OBJECTIVES: We sought to objectivize the overall alveolar bone thickness changes in lower incisors after orthodontic intervention.BACKGROUND: The effect of orthodontic treatment on the cortical bone, specifically the clinical implications of proclination-induced change, have long been a matter of dispute. METHODS: Cone-beam computed tomographs of 58 patients were obtained before and after treatment and labial cortical bone thickness and overall alveolus width were measured in sagittal sections in the distance of 3, 6, 9 and 12 mm apically from the cemento-enamel junction.RESULTS: A statistically significant decrease of the cortical bone thickness in all four incisors was found at the levels 3, 6 and 9 mm (p < 0.05), with mean differences of 0.19, 0.10 and 0.14 mm, respectively. The cortical bone thickness at the level of 12 mm and alveolar width at all the levels showed no significant changes (p > 0.05). Moreover, no correlation was found between bone thickness change and extent of the incisor movement. CONCLUSION: Our results point to a marked cortical bone loss after proclination of lower incisors, furnishing a sound basis for caution in treatment planning due to the considerable risk of alveolar defect development, especially in patients with low initial bone thickness (Tab. 6, Fig. 2, Ref. 25).

• MeSH
• dospělí MeSH
• hrot zubního kořene anatomie a histologie   diagnostické zobrazování   MeSH
• kortikální kost diagnostické zobrazování   MeSH
• lidé MeSH
• malokluze - Angleova II. třída terapie   MeSH
• ortodontické zámky normy   škodlivé účinky   MeSH
• počítačová tomografie s kuželovým svazkem metody   MeSH
• průřezové studie MeSH
• remodelace kosti MeSH
• retrospektivní studie MeSH
• řezáky * anatomie a histologie   diagnostické zobrazování   anatomie a histologie   diagnostické zobrazování   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH

Cortical bone plays a vital role in determining overall bone strength. We investigate the structural, compositional, and nanomechanical properties of cortical bone following ovariectomy (OVX) of 12-week-old Sprague Dawley rats, since this animal model is frequently employed to evaluate the performance of implantable biomaterials in compromised bone healing conditions. Morphological parameters and material properties of bone in the geometrical center of the femoral cortex were investigated four and eight weeks post-OVX and in unoperated controls (Ctrl), using X-ray micro-computed tomography, backscattered electron scanning electron microscopy, Raman spectroscopy, and nanoindentation. The OVX animals showed increase in body weight, diminished bone mineral density, increased intracortical porosity, but increased bone mass through periosteal apposition (e.g., increases in periosteal perimeter, cortical cross-sectional thickness, and cross-sectional area). However, osteocyte densities, osteocyte lacunar dimensions, and the nanomechanical behavior on the single mineralized collagen fibril level remained unaffected. Our correlative multiscale investigation provides structural, chemical, and nanomechanical evidence substantiating earlier reports suggesting that rats ovariectomized at 12 weeks undergo simultaneous bone loss and growth, resulting in the effects of OVX being less obvious. Periosteal apposition contradicts the conventional view of bone loss in osteoporosis but appears advantageous for the greater functional demand imposed on the skeleton by increased body weight and fragility induced by increased intracortical porosity. Through a variety of morphological changes, it is likely that 12-week-old rats are able to adapt to OVX-related microstructural and compositional alterations. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 997-1007, 2018.

• MeSH
• biomechanika MeSH
• extracelulární matrix metabolismus   MeSH
• femur patologie   patofyziologie   MeSH
• kortikální kost diagnostické zobrazování   patologie   patofyziologie   MeSH
• lineární modely MeSH
• minerály metabolismus   MeSH
• nanočástice chemie   MeSH
• osteocyty metabolismus   MeSH
• osteoporóza diagnostické zobrazování   patologie   patofyziologie   MeSH
• počet buněk MeSH
• poréznost MeSH
• potkani Sprague-Dawley MeSH
• rentgenová mikrotomografie MeSH
• tělesná hmotnost MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVES: Recent investigations have evaluated the influence of body composition on long bones in order to overcome the limits of body mass (BM) estimation methods and eventually lead to studying nutrition in past populations. Knowing how fat mass (FM) and fat-free mass (FFM) impact the skeleton would also enhance the understanding of mobility, activity, and locomotion derived from bone architecture. We investigated the relationship between BM and composition, and the architecture of the entire tibial and femoral diaphyses in an adult sample representative of a wide range of variation in age, BM, and composition. MATERIALS AND METHODS: Body composition was measured directly from 78 whole-body CT scans for which the age, sex, BM, and stature were recorded. The entire diaphyseal thickness, volume, curvature, and cross-sectional geometry parameters of both the femur and tibia were numerically extracted. RESULTS: FM correlates with large portions of the femoral thickness in females only. FFM correlates with the femoral diaphysis in males but not in females. FFM correlates with the tibia architecture in both sexes, while FM is correlated in males exclusively. DISCUSSION: BM and body components influence the architecture of the diaphysis of lower limb long bones in sex-specific patterns that are mostly reflected in their thickness and can be recorded, in some cases, for their strength, rigidity, and volume. Our results suggest that (1) long bone diaphyses should be thoroughly studied, as a whole, when possible; and (2) BM and body components should be accounted for when deriving activity, mobility, or locomotion patterns from cortical bone.

• MeSH
• anatomie průřezová MeSH
• dospělí MeSH
• femur anatomie a histologie   diagnostické zobrazování   MeSH
• kortikální kost anatomie a histologie   diagnostické zobrazování   MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• složení těla fyziologie   MeSH
• tělesná hmotnost fyziologie   MeSH
• tibie anatomie a histologie   diagnostické zobrazování   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Teriparatide increases bone mass primarily through remodeling of older or damaged bone and abundant replacement with new mineralizing bone. This post hoc analysis investigated whether dual-energy X-ray absorptiometric (DXA) areal bone mineral density (aBMD) measurement adequately reflects changes of mineral and organic matrix content in cortical and trabecular bone. Paired biopsies and aBMD measurements were obtained before and at end of 2 years of teriparatide treatment from postmenopausal women with osteoporosis who were either alendronate pretreated (mean, 57.5 months) or osteoporosis-treatment naive. Biopsies were assessed by micro-computed tomography (μCT) to calculate mean cortical width (Ct.Wi), cortical area (Ct.Ar), and trabecular bone volume fraction (BV/TV). Fourier transformed infrared imaging (pixel size ∼6.3 × 6.3 μm2 ) was utilized to calculate mineral and organic matrix density (mean absorption/pixel), as well as total mineral and organic contents of cortical and cancellous compartments (sum of all pixels in the compartment). Effect of pretreatment over time was analyzed using mixed model repeated measures. μCT derived Ct.Wi and BV/TV increased, accompanied by similar increases in the overall mineral contents of their respective bone compartments. Mineral density did not change. Marked increases in the total content of both mineral and organic matrix associated with volumetric growth in both compartments consistently exceeded those of aBMD. Increases in organic matrix exceeded increases in mineral content in both cortical and trabecular compartments. For percent changes, only change in Ct.Wi correlated to change in femoral neck aBMD (r = .38, p = 0.043), whereas no other significant correlations of Ct.Wi or BV/TV with lumbar spine, total hip, or femoral neck aBMD were demonstrable. These data indicate that 2 years of teriparatide treatment leads to an increased bone organic matrix and mineral content in the iliac crest. The magnitude of these increases in the iliac crest were not detected with conventional aBMD measurements at other skeletal sites. © 2018 American Society for Bone and Mineral Research.

• MeSH
• infračervené záření * MeSH
• kortikální kost diagnostické zobrazování   účinky léků   MeSH
• kostní denzita účinky léků   MeSH
• lidé středního věku MeSH
• lidé MeSH
• os ilium diagnostické zobrazování   účinky léků   MeSH
• senioři MeSH
• teriparatid farmakologie   MeSH
• trabekulární kostní tkáň diagnostické zobrazování   účinky léků   MeSH
• velikost orgánu MeSH
• zobrazování trojrozměrné MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

We evaluated the degradation of cortical bone tissue by hydrochloric acid (HCl) since intentional bone decalcification in a forensic context has not been studied on a histomorphological level. We used 70 pig metatarsal bones split into subsamples and immersed in one of three concentrations of acidic solutions (0.5M, 1M, 2M HCl) for two and four hours. We analyzed the cortical thicknesses on transversal cross-sections, thicknesses of the three histomorphologically distinct zones present in acid-immersed bones, and number and area of crystals present in one of the zones. Furthermore, we analyzed the ratio of calcium to phosphorus (Ca:P). We observed a division of the cortical bone cross section into three distinctive zones: demineralized matrix (DM) in the periosteal part of bone, middle contact zone (CZ), and mineralized matrix (MM) in the endosteal part of bone. With increasing acid concentration and time of immersion (from 0.5M HCl for 2h to 2M HCl for 4h), the thickness of DM increased by 67%, the thickness of CZ increased by 56%, and the thickness of MM decreased by 32%. The Ca:P ratio in the contact zone of acid-treated samples did not change significantly with changing acid concentration and time of immersion. The Ca:P ratio of the CZ decreased by 10% when compared to the Ca:P ratio of MM in acid-treated samples. Moreover, we observed crystals on the outer periosteal border of the DM zone, in the CZ, and in the MM Haversian/Volkmann's canals. The size and number of the crystals in the CZ of acid-treated bones increased with acid concentration and time of acid immersion. Moreover, we also observed significant differences in all analyzed properties between anatomical regions. Due to varying reactions to acid immersion among anatomical regions, bone micro-degradation should be observed separately for each region.

• MeSH
• fosfor metabolismus   MeSH
• kortikální kost diagnostické zobrazování   metabolismus   ultrastruktura   MeSH
• kyselina chlorovodíková toxicita   MeSH
• metatarzální kosti diagnostické zobrazování   metabolismus   ultrastruktura   MeSH
• mikroskopie elektronová rastrovací MeSH
• okostice diagnostické zobrazování   ultrastruktura   MeSH
• rentgenová mikrotomografie MeSH
• soudní patologie MeSH
• spektrometrie rentgenová emisní MeSH
• Sus scrofa MeSH
• vápník metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Acrylamide (AA) is one of the most common toxins in foods. Its effect on bone microstructure has not been investigated. The aim of our study was to analyze the impact of acute exposure to AA on femoral bone microstructure in mice. Adult animals were treated perorally with 2 doses of AA (E1 group, 1 mg/kg b.w.) in a 24-h period and with 3 doses of AA (E2 group, 1 mg/kg b.w.) in a 48-h period. Mice exposed to AA had smaller sizes of primary osteon's vascular canals. Secondary osteons were significantly smaller in mice from E2 group; however their increased number (from 38 % to 77 %) was identified in both E1 and E2 groups. In these groups, a higher number of resorption lacunae (from 100 % to 122 %) was also found. The values for bone volume, trabecular number were increased and that for trabecular separation was decreased in mice administered AA. Significantly higher value of bone surface was observed in mice from E1 group whereas trabecular thickness was increased in E2 group. The effect of AA on microstructure of compact and trabecular bone tissues is different. In our study, one dose of AA was used and acute effects of AA were investigated. Therefore, further studies are needed to study mechanisms by which AA acts on bone.

• MeSH
• akrylamid toxicita   MeSH
• femur diagnostické zobrazování   účinky léků   patologie   MeSH
• kontaminace potravin * MeSH
• kortikální kost diagnostické zobrazování   účinky léků   patologie   MeSH
• myši MeSH
• rentgenová mikrotomografie MeSH
• trabekulární kostní tkáň diagnostické zobrazování   účinky léků   patologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH