Rate Of Bone Remodeling Research Articles

Long-term Posttransplant-Related Bone Volumetric Changes in Eight Face Transplant Recipients – a Single Center Retrospective Case Series

The long-term stability of allograft or native bone in facial vascularized composite allograft (fVCA) recipients is unclear. This study quantified long-term bone volume changes in facial transplants. Computed tomography scans of eight fVCA recipients (2011-2023) were analyzed with Materialise Mimics. Native bone (soft tissue-only VCAs, n=4) and allotransplanted bone (n=4) were compared. Median bone volumes were assessed for significance using the WilcoxonRanked-Sum Test. Mean follow-up was 10 years (range 5-13). A significant median decrease in both mandibular (-6520mm3; p=0.0078) and maxillary (-3548mm3; p=0.0078) bone volumes was seen in all patients, irrespective of bone origin. Median bone volume loss was -9.92% in the bony allograft cohort and -22.60% in the soft tissue-only cohort, respectively. The histopathological analysis of the limited samples (n=2) showed physiological bone even after ten years. Patients with allotransplanted bone showed less pronounced volume loss compared to those with native bone receiving soft tissue-only allografts. This finding suggests that allotransplanted vascularized bone in fVCAs may not be a primary target of chronic rejection processes that compromise bone volume stability and functionality. Bone volume changes are likely influenced by multiple factors, such as tooth loss, nutrition, chronic immunosuppression (e.g., steroids), mechanical stress/load, varying bone remodeling rates, and other medical comorbidities. Further research is needed to clarify the factors affecting bone volume and remodeling after fVCA.

The role of fibroblast growth factor 23 in the assessment of complications in chronic kidney disease

Secondary hyperparathyroidism is an early-stage complication of CKD (Chronic Kidney Disease). It is associated with disorders in bone metabolism, calcium deposition in vessels and organs, significantly increased risk of cardiovascular disease, and death. In recent years, an increasingly important role has been attributed to fibroblast growth factor (FGF 23) in regulating calcium/phosphate homeostasis, hyperparathyroidism, and its relation to vascular calcification, and left ventricular hypertrophy. This study conducted with 110 patients with varying degrees of renal insufficiency shows an increase in FGF23 and PTH when there is a decrease in glomerular filtration, a direct dependency between the levels of phosphate and PTH and FGF23, and a lack of such between calcium and PTH and FGF23. Of particular interest is the fact that patients treated with Calcitriol and Paricalcitol show a reduction in PTH levels, yet maintain high levels of FGF23. PTH serves as a marker for the rate of bone remodeling in patients, where elevated levels indicate renal bone disease. The analysis of FGF 23 is crucial in evaluating cardiovascular risk.

The relationships between patellofemoral bone remodeling, cartilage composition, and vertical loading rate: PET/MRI in isolated patellofemoral osteoarthritis

Loading is invariably an important factor of consideration for understanding the causality flow and parallel existence of articular cartilage and subchondral bone changes. The goal of this study was to investigate the patterns of subregional 18NaF-SUV vs. T1p-T2 associations and vertical ground reaction force loading rates; in isolated patellofemoral-joint-osteoarthritis (PFJ-OA) patients. Thirty-five isolated PFJ-OA patients, with no tibiofemoral involvement, underwent simultaneous scans in a 3.0T whole-body hybrid positron emission tomography-magnetic resonance imaging scanner. MRI Whole-Organ Magnetic Resonance Imaging Scoring assessments were performed to identify/confirm isolated PFJ-OA knees from bilateral scans. T1p-T2 relaxation and SUV values were automatically computed for both trochlear and patellar cartilage and subchondral bone subregions (deep, superficial, lateral, and medial). Maximum vertical impact loading rates (Loading-RateNorm) were calculated from walking trials. Relationships were explored between SUV uptake, T1p-T2 values, and Loading-RateNorm via linear mixed-effects modeling. Significant and complex association patterns were noted between medial and lateral bone 18NaF-SUV uptakes vs. medial and lateral cartilage sub-regional T1p and T2. SUVMean and SUVMax were positively associated with deep cartilage subregional T1pand T2 values; and negatively associated with superficial cartilage subregional T1p-T2 values in both medial and lateral regions. Both medial and lateral bone 18NaF-SUVMean and SUVMax uptakes remained positively associated with the individual gait characteristics, i.e., peak vertical impact loading rates (Loading-RateNorm). Evidence of simultaneous, complementary, cross-sectional associations between T1p-T2 values and peak vertical loading rates with 18NaF-SUV, have been rare in the isolated PFJ-OA cohort. The clinical implications of such novel associations remain of utmost importance from a gait retraining perspective.

Using portable X-ray fluorescence elemental analysis to explore porous skeletal lesions: Interplay of sex, age at death, and cause of death.

Search for possible associations between bone elemental concentration and the presence of porous skeletal lesions (PSLs), considering the sex, age, and cause of death (COD) of the individuals. The sample comprised 107 non-adult individuals (56 females, 51 males) aged 0-20 (x̄ = 13.2, SD = 5.8) from the Coimbra and Lisbon Identified Skeletal Collections. Cribra cranii, orbitalia, humeralis, and femoralis were recorded as present/absent, and elemental concentrations were assessed by portable x-ray fluorescence (pXRF). A multivariate statistical approach was applied. Well-preserved skeletons with minimal diagenesis showed no sex-related elemental variations or PSL associations. In contrast, age-at-death correlated with elevated Ca, P, Sr, and Pb levels. Cribra cranii increased with age while other cribra declined post-adolescence. Higher concentrations of Fe and lower of S were linked to cribra cranii. Respiratory infections as COD increased the odds of expressing cribra femoralis (OR = 5.25, CI = 1.25-15.14), cribra cranii (OR = 2.91, CI = 0.97-8.69), and cribra orbitalia (OR = 2.76, CI = 1.06-7.24). Feasible pXRF results and low cribra intraobserver error assure replicability. Elevated Ca, P, and Sr in older individuals may relate to skeletal growth, while increased Pb suggests bioaccumulation. Cribra's increase with age reflects different rates of marrow conversion and bone remodeling. Higher Fe and lower S in individuals with cribra cranii possibly reflects poor nutrition, early alcohol use, and sideroblastic anemia, aligning with 19th-20th-century Portugal's living conditions. Respiratory infections increased cribra expression, revealing intricate interplays among inflammation, anemia(s), marrow expansion, and diet. This research highlights a complex scenario and blazes a new path for cribra interpretation.

Chronic secondary orofacial pain as the first symptom of chronic non-bacterial osteomyelitis in the mandible: a case report and literature review

Chronic non-bacterial osteomyelitis clinically manifests with pain, swelling and limitation of movement. When it affects the jaws, it can cause pain, similar to other orofacial conditions, requiring a correct differential diagnosis. The objective of this study was to report a clinical case of chronic secondary orofacial pain as the first manifestation of an inflammatory bone disease located in the mandible, in addition to discussing the diagnostic hypotheses, the pathophysiological aspects and the therapy. A 21-year-old male patient came to the service complaining of pain in the mandible, preauricular and temporal regions bilaterally with one year of evolution, associated with anterior open bite and psychological impairment. So, it was chronic orofacial pain secondary to non-bacterial osteomyelitis with a high rate of bone remodeling. Elevation of pro-inflammatory cytokines can lead to an increased power cycle of nociceptive signaling, chronic inflammation, and bone loss. Pro-inflammatory cytokines that originate in neuronal and glial cells can trigger effects such as chronic hyperexcitability, changes in the phenotypic expression of nociceptors and abnormal processing of noxious signals. The patient is still undergoing treatment and without pain. Careful assessment, ordering tests and multidisciplinary investigation are essential in the care of patients with chronic and complex orofacial pain.

Lymphedema and Paget’s Disease: beyond the nipple

Lymphedema praecox is a rare lymphatic vascular anomaly diagnosed before the age of 35, presenting with unilateral involvement of the lower extremities. Paget's Disease of Bone (PDB) is also a rare osteometabolic disorder characterized by an accelerated rate of bone remodeling, and diagnosis of the disease is challenging. Here, we report a 49-year-old woman with primary lymphedema since the age of 33, who presented with pain and swelling in her right leg. Although the volume of the extremity diminished after complete decongestive therapy, the pain continued. Further evaluation with X-ray, bone scan, and biochemical markers supported the diagnosis of PDB. Following the zoledronic acid infusion, the pain score improved. However, there is no published association between these two diseases. Both lymphedema and PDB are associated with vascular disease and have a genetic background. This is the first case reporting the coexistence of lymphedema and PDB in the same extremity.

Low-intensity pulsed ultrasound reduces alveolar bone resorption during orthodontic treatment via Lamin A/C-Yes-associated protein axis in stem cells.

The bone remodeling during orthodontic treatment for malocclusion often requires a long duration of around two to three years, which also may lead to some complications such as alveolar bone resorption or tooth root resorption. Low-intensity pulsed ultrasound (LIPUS), a noninvasive physical therapy, has been shown to promote bone fracture healing. It is also reported that LIPUS could reduce the duration of orthodontic treatment; however, how LIPUS regulates the bone metabolism during the orthodontic treatment process is still unclear. To investigate the effects of LIPUS on bone remodeling in an orthodontic tooth movement (OTM) model and explore the underlying mechanisms. A rat model of OTM was established, and alveolar bone remodeling and tooth movement rate were evaluated via micro-computed tomography and staining of tissue sections. In vitro, human bone marrow mesenchymal stem cells (hBMSCs) were isolated to detect their osteogenic differentiation potential under compression and LIPUS stimulation by quantitative reverse transcription-polymerase chain reaction, Western blot, alkaline phosphatase (ALP) staining, and Alizarin red staining. The expression of Yes-associated protein (YAP1), the actin cytoskeleton, and the Lamin A/C nucleoskeleton were detected with or without YAP1 small interfering RNA (siRNA) application via immunofluorescence. The force treatment inhibited the osteogenic differentiation potential of hBMSCs; moreover, the expression of osteogenesis markers, such as type 1 collagen (COL1), runt-related transcription factor 2, ALP, and osteocalcin (OCN), decreased. LIPUS could rescue the osteogenic differentiation of hBMSCs with increased expression of osteogenic marker inhibited by force. Mechanically, the expression of LaminA/C, F-actin, and YAP1 was downregulated after force treatment, which could be rescued by LIPUS. Moreover, the osteogenic differentiation of hBMSCs increased by LIPUS could be attenuated by YAP siRNA treatment. Consistently, LIPUS increased alveolar bone density and decreased vertical bone absorption in vivo. The decreased expression of COL1, OCN, and YAP1 on the compression side of the alveolar bone was partially rescued by LIPUS. LIPUS can accelerate tooth movement and reduce alveolar bone resorption by modulating the cytoskeleton-Lamin A/C-YAP axis, which may be a promising strategy to reduce the orthodontic treatment process.

The Vitamin D Receptor Bsm1 Variant is not Associated With Temporomandibular Disorder With or Without Bruxism

Background: Temporomandibular joint disorder (TMD), a set of conditions that affect the temporomandibular joint and related structures, is frequently linked to bruxism. The vitamin D receptor (VDR) affects calcium absorption, bone remodeling, and mineralization rate. The goal of this study was to evaluate the role of the VDR Bsm1 (rs1544410) variant in the susceptibility to bruxism in TMD.
 Method: A total of 321 people [221 TMD patients (135 with bruxism and 86 without bruxism) and 100 healthy controls] were included in the study. The VDR Bsm variant was genotyped using the PCR-RFLP method. 
 Results: We found no significant difference between the all-TMD patient group and the control group regarding the VDR Bsm1 genotype and allele distribution (p>0.05). There was no deviation from HWE for the VDR variant in groups. There was no relationship between pain characteristics and VDR Bsml genotype distribution in patients with bruxism.
 Conclusions: Our results support the conclusion that the VDR Bsm1 variant is not a risk factor for the development of bruxism in TMD. The effect of the VDR Bsml variant on the risk of bruxism in TMD should be investigated in studies involving larger populations and other ethnicities.

Bomb pulse 14 C evidence for consistent remodeling rates of cortical femur collagen in middle-late adulthood.

Bomb pulse (BP) radiocarbon (14 C) dating methods are used by forensic anthropologists to estimate the year-of-death (YOD) of unidentified individuals. Method resolution and accuracy depend on establishing lag times, or the difference between a tissue's BP 14 C-derived year and the YOD, of various tissue types from known deceased persons. Bone lag times span many years and are thought to increase with age as a function of slowing remodeling rates. However, remodeling rates for various skeletal elements, bone structures and phases are not well known. Here a simple method is used to estimate bone remodeling rates from a compilation of published cortical femur bone collagen BP 14 C measurements (n = 102). Linear regression models and nonparametric tests are used to detect changes in lag times and remodeling rates with increasing age-at-death. Remodeling rates and lag times of 3.5%/year and 29 years, respectively, are estimated from individuals aged 40-97 years. In contrast to previous work, the analysis yielded modest and negligible changes in remodeling rates and lag times with advancing age. Moreover, statistically significant differences in remodeling rates and lag times were not found between reported females and males. Implications for the temporal contexts within an individual's lifetime of biogeochemical data in archaeology and forensic anthropology are discussed, warranting additional BP 14 C studies of known individuals and integration with histomorphometric analysis.

Multiscale morphological analysis of bone microarchitecture around Mg-10Gd implants.

The utilization of biodegradable magnesium (Mg)-based implants for restoration of bone function following trauma represents a transformative approach in orthopaedic application. One such alloy, magnesium-10weight percent gadolinium (Mg-10Gd), has been specifically developed to address the rapid degradation of Mg while enhancing its mechanical properties to promote bone healing. Previous studies have demonstrated that Mg-10Gd exhibits favorable osseointegration; however, it exhibits distinct ultrastructural adaptation in comparison to conventional implants like titanium (Ti). A crucial aspect that remains unexplored is the impact of Mg-10Gd degradation on the bone microarchitecture. To address this, we employed hierarchical three-dimensional imaging using synchrotron radiation in conjunction with image-based finite element modelling. By using the methods outlined, the vascular porosity, lacunar porosity and the lacunar-canaliculi network (LCN) morphology of bone around Mg-10Gd in comparison to Ti in a rat model from 4 weeks to 20 weeks post-implantation was investigated. Our investigation revealed that within our observation period, the degradation of Mg-10Gd implants was associated with significantly lower (p<0.05) lacunar density in the surrounding bone, compared to Ti. Remarkably, the LCN morphology and the fluid flow analysis did not significantly differ for both implant types. In summary, a more pronounced lower lacunae distribution rather than their morphological changes was detected in the surrounding bone upon the degradation of Mg-10Gd implants. This implies potential disparities in bone remodelling rates when compared to Ti implants. Our findings shed light on the intricate relationship between Mg-10Gd degradation and bone microarchitecture, contributing to a deeper understanding of the implications for successful osseointegration.

Age estimation in the combined long bones and ribs by histomorphometry: Past, present, and future.

Numerous age estimation methods in unidentified bone have been a long time developing for application in forensic anthropology. The histomorphometric technique is one of the alternative methods that relied upon the evaluation of the cortical bone microstructure over the lifespan as a result of the remodeling process in bone. Remodeling is a sophisticated event occurring from the coupled function of bone formation and resorption cells for maintaining mineral homeostasis and repairment of microdamage in bone tissue. Products derived from remodeling are primary changes in the osteon or haversian system in various regions in the cortical bone, including periosteum, endosteum, and trabecular bone. Throughout life, bone remodeling rate with osteon alteration can be predictable. In the forensic field, histological methods are getting more attention due to the unavailability of macroscopic methods. Histomorphometry approach can be accomplished in fragmentary or incomplete bone remains indicating the limited use of gross morphological methods. In addition, the microscopic methods can aid to increase the more accuracy of analyses and diminish the biased subjective assessment for determining age. Most histomorphometry method utilizes a cross-section of the midshaft of the long bones including the mandible, rib, and clavicle. This review provides the basic knowledge of bone biology and anatomy, several age-estimating methods of histology, and crucial factors for age methods. Studies regarding overall age determination methods from the past until now contribute to obtaining more benefits for developing methods of histomorphometry using human bone in forensic identification.

The Use of Bone-Turnover Markers in Asia-Pacific Populations.

Bone-turnover marker (BTM) measurements in the blood or urine reflect the bone-remodeling rate and may be useful for studying and clinically managing metabolic bone diseases. Substantial evidence supporting the diagnostic use of BTMs has accumulated in recent years, together with the publication of several guidelines. Most clinical trials and observational and reference-interval studies have been performed in the Northern Hemisphere and have mainly involved Caucasian populations. This review focuses on the available data for populations from the Asia-Pacific region and offers guidance for using BTMs as diagnostic biomarkers in these populations. The procollagen I N-terminal propeptide and β-isomerized C-terminal telopeptide of type-I collagen (measured in plasma) are reference BTMs used for investigating osteoporosis in clinical settings. Premenopausal reference intervals (established for use with Asia-Pacific populations) and reference change values and treatment targets (used to monitor osteoporosis treatment) help guide the management of osteoporosis. Measuring BTMs that are not affected by renal failure, such as the bone-specific isoenzyme alkaline phosphatase and tartrate-resistant acid phosphatase 5b, may be advantageous for patients with advanced chronic kidney disease. Further studies of the use of BTMs in individuals with metabolic bone disease, coupled with the harmonization of commercial assays to provide equivalent results, will further enhance their clinical applications.

Diagnostic and Prognostic Value of Indicators of Bone Metabolism Markers in Patients Following Mandibulectomy and Free Fibula Flap Reconstruction with Endosteal Implants.

To evaluate and assess the indicators of bone metabolism markers osteocalcin and β-Cross-Laps in blood serum as a tool for monitoring bone regeneration and determining the time of implantation in patients after mandibulectomy and reconstruction of a free fibular flap with subsequent endosteal implants. Forty-eight patients in a 6-year period participated in this study, due to resection for tumors. All patients underwent reconstruction with fibula free flap after tumor resection, 4-6months after osteoectomy, dental implants were installed with further orthopedic rehabilitation. To assess the rate of bone remodeling after transplantation, the content biochemical markers of bone remodeling osteocalcin and β-Cross-Laps serum were determined by enzyme immunoassay. All 46 fibular free flaps were healed without complications and were survived. A total 326 implants installed, 8 implants failed to osseointegrate, and 6 implants failed after 5years of loading (peri-implantitis). Success rate of implants after 5years was 95,7%. In patients before surgery, the mean of osteocalcin levels was 8.5ng/ml, two months later, there was a sharp increase in the content of osteocalcin by 15.4ng/ml, after four months reached 24.7ng/ml, after six months of 28.6ng/ml, then the indicator began to decrease and after 12months it was approaching the norm of 14.7ng/ml. In patients before surgery, the mean level of β-Cross-Laps was 0.76ng/ml, after two months bone transplantation the mean level of β-Cross-Laps decreased to - 0.65ng/ml, after four months the indicator increased and reached of 0.98ng/ml, after six months the indicator was - 1.56ng/ml, then these indicators began to decrease and after 12months, approaching normal values of - 0.87ng/ml. There is a correlation between different concentrations of osteocalcin or β-Cross- Laps and the success rate of implants. Implants were shown to be unsuccessful low concentrations of osteocalcin and high concentrations of β-Cross-Laps in serum. Studies have shown that the long-term survival and success rates of implants placed in the reconstructed areas may guarantee an excellent prognosis of implant-supported prostheses. Bone markers in blood serum osteocalcin and β-Cross-Laps can be used to evaluate the rate of bone remodeling, which allows you to determine the time of implantation.

Effects of bone type and occlusal loading pattern on bone remodeling in implant-supported single crown: A finite element study.

To assess the influence of bone types and loading patterns on the remodeling process over 12 months according to the variations in stress, strain, strain energy density (SED), and density allocation in the bone of implant-supported single crown. A three-dimensional finite element of a single crown implant was modeled in five different bone types (D1-D4, and grafted bone). A 200N load was applied on an implant crown with three occlusal loading patterns (nonfunctional contact, functional contact at center, and at 2-mm offset loading). During the first 12 months after implant placement, the SED was employed as a mechanical stimulus to simulate cortical and cancellous bone remodeling. Functional contact at 2-mm offset loading led to a higher bone remodeling rate and stress compared to functional contact at center and nonfunctional contact. Under 2-mm offset loading, the greatest remodeling rate after 12 months was achieved with D3 and D4, D2, grafted, and D1 cortical bone with an average peri-implant density of 1.95, 1.77, 1.56, and 1.50g/cm3 , respectively. Meanwhile, the highest von Mises stresses were found in D4 (22.2MPa) and D3 (21.9MPa) bones. A greater stress concentration and remodeling rate were found when an off-axial load was applied on an implant placed in low bone density. Although the fastest remodeling processes resulting in increased bone density and strength were found in D3 and D4 bone types with greater off-axial loading that may provide greater bone engagement, it could increase stress concentrations that are susceptible to inducing implant failure.

Can radiomic features extracted from intra-oral radiographs predict physiological bone remodelling around dental implants? A hypothesis-generating study.

The rate of physiological bone remodelling (PBR) occurring after implant placement has been associated with the later onset of progressive bone loss and peri-implantitis, leading to medium- and long-term implant therapy failure. It is still questionable, however, whether PBR is associated with specific bone characteristics. The aim of this study was to assess whether radiomic analysis could reveal not readily appreciable bone features useful for the prediction of PBR. Radiomic features were extracted from the radiographs taken at implant placement (T0) using LifeX software. Because of the multi-centre design of the source study, ComBat harmonization was applied to the cohort. Different machine-learning models were trained on selected radiomic features to develop and internally validate algorithms capable of predicting high PBR. In addition, results of the algorithm were included in a multivariate analysis with other clinical variables (tissue thickness and depth of implant position) to test their independent correlation with PBR. Specific radiomic features extracted at T0 are associated with higher PBR around tissue-level implants after 3months of unsubmerged healing (T1). In addition, taking advantage of machine-learning methods, a naive Bayes model was trained using radiomic features selected by fast correlation-based filter (FCBF), which showed the best performance in the prediction of PBR (AUC=0.751, sensitivity=66.0%, specificity=68.4%, positive predictive value=73.3%, negative predictive value=60.5%). In addition, results of the whole model were included in a multivariate analysis with tissue thickness and depth of implant position, which were still found to be independently associated with PBR (p-value < .01). The combination of radiomics and machine-learning methods seems to be a promising approach for the early prediction of PBR. Such an innovative approach could be also used for the study of not readily disclosed bone characteristics, thus helping to explain not fully understood clinical phenomena. Although promising, the performance of the radiomic model should be improved in terms of specificity and sensitivity by further studies in this field.

Levels of Pro-Inflammatory and Bone-Resorptive Mediators in Periodontally Compromised Patients under Orthodontic Treatment Involving Intermittent Forces of Low Intensities.

During orthodontic treatment, diverse cytokines, enzymes, and osteolytic mediators produced within the teeth surrounding periodontal tissues determine the rate of alveolar bone remodeling and consequent teeth movement. In patients with teeth presenting reduced periodontal support, periodontal stability should be ensured during orthodontic treatment. Thus, therapies based on the application of low-intensity intermittent orthodontic forces are recommended. To determine if this kind of treatment is periodontally well tolerated, this study aimed to analyze the production of receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), interleukin (IL)-6, IL-17A, and matrix metalloproteinase (MMP)-8 in periodontal tissues of protruded anterior teeth with reduced periodontal support and undergoing orthodontic treatment. Patients with periodontitis-associated anterior teeth migration received non-surgical periodontal therapy and a specific orthodontic treatment involving controlled low-intensity intermittent orthodontic forces. Samples were collected before periodontitis treatment, after periodontitis treatment, and at 1 week to 24 months of the orthodontic treatment. During the 2 years of orthodontic treatment, no significant differences were detected in the probing depth, clinical attachment level, supragingival bacterial plaque, and bleeding on probing. In line with this, the gingival crevicular levels of RANKL, OPG, IL-6, IL-17A, and MMP-8 did not vary between the different evaluation time-points of the orthodontic treatment. When compared with the levels detected during the periodontitis, the RANKL/OPG ratio was significantly lower at all the analyzed time-points of the orthodontic treatment. In conclusion, the patient-specific orthodontic treatment based on intermittent orthodontic forces of low intensities was well tolerated by periodontally compromised teeth with pathological migration.

Viable cryopreserved human bone graft exhibit superior osteogenic properties in mandibular lateral augmentation

Lack of bone volume to place dental implants is frequently a problem in the reconstruction of edentulous patients. Even though autografts are the gold standard for jaw regeneration, morbidity associated with the harvesting site stimulates the demand for other substitutes. The aim of this study is to characterize the incorporation and the osteogenic ability of a viable cryopreserved human bone graft (VC-HBG) in the mandibular augmentation in rats. Bone chips from fresh human vertebrae cadaveric donors were processed, cryoprotected and deep-frozen at − 80 °C maintaining its cell viability. A jaw augmentation model was used in 20 athymic nude rats allocated into 2 groups to either receive the VC-HBG or an acellular graft as control (A-HBG). The assessment of the grafts' incorporation was performed at 4 and 8 weeks by micro-CT, histomorphometry and immunohistochemistry. Bone volume gain was significantly higher for the VC-HBG group at both time points. At 4 weeks, the A-HBG group presented significantly higher mineral density, but at 8 weeks, the VC-HBG group showed significantly higher values than the A-HBG. There was no statistical difference between VC-HBG and A-HBG groups at 4-weeks for remaining graft particles, while at 8 weeks, the VC-HBG group showed significantly less graft remnants. Collagen I, osteopontin and tartrate-resistant acid phosphatase expression were significantly higher in the VC-HBG group at both time points, while osteocalcin expression was significantly higher in the VC-HBG group at 8-weeks compared to the A-HBG group. This experimental research demonstrated that the VC-HBG shows positive osteogenic properties, greater bone formation, higher rate of bone remodeling and a better overall incorporation in rats' mandibles compared to the A-HBG.

Utility of bone turnover markers in metabolic bone diseases

Bone turnover markers (BTMs) are biochemical indicators that provide information about the rate of bone remodeling, which involves the continuous process of bone formation and bone resorption. BTMs are measured in blood or urine samples and are used in the diagnosis, monitoring, and management of various metabolic bone diseases. They aid in the diagnosis of metabolic bone diseases by providing information about the bone turnover status. Abnormal levels of BTMs can indicate increased bone resorption or decreased bone formation, which are characteristic of certain conditions such as osteoporosis, osteomalacia, or Paget's disease. BTMs can provide insights into the severity of metabolic bone diseases. For example, in osteoporosis, elevated levels of bone resorption markers such as C-terminal telopeptide of type I collagen (CTX) or tartrate-resistant acid phosphatase 5b (TRACP-5b) indicate increased bone breakdown and higher fracture risk. Similarly, low levels of bone formation markers like procollagen type I N-terminal propeptide (PINP) or osteocalcin can indicate reduced bone formation and decreased bone strength. BTMs are valuable tools for assessing the response to treatment in metabolic bone diseases. Changes in BTM levels over time can indicate the effectiveness of interventions such as pharmacotherapy, lifestyle modifications, or surgical interventions. Decreased levels of bone resorption markers or increased levels of bone formation markers suggest a positive response to treatment, whereas persistent abnormal BTM levels may indicate the need for treatment adjustment. It's important to note that BTMs should be interpreted in conjunction with other clinical factors and imaging studies. They provide valuable information about bone turnover dynamics but should not be relied upon as standalone diagnostic or prognostic tools.

The allogeneic shell technique for alveolar ridge augmentation: a multicenter case series and experiences of more than 300 cases

PurposeAllogeneic cortical bone plates (CP) might be used for alveolar ridge augmentation as an alternative to autogenous grafts (AG) and bone substitutes (BS). We report about a multicenter case series and our experiences of more than 300 cases using CP and the shell technique for reconstruction of the alveolar process to illustrate surgical key steps, variations, and complication management.MethodsDifferent types of alveolar ridge defects were augmented using the shell technique via CP. The space between the CP and the alveolar bone was filled with either autogenous or allogeneic granules (AUG, ALG) or a mixture of both. Implants were placed after 4–6 months. Microscopic and histological assessments were performed. In addition, space filling using AUG, ALG and bovine BS was discussed.ResultsScanning electron microscopy demonstrated the compact cortical structure of CP and the porous structure of ALG allowing micro-vessel ingrowth and bone remodeling. Histological assessment demonstrated sufficient bone remodeling and graft resorption after 4–6 months. In total, 372 CP cases and 656 implants were included to data analysis. The mean follow-up period was about 3.5 years. Four implants failed, while all implant failures were caused by peri-implantitis. Next, 30 CP complications were seen, while in 26 CP complications implant placement was possible. CP rehydration, stable positioning by adjusting screws, smoothing of sharp edges, and a tension-free wound closure were identified as relevant success factors. Space filling using ALG and a mixture of AUG/ALG resulted in sufficient bone remodeling, graft resorption and stability of the augmented bone.ConclusionsCP and the shell technique is appropriate for alveolar ridge augmentation with adequate bone remodeling and low complication rates. Allografts can prevent donor site morbidity and therefore may decrease discomfort for the patient.

A Retrospective Observational Study Assessing the Clinical Outcomes of a Novel Implant System with Low-Speed Site Preparation Protocol and Tri-Oval Implant Geometry.

A novel, biologically friendly implant concept system introduces low-speed (50 rpm) site preparation instruments used without irrigation and a tri-oval, tapered implant designed to reduce stress on cortical bone without sacrificing mechanical stability. This retrospective, observational, multicenter study (clinicaltrials.gov NCT04736771) collected data from consecutive patients treated with at least one novel concept system implant to evaluate clinical outcomes after 1 year in function. The primary endpoint was a marginal bone level change (MBLC) from loading to 1 year, and secondary endpoints included implant survival and clinician feedback. Ninety-five patients (54 women and 41 men, mean age: 58 ± 12 years) were treated with 165 implants. For 94.5% of implants, site preparation was performed in two steps. The mean follow-up from implant insertion was 1.8 ± 0.2 years. Mean MBLC from implant loading to 1-year follow-up was +0.15 ± 0.85 mm (n = 124 implants). At the last follow-up, the implant survival rate was 98.0%. Clinician satisfaction with the novel concept system was high. The novel concept system offers an easy-to-use implant placement protocol, with most implants placed using two steps. The minimal bone remodeling and high survival rate observed across a variety of indications and treatment protocols demonstrate broad versatility and confirm the clinical benefits of this biologically friendly innovation.