Low Bone Research Articles

CBCT Analysis of the Hyoid and Pharyngeal Airway Changes in Class III Patients With Orthognathic Surgery.

This study was designed to investigate the response of the respiratory structures to orthognathic surgery in patients with Class III malocclusion, with a specific emphasis on the vertical placement of the hyoid bone. The correlations of these changes were also analysed, followed by further subgroup analyses based on preoperative conditions. Dolphin software was used to obtain cephalometric landmarks, airway and hyoid bone measurements from pre- and postoperative CBCT scans of 31 patients. Statistical analyses included paired t-tests and Pearson's correlation analysis. Stomatological mandibular values and the nasopharynx height showed significant changes. Pearson's correlation identified significant correlations between changes in B and H horizontal coordinates (p < 0.05), as well as between changes in H longitudinal coordinates and specific airway dynamics (p < 0.05). Patients with a lower preoperative hyoid position experienced a more pronounced decrease in hypopharyngeal airway volume after surgery compared to those with a higher preoperative hyoid position, as evidenced by the significant mean differences and p values (p < 0.01). Class III patients experienced airway constriction following orthognathic surgery, particularly those with a lower preoperative hyoid bone position, who showed a more significant decrease in hypopharyngeal airway volume postsurgery compared to those with a higher preoperative hyoid position. These findings underscored the importance of individualised surgical planning and highlighted the need for further research with dynamic assessments to optimise respiratory outcomes.

Amorphous Calcium Carbonate Enhances Fracture Healing in a Rat Fracture Model

Background: Delayed and failed fracture repair and bone healing remain significant public health issues. Dietary supplements serve as a safe, inexpensive, and non-surgical means to aid in different stages of fracture repair. Studies have shown that amorphous calcium carbonate (ACC) is absorbed 2 to 4.6 times more than crystalline calcium carbonate in humans. Objectives: In the present study, we assessed the efficacy of ACC on femoral fracture healing in a male Wistar rat model. Methods: Eighty male Wistar rats were randomly divided into five groups (n = six per group): sham, fracture + water, fracture + 0.5× (206 mg/kg) ACC, fracture + 1× ACC (412 mg/kg), and fracture + 1.5× (618 mg/kg) ACC, where ACC refers to the equivalent supplemental dose of ACC for humans. A 21-gauge needle was placed in the left femoral shaft, and we then waited for three weeks. After three weeks, the sham group of rats was left without fractures, while the remaining animals had their left mid-femur fractured with an impactor, followed by treatment with different doses of oral ACC for three weeks. Weight-bearing capacity, microcomputed tomography, and serum biomarkers were evaluated weekly. After three weeks, the rats were sacrificed, and their femur bones were isolated to conduct an evaluation of biomechanical strength and histological analysis. Results: Weight-bearing tests showed that treatment with ACC at all the tested doses led to a significant increase in weight-bearing capacity compared to the controls. In addition, microcomputed tomography and histological studies revealed that ACC treatment improved callus formation dose-dependently. Moreover, biomechanical strength was improved in a dose-dependent fashion in ACC-treated rats compared to the controls. In addition, supplementation with ACC significantly lowered bone formation and resorption marker levels two–three weeks post-fracture induction, indicating accelerated fracture recovery. Conclusions: Our preliminary data demonstrate that ACC supplementation improves fracture healing, with ACC-supplemented rats healing in a shorter time than control rats.

Clinical Observations of the Effectiveness of the Masquelet Induced Membrane Technique in the Treatment of Critical Long-Bone Defects of the Lower and Upper Extremities

Background and Objectives: Successful treatment of severe trauma and fractures of the long bones with successful healing and bone union is still a significant challenge for surgeons. Unfortunately, up to 10% of long-bone fractures develop bone healing disorders. The aim of this study was to evaluate the results of treating bone defects with different etiologies in the upper and lower extremities using the induced membrane technique. Materials and Methods: We prospectively evaluated the radiological and clinical outcomes of 45 patients with severe bone defects treated with the induced membrane technique during the period from May 2021 to October 2023. The time to bone defect regeneration, size of the bone defect, and the cost of treatment were evaluated. Functional outcomes were assessed using the Disabilities of the Arm Shoulder and Hand (DASH) scale, SF-36, and the Lower Limb Functional Index (LLFI). Results: The mean follow-up time was 31 months (12–35). There were 20 patients with upper extremity bone defects and 25 with lower extremity bone defects. The mean defect length was 7.9 cm for the upper extremity (3.5–18) and 5.3 cm for the lower extremity (3–11). The mean times to achieve bone union and remodeling were 6.0 months (3–12) and 9 months (3–13) for the upper and lower limbs, respectively. Clinical evaluation at the end of treatment (achieving bone union) showed statistically significant improvements in the DASH, SF-36, and LLFI scales for pre- and postoperative outcomes. There was no statistical significance in the SF-36 clinical scale scores after surgical treatment compared to reconstructive treatment of upper and lower extremity bone defects. Results: The presented reconstructive approach to the treatment of bone defects and healing disorders and extensive analysis demonstrate the effectiveness of the induced membrane technique in a short follow-up period, with a relatively high level of patient comfort and good clinical results in the treatment of severe bone defects with particularly infectious etiologies.

NDR2 is critical for the osteoclastogenesis by regulating ULK1-mediated mitophagy.

Bone homeostasis primarily stems from the balance between osteoblasts and osteoclasts, wherein an augmented number or heightened activity of osteoclasts is a prevalent etiological factor in the development of bone loss. Nuclear Dbf2-related kinase (NDR2), also known as STK38L, is a member of the Hippo family with serine/threonine kinase activity. We unveiled an upregulation of NDR2 expression during osteoclast differentiation. Manipulation of NDR2 levels through knockdown or overexpression facilitated or hindered osteoclast differentiation respectively, indicating a negative feedback role for NDR2 in the osteoclastogenesis. Myeloid NDR2-dificient mice (Lysm+NDR2f/f) showed lower bone mass and further exacerbated ovariectomy-induced or aging-related bone loss. Mechanically, NDR2 enhanced autophagy and mitophagy through mediating ULK1 instability. In addition, ULK1 inhibitor (ULK1-IN2) ameliorated NDR2 cKO-induced bone loss. Finally, we clarified a significant inverse association between NDR2 expression and the occurrence of osteoporosis in patients. In a word, NDR2-ULK1-mitophagy axis was a potential innovative therapeutic target for the prevention and management of bone loss.

Factors Affecting MARPE Success in Adults: Analysis of Age, Sex, Maxillary Width, and Midpalatal Suture Bone Density

Microimplant-assisted rapid palatal expansion (MARPE) is a technique widely used to treat transverse discrepancies in adult patients. The present study aims to examine how age, sex, maxillary width, and suture bone density might influence MARPE efficacy. It also analyzes bone density variations across the midpalatal suture regions. Materials and Methods: This retrospective study included 30 adult patients who underwent MARPE treatment. Pre- and post-treatment CT scans were analyzed to quantify the maxillary width and bone density measured in Hounsfield units (HUs) in the anterior, middle, and posterior nasal spine regions. Statistical analyses were carried out and included descriptive statistics, t-tests, and effect size calculations. Results: Younger patients (age 22.13 ± 4.58) had significantly higher success rates compared to older patients (aged 25.66 ± 4.67). No significant differences were found regarding sex or the initial maxillary width. Lower bone density in the middle and posterior nasal spine regions was correlated with higher success rates. Data showed that the anterior nasal spine exhibited higher bone density, but this finding did not affect treatment outcomes significantly. Conclusions: Age seems to be a crucial factor in MARPE success, with younger patients showing better outcomes. Regarding bone density, results showed that its values in the middle and posterior nasal spine regions could be a determinant of treatment success. On the contrary, sex and the initial maxillary width did not appear to affect outcomes. These findings emphasize the importance of preoperative assessments and the consideration of individual anatomical variations for optimal MARPE treatment planning.

Bone phenotyping of murine hemochromatosis models with deficiencies of Hjv, Alk2, or Alk3: The influence of sex and the bone compartment.

Osteopenia is frequently observed in patients with iron overload, especially in those with HFE-dependent hereditary hemochromatosis (HH). Interestingly, not all mouse models of HH show bone loss, suggesting that iron overload alone may not suffice to induce bone loss. In this study, the bone phenotypes of Hjv-/- and hepatocyte-specific Alk2- and Alk3-deficient mice as additional mouse models of HH were investigated to further clarify, how high iron levels lead to bone loss and which signaling mechanisms are operational. Neither male nor female 12-week-old Hjv-/- mice had an altered trabecular or cortical bone mass or bone turnover, despite severe iron overload. Male 12-month-old Hjv-/- mice even presented with a higher femoral trabecular bone volume compared to wildtype mice. Similarly, female mice with hepatocyte-specific Alk2 or Alk3 deficiency did not show an altered bone phenotype at 3, 6, and 12 months of age. Male hepatocyte-specific Alk3-deficient mice also had a normal trabecular bone mass at all ages analyzed, despite showing increased bone resorption and decreased bone formation parameters. Interestingly, hepatocyte-specific Alk2-deficient mice showed reduced femoral trabecular bone at 6 months of age due to suppressed bone formation. Cortical thickness at the femur was reduced in both, 6-month-old male hepatocyte-specific Alk2- and Alk3-deficient mice. Raising hepatocyte-specific Alk2-deficient male mice on an iron-deficient diet rescued the bone phenotype. Taken together, despite iron overload, trabecular bone microarchitecture was not altered in mice deficient of Hjv or Alk3. Only male hepatocyte-specific Alk2-deficient mice showed site-specific lower trabecular and cortical bone mass at the femur, which was dependent on iron. Thus, bone loss does not correlate with the extent of iron overload in these mouse models, but may relate to the amount of iron-loaded macrophages, as precursors of osteoclasts, in the bone marrow.

The Use of Osteogenon as an Adjunctive Treatment in Lower Leg Fractures.

Background: The goal of the orthopedic treatment of fractures is to achieve bone union as rapidly as possible in the largest possible number of patients and to minimize the number of complications. The purpose of this study was to assess if the use of Osteogenon would have a positive effect on radiological and clinical parameters in patients with lower leg bone fractures treated with the Ilizarov method. Methods: We evaluated 26 patients who had their lower leg bone fractures treated with the Ilizarov method and received Osteogenon at our clinic in the years 2021-2023. The control group comprised 25 patients with lower leg bone fractures treated with the Ilizarov method who did not receive Osteogenon. We assessed the following parameters: time to achieving bone union, bone union rate, time to resuming normal physical activity, time to achieving pain relief, the number of patients reporting pain relief, and the rate of complications. Results: The median time to achieve bone union after lower leg bone fracture treated with the Ilizarov method was shorter in the Osteogenon group (108.5 days) compared to the control group (134 days), p < 0.001. Bone union was achieved in all the patients in the Osteogenon group and in 96% of the patients in the control group; the difference was not statistically significant. The median time to resuming normal physical activity was shorter in the Osteogenon group (22.5 weeks) compared to the control group (27 weeks), p < 0.001. The median time to achieving pain relief was shorter in the Osteogenon group (21 weeks) compared to the control group (30 weeks), p < 0.001. The proportion of patients who reported pain relief was 88.46% in the group receiving Osteogenon and 76% in the control group; this difference was not statistically significant. The number of complications was lower in the Osteogenon group (8 patients; 30.77%) compared to the control group (15 patients; 60%), p = 0.035. Conclusions: The use of Osteogenon has a beneficial impact on the treatment of lower leg bone fractures with the Ilizarov method. Osteogenon shortens the time to achieve bone union. Moreover, the use of the ossein-hydroxyapatite complex helps reduce the number of complications and shortens the time to achieve pain relief and to resume normal activities.

Bone microarchitecture evaluated by HR-pQCT in Chinese adolescent and pediatric patients with X-linked hypophosphatemia.

X-linked hypophosphatemia (XLH) is the most common form of heritable hypophosphatemic rickets. Previous studies have found deteriorated bone microarchitecture in the XLH adults. Detailed studies on the skeletal microarchitecture of XLH adolescent and pediatric patients are still lacking. This study aimed to evaluate bone geometry, density, microarchitecture, stiffness in XLH adolescent and pediatric patients by using high-resolution peripheral quantitative computed tomography (HR-pQCT).Method: This study utilized HR-pQCT to assess bone geometry, density, microarchitecture, and stiffness in 106 Chinese adolescent and pediatric patients with XLH. Compared with the sex- and age-matched controls, XLH patients had significantly higher trabecular area (Tb.Ar), lower total volumetric bone mineral density (Tot.vBMD), lower cortical volumetric BMD (Ct.vBMD), and lower stiffness at both the distal radius and the tibia after adjusting for height and weight. Alkaline phosphatase Z score (ALP-Z), a marker to reflect the disease activity of rickets, was negatively correlated with Ct.vBMD and cortical thickness (Ct.Th) at the distal radius, and Ct.vBMD at the distal tibia, and positively correlated with cortical porosity (Ct.Po) at the distal tibia. We developed an online calculator to estimate Tb.Ar, Ct.vBMD, and stiffness of the distal tibia of XLH adolescent and pediatric patients based on clinical general characteristic and biochemical indicators. The bone microarchitecture of XLH adolescent and pediatric patients was deteriorated, and ALP-Z was negatively correlated with the skeletal quality of XLH adolescent and pediatric patients, especially in the cortical bone. HR-pQCT parameters can be estimated using clinical characteristics and biochemical indicators, which may assist physicians to monitor the disease progression in areas without HR-pQCT access.

Sex hormone deficiency in male and female mice expressing the Alzheimer’s disease-associated risk-factor TREM2 R47H variant impacts the musculoskeletal system in a sex- and genotype-dependent manner

Abstract The R47H variant of the Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) is a risk factor for Alzheimer’s disease in humans and leads to lower bone mass accrual in female but not male 12-month-old mice. To determine whether, as with aging, gonadectomy results in sex-specific musculoskeletal effects, gonad removal or SHAM surgery were performed in 4-month-old TREM2R47H/+ mice and wild type (WT) male and female littermates (n = 10-12/group), with sexes analyzed separately. Body weight was lower in males, but higher in females after gonadectomy, independently of their genotype. Gonadectomy also lead to decreased BMD in males at all sites and in whole body (total) and spine in female mice for both genotypes. Total and femur BMD was lower in gonadectomized male mice 6-weeks post-surgery, independently of the genotype. On the other hand, BMD was only lower in ovariectomized WT but not TREM2R47H/+ mice in all sites measured at this time point. Bone formation and resorption markers levels were not affected by orchiectomy, whereas CTX was higher 3 weeks after surgery and P1NP showed a tendency towards lower values at the 6 weeks timepoint only in ovariectomized WT mice. μCT analyses showed no differences resulting from gonadectomy in structural parameters in femoral cortical bone for either sex, but lower tissue mineral density in males of either genotype 6 weeks post-surgery. Nevertheless, biomechanical properties were overall lower in gonadectomized males of either genotype, and only for WT ovariectomized mice. Distal femur cancellous bone structure was also affected by gonadectomy in a genotype- and sex-dependent manner, with genotype-independent changes in males, and only in WT female mice. Thus, expression of the TREM2 R47H variant minimally alters the impact of gonadectomy in the musculoskeletal system in males, whereas it partially ameliorates the consequences of ovariectomy in female mice.

Using micro-CT to explore bone density variations in the skulls of the vulnerable Opsariichthys uncirostris uncirostris (Three-lips fish) during reproductive migration to a Lake Biwa tributary.

Not much is known about the changes in bone density due to fish reproductive migration. We used micro-CT and inferential statistics to determine whether the relative bone density in the skulls of adult Three-lips fish, that seasonally upstream migrated to a Lake Biwa tributary, changed across their known reproductive season. The relative bone density significantly decreased as standard length and condition factor (K) increased in both sexes. This negative relationship is likely due to age and hormonal effects in the fish. Results from the bone density analysis also revealed that male Three-lips fish had potentially lower relative bone density (although not significantly different) than females during peak reproductive migration, i.e., July to August. On average, male Three-lips fish are larger in length and weight than females, and in many species, females prefer larger males to smaller males, viewing their size as an indicator of genetic fitness and their ability to provide protection. Resources in the skulls of Three-lips males may be distributed in such a way that increases reproductive success, i.e., size at the expense of quality. In addition, individuals with slightly less dense bones, particularly males, appeared later than those with denser bones during the peak of the reproductive season. The high energy demands involved with aggression in males, often requires resource mobilization from various tissue compartments and could explain the slightly lower density in the latter half of the peak migration. Furthermore, Three-lips individuals that migrated earlier and later during the reproductive season may have more energy reserves than those that had been in the river for some time, hence the variable bone density between individuals. This study serves as a foundation for future studies on the effects of migration, changes in physiology and age on bone density analysis of Three-lips fish and other species in various ecosystems.

Impaired Bone Tissue Quality Associated with Inflammation in HIV-Immunological Non-Responders: A Cross-Sectional Analysis.

People with HIV (PWH) with poor immune response despite adequate antiretroviral treatment (ART) are susceptible to non-AIDS-related health issues. This study seeks to evaluate bone quality in Immunological Non-Responders (INRs) in comparison to those with proper immune response (IRs) using in vivo microindentation to quantify bone quality, in addition to conventional bone mineral density (BMD) evaluations. A cross-sectional study was conducted at Hospital del Mar in Barcelona from January 2019 to June 2023. Participants were matched in a 1:2-ratio (INRs:IR) based on age, sex, body mass index (BMI), and ART. Participants underwent bone quality assessment using in vivo microindentation, BMD and analysis of bone turnover and inflammation markers. Statistical analyses involved multivariable regression to adjust for potential confounding variables. A total of 159 PWH were included, 53 INRs and 106 IRs. INRs had worse bone quality, with lower median Bone Material Strength index (BMSi) compared to IRs (79 (76-87) vs. 86 (82-89); p<0.001), and similar BMD. INRs shown increased high-sensitive C-Reactive Protein levels with lower 25-(OH)-Vitamin D3. A significant negative correlation between inflammation and bone quality was found, especially noticeable in INRs. Multivariable linear regression shown that INR status is a major predictor of decreased bone quality, regardless of conventional risk factors. INRs condition is significantly associated with higher inflammatory levels, which may contribute to a deleterious effect on bone quality as measured by in vivo microindentation. Further studies are needed to confirm these results and to focus on non-AIDS comorbidities in this subgroup of PWH.

Risk factors for healing failure after arthroscopic rotator cuff repair in small to medium-sized tears: a retrospective cohort study.

To identify risk factors for tendon healing failure following arthroscopic rotator cuff repair (ARCR) in patients with small to medium-sized rotator cuff tears (RCTs). A retrospective study was conducted on 320 patients with RCTs who underwent arthroscopic repair between June 2018 and June 2021. All patients had at least 2 years of postoperative follow-up, with MRI scans at the final assessment. Based on MRI results, patients were categorized into the healing success group (Group A: types I-III) or the healing failure group (Group B: types IV-V). Variables associated with rotator cuff healing, including patient characteristics, baseline symptoms, imaging data, and surgery-related factors, were analyzed using univariate and multivariate logistic regression. Healing failure occurred in 54 of the 320 patients (16.9%). Functional status improved significantly across all patients (P < 0.05), irrespective of healing outcomes. Multifactorial analysis identified smoking (OR = 1.931, P = 0.028), diabetes (OR = 3.517, P = 0.038), lower bone mineral density (BMD) (OR = 1.551, P = 0.018), higher fatty infiltration (FI) (OR = 4.025, P = 0.009), and smaller acromiohumeral distance (AHD) (OR = 2.546, P = 0.006) as independent risk factors for healing failure. Smoking, diabetes, lower BMD, higher FI, and smaller AHD are independent risk factors for healing failure following ARCR.

A Longer Biliopancreatic Limb and Shorter Common Channel Enhance Weight Loss But May Have Harmful Effects in Mouse Models of Roux-en-Y Gastric Bypass.

RYGB consists of the Roux limb (RL), the biliopancreatic limb (BPL), and the common channel (CC). There is no consensus on the optimal limb lengths. Using a mouse model of RYGB, 30 diet-induced obese mice were divided into two groups with varying BPL and CC lengths: a standard BPL with a long CC (RYGB S) and a long BPL with a short CC (RYGB L). Additionally, 9 age-matched, lean control mice (LC) were also included in this study. RYGB S had limb lengths of RL = 17%, BPL = 24%, and CC = 59%. RYGB L had limb lengths of RL = 17%, BPL = 32%, and CC = 51%. RYGB S and RYGB L had 67% and 40% survival, respectively. Mortality in RYGB L included more instances where the cause of death was not apparent. RYGB L demonstrated greater weight loss, lower energy expenditure, and lower heart mass as compared to RYGB S. Both RYGB groups had lower epidydimal fat mass, spleen mass, and bone mineral density compared to LC. RYGB L had a lower heart mass than RYGB S and LC. While the relative abundance of Eubacterium was lower in RYGB L than in RYGB S, no other gut microbiota differences were observed. A longer BPL with a shorter CC induces greater weight loss but may lead to adverse effects, including lower heart mass, reduced bone density, and deaths with unclear causes.

Enhancing fixation stability in proximal humerus fractures: screw orientation optimization in PHILOS plates through finite element analysis and biomechanical testing

The optimal treatment strategy for proximal humerus fractures (PHFs) is debatable owing to the relatively high failure rate of locking plates. Optimizing implants may enhance the fixation stability of PHFs and reduce the rate of mechanical failures. We developed a finite element (FE) model to simulate the treatment of PHFs with Proximal Humerus Internal Locking System (PHILOS) plates. The model evaluated the average bone strain around the screw tips under vertical loading (as an alternative to the risk of cyclic screw cutout failure verified through biomechanical testing) to minimize this strain and maximize predicted fixation stability. After determining the optimal screw configuration, further FE analysis and in vitro biomechanical testing were conducted on both standard and optimized PHILOS screw orientation to assess whether the optimized plates have biomechanical advantages over the standard plates. The FE-based optimized configuration exhibited significantly lower bone strain around the implant than the standard PHILOS screw orientation (− 17.24%, p < 0.001). In both FE analysis and in vitro biomechanical testing, the optimized PHILOS plates achieved significantly lower average bone strain around the screws (p < 0.05), more uniform stress distribution, and greater structural stiffness (p < 0.05) than the standard PHILOS screw orientation. Our results show that biomechanical performance of the PHILOS plates can be improved by altering the orientation of the locking screws. This approach may be useful for future patient-specific design optimization of implants for other fractures.

A Comparative Analysis of Marginal Bone Loss of Hydrophilic Implants versus non-hydrophilic Implants placed on Edentulous Ridge in Mandibular Implant Overdenture

Objective: This systematic review aims to evaluate the clinical outcomes of hydrophilic versus non-hydrophilic dental implants, focusing on key parameters such as marginal bone loss, implant survival rates, and bone-to-implant contact (BIC). The review seeks to determine whether hydrophilic surfaces offer a significant clinical advantage and to identify areas for future research. Materials and Methods: A comprehensive literature search was conducted across databases including PubMed, Scopus, and Cochrane Library, covering studies published from 2015 to 2023. Inclusion criteria were randomized controlled trials, prospective and retrospective studies, and in vivo experiments comparing hydrophilic and non-hydrophilic implants. Data extraction focused on outcomes related to marginal bone loss, implant survival, and BIC. Studies were assessed for methodological quality using the Cochrane Risk of Bias tool and the Newcastle-Ottawa Scale. Results: A total of 10 studies met the inclusion criteria, encompassing 450 implants in various clinical settings. The findings revealed that hydrophilic implants generally demonstrated lower marginal bone loss and higher BIC percentages compared to non-hydrophilic implants, with survival rates exceeding 97% in most studies. However, the differences in outcomes were not consistently significant across all studies, highlighting variability in results based on implant type, patient demographics, and follow-up duration. Conclusion: Hydrophilic implants show potential advantages in terms of marginal bone loss and BIC, particularly in early loading protocols. However, further long-term studies with standardized methodologies are needed to confirm these benefits and optimize clinical guidelines for implant selection.

Could point-of-care bioimpedance analysis be another tool in the prevention of osteoporotic fractures?

A treatment gap exists in osteoporosis, with people at risk of fracture often not identified. Dual X-Ray Absorptiometry is the gold standard technique for the identification of low bone mass, but it is not always easily accessible. Bioimpedance analysis (BIA) is a non-invasive, safe and portable technology, which can provide a calculated estimate of bone mass. However, the validity of using BIA in the assessment of bone health is largely unknown. The objective of this study was to examine BIA-derived bone mass (BBM) data from a local population, with the aim of exploring its potential for use as a preliminary osteoporosis screening tool.A convenience sample of 124 participants (40 males, 84 females) was recruited from the local population. BIA was performed on participants according to standard procedures. BBM data was analysed in relation to weight, height, sex, age and BMI. Data was analysed using ANOVA, hierarchial regression, and bivariate correlation as appropriate.Weight was strongly associated with BBM (R2 = 0.637, p < 0.001), providing the greatest contribution to variance, of the factors examined. BBM was also positively associated with height, in a model that included weight (ΔR2 = 0.218, p < 0.001). Females had a significantly lower bone mass than males, independent of weight and height (ΔR2 = 0.055, p < 0.001). There was a small negative association of BBM with age, in a model that included weight and sex (ΔR2 = 0.011; p = 0.002). A positive correlation between BMI and BBM was found in both males (rs(38) = 0.482, p = 0.002), and females (rs(82) = 0.565, p < 0.001). The finding that BBM values are associated with factors known to be relevant to fracture risk, provides a rationale to perform further studies to investigate if BBM values could have validity for point-of-care assessment of bone health.

Comparative study of 3D contact area percentage between zygomatic implant and bone in different surgical approaches: clinical and biomechanical perspectives

BackgroundZygomatic implants, either alone or in combination with dental implant placement, have emerged as a viable surgical option for elderly patients with severe bone atrophy for occlusal restoration. This study aims to examine the biomechanical impact of the three-dimensional contact area between zygomatic implants and bone on biomechanics under different surgical methods. Material and MethodsUsing Cone Beam Computed Tomography (CBCT) images from 10 patients with severe bone atrophy, we reconstructed 3D maxillary bone models and created corresponding 3D zygomatic implant models. Two distinct surgical methods (extramaxillary or intrasinus approaches) were employed based on the position and angle of the zygomatic implant for each patient. The 3D bone-to-implant contact percentage (BIC%) was calculated, and finite element analysis with nonlinear contact was conducted to assess the relationship between 3D BIC% and surrounding bone stress for both surgical methods. ResultsThe 3D BIC% of extramaxillary approach (57.63 %) and intrasinus approach (56.49 %) for total bone (including cortical and cancellous bone) was similar (P = 0.425) in zygomatic implant surgery. In contrast, the intrasinus method exhibited higher 3D BIC% in cortical bone contact (28.08 %) compared to the extramaxillary approach (21.92 %) (P = 0.011). The correlation between 3D BIC% and high bone stress was stronger in the intrasinus approach, likely due to increased contact area in cortical bone. ConclusionThe intrasinus approach led to lower bone stress and a more robust correlation between bone stress and 3D BIC%, particularly in cortical bone contact. Importantly, the coverage area of cortical bone surrounding the zygomatic implant significantly influenced biomechanical performance of the zygomatic implants.

In-utero exposure to tenofovir-containing pre-exposure prophylaxis and bone mineral content in HIV-unexposed infants in South Africa.

Tenofovir disoproxil fumarate (TDF) is a common drug of choice for pre-exposure prophylaxis (PrEP) or as a combination HIV treatment for pregnant women. In-utero exposure to TDF was found to be associated with lower bone mineral content (BMC) in HIV-exposed uninfected neonates. Data for infants born to women taking TDF-PrEP are lacking. The CAP016 randomized control trial was conducted in South Africa between September 2017 and August 2021 and pregnant women either initiated TDF/FTC PrEP in pregnancy (Immediate PrEP arm-IP) or at cessation of breastfeeding (Deferred PrEP arm-DP). In a secondary data analysis, we evaluated BMC in HIV-unexposed infants in the CAP016 trial in the first 18 months of life in association with maternal TDF-PrEP use during pregnancy. Infants born to women randomized to the IP arm or DP arm in the CAP016 clinical trial had BMC measurements of the whole body with head (WBH) and lumbar spine (LS) by dual energy X-ray absorptiometry (DXA) at 6, 26, 50 and 74 weeks. Of 481 infants born to women enrolled in the CAP016 clinical trial, 335 (69.6%) infants had a minimum of one DXA scan of the WBH and LS between 6 and 74 weeks of age (168 IP and 167 DP). Women in the IP arm received TDF-FTC PreP for a median of 19 weeks between initiation in pregnancy and delivery. Using a mixed linear regression model and adjusted for gestational age, sex and ever-breastfed, the mean difference (95% CI) for BMC of the WBH between IP and DP arms were -0.74 (-8.69 to 7.20), -1.26 (-10.75 to 8.23), -9.17 (-20.02 to 1.69) and 5.02 (-6.74 to 16.78) g at 6, 26, 50 and 74 weeks (p = 0.283). Mean differences in BMC of the LS were 0.07 (-0.10 to 0.23), 0.02 (-0.18 to 0.22), -0.14 (-0.36 to 0.09) and 0.14 (-0.11 to 0.38) g at 6, 26, 50 and 74 weeks, respectively (p = 0.329). In a randomized controlled trial, there were no differences in BMC of the WBH and LS between infants exposed to in-utero TDF-FTC PrEP and unexposed infants in the first 18 months of life.

Lactobacillus rhamnosus 1.0320 Postbiotics Ameliorate Dextran Sodium Sulfate-Induced Colonic Inflammation and Oxidative Stress by Regulating the Intestinal Barrier and Gut Microbiota.

Probiotics are increasingly being used as an adjunctive therapy for ulcerative colitis. However, some safety issues have been found in the clinical use of probiotics. Postbiotics have attracted much attention due to their storage stability, safety, and potential functions, but the dose required to exert a significant protective effect is unknown. Therefore, this study evaluated the potential mechanisms of different doses (200, 400, 600 mg/kg) of Lactobacillus rhamnosus 1.0320 postbiotics (1.0320P) in alleviating dextran sodium sulfate (DSS)-induced colitis. The study revealed that 1.0320P could mitigate DSS-induced colitis with signs of reductions in the disease activity index, amelioration of colon tissue damage, decreased secretion of proinflammatory cytokines, reduced oxidative stress levels, and lower bone marrow peroxidase activity. Furthermore, high dose of 1.0320P could upregulated the expression of key proteins in the Nrf2/ARE pathway (NQO1, Nrf2, and HO-1) and downregulated the expression of key proteins in the TLR4/NF-κB signaling pathway (TLR4, MyD88, and NF-κB p65). In addition, high dose of 1.0320P could upregulate the expression of tight junction (TJ) proteins including ZO-1, Occludin, and Claudin-1, contributing to the restoration of the intestinal mucosal barrier function. Additionally, 1.0320P was found to effectively correct imbalances in the intestinal microbiota and enhance the synthesis of short-chain fatty acids (SCFAs), thereby regulating homeostasis in the intestinal internal environment. Overall, our findings suggest that postbiotics could ameliorate colonic inflammation while being somewhat dose-dependent. This study provides new insights into postbiotics as a next-generation biotherapeutic agent for the treatment of ulcerative colitis and even other diseases.

Implant Stability and Marginal Bone Changes Associated with Different Staged Ridge-splitting Techniques Using Piezoelectric Surgery in Atrophic Posterior Mandible:A Comparative Study.

The ridge-splitting technique is considered one of the common solutions for horizontal ridge augmentation. The study evaluated implant stability and marginal bone loss after two vs three staged ridge-splitting technique. Twelve dental implants were inserted into 10 patients through staged ridge-splitting approach. In group I, six dental implants were inserted through a full mucoperiosteal flap reflection and bony incision. After 3 weeks, a closed buccal plate expansion and grafting were done, with sequential implant insertion 3 months later. While in group II, six dental implants were inserted through the same procedure as the first stage. Then bone expansion, grafting, and implant insertion were made at the second stage. All implants were loaded after 3 months and assessed clinically regarding implant stability and radiographically through marginal bone loss. One-way ANOVA test was used. Implant stability quotient (ISQ) values showing highly significant difference (p = 0.003) were recorded at implant placement. In contrast, no statistically significant differences were recorded among the studied groups at the other assessment time intervals (p = 0.219, 0.366, and 0.394, respectively). Meanwhile, group II reported lower marginal bone loss values than group I with a highly significant difference between both groups over all assessment time intervals (p = 0.001, 0.008, and 0.002, respectively). Two staged ridge-splitting technique offered a shorter treatment time with lower marginal bone loss and comparable implant stability. Two-staged ridge-splitting technique provided less patients' recall visits with a less surgical intervention than the three-staged technique. This may be prospectively reflected in further research for its clinical merits. How to cite this article: Elsaieed MT, El-belasy FA, Ibraheim SA, et al. Implant Stability and Marginal Bone Changes Associated with Different Staged Ridge-splitting Techniques Using Piezoelectric Surgery in Atrophic Posterior Mandible: A Comparative Study. J Contemp Dent Pract 2024;25(7):661-668.