Bone Thickness Research Articles

A bone graft from the tibial resection or patella that rectified a tibial over-resection reliably healed and improved clinical outcome scores: A retrospective study of kinematically aligned TKA.

During kinematically aligned (KA) total knee arthroplasty (TKA), the surgeon may need to rectify an over-resection of the medial, lateral or posterior tibia. This study tested the hypothesis that a bone graft taken from the tibial resection or patella and impacted beneath a tibial baseplate would heal, regardless of whether the tibial component and knee were in outlier ranges according to mechanical alignment (MA) criteria. The study also tested the hypothesis that the Oxford Knee Score (OKS) and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) would improve beyond the substantial clinical benefit and that the source and thickness of the bone graft would not influence their improvement. This retrospective study radiographically assessed the healing of a bone graft from the tibial resection (n = 19) or patella (n = 10) in 29 KA TKAs (18 females, mean age 65 years). The tibial component and knee alignment were categorized as in-range or outliers based on reported MA criteria for bone graft healing and implant survival. The one-sample t test identified differences in the improvement of the OKS and KOOS JR from their reported substantial clinical benefit of 16 and 20 points, respectively. At an average follow-up of 37 months, all bone grafts healed even though ≥55% of tibial components and 34% of knees were varus outliers according to MA criteria for bone healing and implant survival. Amongst the 29 patients, the mean OKS and KOOS JR improvements of 25 ± 11 and 47 ± 21 points, respectively, surpassed the threshold of their respective substantial clinical benefit (p < 0.01) and were not influenced by the bone graft's source and thickness (p ≥ 0.51). During cemented KA TKA, the surgeon can use a bone graft from the tibial resection or patella to rectify a tibial over-resection. This technique led to consistent bone healing and improved outcome scores. Level IV.

Changes in the Articular Cartilage Thickness in Patients with Symptomatic Rotator Cuff Tears: A Prospective Study with a Mean 5-Year Follow-Up.

Objectives: The purpose of this study was to prospectively investigate the progression of cartilage thinning in patients with symptomatic rotator cuff tears using MRI. Methods: Two hundred twenty-five consecutive patients with symptomatic rotator cuff tears visited our institute between 2009 and 2019. Of these, 28 shoulders of 27 patients (mean age, 65 years) who underwent at least two magnetic resonance imaging (MRI) examinations were prospectively enrolled. They all received conservative treatment. The mean follow-up was 67 months. Changes in cartilage thickness and the combined cartilage and subchondral bone thickness at the initial and final MRI were measured using a RadiAnt DICOM-viewer (Medixant, Poznan, Poland). The cartilage thickness of the humeral head was measured in the oblique coronal and sagittal images. The glenoid cartilage was measured in the axial and oblique coronal images. Results: At an average period of 5 years, 12 of 28 shoulders (42%) showed more than a 30% decrease in cartilage thickness in the humeral head. The glenoid showed cartilage thinning in only one shoulder (4%). In the humeral head, progressive cartilage thinning was seen mainly in the anterior and posterior parts of the humeral head in the sagittal plane. In the glenoid, progressive cartilage thinning was seen on the entire surface except the posterior area. There was no significant difference in cartilage thickness between the first and final follow-ups for both the humeral head and the glenoid. Conclusions: A total of 12 of 28 shoulders (42%) showed more than a 30% decrease in cartilage thickness in the humeral head, which was mainly observed in the anterior and posterior areas of the humeral head.

Evaluation of tooth angulation and vestibular bone table in anterosuperior teeth prior to immediate implant placement. Descriptive study with cone beams computed tomography

The present study evaluated dental angulation and vestibular bone table thickness in anterosuperior teeth in order to optimize immediate implant placement. Cone beam computed tomography (CBCT) scans of 30 teeth in 15 patients were analyzed, considering the distance between the amelo-cementary boundary and the bone crest, as well as tooth angulation. The results indicated that bone thickness varies at different heights and that the average angulation is greater in men than in women. However, a clear correlation between bone thickness and dental angulation could not be established due to the sample size. The study highlights the importance of these factors in achieving an esthetic and functional result in implant dentistry, suggesting the need for further research to validate these findings and optimize implantation techniques.

Anatomical Factors Affecting the Complexity of Maxillary Sinus Augmentation in Saudi Patients: A Cone Beam Computed Tomography (CBCT) Study.

This study aims to evaluate the anatomical variations of the maxillary sinus and determine the difficulty score of maxillary sinus augmentation (MSA) in Saudi patients seeking dental implant rehabilitation of the posterior maxilla using cone beam computed tomography (CBCT). CBCT records of dental patients seeking treatment at a University Dental Teaching Hospital between 2019 and 2023 were retrospectively analyzed. Measurements were obtained from CBCT images, including membrane thickness, sinus width, buccal bone thickness, presence of maxillary sinus septa, residual alveolar ridge height, angle of the buccolingual sinus wall, and the presence of the alveolar antral artery (AAA). The difficulty score for MSA was determined based on these anatomical factors. A total of 107 maxillary sinuses in 86 subjects were evaluated. The average membrane thickness was 2.23 mm, with males showing significantly higher thickness than females. Sinus septa were found in 54 (50.5%) sinuses, with 18 (17%) of sinuses having interfering septa. Twenty-three (21.5%) sinuses had a residual alveolar ridge height of less than 4 mm. The average angle of the buccolingual sinus wall was 79.39°, indicating a high prevalence of wide-shaped sinuses. The average sinus width was 14.09 mm, with 55 sinuses (51.4%) less than 15 mm. The average buccal bone thickness was 1.07 mm, in29 (27%) sinuses, the thickness was more than 2 mm. AAA was visualized in 60 (56%) of sinuses, with 45 (42%) of sinuses having AAA interfering with the MSA window. In this study, most sinuses were classified as simple or moderate difficulty, with higher membrane thickness, presence of septa, and AAA being the significant risk factors for complications. These findings provide valuable insights for implant surgeons in Saudi patients seeking dental implant rehabilitation of the posterior maxilla, enabling them to anticipate and minimize potential complications during MSA procedures.

Craniometric values of the domestic horse (Equus caballus) in the context of mechanical stunning anatomy – preliminary studies

Abstract This study presents selected craniometric measurements compared to the thickness of the frontal bone of the domestic horse. The study was carried out on 10 domestic horse skulls from the collection of the Institute of Veterinary Medicine at Nicolaus Copernicus University in Torun. On the basis of the results obtained, correlation was carried out according to Pearson’s method, and a trend graph was created, showing the relationship of individual values to frontal bone thickness. The present research is a preliminary study, and further research, based on a larger study group, can help minimize their suffering. According to the study, the greatest positive correlation and relationship is shown by the length between the alveolar borders of the third incisor, while a negative correlation was found for the width of the cerebrocranium. In the future, it is possible to develop a formula to estimate the thickness of the frontal bone in horses.

A Randomized Controlled Trial on the Timing of Soft-Tissue Augmentation in Immediate Implant Placement: Hard-Tissue Changes and Clinical Outcome.

To assess the impact of the timing of soft-tissue augmentation (STA) on mean buccal bone changes following immediate implant placement (IPP) in the anterior maxilla. Patients with a failing tooth and intact buccal bone wall in the anterior maxilla (15-25) were enrolled in this randomized controlled trial. Following single IIP and socket grafting, they were randomly allocated to the control group (immediate STA performed during the same surgical procedure) or the test group (delayed STA performed 3 months later). Implants were placed with a surgical guide and immediately restored with an implant-supported provisional crown. Changes in bone dimensions were assessed using superimposed CBCT images taken prior to surgery and at 1-year follow-up. Clinical outcomes were registered at 1-year follow-up. Twenty patients were randomized to each group (control: 16 females, 4 males, mean age 57.6; test: 9 females, 11 males, mean age 54.2). Ten patients in the control group and 13 patients in the test group had a thick bone wall phenotype. Estimated marginal mean horizontal buccal bone loss at 1 mm below the implant shoulder was -0.553 and -0.898 mm for the control and test group, respectively. The estimated mean difference of 0.344 mm in favour of the control group was not significant (95% CI: -0.415 to 1.104; p = 0.363). Also at all other horizontal and vertical levels, no significant differences could be observed between the groups. The combination of socket grafting and STA enabled counteraction of any buccal soft-tissue loss (≥ 0 mm) at 1 mm below the implant shoulder in 82% of the patients in the control group and in 75% of the patients in the test group (p = 1.000). The clinical outcome was favourable in both groups, yet implants in the control group demonstrated slightly less marginal bone loss (median difference 0.20 mm; 95% CI: 0.00-0.44; p = 0.028). In patients with an intact and mainly thick buccal bone wall in the anterior maxilla, the timing of STA following IIP had no significant impact on mean buccal bone loss. ClinicalTrials.gov identifier: NCT05537545.

Changes in Periodontal Tissues With Periodontally Accelerated Orthodontics: A Systematic Review and Meta-Analysis.

Periodontally accelerated orthodontic (PAO) therapy has been found to increase hard tissue, helping to decrease orthodontic relapse rates and improve retention capacity. The aim of this study was to synthesize available evidence on clinical and tomographic changes in periodontal tissues when using PAOtechniques. A systematic review with meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and registered in the International Prospective Register of Systematic Reviews (PROSPERO). The search was carried out in PubMed, Embase, Cochrane, Web of Science, Scopus, and Google Scholar. Randomized and non-randomized clinical trials comparing PAO versus conventional orthodontics were included. Quality assessment was performed using the Downs & Black scale, and the risk of bias was assessed using the revised Cochrane risk-of-bias tool. Mean differences and 95% confidence intervals (CIs) were calculated, and the mean difference was divided by a t-test. During the initial search, 465 studies were identified. Five articles studying 130 patients were included, which assessed both clinical and tomographic changes, along with treatment duration. PAO was administered to patients with skeletal class III in three studies, to class II patients in one study, and to individuals with dental crowding in another study. Two studies showed a moderate risk of bias, and the rest showed a low risk. The meta-analysis revealed a vestibular bone thickness increase of 0.32 mm (0.56-008; P = 0.008), a reduction of 3.12 mm (2.15-4.08; P= 0.001) in gingival retraction, and a treatment duration that was 7.07 months (8.79-5.36;P = 0.001) shorter in patients subjected to PAO compared to those undergoing conventional orthodontic treatment. Considering the limitations of the study and acknowledging that definitive conclusions cannot be drawn, the findings suggest that treatment time decreased in patients undergoing PAO, with an increase in vestibular bone thickness and less gingival retraction observed in those undergoing this intervention.

Effectiveness of using implant fixture as a ridge expander.

Adequate bone thickness around dental implants is vital for their stability and to reduce resorption. This study evaluated the ability of implant fixtures to serve as ridge expanders by measuring width changes pre- and post-implantation. Measurements including initial alveolar bone width, post-osteotomy width, post-expansion width, and buccal bone thickness were recorded for patients undergoing implant placement. Bone quality was assessed using established criteria. Of the 102 subjects (52% male, 48% female), significant ridge width increases at 0mm and 2mm levels were noted (p < 0.05). Larger implant diameters resulted in greater ridge expansion. Absence of prior augmentation was linked to higher bone quality (B = -1.684, p = 0.001), explaining 15% of bone quality variance. Ridge expansion effects also correlated with the site, implant diameter, and design. Dental implant fixtures can effectively expand the ridge, with expansion influenced by implant diameter, anatomical location, prior augmentation, and implant design. These factors must be considered for tailored treatment planning in implant dentistry. This study's clinical relevance lies in its exploration of the potential benefits of dental implant fixtures can effectively to expand the ridge taking into consideration implant diameter, anatomical location, prior augmentation, and implant design.

Impact of labially inclined implant axes on immediate implant placement and provisionalization in anterior maxilla: A prospective cohort study.

To investigate whether a labially inclined implant axis compromises the clinical outcomes of immediate implant placement and provisionalization (IIPP) in the anterior maxilla. Patients with unsalvageable central or lateral maxillary incisors were enrolled. IIPP with simultaneous connective tissue graft (CTG) was performed in all participants. In the control group, the alveolar ridge had a long axis aligned with the tooth, which ensured that the immediate implant was aimed at the incisor edge or the cingulum of future restoration. The test group had a large angle between the axes of the ridge and tooth. To avoid bone fenestration, the implants were placed labially inclined and emerged from the labial side of future restoration. Intra-oral scanning and cone-beam computed tomography were performed to record soft and hard tissue profiles at baseline and 1 year later. Soft tissue stability, bone remodeling, and pink esthetic score (PES) were evaluated and compared between two groups. Thirty-nine participants (19 tests and 20 controls) completed the study. At 1-year post-surgery, the mid-facial gingival margin migrations were 0.85 ± 0.37 mm (test) and 0.81 ± 0.33 mm (control), without significant differences. No differences were identified in buccal profile alteration, linear ridge reduction, buccal bone thickness, or PES scores. The test group demonstrated thinner buccal soft tissue at the crestal level than the control group. When large tooth-ridge angulation presented, labially inclined implant, avoiding buccal ridge fenestration in IIPP with CTG, did not compromise the clinical outcome in short term.

Morphometric Analysis of the Mandibular Canal and Its Anatomical Variants in a Chilean Subpopulation: Cone Beam Computed Tomography Study.

The inferior alveolar nerve (IAN), contained within the mandibular canal (MC), is a structure prone to damage in clinical and surgical procedures on the mandible. This study aimed to analyze the MC morphology and its anatomical variants in a Chilean subpopulation using cone beam computed tomography (CBCT). In total, 342 images from patients with the following parameters were observed: 120 kV, 9 mA, field of view 12 × 9 MC, and voxel size 0.12 mm. The average length of the MC recorded a mean value of 70.493 ± 4.987 mm on the right side and 70.805 ± 5.177 mm on the left side. The location of the mental foramen (MF) was most frequently found between the mandibular first and second premolar. The greatest bone thickness was found at the level of the basilar border of the 2MPM. The root closest to the MC was distal from the mandibular second molar. The lowest thickness was in the lingual area at 1MM. The prevalence of the anterior loop (AL) (61.5%) and the retromolar canal (RC) (17.5%) showed no significant differences between men and women. The results obtained showed that the morphology of the MC in the Chilean subpopulation can vary.

Advanced 3D-DXA insights into bone density changes in hyperparathyroidism

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

In vivo analysis of hybrid hydrogels containing dual growth factor combinations, and skeletal stem cells under mechanical stimulation for bone repair

Bone tissue engineering requires a combination of materials, cells, growth factors and mechanical cues to recapitulate bone formation. In this study we evaluated hybrid hydrogels for minimally invasive bone formation by combining biomaterials with skeletal stem cells and staged release of growth factors together with mechanotransduction. Hybrid hydrogels consisting of alginate and decellularized, demineralised bone extracellular matrix (ALG/ECM) were seeded with Stro-1+ human bone marrow stromal cells (HBMSCs). Dual combinations of growth factors within staged-release polylactic-co-glycolic acid (PLGA) microparticles were added to hydrogels to mimic, in part, the signalling events in bone regeneration: VEGF, TGF-β3, PTHrP (fast release), or BMP-2, vitamin D3 (slow release). Mechanotransduction was initiated using magnetic fields to remotely actuate superparamagnetic nanoparticles (MNP) targeted to TREK1 ion channels. Hybrid hydrogels were implanted subcutaneously within mice for 28 days, and evaluated for bone formation using micro-CT and histology. Control hydrogels lacking HBMSCs, growth factors, or MNP became mineralised, and neither growth factors, HBMSCs, nor mechanotransduction increased bone formation. However, structural differences in the newly-formed bone were influenced by growth factors. Slow release of BMP-2 induced thick bone trabeculae and PTHrP or VitD3 increased bone formation. However, fast-release of TGF-β3 and VEGF resulted in thin trabeculae. Mechanotransduction reversed the trabecular thinning and increased collagen deposition with PTHrP and VitD3. Our findings demonstrate the potential of hybrid ALG/ECM hydrogel–cell–growth factor constructs to repair bone in combination with mechanotransduction for fine-tuning bone structure. This approach may form a minimally invasive reparative strategy for bone tissue engineering applications.

The Hounsfield Unit Values of Talar Subchondral Bone Predict Articular Cartilage Degeneration in Patients With Ankle Osteoarthritis.

Therapeutic strategies for ankle osteoarthritis (OA) are determined based on OA staging, alignment, and articular cartilage conditions. However, it is difficult to evaluate the degeneration of the remaining cartilage using imaging modalities. Subchondral bone plays a crucial role in maintaining cartilage homeostasis. Measurement of local Hounsfield unit (HU) values allows for the quantitative assessment of small changes in the subchondral bone. This study aimed to evaluate a relationship between the HU values of the subchondral bone and the histologic findings of articular cartilage in ankle OA. The talar articular surface was harvested from 14 ankles during arthroplasty. The talus was divided into anterior, middle, and posterior parts, and histologic specimens were prepared. Safranin O staining was performed and histologic findings were evaluated using the modified Mankin score. The regions of interest (ROIs) were set in the medial, central, and lateral regions of the specimens and computed tomography (CT) images, and the relationship between the HU values and histologic findings was analyzed. As OA progressed, cartilage defects increased. In conjunction with cartilage degeneration, the subchondral bone plate thickened, and the HU values increased. The HU value significantly and positively correlated with the modified Mankin score (r = 0.756), subchondral bone thickness (r = 0.674, P < .01), and trabecular bone area (r = 0.637). The cutoff HU values were 594 (sensitivity, 0.813; specificity, 0.944) for 3 points and 727 (sensitivity, 0.929; specificity, 0.782) for 11 points on the modified Mankin score. Significant correlations between HU values and cartilage degeneration in ankle OA were noted. Measuring HU values on CT images can be useful for evaluating the joint surface condition, including histologic findings of the remaining cartilage.

Targeting CDC42 reduces skeletal degeneration after hematopoietic stem cell transplantation

AbstractOsteopenia and osteoporosis are common long-term complications of the cytotoxic conditioning regimen for hematopoietic stem cell transplantation (HSCT). We examined mesenchymal stem and progenitor cells (MSPCs), which include skeletal progenitors, from mice undergoing HSCT. Such MSPCs showed reduced fibroblastic colony-forming units frequency, increased DNA damage, and enhanced occurrence of cellular senescence, whereas there was a reduced bone volume in animals that underwent HSCT. This reduced MSPC function correlated with elevated activation of the small Rho guanosine triphosphate hydrolase CDC42, disorganized F-actin distribution, mitochondrial abnormalities, and impaired mitophagy in MSPCs. Changes and defects similar to those in mice were also observed in MSPCs from humans undergoing HSCT. A pharmacological treatment that attenuated the elevated activation of CDC42 restored F-actin fiber alignment, mitochondrial function, and mitophagy in MSPCs in vitro. Finally, targeting CDC42 activity in vivo in animals undergoing transplants improved MSPC quality to increase both bone volume and trabecular bone thickness. Our study shows that attenuation of CDC42 activity is sufficient to attenuate reduced function of MSPCs in a BM transplant setting.

Male-female spatio-temporal differences of age-related bone changes show faster bone deterioration in older women at femoral regions associated with incident hip fracture.

A better understanding of how age-related bone loss affects the fracture-prone regions of the proximal femur could lead to more informed fracture-prevention strategies. Therefore, the aim of this work was to assess the spatio-temporal distribution of bone deterioration in older men and women with aging. A subset of 305 men (74.87 ± 4.76years; mean ± SD) and 371 age-matched women (74.84 ± 4.71years) with no history of fracture was randomly selected from the Age, Gene/Environment Susceptibility-Reykjavik study. Quantitative computed tomography (QCT) scans of the left proximal femur obtained at baseline and at 5.2 ± 0.4years follow-up were processed to assess local changes in volumetric bone mineral density (vBMD), cortical bone thickness (Ct.Th), and internal bone structure using voxel-based morphometry (VBM), surface-based statistical parametric mapping (surf-SPM), and tensor-based morphometry (TBM). Local parametric changes within each sex and sex differences in these changes were statistically assessed using linear mixed effects models allowing for baseline and time-varying covariates, yielding Student's t-test and p-value statistical maps of the proximal femur. The statistical maps indicated regions with significant parametric changes in each sex and with significant different parametric changes between older men and older women with aging. Older women manifested significantly larger losses in vBMD, (Ct.Th), and structure than older men, and they did so in regions where deficiency in these parameters has been associated with incident hip fracture. Using longitudinal QCT scans of the proximal femur and Computational Anatomy, we provided new insights into the higher fracture rates of the proximal femur in older women compared with men of similar age providing new information on the pathophysiology of osteoporosis.

To evaluate the cortical bone thickness for ideal placement of infrazygomatic crest (IZC) and mandibular buccal shelf (MCS) bone screws in patients with different facial pattern using cone-beam computed tomography (CBCT)

This study aimed to measure the cortical bone thickness at different anatomical sites of InfraZygomatic Crest and Mandibular Buccal Shelf region for the ideal placement of IZC and MBS screws respectively in patients with different facial patterns using CBCT.Total participants were divided into 3 groups- GROUP A: horizontal growth pattern (FMA &amp;#60;22°); GROUP B: average growth pattern (FMA 22°-28°); GROUP C: vertical growth pattern(FMA &amp;#62;28°). Sixty CBCT images were taken into consideration. They were converted into standard DICOM format. Bone thickness were measured in the InfraZygomatic Crest (IZC) of the maxilla and in the Mandibular Buccal Shelf (MBS) region of the mandible using the Kodak CareStream CS 9300 Software.The results indicate that there was a highly statistical significant difference seen in the overall cortical bone thickness of IZC and MBS at various anatomical sites. The highest mean thickness was found to be at the MB70◦ maxillary 1st molar and distal root of the mandibular 1st molar. There was no difference in the bone thickness at the IZC region and at the MBS region seen between the horizontal and vertical facial patterns whereas the average facial patterns show the highest mean thickness but was not statistically significantThe study conducted on the Indian population yielded results demonstrating the possibly appropriate position for the IZC bonescrews and MBS bonescrews suggested that placing the IZC bonescrews at the mesiobuccal root of the maxillary 1st molar at an angulation of 70◦ and the MBS bonescrews at the distal root of the mandibular 1st molar at 11mm from the cementoenamel junction irrespective of the facial patterns could provide positive results.

Immediate single-tooth implant placement in bony defect sites: A 10-year randomized controlled trial.

It is unclear whether an intact buccal bony plate is a prerequisite for immediate implant placement in postextraction sockets. The aim of this 10-year randomized controlled trial was to compare peri-implant soft and hard tissue parameters, esthetic ratings of, and patient-reported satisfaction with immediate implant placement in postextraction sockets with buccal bony defects ≥5mm in the esthetic zone versus delayed implant placement after alveolar ridge preservation. Patients presenting a failing tooth in the esthetic region and a buccal bony defect ≥5mm after an extraction were randomly assigned to immediate (Immediate Group, n=20) or delayed (Delayed Group, n=20) implant placement. The second-stage surgery and provisional restoration placement occurred 3months after implant placement in both groups, followed by definitive restorations 3months thereafter. During a 10-year follow-up period, marginal bone levels (primary outcome), buccal bone thickness, soft tissue parameters, esthetics, and patient-reported satisfaction were recorded. The mean marginal bone level change was -0.71±0.59mm and -0.36±0.39mm in the Immediate Group and the Delayed Group after 10years (p=0.063), respectively. The secondary outcomes were not significantly different between both groups. Marginal bone level changes, buccal bone thickness, clinical outcomes, esthetics, and patients' satisfaction following immediate implant placement, in combination with bone augmentation in postextraction sockets with buccal bony defects ≥5mm, were not statistically different to those following delayed implant placement after ridge preservation in the esthetic zone. Immediate implant placement in case of a failing tooth is a favorable treatment option for patients because it considerably shortens treatment time and the number of surgical treatments. The question is if an intact buccal bone wall is necessary for immediate implant placement. A 10-year study was performed in which 20 patients with a failing tooth in the frontal region of the upper jaw were treated with immediate implant placement and were compared with 20 patients in whom a more conventional treatment strategy was followed in which the failing tooth was first removed and the bone gap restored and the implant placed in a second step. After a 10-year follow-up period, it appeared that the bone around the implant was very stable, gums were healthy, and patients were very satisfied with the result. There was no difference between the two treatment procedures. Such results mean that professionals can discuss the procedure with the patient and apply the individual's preference.

Quantitative metrics of bone quality determined at the distal radius using photon-counting CT.

To determine the accuracy of photon-counting-detector CT (PCD-CT) at deriving bone morphometric indices and demonstrate utility in vivo in the distal radius. Ten cadaver wrists were scanned using PCD-CT and high-resolution peripheral quantitative CT (HRpQCT). Correlation between PCD-CT and HRpQCT morphometric indices was determined. Agreement was assessed by Lin's concordance correlation coefficient (Lin's CCC). Wrist PCD-CTs of patients between 02/2022 and 08/2023 were also evaluated for clinical utility. Morphometric indices of the in vivo distal radii were extracted and compared between patients with or without osteoporosis. In cadavers, strong correlation between PCD-CT and HRpQCT was observed for cortical thickness (Spearman correlation, ρ, 0.85), trabecular spacing (ρ = 0.98), and trabecular bone volume fraction (ρ = 0.68). Moderate negative correlation (ρ = - 0.49) was observed for trabecular thickness. PCD-CT shows good agreement to HRpQCT for cortical thickness, trabecular spacing, and trabecular bone volume fraction (Lin's CCC = 0.80, 0.94, and 0.86, respectively) but poor agreement (Lin's CCC = - 0.1) for trabecular thickness. In forty participants (31 adults and 9 pediatric), bone morphometrics indices for cortical thickness, trabecular thickness, trabecular spacing, and trabecular bone volume fraction were 0.99mm (IQR, 0.89-1.06), 0.38mm (IQR, 0.25-0.40), 0.82mm (IQR, 0.72-1.05), and 0.28 (IQR, 0.25-0.33), respectively. Patients with osteoporosis had statistically significantly larger trabecular spacing (p = 0.025) and lower trabecular volumetric bone mineral density (p = 0.042). This study demonstrates the agreement of PCD-CT to HRpQCT in cadavers of most cortical and bone morphometrics examined and provide in vivo quantitative metrics of bone microarchitecture from routine clinical PCD-CT images of the distal radius.

The Utility of Radiomorphometric Mandibular Indices on Cone Beam Computer Tomography in the Assessment of Bone Mass in Postmenopausal Women: A Cross-Sectional Study.

The present study examined the potential use of computed tomography radiomorphometric mandibular indices on cone beam CT (CBCT) for the assessment of bone density in postmenopausal women with low bone mass. We included 104 postmenopausal women who received dual-energy X-ray absorptiometry (DXA) using a DXA scanner and mental foramen (MF) region CBCT using a NewTom VGi EVO Cone Beam 3D system. We assessed the relationships between the following DXA parameters: lumbar, femoral neck, and total hip T-scores, bone mineral density (BMD), lumbar trabecular bone score (TBS), and mandibular inferior cortical bone thickness at 4 sites. The cross-sectional images were obtained, as follows: anterior (A)-10 mm anterior from the MF; molar (M)-10 mm posterior from the MF; posterior (P)-25 mm posterior from the MF; symphysis (S)-equidistant from the centers of the right and left MF. We found that A and M indices showed statistically significant moderate positive correlations with lumbar spine, femoral neck, and total hip BMD, as well as TBS. The P index demonstrated moderate positive correlations with these measurements, while the S index did not show significant correlations with BMD or TBS in postmenopausal women. These findings support the potential usefulness of CBCT-derived radiomorphometric mandibular indices for non-invasive bone health assessment in clinical practice.

Dimensional changes in free gingival grafts at implant sites in the reconstructed mandible: a retrospective study.

To evaluate the dimensional changes in free gingival grafts (FGG) at implant sites in mandibular reconstruction patients. Patients who received FGG 4 months after implant placement in the reconstructed mandible with no keratinized mucosa (KM) present were invited for re-examination after 36.7 ± 16.8 months (3.06 ± 1.4 years). Immediately after graft extraction (T0), graft width (GW), graft length (GL), graft thickness (GT), graft dimension (GD), and vertical bone height were documented. Re-examination (T1) included clinical examinations (GW, GL, GD, peri-implant probing depths, and modified Sulcus Bleeding Index), radiographic examination (marginal bone level), and medical chart review. Twenty patients and 62 implants (47 in fibula flaps and 15 in iliac flaps) were included. A significant decrease in GW (51.8%), GL (19.2%), and GD (60.2%), were found between T0 and T1 (p < .001). The univariate analysis showed that GW change was not significantly associated with reconstruction technique, baseline GL, baseline GT, baseline GD, implant location, or type of prosthesis. Implant survival rate of 100% was observed at follow-up. Within the limitations of the study, free gingival grafts at implant sites in the reconstructed mandible undergo dimensional change that result in a reduction of approximately 60% of the original graft dimension. Graft width decreased over 50%. FGG is the standard of care intervention for increasing the amount of KM around implants. This study was the first to evaluate the dimensional change in FGG at implant sites in mandibular reconstruction patients after a medium-term follow-up. Clinical trial registration is not applicable as this study comprehends a retrospective analysis.