The osteoclasts were observed in the subsurface region adjacent to the loading contact and the peripheral region of the marrow space in the intracortical region of the cortical bone in the mouse maxilla in both stimulation groups. An average of more than 90% of the osteoclasts was observed in the areas with strain intensity higher than 85.0 micro strain for the high stimulation group. The result suggests that the osteoclastic resorption is location-dependent and is also sensitive to the local strain intensity.

Kost; osteoklast; mechanické namáhání; metoda konečných prvků; přetvoření

Bone; Osteoclast; Mechanical stimulation; Finite element analysis; Strain

2013

01.04.2013

Springer

Germany

1617-7959

12

2

325–333

9