Evaluation of osteoporosis features in cortical bone models using pattern recognition methods applied to ultrasound data.

<p>The objective of this research was to evaluate the relationships between greater adiposity and bone development during adolescence. Bone was evaluated from age 11 to 17 years in the Iowa Bone Development Study using peripheral quantitative computed tomography (pQCT). Body composition (fat and lean mass) was estimated by dual energy x-ray absorptiometry (DXA).</p> <p>The first research aim evaluated the associations between greater overall adiposity and subsequent maturation and bone strength in 135 girls and 123 boys. Greater adiposity was defined according to age 8 Body Mass Index (BMI) to categorize participants as overweight (OW) or healthy-weight (HW). Maturation was defined as the age of peak height velocity (PHV). Bone strength was assessed at the radius and tibia (bone strength index, BSI, and strength-strain index, SSI). Differences in bone strength between OW and HW were evaluated with sex-specific multi-level regression models to account for individual growth and correlation between repeated measurements. Analyses were adjusted for centered age (measurement visit age - grand mean age of cohort), change in fat mass, and limb length in Model 1, with additional adjustment for lean mass in Model 2. Analyses were repeated using biological age (visit age - age PHV). BMI was positively associated with age of maturation in girls and boys (p< 0.05). HW versus OW girls had significantly lower BSI and SSI at the radius and tibia (p< 0.05) in Model 1. Results remained significant except for radial BSI in Model 2. HW versus OW boys had significantly lower BSI and SSI (all p< 0.05) at the tibia, but not radius, in Model 1. Significant differences were sustained in Model 2. Analyses were repeated using biological age, which yielded similar results for boys, but reduced parameter estimates were observed in girls, with only tibial SSI significant in Model 2 (p< 0.05). These findings support a stronger role for greater adiposity in the occurrence of earlier maturation and greater bone strength in girls than boys while greater lean mass appeared to play a greater role in boys.</p> <p>The second research aim evaluated associations between abdominal adiposity and bone in 132 girls and 122 boys. Visceral adipose tissue area (VAT, cm2) and subcutaneous adipose tissue area (SAT, cm2) were estimated from DXA scans. Sex-specific analyses evaluated the fat-bone relationship with growth models using biological age as the time variable adjusted for limb length and lean mass. There were no significant associations between bone parameters and VAT or SAT in girls. In boys, greater VAT was associated with lower trabecular bone density (tBMD) and BSI (all p< 0.05) at the tibia, but not radius. Greater VAT and SAT were associated with smaller cortical bone size and thickness (all p< 0.01) at the radius, but not tibia. Analyses limited to overweight participants showed VAT was negatively associated with periosteal circumference at the radius and tibia, cortical bone thickness at the tibia and SSI (all p< 0.05) at the radius in girls. In boys, the results were relatively unchanged for VAT, while SAT was only significantly associated with lower tBMD (p< 0.05) at the tibia. These results suggest the bone-fat relationship may vary depending on adiposity and bone site.</p> <p>The third research aim evaluated the longitudinal association between intramuscular fat and cortical bone at the tibia from age 11 to 17 years in 153 girls and 143 boys. Muscle density (MD) was used to estimate intramuscular fat (IMF). Lower MD indicates greater IMF. The relationships between muscle density and cortical bone parameters were modeled using multi-level regression models adjusted for biological age, limb length and muscle cross-sectional area measured by pQCT. In the adjusted multi-level regression models, MD was positively associated with cortical bone parameters, but only reached statistical significance for BMD, bone mineral content (BMC), bone cross-sectional area, cortical thickness and SSI in girls, while only SSI was significant in boys (all p< 0.05). These results suggest that greater fat content within muscle may be harmful to weight-bearing cortical bone during adolescence.</p> <p>In conclusion, findings from the first aim suggest there are sex- and site-specific differences in the relationship between adiposity and bone during adolescence. Findings from the second and third aims indicate these differences could be explained, in part, by the existence of specific fat depots (abdominal more so than intramuscular fat) that could be harmful to bone and that may be more apparent in boys due to a sex-specific fat distribution pattern that favors accumulation of abdominal rather than peripheral fat.</p>

ABSTRACTIntroduction: Controversial reports suggest a relationship between growth pattern and cortical alveolar bone thickness, and its effect in the use of mini-implants. Objective: The main purpose of this study was to assess the influence of the growth pattern on the cortical alveolar bone thickness and on the stability and success rate of mini-implants. Methods: Fifty-six mini-implants were inserted in the buccal region of the maxilla of 30 patients. These patients were allocated into two groups, based on their growth pattern (horizontal group [HG] and vertical group [VG]). Cortical thickness was measured using Cone Beam Computed Tomography. Stability of mini-implants, soft tissue in the insertion site, sensitivity during loading and plaque around the mini-implants were evaluated once a month. Intergroup comparisons were performed using t tests, Mann-Whitney tests, and Fisher exact tests. Correlations were evaluated with Pearson’s correlation coefficient. Results: The cortical bone thickness was significantly greater in the HG at the maxillary labial anterior region and at the mandibular buccal posterior and labial anterior regions. There was a significant negative correlation between Frankfort-mandibular plane angle (FMA) and the labial cortical thickness of the maxilla, and with the labial and lingual cortical bone thicknesses of the mandible. No significant intergroup difference was found for mini-implant mobility and success rate. No associated factor influenced stability of the mini-implants. Conclusions: Growth pattern affects the alveolar bone cortical thickness in specific areas of the maxilla and mandible, with horizontal patients presenting greater cortical bone thickness. However, this fact may have no influence on the stability and success rate of mini-implants in the maxillary buccal posterior region.

A Structural Approach to Renal Bone Disease

This study analyzes the relationship between cortical bone thickness and shape in the greater sciatic notch (GSN). This bony feature is sexually dimorphic in humans, with males typically exhibiting narrow GSNs and shorter posterior aspects, or cords. In contrast, females typically exhibit wide notches with expanded posterior aspects and more even anterior and posterior cords. The expanded posterior aspect in females appears to contribute to spacious birth canals and is often attributed to obstetric selection. Nevertheless, the proximate mechanisms that produce pelvic sexual dimorphism are unclear.Here I assess GSN variation in 48 females and 50 males aged 0–20 years using decedent computed tomography (CT) data from the Center for Forensic Imaging at the University of New Mexico. I measured cortical bone thickness at the GSN edge and at the pelvic and gluteal aspects adjacent to the notch in Amira software on CT slice planes axial to the posterior and anterior cords. Paired t‐tests assessed cortical thickness differences between the anterior and posterior cords in the three regions. Relative cortical thicknesses were calculated in each of the three regions as the ratio of cortical thickness of the posterior GSN cord to that of the anterior cord. Two‐block partial least‐squares (2B‐PLS) analysis assessed the relationship between relative cortical thicknesses and GSN shape as measured by Procrustes‐aligned 3D landmark coordinates.I also tested for the effects of age on GSN shape and relative cortical bone thickness. For example, results from the 12–14 year and 15–20 year age cohorts indicate that the difference in cortical bone thickness between the posterior and anterior GSN cords at the gluteal aspect is significant (p<0.01), with the posterior cord typically showing greater cortical thickness in this region. Results from the 2B‐PLS analyses suggest moderate but not significant covariation between GSN shape and relative cortical thickness. Among 12–14 year‐olds, deeper GSNs trend with a greater amount of cortical bone in the posterior cord relative to the anterior cord. Among 15–20 year‐olds, greater relative cortical bone in the posterior cord at the GSN edge and gluteal aspect tends to be associated with a lack of a piriform tubercle and a posteriorly displaced notch apex, such that the posterior GSN cord appears shorter. Less relative cortical thickness in the posterior cord tends to be associated with a prominent piriform tubercle and anterior expansion of the superior portion of the anterior cord, such that the notch appears relatively wider. Variables do not clearly associate by sex.Greater cortical thickness in the posterior GSN cord's gluteal aspect relative to that in the anterior cord suggests that the former can better withstand compressive strains related to bipedal posture. Despite insignificant covariation, moderate relationships between relative cortical bone thickness and GSN shape, particularly in terms of notch expansion patterns, suggests that biomechanical mechanisms contribute to GSN morphological variation.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Biomechanical effectiveness of cortical bone thickness on orthodontic microimplant stability: An evaluation based on the load share between cortical and cancellous bone

Nutrient canals and porosity of the bony palate: A basis for the biological plausibility of the anterior middle superior alveolar nerve block

Using modern human cortical bone distribution to test the systemic robusticity hypothesis

Beginning with the report in 1994 that an adult male with homozygous loss of estrogen receptor α (ERα) had unfused epiphyses and osteopenia,(1) there is now considerable evidence from observational and interventional studies (summarized in Khosla and colleagues(2)) that estrogen is the dominant regulator of bone metabolism in men. Indeed, a legitimate argument can be made that testosterone is largely a prohormone for the skeleton, with its effects on bone mediated principally via aromatization to estrogen, although it remains likely that testosterone contributes to bone size via effects on periosteal apposition and perhaps indirectly to bone mass by increasing muscle mass.

Aim:This study aimed to determine the potential of honey as anti-osteoporosis by evaluating its effectiveness in increasing bone impact strength and cortical thickness, through scanning electron microscopy (SEM) examination.Materials and Methods:Forty-five female rats at 3 months of age, weighing 150-200 g were used in the study. They were placed in individual cages and adapted to food and environment for 10 days. On the 11th day, after the animals were adapted for 10 days, the animals were randomly divided into five treatment groups (n=9): Sham operation group (SH); ovariohysterectomized (OVX) group with no treatment; OVX with treatment Apis dorsata 1 g/kg BW (AD-1); OVX with treatment A. dorsata 2 g/kg BW (AD-2); and OVX with treatment A. dorsata 4 g/kg BW (AD-3). Furthermore, those nine rats in each treatment group were divided into three groups. Three of them were observed at months 1st, 2nd, and 3rd so that in each observation taken three rats in each treatment group. At the end of the study, the rats were euthanized and necropsy for taking their second femoral bone, i.e. dexter region for examining their bone impact strength, while the sinister region was used for measure the cortical thickness of the femoral diaphysis and examining their bone microarchitecture using SEM analysis.Results:Based on results of the ANOVA test, the cortical thickness measurements of femoral diaphyseal can be seen that from month 1 to month 3 the lowest result was found in the group of rats that were OVX-I. Meanwhile, the highest result was found in the group of rats that were not OVX (SH-III). It was significantly different from the other treatment groups (p<0.05). The groups of rats were OVX with honey supplementation at doses of 2 g/kg BW had shown an increasing pattern in the cortical bone thickness from month 1 to month 3. Even on the observation of the 3rd month, the cortical bone thickness in the AD-2 (AD-2-III) group was not significantly different (p>0.05) from that in the group of rats was not OVX in month 1 (SH-I). The results of the bone impact strength measurement from month 1 to month 3 indicated that the groups of rats were OVX without the administration of honey supplements had the lowest value. The highest bone impact strength was found in the group of rats that was not OVX, but not significantly different (p>0.05) with the groups of rats that were OVX administered honey supplement with a dose of 2 g/kg BW (AD-2) and 4 g/kg BW (AD-3).Conclusion:The supplement of honey A. dorsata at doses of 2 g/kg BW in the group of rats was that OVX can inhibit the decreasing of the cortical bone thickness and repair damage in microarchitecture to generate bone impact strength. As a result, bones are not easily broken.

Identifying indicators of locomotor differences in extant and fossil taxa has been an ongoing endeavor in functional morphology. However, overlap between locomotion and phylogeny in primates makes overall interpretation of morphology, function, and behavior difficult. The distal radius is a particularly crucial area to understand loading patterns in the forelimb. This study aims to quantify trabecular and cortical bone properties in humans (bipeds), chimpanzees (knuckle‐walkers), cercopithecids (quadrupeds), and anteaters (quadrupeds) in order to discern different loading patterns in animals that vary in phylogeny and locomotion. Using a combination of whole bone analysis with point cloud correspondence registration and Bayesian mapping, we found locomotor signals in the trabecular and cortical bone properties. Importantly, we found a correspondence between cortical bone thickness and bone volume fraction in accordance with previously hypothesized patterns. Humans, unsurprisingly, have relatively low values for bone volume fraction and cortical bone thickness overall. Knuckle‐walking chimpanzees have increased cortical and trabecular bone along the palmar articular surface, reflecting increased loading in that region when compared to palmigrade or digitigrade cercopithecids. Anteaters have increased cortical bone thickness and trabecular bone volume fraction on the medial side of the radius, which reflects their unique loading patterns. Overall, trabecular and cortical bone variation in the distal radius appears to reflect differences in loading patterns due to differences in locomotion. Whole bone analysis of both cortical and trabecular bone can provide valuable insights into the skeletal response to locomotor loading and can be useful for reconstructing behavior in the past.

Comparison of dental implant stabilities by impact response and resonance frequencies using artificial bone

Effect of cortical bone thickness and density on pullout strength of mini-implants: An experimental study

Micro-finite element analysis applied to high-resolution (0.234-mm length scale) MRI reveals greater whole and cancellous bone stiffness, but not greater cortical bone stiffness, in the distal femur of female dancers compared to controls. Greater whole bone stiffness appears to be mediated by cancellous, rather than cortical bone adaptation. The purpose of this study was to compare bone mechanical competence (stiffness) in the distal femur of female dancers compared to healthy, relatively inactive female controls. This study had institutional review board approval. We recruited nine female modern dancers (25.7±5.8 years, 1.63±0.06 m, 57.1±4.6 kg) and ten relatively inactive, healthy female controls matched for age, height, and weight (32.1±4.8 years, 1.6±0.04 m, 55.8±5.9 kg). We scanned the distal femur using a 7-T MRI scanner and a three-dimensional fast low-angle shot sequence (TR/TE=31 ms/5.1 ms, 0.234 mm×0.234 mm×1 mm, 80 slices). We applied micro-finite element analysis to 10-mm-thick volumes of interest at the distal femoral diaphysis, metaphysis, and epiphysis to compute stiffness and cross-sectional area of whole, cortical, and cancellous bone, as well as cortical thickness. We applied two-tailed t-tests and ANCOVA to compare groups. Dancers demonstrated greater whole and cancellous bone stiffness and cross-sectional area at all locations (p<0.05). Cortical bone stiffness, cross-sectional area, and thickness did not differ between groups (>0.08). At all locations, the percent of intact whole bone stiffness for cortical bone alone was lower in dancers (p<0.05). Adjustment for cancellous bone cross-sectional area eliminated significant differences in whole bone stiffness between groups (p>0.07), but adjustment for cortical bone cross-sectional area did not (p<0.03). Modern dancers have greater whole and cancellous bone stiffness in the distal femur compared to controls. Elevated whole bone stiffness in dancers may be mediated via cancellous, rather than cortical bone adaptation.

An investigation of cortical bone loss and fracture patterns in the neolithic community of Çatalhöyük, Turkey using metacarpal radiogrammetry

Few studies have evaluated interradicular anatomy for cortical bone thickness and root proximity when placing a mini-implant for orthodontic anchorage. The purpose of this study was to provide a clinical guideline to indicate the best location, according to different insertion angles, for placement of a mini-implant with respect to the thickness of cortical bone and root proximity. CT images from 14 men and 14 women (mean age, 27 years; range, 23-35 years) were used to evaluate the buccal interradicular cortical bone thickness and root proximity from and mesial to the central incisor to the second molar. A measure of cortical bone thickness was performed at four different angles. Generally, thin cortical bone thickness was found in the central/central incisors and central/lateral incisors interradicular sites. Cortical bone thickness increased significantly as the insertion angle increased except for interradicular sites at the 2 mm level from the alveolar crest. The volume of cortical bone engagement increased significantly at the 4 and 6 mm levels from the alveolar crest with an insertion angle of 30 degrees and 45 degrees in most interradicular sites. The lateral incisor/canine and second premolar/first molar interradicular sites showed greater space between roots compared with other sites, although this was not statistically significant. Based on the findings of this study, we recommend that mini-implants be placed at the 4 and 6 mm levels from the alveolar crest with 30 degrees and 45 degrees angles for the majority of interradicular sites to ensure better cortical bone to mini-implant contact without root damage.