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Objectives: Primary hyperparathyroidism (PHPT) is a disorder marked by chronic parathyroid hormone hypersecretion, which affects bone turnover and remodelling processes. With a loss of bone density and an increase in bone porosity, the cortical compartment is most severely impacted. The study's goal is to assess PHPT's effects on the volumetric bone mineral density (vBMD) of the femur's trabecular compartment as well as the vBMD and thickness of the cortical bone. Methods: This is a retrospective case–control study, valuating age, biochemical doses, anthropometric measurements, and bone measurements. Between 2011 and 2016, 74 Caucasian Italian women and men with PHPT were sought out. Biochemical analyses were added to bone mineral density (BMD) values found in the lumbar spine and femoral neck. Proximal femur parameters such as cortical and trabecular volumetric (v) BMD, cortical thickness (CTh) and surface (s) BMD were analyzed by 3D-DXA software (3D-SHAPER Medical, Spain). Results: The findings showed a negative correlation between PHPT patients and controls, which was equally affecting the cortical and trabecular compartments. This correlation was especially evident in the areal BMD (aBMD) and vBMD measurements. Nonetheless, no appreciable correlation was found between the cortical level and the thickness of the cortical bone. Conclusions: Parathormone (PHT) levels had an adverse effect on the cortical, trabecular volumetric density in this investigation, as was expected. Cortical thickness, however, is unaffected significantly. The literature and these findings are consistent. [ABSTRACT FROM AUTHOR]

During their development, some species of salmonids may occasionally experience skeletal deformations. Several methodologies are currently being used for the diagnosis of such malformations, among which X-rays, histological techniques, diaphanization coupled either with Alizarin Red or Alcian Blue stains, as well as Scanning Electron Microscopy (SEM) can be mentioned. Each one of those methods presents inherent advantages and disadvantages. The purpose of this study was twofold: Firstly, to evaluate and compare the effectiveness of microcomputed tomography (Micro-CT) technology for anatomical analysis, three-dimensionally reconstructing the obtained images; and secondly, to contrast those images with the results obtained through the diaphanization technique. The caudal fins of five specimens of the Oncorhynchus kisutch salmon were analyzed: Two specimens were subjected to diaphanization and three were processed for Micro-CT analysis, using the BRUKER SkyScan 1272 equipment. The Micro-CT technology demonstrated superiority in the resolution of bone structures, facilitating a detailed exploration of morphological variations, as well as the distribution of mineral density. This experimental approach allowed us to identify anomalies in the morphology and growth of the last vertebrae and dorsal lepidotrichiae, as well as an increased mineral density in the malformed dorsal lepidotrichiae. The higher resolution provided by Micro-CT not only enhances our understanding of the fish ontogeny and its adaptation to diverse environments, but also opens innovative perspectives for the study of the evolution of locomotor strategies and adaptive responses to environmental changes. [ABSTRACT FROM AUTHOR]

Backgrounds: We aimed to explore the relationship between diabetes status and bone mineral density (BMD) among adults with pre-diabetes and diabetes. Methods: We collected and analyzed five cycles (2005–2006, 2007–2008, 2009–2010, 2013–2014, and 2017–2018) data from NHANES. We removed the individuals containing missing values. The linear regression models were used to explore the relationship between diabetes status and bone mineral density. Finally, we performed subgroup analyzes by age, sex and race to find special populations. Result: Finally, 9661 participants with complete data were involved in the study. 944 were diagnosed with pre-diabetes, and 2043 were with diabetes. We found that bone mineral density in the hip, femoral neck, and lumbar spine showed an upward trend in both prediabetic and diabetic patients in the three linear regression models. Further, after subgroup analysis, we found that this trend was more prominent in whites race, women, and those over 50 years old. Conclusion: Using NHANES data from 2005 to 2018, we found that patients with abnormal glucose metabolism had increased bone mineral density. [ABSTRACT FROM AUTHOR]

The lack of standardized X-ray imaging remains a challenge for comparative studies on spatial scans acquired from different clinic-specific X-ray scanners. The central objectives of this study are: 1) to delineate mineral density (MD) values, and 2) generate spatial MD maps of various physiologic and pathologic biominerals, and 3) propose a standardization protocol within the safe-operating zone of a CT scanner that underpins normalization of absorbed dose to shape and density of tissues. A systematic approach to propose a standardization protocol for CT imaging in vivo included: 1) estimation of pathologic MD ranges by performing a comparative meta-analysis on 2009–2019 data from the PubMed database; 2) calibration of cone-beam CT (CBCT) and micro-CT scanners with phantoms of known mineral densities (0, 250, 500, 750 and 3000 mg/cc) and shapes (cylinders and polyhedrons); 3) scanning craniofacial bones (N = 5) and dental tissues (N = 5), and ectopic minerals from humans (N = 3 each, pulp, salivary gland, kidney and prostrate stones, and penile and vascular plaques); 4) underscoring the effect of shape-factor (surface area-to-volume ratio) on MD of biominerals. Higher MDs of physiologic and pathologic cortical bones (504–1009 mg/cc) compared to trabecular bone (82–212 mg/cc) were observed. An increase in shape-factor increased the CBCT error in MD measurement and revealed that the scanner resolution is dependent on the absorbed dose and shape-factor of detectable features. CT scanners should be calibrated with phantoms containing segments of known shape-factors and mineral densities to identify safe-operating zones. The calibrated approach will narrow the gap between length-scale dependent measurements, and will permit spatiotemporal quantitative and reliable detection of pathologies. • Existing literature illustrated a significant overlap between physiologic and pathologic mineral densities of biominerals. • Micro-CT, however, revealed significant heterogeneities in mineral densities and structures of ectopic biominerals. • An increase in shape-factor, increased the measured error cone-beam CT mineral density. • Scanner resolution is absorbed dose and shape-factor dependent. • Systematic CT imaging in vivo will permit spatiotemporal quantitative and reliable evaluation of pathologies. [ABSTRACT FROM AUTHOR]

Objectives: Autosomal‐dominant hypocalcified amelogenesis imperfecta (ADHCAI) shows phenotypic heterogeneity. Our aim was to characterise the ADHCAI phenotypes, tooth properties and genotypes. Methods: Three unrelated ADHCAI probands and seven additional affected members of the three families were recruited. Mutations were identified by exome and Sanger sequencing, and haplotypes by SNP array. Tooth colour, roughness, density, nanohardness, minerals and ultrastructure were investigated. Results: Ten participants were heterozygous for the FAM83H mutation c.1387C>T (p.Gln463*). All shared a 3.43 Mbp region on chromosome 8q24.3 encompassing the FAM83H variant, indicating a common ancestry. The c.1387C>T was estimated to be 23.8 generations or 600 years. The FAM83H enamel had higher roughness and lower lightness, density, nanohardness, and calcium and phosphorus levels than controls. Blunted enamel rods, wide interrod spaces and disorganised dentinoenamel junctions were observed. Evaluating the patients with the same mutation and reviewing others with different mutations in FAM83H revealed that the FAM83H heterogeneous phenotypes are age‐influenced. Tooth colour and surface texture change with ageing. Conclusions: FAM83H enamel demonstrated decreased lightness, density, hardness, calcium, phosphorus and defective ultrastructure. We have identified that the phenotypic variation in FAM83H‐associated ADHCAI is age‐related. Awareness of the correlation between age and clinical features of FAM83H‐ADHCAI can help dentists make an accurate diagnosis. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) and osteoporosis (OP) are historically considered to be inversely correlated but there may be an overlap between the pathophysiology of the two diseases. This study aimed to investigate the subchondral bone microarchitecture and matrix mineralization, and the association between them in OA and OP in relation to the degree of cartilage degeneration. Fifty‐six osteochondral plugs were collected from 16 OA femoral heads. They were graded on a regional basis according to the stages of cartilage degeneration, as evaluated by a new macroscopic and a modified microscopic grading system. Twenty‐one plugs were collected from seven femoral heads with OP. Plugs were scanned by microcomputed tomography and the microarchitectural and mineral properties were obtained for both subchondral plate and trabecular bone. Microarchitecture and material and apparent densities of subchondral bone in OP were similar to regions with early cartilage degeneration but different from regions with advanced cartilage degradation in OA femoral heads. Subchondral trabecular bone was more mineralized than subchondral plate in both OP and OA, and this compartmental difference varied by severity of cartilage degradation. Furthermore, the relationship among trabecular bone volume fraction, tissue mineral density, and apparent bone density was similar in OP and different stages of OA. Subchondral bone microarchitecture and mineral properties in OP are different from OA in a regionalized manner in relation to stages of cartilage degeneration. Both regional and compartmental differences at structural, material, and cellular levels need to be studied to understand the transition of OA subchondral bone from being osteoporotic to sclerotic. [ABSTRACT FROM AUTHOR]

Context. Parental history of osteoporosis is associated with an increased risk of fracture. However, there are not many data on the mechanism of action. Our objective was to determine if heredity influences fracture rate: independently or through the bone mineral density; to identify also the strongest independent risk factors of osteoporotic fractures among our study population. Methods. We processed data of 541 women outpatients with an average age of 55 years, participating in an osteoporosis screening program. Our results confirm that the presence of family history significantly increases fracture prevalence, (37% vs. 17%, p<0.001, OR 2.853, p=0.001) and decreases BMD scores. Fractures occur at higher (better) T and Z-scores. The risk of having T values in the range of (0--1) and Z values in (-1--2) is much higher in the positive group. The logistic regression analysis confirms the BMD-independent influence of heredity on fracture risk. Conclusions. Parental history of osteoporosis negatively affects bone density and significantly increases the incidence of fractures. The latter happens also independently of the bone density values. Timely intervention in these easy-to-detect cases may be the most effective prevention of osteoporotic fractures. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the effect of ionizing radiation and cariogenic biofilm challenge using two continuous flow models, normal and reduced salivary flow, on the development of initial root-dentin caries lesions. Materials and methods: Microcosm biofilms were grown under two salivary flow rates (0.06 and 0.03 mL min−1) and exposed to 5% sucrose (3 × daily, 0.25 mL min−1, 6 min) dripped over non-irradiated and irradiated root-dentin blocks for up to 7 days. The vibration modes of root dentin, matrix/mineral (M/M), and carbonate/mineral (C/M) ratios were evaluated by FTIR. The mineral density was assessed by micro-CT. Results: With normal salivary flow, FTIR revealed an increase in the organic matrix (amide III) and a decrease in the mineral phase (ν4, ν2 PO43−, AII + ν2 CO32−, C/M) in caries lesions. Irradiated dentin exhibited a reduction in the mineral phase (ν1, ν3 PO43−, ν2 CO32−, C/M). Differences in mineral densities were not significant. With reduced salivary flow, FTIR also revealed increased organic matrix (amide III) for irradiated caries lesions and decrease in mineral phase (v4, v2 PO43−, v2 CO32−, and C/M) in caries lesions. ν1, ν3 PO43− precipitated on the surface of irradiated dentin and a lower mineral density was observed. Conclusions: Initial caries lesions differed between non-irradiated and irradiated dentin and between normal and reduced salivary flow rates. Significant mineral loss with exposure of the organic matrix and low mineral density were observed for irradiated dentin with a reduced salivary flow rate. Clinical relevance: Ionizing radiation associated with a reduced salivary flow rate enhanced the progression of root-dentin caries. [ABSTRACT FROM AUTHOR]

Gaucher disease (GD) is caused by pathogenic mutations in GBA1 , the gene that encodes the lysosomal enzyme β-glucocerebrosidase. Despite the existence of a variety of specific treatments for GD, they cannot completely reverse bone complications. Many studies have evidenced the impairment in bone tissue of GD, and molecular mechanisms of bone density alterations in GD are being studied during the last years and different reports emphasized its efforts trying to unravel why and how bone tissue is affected. The cause of skeletal density affection in GD is a matter of debates between research groups. and there are two opposing hypotheses trying to explain reduced bone mineral density in GD: increased bone resorption versus impaired bone formation. In this review, we discuss the diverse mechanisms of bone alterations implicated in GD revealed until the present, along with a presentation of normal bone physiology and its regulation. With this information in mind, we discuss effectiveness of specific therapies, introduce possible adjunctive therapies and present a novel model for GD-associated bone density pathogenesis. Under the exposed evidence, we may conclude that both sides of the balance of remodeling process are altered. In GD the observed osteopenia/osteoporosis may be the result of contribution of both reduced bone formation and increased bone resorption. [ABSTRACT FROM AUTHOR]

Objective: The estimation of time of death or the determination of the postmortem interval (PMI) is one of the most important issues in forensic medicine and odontology. However, evaluation of bone and dental hard tissues in PMI could be challenging due to the lack of objective methods with high accuracy. In this respect, micro-CT analysis which has not been used for postmortem evaluation would be beneficial in evaluating hard tissues such as bones and teeth. Therefore, the aim of the present study was to determine the alterations in the hard dental tissue, mineral density of enamel, and the surface abrasion of hard dental tissues of rats in the PMI period with a relatively novel method, micro-CT. Methods: The present study included 60 female Wistar rats which were divided into six study groups. The rats were sacrificed at the baseline and were left into nature putrefaction process. The study groups were created based on the PMI period as week—0, week—1, week—2, week—4, week—8, and week—12, which included 10 rats in each group. All hemi-mandibles were collected in the determined timelines and the micro-CT analysis was carried out on each group. Mineral density of enamel and the surface abrasion of hard dental tissues were determined. Results: The enamel and cement thickness remained the same in the examined PMI periods. Mineral density of the enamel tissues were also similar until the 8th week but the decrease was significant at 12th week (2.313 gHAp cm3). Surface abrasion of the dental tissues on weeks 4, 8, and 12 were 0.006, 0.024, and 0.024 mm, respectively. Conclusion: The present study indicated that surface abrasion and enamel mineral density evaluation via micro-CT can be considered as objective and precise parameters in PMI evaluation in forensic medicine and odontology. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to compare the remineralizing effect of sodium fluoride (NaF) mouth rinse or NaF gel as an adjunct to NaF dentifrice on incipient caries-like lesions in an in situ cross-over design study, with three sessions of 30 days each. Materials and methods: Orthodontic brackets with artificial demineralized enamel slabs were attached to the upper first molars of 12 participants. A set of 3 test specimens from the same tooth was randomly assigned to each participant and allocated into three 30-day sessions: 1) brushing with 0.22% NaF dentifrice 2 times/day (F dentifrice), 2) brushing with 0.22% NaF dentifrice 2 times/day+ rinsing with 0.05% NaF before bedtime (F mouth rinse), 3) brushing with 0.22% NaF dentifrice 2 times/day + brushing with 1.1% NaF gel before bedtime (F brush-on gel). The mineral gain and lesion depth of the specimens were evaluated by micro-computed tomography. Results: The mean mineral gain from the NaF mouth rinse and the NaF brush-on gel was similar, but greater than that from the NaF dentifrice (p < .05). The NaF brush-on gel yielded the greatest mean depth of remineralization (168 µm), followed by the NaF mouth rinse (144 µm). Both depths were significantly greater than that of the NaF dentifrice (84 µm) (p < .05). Conclusions: Both 0.05% NaF mouth rinse and 1.1% NaF brush-on gel, used at bedtime, increased incipient caries-like lesion remineralization in situ in combination with brushing with NaF dentifrice twice a day. [ABSTRACT FROM AUTHOR]

Bone remodeling is a physiological phenomenon coupling resorption and formation processes that are mainly mediated by osteoclasts and osteoblasts, in response to mechanical stimuli transduced by osteocytes to biochemical signals activating the bone multicellular unit. Under normal loading conditions, bone resorption and formation are balanced by a homeostasis process. When bone is subjected to overstress, microdamaging occurs, which induces a modification of the structural integrity and microarchitecture. This has drawn significant attention to the mechanical properties of bone. In this context, the current study has been carried out with the aim of numerically investigating the impact of the mechanical properties on the remodeling process of the trabecular bone under cyclic loading, highlighting the effects of different values of the mineral density and the Young's modulus. This was performed using a mechanobiological model, coupling mechanical and biological approaches, allowing to numerically simulate the effect of the selected parameters for a 20-year-period of cyclic loading for 2D and 3D models of a human femur head. The current work is an explorative numerical study, and the obtained results revealed the changes in the overall stiffness of the bone according to the mechanical properties. [ABSTRACT FROM AUTHOR]

Using micro‐computed tomography (micro‐CT), this study assessed the inhibitory effect of three different types of restorations on root‐caries formation under a cariogenic challenge. Bovine‐root dentin blocks with a cylindrical cavity were divided into three restoration groups: a fluoride‐free self‐etch adhesive and a resin composite (SE‐ES); a self‐etch adhesive and a resin composite with multi‐ion release (FL‐BF); and a glass ionomer cement (Fuji‐VII). After the restorative procedures, the specimens were stored in artificial saliva for 1 d, then subjected to a demineralization solution for 4 d and a remineralization solution for 28 d. Mineral density and mean mineral loss of dentin around the restorations were measured using micro‐CT. The mean mineral loss values of dentin around the restorations were highest among SE‐ES restorations and lowest among Fuji‐VII restorations. Fuji‐VII showed the highest mineral density and the lowest mineral loss after 28 d of remineralization. The observations made by scanning electron microscopy demonstrated that Fuji‐VII created the smallest outer lesion followed by FL‐BF and SE‐ES. Fuji‐VII has a larger inhibitory effect on root caries around the restorations and enhances remineralization more effectively than either FL‐BF or SE‐ES. Multi‐ion and fluoride release from the restorative materials may be beneficial for inhibition of root‐dentin caries around the restorations. [ABSTRACT FROM AUTHOR]

Background: To investigate the effect of intra-articular injection of Chitosan (Cs) added to hyaluronic acid (HA) on subchondral bone during osteoarthritis (OA), microarchitectural parameters and mineral density were measured in a rabbit model of early OA. A novel hybrid hydrogel adding reacetylated Cs of fungal origin to HA was compared to high molecular weight HA commercial formulation.Method: Eighteen rabbits underwent unilateral anterior cruciate ligament transection (ACLT) and were divided into three groups (Saline-group, HA-group and Hybrid-group) depending on the intra-articular injection compound. Eight contralateral knees were used as non-operated controls (Contralateral-group). Micro-computed tomography was performed six weeks post-ACLT to study subchondral bone microarchitectural parameters and mineral density at an early stage of OA development.Results: Cartilage thickness mean value was reduced only in Saline-group compared to Contralateral-group. When the Hybrid-group was compared to Saline-group, subchondral bone microarchitectural parameters (trabecular thickness and trabecular bone volume fraction) were significantly changed; subchondral bone plate and trabecular bone mineral densities (bone mineral density and tissue mineral density) were reduced. When the Hybrid-group was compared to HA-group, subchondral bone microarchitectural parameters (subchondral plate thickness and trabecular thickness) and trabecular bone mineral densities (bone mineral density and tissue mineral density) were significantly decreased.Conclusion: Conclusion: Compared to HA alone, the novel hybrid hydrogel, constituted of Cs added to HA, enhanced microarchitectural parameters and mineral density changes, leading to subchondral bone loss in a rabbit model of early experimental OA. [ABSTRACT FROM AUTHOR]

This study sought to 1) investigate the spatial distribution of mineral density of dog dentin using µ-CT and 2) characterize the relationship between the elastic modulus and mineral density of dog dentin using nanoindentation and µ-CT. Maxillary canine teeth of 10 mature dogs were scanned with a µ-CT then sectioned in the transverse and vertical planes and tested using nanoindentation. Spatial distribution of mineral density and elastic modulus was quantified. Results demonstrated significant spatial variation in mineral density and elastic modulus. Mineral density and elastic modulus generally increased from the dentin-pulp interface to the dentino-enamel junction and from the crown base to the crown tip. Significant site dependent correlations between mineral density and elastic modulus were determined (0.021 > R2 > 0.408). The results of this study suggest that while mineral density is a mediator of elastic modulus, other mediators such as collagen content may contribute to the mechanical behavior of dog dentin. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the present study was to evaluate the percent mean mineral density (MD) change of early caries lesions after the application of silver diamine fluoride (SDF) or glass ionomer cement (GIC). Materials and methods: This double-blind, crossover study involved two experimental phases of 28 days each. Thirty-two pairs of enamel slabs were created from the proximal surfaces of 16 premolars. Each pair of artificial carious slabs was randomly divided into the control or test group (38 % SDF or GIC). The slabs were attached to orthodontic brackets and bonded to the maxillary first permanent molars of 16 subjects for 28 days. After a 7-day washout period between phases, the subjects received the other material for the second phase. The mean MD of the lesions was measured by microcomputed tomography. Results: SDF yielded a percent mean MD increase at a depth of 0-84 μm, although increase in the GIC group was observed at a depth of 24-108 μm. The percent mean MD changes of the SDF and GIC groups were similar ( p = 0.100) and significantly higher than in control ( p < 0.001, p = 0.003, respectively). Conclusions: The two materials increased the percent mean MD change of early proximal caries lesions to a similar extent, but with different spatial patterns. Clinical relevance: Due to deeper level of GIC remineralization, the refractive index of the GIC applied enamel might be closer to sound enamel. Hence, GIC is recommended for remineralization of anterior teeth. SDF staining makes it unsuitable for use in anterior teeth; thus, it is reserved for use in posterior teeth. [ABSTRACT FROM AUTHOR]

The bone development in lambs is extremely important, as this will reflect in the performance of the animals when they are adults. Bone problems in sheep affect the productivity of animals, increasing mortality rates and infection. Therefore, the evaluation of lambs skeletal development should be taken into account when they are fed different types and concentrations of bulk. There are no studies in the literature that demonstrate this relationship. Twenty Ile de France male lambs were used. They were uncastrated and weaned at 15 kg body weight then distributed in four treatments, with five animals per treatment. The treatments consisted of roughage: concentrate 60:40 (corn silage:concentrate); 60:40 ( sugar cane: concentrate); 40:60 (corn silage: concentrate); 40:60 ( sugar cane:concentrate). For morphometric evaluation, weighing of the femurs was performed and the length the perimeter of the proximal and distal epiphysis and the diaphysis of femurs and bone mineral density of the respective treatments were evaluated. No significant differences in the morphometric and densitometric evaluation was found between different treatments, with the exception of diaphysis bone mineral density, which was significantly (p <0.05) higher in the treatment with 40% corn silage in relation to the treatment 60% sugar cane. The use of diets containing of corn silage and sugarcane associated with addition of concentrate maintained the anatomical features. However, the proportion of 40% corn silage and 60% concentrate, showed better diaphysis bone mineral density due to a higher intake of nutrients and minerals present in this diet and consequently a higher energy intake, as well as an increased supply of dietary calcium. [ABSTRACT FROM AUTHOR]

Introduction: A total of 42 intact mandibles from aged 8 weeks to 76 years were assessed for variations in mineralization, bone deposition and resorption, and osteoporosis. The results indicate that there is marked constructive activity in young bone, then a diminution of activity until early middle life. In later middle life and old age, there is a comparative rise in bone resorption and osteoporosis and an increased variation in mineral density. Materials and Methods: A total of 42 mandibles were used for this research from the Anatomy Department of Saveetha Dental College. Results: Through this research, it was found that the length and breadth of ramus increases from birth to adult and to old age, whereas the angle of the mandible decreases with age from infant to adult, then again it increases in old age. There is a shift of mental foramen as well. Conclusions: Through this research, it was known that change in the mandible occurs due to aging. Hence, the age of the individual should be known for clinical procedure. The most important is the shifting of mental foramen. The most common position of the mental foramen is between the first and second premolar. The knowledge on the position of the mental foramen is important during clinical practices. This study also helps in determining the age of the mandible approximately which, in turn, will help in forensic science-related cases. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to develop a novel-designed phantom that could be scanned with a sample in the same image, that specialize for quantitative analyses of human dentin mineral density using the X-ray attenuation method. A further attempt was made to demonstrate the intracoronal dentin mineral density using this phantom in mandibular incisors. The phantom prepared with a 15 mm hole in the center of an acrylic resin bar having an outside diameter of 25 mm and 8 small holes (diameter, 3 mm) were made at equal intervals around the center. Liquid dipotassium hydrogen phosphate (K2HPO4) solutions were established at 0.4, 0.6, 0.8 and 1.0 g/cm3, and were arranged to these holes. The mean value of the intracoronal dentin mineral density was 1.486 ± 0.016 g/cm3 in the present study. As the results of the present study corresponded to previous reports, this new phantom was considered to be useful. This phantom enables the analysis of samples that are not readily available by conventional mechanical tests and may facilitate biomechanical investigations using X-ray images. It was suggested that this system is a simple, accurate and novel mineralization measuring system. [ABSTRACT FROM AUTHOR]

The effects of supplemental protein source, and amino acid (AA) and apparent metabolizable energy (AME) densities in the diets of broilers on their growth performance and intestinal development were reported in companion studies. The effects of protein source, and AA and AME densities on the tibias of male Ross x Ross 708 broiler chicks were investigated in the current study. A completely randomized block design with a 2x2x2 factorial arrangement of treatments was applied (10 blocks, 8 treatments/block, 14 chicks/pen). Diets fed from 8 to 21 days of age (d) were formulated to contain two protein sources [high inclusion of distiller's dried grains with solubles diet (hDDGS) or high inclusion of meat and bone meal diet (hMBM)], two AA densities (moderate or high) and two AME densities (moderate or high). Tibias from 2 chicks/pen at 21 d were sampled. Chicks fed a high AA diet exhibited longer tibias than did chicks fed a moderate AA diet. Chicks fed hDDGS diets with a high AME density exhibited larger tibia circumferences as compared to those fed hMBM diets with a high AME density. Dietary treatment did not affect tibia breaking strength, ash content, or calcium, phosphorus, potassium, zinc, manganese, and magnesium concentrations in the tibia. Because feeding chicks high AME diets increased their BW, the weights of their tibia, and tibial calcium and phosphorus weights relative to BW were decreased. In birds fed high AA diets, the feeding of hMBM diets improved tibia breaking strength relative to BW when compared to the feeding of hDDGS diets. In conclusion, either hDDGS or hMBM diets can be fed to male broilers from 8 to 21 d without affecting mineral deposition in their tibias. In addition, high AME diets may improve broiler BW without affecting tibia strength. [ABSTRACT FROM AUTHOR]

Chronic metabolic acidosis (CMA) might result in a decrease in vivo in bone mass based on its reported in vitro inhibition of bone mineralization, bone formation, or stimulation of bone resorption, but such data, in the absence of other disorders, have not been reported. CMA also results in negative nitrogen balance, which might decrease skeletal muscle mass. This study analyzed the net in vivo effects of CMA's cellular and physicochemical processes on bone turnover, trabecular and cortical bone density, and bone microarchitecture using both peripheral quantitative computed tomography and μCT. CMA induced by NH4Cl administration (15 mEq/kg body wt/day) in intact and ovariectomized (OVX) rats resulted in stable CMA (mean Δ[HCO3 -]p = 10 mmol/l). CMA decreased plasma osteocalcin and increased TRAP5b in intact and OVX animals. CMA decreased total volumetric bone mineral density (vBMD) after 6 and 10 wk (week 10: intact normal ±2.1 ± 0.9% vs. intact acidosis ±3.6 ± 1.2%, P ± 0.001), an effect attributable to a decrease in cortical thickness and, thus, cortical bone mass (no significant effect on cancellous vBMD, week 10) attributed to an increase in endosteal bone resorption (nominally increased endosteal circumference). Trabecular bone volume (BV/TV) decreased significantly in both CMA groups at 6 and 10 wk, associated with a decrease in trabecular number. CMA significantly decreased muscle cross-sectional area in the proximal hindlimb at 6 and 10 wk. In conclusion, chronic metabolic acidosis induces a large decrease in cortical bone mass (a prime determinant of bone fragility) in intact and OVX rats and impairs bone microarchitecture characterized by a decrease in trabecular number. [ABSTRACT FROM AUTHOR]

Objectives: We report the mineral (hydroxyapatite) density of sound and opaque areas in DMH molars with sound parts of (carious) deciduous teeth serving as controls. Methods: Twenty-nine extracted second primary molars obtained from 15 children were studied. Thirteen of these molars were DMH molars with yellow opacities, seven were DMH molars with white opacities, three DMH molars with brown opacities and eleven were molars without DMH. Prior to microCT scanning, the teeth were mounted in impression material (Impregum®) and stored in water with a thymol crystal. Spot analysis and line scans were performed in areas with opacities and in sound areas. An ANOVA test and t-tests were used to test if there were significant differences between the groups. Results: The average densities of the hydroxyapatite in yellow and brown opacities (1368 mg HA/cm² and 1407 mg HA/cm², respectively) were significantly lower than in clinically unaffected enamel (1747 mg HA/cm²) of DMH molars or of sound molars (1758 mg HA/ cm²). The mineral density in white opacities (1737 mg HA/cm²) was not different from that in the enamel of sound molars. The mineral density values in yellow and brown enamel opacities were in between those of dentine (1018 mg HA/cm²) and enamel. Conclusions: DMH molars with yellow or brown opacities had a 20-22% lower mineral density in the hypomineralised enamel compared with sound molars. White opacities do not show a lower mineral content. The reduction in enamel mineral content in DMH molars stressed the need for a preventive approach in DMH. [ABSTRACT FROM AUTHOR]

A comparison between the healthy bone and the amputated bone of twenty unilateral transfemoral amputees was done by generating three Hounsfiled Unit (HU) histograms at different parts of the femur (femoral head neck, metaphysis and diaphysis), based on images obtained by Computer Axial Tomography. The results show a significant statistical difference (p-value<0.05) of HU, which is reflected by the bone mineral density between the bones of amputated and healthy limb. These differences demonstrate that the exoprosthesis use, generates bone demineralization which is also related with stress shielding phenomenon. [ABSTRACT FROM AUTHOR]

Abstract: Fetal and postnatal bone development in humans is traditionally viewed as a process characterized by progressively increasing mineral density. Yet, a temporary decrease in mineral density has been described in the long bones of infants in the immediate postnatal period. The mechanism that underlies this phenomenon, as well as its causes and consequences, remain unclear. Using daily μCT scans of murine femora and tibiae during perinatal development, we show that a temporary decrease in tissue mineral density (TMD) is evident in mice. By monitoring spatial and temporal structural changes during normal growth and in a mouse strain in which osteoclasts are non-functional (Src-null), we show that endosteal bone resorption is the main cause for the perinatal decrease in TMD. Mechanical testing revealed that this temporary decrease is correlated with reduced stiffness of the bones. We also show, by administration of a progestational agent to pregnant mice, that the decrease in TMD is not the result of parturition itself. This study provides a comprehensive view of perinatal long bone development in mice, and describes the process as well as the consequences of density fluctuation during this period. [Copyright &y& Elsevier]

Abstract: Pathogenesis of atypical fractures in patients on long term bisphosphonate therapy is poorly understood, and the type, the manner in which they occur and the fracture sites are quite different from the usual osteoporotic fractures. We hypothesized that the tissue-level mechanical properties and mean degree of mineralization of the iliac bone would differ among 1) patients with atypical fractures and severely suppressed bone turnover (SSBT) associated with long-term bisphosphonate therapy, 2) age-matched, treatment-naïve osteoporotic patients with vertebral fracture, 3) age-matched normals and 4) young normals. Large differences in tissue-level mechanical properties and/or mineralization among these groups could help explain the underlying mechanism(s) for the occurrence of typical osteoporotic and the atypical femoral shaft fractures. Elastic modulus, contact hardness, plastic deformation resistance, and tissue mineral densities of cortical and trabecular bone regions of 55 iliac bone biopsies—12 SSBT patients (SSBT; aged 49–77), 11 age-matched untreated osteoporotic patients with vertebral fracture (Osteoporotic), 12 age-matched subjects without bone fracture (Age-Matched Normal), and 20 younger subjects without bone fracture (Young Normal)—were measured using nanoindentation and quantitative backscattered electron microscopy. For cortical bone nanoindentation properties, only plastic deformation resistance was different among the groups (p <0.05), with greater resistance to plastic deformation in the SSBT group compared to all other groups. For trabecular bone, all nanoindentation properties and mineral density of the trabecular bone were different among the groups (p <0.05). The SSBT group had greater plastic deformation resistance and harder trabecular bone compared to the other three groups, stiffer bone compared to the Osteoporotic and Young Normal groups, and a trend of higher mineral density compared to the Age-Matched Normal and Osteoporotic groups. Lower heterogeneity of modulus and contact hardness for cortical bone of the SSBT and trabecular bone of the Osteoporotic fracture groups, respectively, compared to the non-fractured groups, may contribute to fracture susceptibility due to lowered ability to prevent crack propagation. We tentatively conclude that, in addition to extremely low bone formation rate, atypical fractures in SSBT and/or long-term bisphosphonate treatment may be associated with greater mean plastic deformation resistance properties and less heterogeneous elastic properties of the bone. [Copyright &y& Elsevier]

Abstract: Tissue level density and elastic modulus are intrinsic properties that can be used to quantify bone material and analyses incorporating those quantities have been used to evaluate bone on a macroscopic scale. Micro-computed tomography (microCT) technology has been used to construct tissue level finite element models to simulate macroscopic fracture strength, however, a single method for assigning voxel-specific tissue density and elastic modulus based on those data has not been universally accepted. One method prevalent in the literature utilizes an empirical relationship that derives tissue stiffness as a function of bone calcium content weight fraction. To derive calcium content weight fraction from microCT scans, a measure of tissue density is required and a constant value is traditionally used. However, experimental data suggest a non-trivial amount of tissue heterogeneity suggesting a constant tissue density may not be appropriate. A theoretical derivation for determining the relationship between voxel-specific tissue density and microCT scan data (i.e., microCT derived tissue mineral density (TMD), mgHA/cm3) and bone constituent properties is proposed. Constant model parameters used in the derivation include the density of water, ash, and organics (i.e., bone constituents) and the volume fraction of the organics constituent. The effect of incorporating the theoretically derived tissue density (instead of a constant value) in determining voxel-specific elastic modulus resulted in a maximum observed increase of 12GPa (5.9GPa versus 17.9GPa, for the constant value and derived tissue density formulations, respectively) for a measured TMD of 1.02gHA/cm3. Average and bounding quantities for the four constant model parameters were defined from the literature and the influence of those values on the derived tissue density and elastic modulus relationships were also evaluated. The theoretical relationships of tissue density and elastic modulus, with the average constant model parameters applied, were consistent with previously published empirical relationships derived from experimental data. Tissue density as a function of microCT TMD was formulated as a linear relationship and the density of water and ash was shown to solely influence the proportionality (i.e., slope) between those values. The density of water and organics (i.e., collagen) and the volume fraction of the organics constituent were shown to influence the constant offset (intercept) between tissue density and TMD with no influence from ash density. Incorporating tissue density heterogeneity into the derivation of elastic modulus resulted in a significant increase in predicted modulus (for microCT TMD ranges observed for healthy tissue) as compared to when a constant tissue density was used. The presented approach provides a novel method for deriving tissue-level bone material properties and quantifies the effect of assuming tissue homogeneity when calculating elastic modulus (when using a prevalent method in the literature) from microCT scan data. [Copyright &y& Elsevier]

Abstract: Objectives: This study aims to evaluate the mineral density, calcium (Ca), and phosphorus (P) weight percent of healthy human enamel of varying human teeth age and enamel layers. Methods: Twenty human teeth were divided into “young” (18–24years) and “old” (55≤ years) age groups. From each tooth, one enamel slab (approximately 8mm×2mm×1.5mm) was obtained. All enamel slabs were embedded and scanned by micro-computed tomography. The scanned slices were reconstructed into a 3D image and regions of interest (ROIs) were defined. Then, the mineral density for each ROI was calculated. The Ca and P weight percent in the outer, middle, and inner enamel layers were quantified by scanning electron microscopy with energy dispersive spectroscopy. Finally, the data were analysed using one-way ANOVA and Student''s t-test. Results: In the two age groups, the mineral density, Ca and P weight percent decreased from outer to the inner enamel layer. The mineral density, Ca and P weight percent in the outer enamel layer in the old age group were significantly higher than those in the young age group (P <0.05); however, no age-dependent differences were observed for these properties in the middle and inner enamel layers (P >0.05). Conclusions: The mineral density, Ca and P weight percent decreased from the outer to the inner enamel layers in the two age groups. In the outer enamel layer, the differences in these properties between the two age groups were significantly different; however, no region-dependent differences were observed in the middle and inner enamel layers. [Copyright &y& Elsevier]

Abstract: Today we are witnessing a genuine revolution in diagnostic imaging techniques. Dual X-ray absorptiometry (DEXA) quantifies bone mineral density (BMD) and bone mineral content (BMC). This technique has rarely been used in Forensic Anthropology, although its practical application has been demonstrated by various authors. In this article, we look into the conduct of bone mineral density in the femoral neck, the trochanter, the intertrochanter, the proximal femur and Ward''s triangle, in relation to anthropometric age and sex parameters. The research was carried out on 70 persons – 38 men and 32 women – and the results obtained show significant correlations between bone mineral density measurements and anthropometric values. The research demonstrates bone mineral density to be a useful technique for sex and age data in forensic anthropology, particularly in the measurements observed in the Ward''s triangle area. [Copyright &y& Elsevier]

Abstract: Objectives: To compare mineral density of residual dentine after excavation with different caries-removal techniques and to evaluate the diagnostic potential of laser-induced fluorescence (LIF), measured by DIAGNOdent, as a tool to determine the caries-removal endpoint. Methods: Carious teeth were excavated by tungsten-carbide round burs (Komet), ceramic burs (CeraBurs, Komet), sono-abrasion (Cariex TC tips, Kavo), and by chemo-mechanical excavation using two enzyme-based solutions (exp. SFC-V and SFC-VIII, 3M-ESPE) or a sodium hypochlorite-based solution (Carisolv, MediTeam). The caries-excavated teeth were scanned by micro-CT (1172, Skyscan), after which the mineral density at the bottom dentine was correlated to LIF measurements at the same region. A micro-CT threshold for dentine caries was defined by comparison with surface-hardness measurements. The intensity of dentine staining was evaluated by analysing the component ‘L*’ in CIE-L*a*b-converted images from the excavated teeth. Results: No statistically significant difference in mineral density was found at the bottom of the cavities prepared with the different caries-excavation techniques, except for exp. SFC-V that left residual dentine with a significantly higher mineral density than when CeraBurs were used (Tukey–Kramer, p <0.05). Absence of residual caries was associated with darker staining of dentine. No significant correlation was found between the distance from the deepest cavity point to the pulp-chamber roof and LIF measurements. A strong negative correlation (R =−0.86, p <0.01) was however found between L* values and LIF measurements, indicating that staining in residual dentine leads to higher LIF measurements. Conclusions: LIF measured by DIAGNOdent is influenced by staining in residual dentine. Therefore, its use to determine the caries-removal endpoint is doubtful. [Copyright &y& Elsevier]

Abstract: Analysis of edible leaves and grain of 27 nodulated cowpea genotypes in 2005 and 2006 revealed differences in mineral density. Cowpea genotype IT82D-889 exhibited high concentrations of P, K, Ca, Mg and S in grain relative to Brown Eye, IT84S-2246 and TVx3236. Fe concentration in cowpea grain ranged from 63mg/kg in Ngonji to 137mg/kg in Soronko, while Zn was 44mg/kg in Ngonji and 65mg/kg in Vuli-1. Leaf concentrations of Cu, Mn, B and Fe were consistently higher in the genotypes Apagbaala, IT84S-2246, Fahari and IT97K-499-39, while Fe, Cu, B and Zn were lower in TVu11424, Brown Eye, Vuli-1, Soronko and Glenda. Compared with spinach, cowpea leaves had greater levels of Fe (5-fold in magnitude), Mn, P, Ca, K and Mg. Based on these data it is likely that when and where the dietary intake of cowpea leaves is high in Africa, children would suffer less from micronutrient deficiency. [ABSTRACT FROM AUTHOR]

A study on the bone system state in healthy volunteers has been performed before and after 105-day experiment in hermetically isolated environment (the Mars-105 experiment) using dual energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). The values of bone mineral density (BMD), volumetric bone mineral density (VBMD), and bone structural characteristics of distal segments in radius and tibia have been evaluated. No significant DXA changes have been revealed in segments of skeleton critically important in terms of biomechanics. Microarchitectural deterioration (a decrease in the trabecula number and increase in the bone tissue heterogeneity) has been found using the pQCT technique in the radius of the majority of subjects. A VBMD decrease has been revealed for both cortical and trabecular bones in tibia, along with an unexpected trabecular bone improvement in the form of an increase in the trabecula quantity and decrease in bone tissue heterogeneity. Comprehensive studies, including estimation of projective and volumetric bone mineral densities (the bone mineral content) and bone structural characteristics (bone quality) are required to have a clear view on the changes in the bone system under the conditions of a simulation experiment. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: To optimize a microtomographic (micro-CT) technique to quantitatively evaluate the effectiveness of contemporary caries-excavation techniques. Methods: A beam-hardening curve was obtained from an initial reconstruction of a wedge-shaped hydroxyapatite (HAp) block and fitted with a 5th order polynomial function, after which each micro-CT tooth slice was corrected accordingly. Calibration of the 8-bit gray values into mineral-density values was obtained by scanning, reconstructing and processing volume of interests (VOIs) of HAp phantoms with different mineral densities (0.25, 0.75, 3.14g/cm3). One carious tooth was scanned before and after caries removal with an experimental enzyme-based gel. After reconstruction, a 3D-median filter was applied to each micro-CT slice, and a connected threshold grower algorithm was used to blank-out undesired structures in each slice. Volume rendering with a look-up-table (LUT), based on mineral densities, was accomplished for the tooth before and after caries removal. Finally, the actual volume of excavated tissue was quantified. Results: Correction for beam hardening produced tooth slices with relatively homogeneous gray values along the whole area of enamel and dentin. Accurate mineral-density values were obtained for enamel, dentin and carious regions (2.89, 1.74 and 0.27g/cm3, respectively). After pre-processing (3D-median filtering and connected threshold grower algorithm), acceptable segmentation of carious dentin based on gray values was accomplished (Otsu method, gray value=75 or mineral density=1.12g/cm3), from which quantitative volumetric parameters were calculated. Significance: Accurate calibration, standardization of scanning and reconstruction steps and adequate pre-processing of micro-CT slices allowed detailed volumetric calculation of caries-excavation techniques. [Copyright &y& Elsevier]

Objectives: To characterize molar-incisor hypomineralisation (MIH) defects of different severities quantitatively and qualitatively using X-ray microtomography (XMT) and to measure the range of reduction in mineral density (MD) of MIH enamel compared with the normal range.Methods: Ten sound teeth and ten MIH teeth were scanned using a commercial XMT system. Four hydroxyapatite phantoms of different densities were used as calibration standards with each scan. A calibration equation derived from the phantoms with each tooth was used for MD calibration. MD was traced from the cementum-enamel junction (CEJ) to the cusp tip and from the dentine-enamel junction (DEJ) to the outer enamel surface.Results: In sound teeth, MD increased from CEJ to cusp/incisal tip, while in MIH teeth MD dropped from the CEJ to the occlusal region, then increased again at the cusp tip. MD was highest midway between DEJ and outer enamel in sound teeth. In MIH, enamel showed normal thickness and MD was highest near the DEJ and then decreased towards the outer enamel. MD of MIH enamel was on average about 19% lower than sound enamel. The MIH defects seemed to follow the incremental lines of enamel formation.Conclusions: MIH defects are hypomineralised defects of different severities that follow the natural incremental lines of enamel formation. Cuspal areas are usually only mildly affected and cervical enamel always appears to be sound. [ABSTRACT FROM AUTHOR]

Abstract: Accurate bone mineral density (BMD) quantification is critical in clinical assessment of fracture risk and in the research of age-, disease-, and treatment-related musculoskeletal changes. The development of high-resolution peripheral quantitative computed tomography (HR-pQCT) imaging has made possible in vivo assessment of compartmental volumetric BMD (vBMD) and bone micro-architecture in the distal radius and tibia. HR-pQCT imaging relies on a polychromatic X-ray source and therefore is subject to beam hardening as well as scatter artifacts. In light of these limitations, we hypothesize that the accuracy of HR-pQCT vBMD measurement in the trabecular compartment (vBMDtrab) is not independent of bone density and geometry, but rather influenced by variations in trabecular bone volume fraction and cortical thickness. The goal of this study, therefore, was to evaluate the accuracy of HR-pQCT vBMDtrab measurement in the radius and tibia, and to determine the dependence of this measurement on geometric and densitometric parameters. Our approach was to use a series of idealized hydroxyapatite (HA) phantoms with varying densities and geometries to quantify the accuracy of HR-pQCT analysis. Two sets of custom-made HA phantoms designed to mimic the distal tibia and distal radius were manufactured. Geometric and densitometric specifications were based on a dataset of healthy volunteers and osteopenic patients. Multiple beam hardening correction (BHC) algorithms were implemented and evaluated in their ability to reduce measurement error. Substantial errors in measured vBMDtrab were found. Overestimation of vBMDtrab increased proportional to cortical shell thickness and decreased proportional to insert density. The most pronounced vBMDtrab overestimation therefore occurred in the phantoms with the lowest insert densities and highest shell thickness, where error was as high as 20 mg HA/cm3 (33%) in the radius phantom and 25 mg HA/cm3 (41%) in the tibia phantom. Error in vBMDtrab propagates to the calculation of micro-architectural measures; 41% error in vBMDtrab will produce 41% error in volume fraction (BV/TV) and trabecular thickness (Tb.Th), and 5% error in trabecular separation (Tb.Sp). BHC algorithms supplied by the manufacturer failed to eliminate these errors. Our results confirm that geometric and densitometric variations influence the accuracy of HR-pQCT vBMDtrab measurements, and must be considered when interpreting data across populations or time-points. [Copyright &y& Elsevier]

A study was carried out in the experimental facilities of FMVZ/UNESP-Botucatu, with the aim of following-up the development and the incidence of femoral degeneration (FD). A total of 305 one-day-old male broilers were housed in six pens of 5m2 each. A completely randomized experimental design, with 3 treatments (T1-traditional nutritional density diet; T2-high nutritional density diet) of 3 replicates each was applied. Femoral head of the broilers were submitted to gross examination at 0, 7, 14, 21, 28, 35, and 42 days of aged. At 42 days of age, 60 birds (30 per treatment) were submitted to the Veterinary Hospital of FMVZ to determine bone mineral density by radiography. Birds were then sacrificed for gross examination of the legs, and FD scoring. Five legs per treatment within each FD score were submitted to computed tomography for femur head integrity and bone mineral density. Treatments did not influence FD incidence, and the first gross FD lesions appeared when birds were 28 days old. It was concluded that radiographic optical densitometry and computed tomography are efficient methods to evaluate femoral degeneration, and both techniques expressed the same profile. In addition, using radiographic optical densitometry and computed tomography, these results also allowed us to establish bone mineral density value ranges within each gross FD score. These finding may provide an excellent non-invasive tool to describe femoral degeneration. [ABSTRACT FROM AUTHOR]

Background: Mechanical properties of bones are greatly influenced by percentages of organic and mineral constituents. Nevertheless, information about mineralization level on a microscopic scale and collagen fiber organization in peri-implant bone after immediate loading is scarce. Purpose: The aim of this work was to analyze and compare the degree of mineralization and collagen fiber orientation in alveolar bone (AB) and peri-implant bone of immediately loaded (IL) and unloaded (NL) implants. Materials and Methods: A total of 25 dental implants of 3.8 mm in diameter and 11 mm in length were used in the present study. In five minipigs, three premolars and the first molar were removed from the left side of the mandible. Three months later, five implants for each animal were inserted. Four implants were loaded immediately with a fixed restoration, while one implant was left unloaded. After a 4-month healing period, all implants were retrieved. Circularly polarized light and scanning electron microscope with backscattered electron imaging were used to analyze both peri-implant and AB retrieved 5 mm from the implant. Results: The bone/implant contact ratio (BIC %) was 77.8 ± 5.9% for the IL implants and 78.0 ± 5.8% for the NL implants; the difference was not statistically significant ( p = 0.554). In the peri-implant bone, the area related to transverse collagen fibers was 112,453 ± 4,605 pixels for IL implants and 87,256 ± 2,428 pixels for NL implants. In the AB, the area related to transverse collagen fibers was 172,340 ± 3,892 pixels. The difference between groups was statistically significant ( p < .001). The degree of mineralization of peri-implant bone was 137 ± 19 gray level for IL implants and 115 ± 24 gray level for NL implants, while in the AB, the degree of mineralization was 125 ± 26 gray level. This difference was statistically significant ( p < .001). Conclusion: In this study, it was found that IL and NL implants showed the same degree of osseointegration. The bone matrix around IL implants had a higher quantity of transverse collagen fibers and presented a higher level of mineralization. [ABSTRACT FROM AUTHOR]

Subsidence of various constructs into the vertebral body is a well-known complication in anterior fusion. Information on bone structure is needed, as a basis for improving these procedures. There are, however, no data available on the distribution of mineral density within vertebral endplates. In this study the regional distribution of mineralization within the cervical endplates with respect to endplate orientation (inferior and superior endplate) and level distribution (C3–C7) was examined by means of computed tomographic osteoabsorptiometry (CT-OAM). The distribution of mineralization in 80 cervical endplates of 8 spinal columns (4 male, 4 female, age range 38–62 years) in vertebrae C3–C7 was investigated by CT osteoabsorptiometry (CT-OAM). The subchondral mineralization distribution revealed considerable topographic differences within each endplate, whereby the areas of greatest density were found in the peripheral marginal zones with maxima in the posterolateral surface, whereas mineralization density was much lower in the central areas. The superior endplates showed an additional posteromedial maximum, whereas the inferior endplates showed an additional anterior mineralization maximum. Comparison of the distribution patters of inferior and superior endplates at different levels from C3 to C7 reveals a uniform increase of mineralization in the anterior portions from cranial to caudal. The mineralization distribution showed characteristic reproducible patterns. The maximal values occurred in the posterolateral parts, and can thus be considered a morphological substrate of high long-term loading. This can serve as a basis for improved prosthesis design and the anchorage point for various fusion techniques. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The aim of this study was to characterise the mineral density (MD) of natural enamel white spot lesions (WSLs) using X-ray micro-tomography calibrated with different density hydroxyapatite phantoms. Methods: Seven natural WSLs from four extracted non-carious premolar teeth were scanned at a voxel size of 7.6μm using a desktop X-ray micro-tomography system. Five hydroxyapatite phantoms (sintered pellets of hydroxyapatite powder) with densities ranging from 1.52 to 3.14g/cm3 were used as calibration standards for each scan. Three-dimensional image reconstruction enabled MD gradients throughout the lesion to be quantified using an MD calibration equation derived from hydroxyapatite phantoms. Background noise generated during the measurement of MD was reduced using a Gaussian filter. Results: Gaussian filter reduced the signal-to-noise ratio (standard deviation) significantly while the basic MD information (average value) remained intact. The mineral gradients through the WSLs examined were compared and are discussed in terms of existing literature. The MD of sound enamel, apparent intact surface layer of WSL, and lowest level of WSL was found to be 2.65–2.89g/cm3, 2.23–2.58g/cm3 and 1.48–2.03g/cm3, respectively. Our MD results are comparable with other studies. Conclusions: X-ray micro-tomography is a sensitive in vitro technique capable of characterising and quantifying MD of small non-cavitated WSLs. This method has a promising potential for future carious and quantitative remineralisation studies. [Copyright &y& Elsevier]

Abstract: In this study we sought to understand the material level basis for local variations in the uniaxial micromechanical properties of mouse cortical bone. It was hypothesized that the opposing anterior and posterior quadrants will significantly differ in terms of their mechanical function, such that, the anterior portion will be stronger in tension whereas the posterior quadrant will be stronger in compression. Mechanical properties were assessed via microtensile and microcompressive tests of standardized coupon-shaped specimens from femurs of Swiss Webster mice (9 weeks). The mineralization and mineral quality was assessed via Raman spectroscopy and the overall collagen orientation was investigated with quantitative polarized imaging. Micromechanical tests demonstrated that the modulus, yield stress, maximum stress and fracture energy of the posterior quadrant was 66%, 53%, 42% and 31% of anterior quadrant; however, the compressive properties did not differ between the two quadrants. Raman microspectroscopic analysis indicated that the mineral matrix ratio, mineral crystallinity and carbonation did not vary between the quadrants. However, the collagen fibers in the anterior quadrant were significantly () more oriented along the longer axis of the diaphyseal shaft than the collagen fibers of the posterior quadrant. Therefore, we concluded that the orientation of collagen fibers with respect to the anatomical loading axis has a profound effect on the uniaxial mechanical function of murine bone. It will be a matter of further research to reveal the role of local variations in the mode of stress on this material level dichotomy in tissue organization and mechanical function. [Copyright &y& Elsevier]

Abstract: Objective: The mechanical properties of bone are greatly influenced by the percentages of organic and mineral constituents. Nevertheless, the information about the mineral content on a microscopic scale in peri-implant bone is scarce. The aim of this work was to analyze the bone mineral density of peri-implant bone under different techniques. Design: Five unloaded titanium dental implants with a micro-structured surface (three XiVE plus and two Frialit 2, DENTSPLY-Friadent, Mannheim, Germany) were retrieved from the mandible of five patients after a 6-month period. scanning electron microscopy with backscattered electron signal (BSE), light microscopy (LM) with a double staining technique, fluorescence microscopy and confocal laser microscopy were used for measuring microscopic mineral content variations in peri-implant bone. Histomorphometry and image intensity (grey level) were evaluated using a software package for image analysis. Results: The low mineral density index (LMDI) for LM was of 29.2±3.1 (mean±S.D.), while the high mineral density index (HMDI) was of 88.2±3.6 (mean±S.D.). The one-way ANOVA analysis showed a significant difference (P <0.001) among the groups. The pairwise Holm–Sidak test identified the differences among HMDI indexes for both LM and SEM values and also for cross-evaluation of the LMDI and HMDI values. The comparison between LMDI indexes for both SEM and LM did not show any significance. The florescence microscopy analysis showed clearly the difference between old (high mineralized) and new (low mineralized) bone tissue near the implant surface. Under confocal laser microscopy the same sections showed the area of bone modelling closest to implant surface. Conclusion: In this study it was found that bone around unloaded implants showed a low mineral density index under all the investigation methods used. It was also found that the conventional LM technique with the double staining method was able to intensely stain the bone area with a low mineral content. [Copyright &y& Elsevier]

Abstract: Micro-tomographic imaging of bone micro-architecture is increasingly used on wild and transgenic mice to follow effects of diseases or therapeutics. Synchrotron radiation micro-tomography (SR micro-CT) provides quantitative images at very high spatial resolution but has mainly been used in vitro. The aim of this work was to show the feasibility of SR micro-CT for assessing bone mineral density and micro-architecture in vivo in mice. Imaging with a pixel size of 10μm was performed on beam line ID19 at the ESRF using a special mouse holder. Two strains of mice (C3H/HeJ and C57BL/6J) were used for the experiment. First tests were performed in order to optimize the imaging conditions with respect to dose. Then, six mice of each group were imaged at doses of 7 and 13Gy (total scan time &#60;5min). A similar volume of interest was selected in each image to perform quantitative analysis. The first results on bone volume and mineralization revealed significant differences between the strains as expected. Although there was no apparent damage, the imaged femurs will be further investigated by histology to evaluate the effect of irradiation on bone cells. In conclusion, SR micro-CT provides in vivo images with high signal-to-noise ratio (SNR), very short scan time and may be used in longitudinal studies. [Copyright &y& Elsevier]

The objective of this study was to evaluate the influence of heterozygous inactivation of one allele of the type II collagen gene ( Col2a1) on biomechanical properties and mineral density of bone under physical loading conditions. C57BL/6−TGN mice with heterozygous knockout (HZK) inactivation of Col2a1 gene and their nontransgenic littermate controls were housed in individual cages with running wheels for 9 and 15 months. The running activity of each mouse was monitored continuously throughout the experiment. Bone mineral density (BMD) of mice femora was measured using dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computerized tomography (pQCT). Biomechanical properties were determined using three-point bending tests. Vertebral bone samples were prepared for quantitative polarized light microscopy and digital densitometry of proteoglycans. The concentration of total collagen and collagen cross-links were analyzed using high-performance liquid chromatograpy (HPLC). The average daily running distance was shorter for the HZK mice between the age of 4 and 15 months as compared with normal runners ( P < 0.05). The ultimate breaking force was 14.8% and 23.6% (9 vs. 15 months) lower in HZK-runners than in wild-type runners. BMD of the femur was 6.1% lower in HZK-runners at the age of 9 months ( P < 0.05). Physical activity increased cortical BMD in wild-type runners but not in the HZK runners at the age of 9 months. The collagen network of the HZK mice was less organized. There were only minor changes in BMD and mechanical and structural properties between sedentary HZK mice and their wild-type controls. Increased physical activity induced significantly lower bone density, mechanical properties, and organization of collagen fibers in male HZK mice. However, there were no major differences in biomechanical parameters between sedentary HZK and wild-type male mice. This suggests an important guiding role of collagen type II in bone remodelling and maturation. [ABSTRACT FROM AUTHOR]

Abstract: Volumetric quantitative computed tomography (vQCT), using multiple thin-slice acquisition, measures three-dimensional volumetric bone mineral density (BMD, mg/cm3). vQCT is often used to measure BMD of lumbar vertebrae and may detect early changes in trabecular, cortical, or integral BMD that extend beyond the technical limits of areal dual X-ray absorptiometry (DXA) BMD measurements. The objective of this study was to determine the effect of 2 years of raloxifene (RLX) treatment on several volumetric BMD measures in a subset of postmenopausal women (n = 58) enrolled in the Multiple Outcomes of Raloxifene Evaluation (MORE) trial. Patients in this study were randomized to one of three treatment groups: placebo (n = 21), RLX 60 mg/day (n = 17), or RLX 120 mg/day (n = 20), and all patients received daily calcium (500 mg) and vitamin D (400–600 IU) supplementation. Data from the raloxifene treatment groups were pooled for each analysis. Following 2 years of raloxifene treatment, there was a significant percent change from baseline in the vQCT regions of interest (ROIs) of midintegral BMD, total trabecular BMD, and total integral BMD (P < 0.05) compared to placebo, while there was no significant change in the spinal DXA BMD measurement. These data provide the first longitudinal assessment by vQCT of changes in vertebral bone density after 2 years of treatment with raloxifene. vQCT appears to be a valuable technique for measuring the effects of raloxifene treatment in this population of postmenopausal women with osteoporosis. [Copyright &y& Elsevier]

Objective: To establish whether T1DM can affect bone mineral density (BMD) in children and adolescents. Research design and methods: We performed a cross-sectional and longitudinal study of 57 diabetic children and adolescents and 57 normal controls. Total body and lumbar BMD and bone mineral content (BMC) were assessed by DXA (Lunar DPX) and volumetric transformation was calculated using the Katzman formula for total body BMD (BMAD) and using the Kroger formula for Lumbar BMD (L2L4BMDvol). BMC, BMAD, BMDspine, and L2L4BMDvol were adjusted for confounding factors such as age, gender, BMI, height, weight, and pubertal stage. Results: BMDspine in the control group increased by 0.006 (g/cm2)/year; while in the 39 diabetic patients longitudinally studied, it dropped by 0.006 (g/cm2)/year during a follow-up period of 51 ± 27 months. The average time spent weekly doing physical activity resulted in T1DM group directly correlated to BCM (P < 0.001) and inversely correlated with BMDspine (P < 0.05) and L2L4BMDvol (P < 0.01). L2L4BMDvol resulted significantly correlated with previous BMD spine (R = 0.63; P < 0.0001) and BMC evaluation (R = 0.42; P < 0.01) but not with BMAD. A second lumbar DXA evaluation performed in 38 patients after 1.00 ± 0.16 years confirmed a small but significant decrease of 1.6% per year in L2L4BMDvol. The percentage of variation of L2L4BMDvol between the two evaluations was not correlated with the level of metabolic control, insulin requirement, and duration of the disease. Patients with complications showed similar L2L4BMDvol to patients without complications. Conclusions: Diabetic children and adolescents show a slight negative pattern of spine mineralization, which does not depend on metabolic control and microvascular complications. [Copyright &y& Elsevier]

Mineral trioxide aggregate (MTA) is an alternative endodontic material that predicts conductive or inductive calcified tissue formation from immature pulp mesenchymal stem cells (IPMSCs). The purpose of this study was to investigate whether MTA could promote reparative odontoblast differentiation via IPMSCs in the early phase of regeneration and compare with calcium hydroxide (CH). Direct pulp capping using calcium hydroxide (CH), MTA, and MTA with platelet-rich plasma (MTA + PRP) was performed on maxillary first molars of 8-week-old male Wistar rats (n = 36). After 3, 7, or 14 days, the teeth were analyzed for mineral density (MD) and volume of MD (VMD) via micro-focusing computed tomography (µCT), nestin, dentin matrix acidic phosphoprotein 1 (DMP1) immunohistochemistry, and real-time PCR for DMP1 mRNA expression. MTA stimulated the early phase differentiation of the IPMSCs into odontoblasts, with positive results for nestin and DMP1 compared with CH. Moreover, MTA + PRP stimulated calcified granule and dentin bridge formation through calcium mineral deposition, following the induction of DMP1 mRNA expression in IPMSCs. Our results suggested that the combination of MTA and PRP is an effective and clinically applicable method for activating endogenous dental pulp stem cells into odontoblasts in the early stages of pulp regeneration. [ABSTRACT FROM AUTHOR]

An abstract of the article "Structural and behavioural analysis of children's cortical bones," by E. Lefèvre and colleagues is presented.