Bone Volume Measurements Research Articles

Microstructural Evaluation of Dental Implant Success Using Micro-CT: A Comprehensive Review

Micro-computed tomography (micro-CT) is an invaluable tool for the evaluation of dental implant success, whereby the assessment of bone microstructure is conducted. This review examines the role of micro-CT in evaluating bone microstructure in dental implants. A review of the current literature reveals that micro-CT enables the accurate measurement of bone volume, trabecular morphology, and connectivity density, all of which play a crucial role in implant stability. The high-resolution three-dimensional visualization capabilities of micro-CT are also beneficial for the analysis of osseointegration and the evaluation of bone augmentation biomaterials. Despite the existence of challenges such as imaging artifacts and limitations in in vivo applications, advancements in sub-micron resolution and artificial intelligence integration offer promise for improving diagnostic capabilities. Micro-CT provides valuable insights into bone microarchitecture and osseointegration dynamics, which have the potential to enhance pre-operative planning and clinical outcomes in dental implantology. Future research should prioritize the standardization of micro-CT analysis protocols and the exploration of direct clinical applications of this technology.

Effect of interproximal enamel reduction on interradicular bone volume in clear aligner therapy: a three-dimensional cone-beam computed tomography study.

To assess the effect of inter-proximal enamel reduction (IPR) on interradicular bone volume and incisal inclination in patients undergoing clear aligner therapy (CAT). The study sample consisted of 60 cases which underwent orthodontic CAT, in a private clinic in Dammam, KSA. A total of 120 CBCT scans (60 pre-treatment and 60 post- treatment) were measured using the CS 3D Imaging software to examine bone volume (using height, width, and depth of the interproximal area) and incisal inclination. The corresponding ClinCheck models were collected to determine the amount and locations of interproximal reduction performed. Little's Irregularity Index values were measured using OrthoCAD software. Paired sample t-test was used to address the measurements of bone height, width, depth, bone volume, and inclination of upper and lower incisors before and after IPR. IPR did not affect the upper or lower bone volume except at LR3-2 and UL 2 - 1 where a significant difference between the bone volume with and without IPR was detected (p = 0.02 and p = 0.04 respectively). Upper and lower incisor inclination showed a statistically significant decrease after IPR. There was no correlation between IPR and bone volume difference between upper and lower teeth except at LR3-2 and UL 2 - 1. IPR had no significant effect on inter-radicular bone volume except at areas of lower right canine-lateral and at areas of upper left central-lateral. There was a positive correlation between the amount of IPR and incisal inclination. The current study findings suggest that while IPR has a minimal and localized effect on bone volume in certain areas, it plays a role in adjusting incisal inclination, highlighting its significance in the careful planning of orthodontic treatment using clear aligners.

A Concise and Accurate Method for Evaluating Alveolar Cleft ReconstructionDiet al Concise and Accurate Method for Evaluating.

Currently, there remain unresolved issues in the treatment of alveolar clefts, the resolution of which could greatly benefit many patients with cleft lip and palate. In alveolar cleft treatment research, a reliable tool for pre- and postoperative assessment is crucial. This study presents a concise and accurate method for postoperative evaluations of alveolar treatment, which can rapidly and accurately obtain the shape and volume of the newly formed bone. This study included helical computed tomography (CT) datasets of 20 patients who underwent alveolar bone grafting at our institute. Two observers independently measured the volume of newly formed bone in the patient's CT images one year postoperatively, with each observer performing the measurement twice. To acquire the volume of the newly formed bone at 1 year postoperatively, the model of the newly formed bone must be constructed first. The acquisition of this model involves Boolean operations on registered preoperative and postoperative cranial 3-dimensional (3D) images. The registration of the preoperative and postoperative models is performed in MIMICS software, and the registration results can be directly confirmed layer by layer on the CT images to ensure accuracy. The mean newly formed bone ratio in this study was 39.81%±17.96%, and the mean processing time was 05:11±01:41 minutes. The intraclass correlation coefficient for bone volume measurements between the two observers was 0.999, indicating high consistency and reproducibility. This method enhances accuracy, is time-efficient, and demonstrates high reliability in evaluating postoperative bone formation.

Development of a continuum-based, meshless, finite element modeling approach for representation of trabecular bone indentation

Implant subsidence into the underlying trabecular bone is a common problem in orthopaedic surgeries; however, the ability to pre-operatively predict implant subsidence remains limited. Current state-of-the-art computational models for predicting subsidence have issues addressing this clinical problem, often resulting from the size and complexity of existing subject-specific, image-based finite element (FE) models. The current study aimed to develop a simplified approach to FE modeling of subject-specific trabecular bone indentation resulting from implant penetration.Confined indentation experiments of human trabecular bone with flat- and sharp-tip indenters were simulated using FE analysis. A generalized continuum-level approach using a meshless smoothed particle hydrodynamics (SPH) approach and an isotropic crushable foam (CF) material model was developed for the trabecular bone specimens. Five FE models were generated with CF material parameters calibrated to cadaveric specimens spanning a range of bone mineral densities (BMD). Additionally, an alternative model configuration was developed that included consideration of bone marrow, with bone and marrow material parameters assigned to elements randomly according to bone volume (BV%) measurements of experimental specimens, owing to the non-uniform nature of trabecular bone tissue microstructure.Statistical analysis found significant correlation between the shapes of the numerical and experimental force-displacement curves. FE models accurately captured the bone densification patterns observed experimentally. Inclusion of marrow elements offered improved response prediction of the flat-tip indenter tests.Ultimately, the developed approach demonstrates the ability of a generalizable continuum-level SPH approach to capture bone variability using clinical bone imaging metrics without needing detailed image-based geometries, a significant step towards simplified subject-specific modeling of implant subsidence.

Assessment of cone-beam CT technical image quality indicators and radiation dose for optimal STL model used in visual surgical planning.

The aim of this study was to identify cone-beam computed tomography (CBCT) protocols that offer an optimal balance between effective dose (ED) and 3D model for orthognathic virtual surgery planning, using CT as a reference, and to assess whether such protocols can be defined based on technical image quality metrics. Eleven CBCT (VISO G7, Planmeca Oy, Helsinki, Finland) scan protocols were selected out of 32 candidate protocols, based on ED and technical image quality measurements. Next, an anthropomorphic RANDO SK150 phantom was scanned using these 11 CBCT protocols and 2 CT scanners for bone quantity assessments. The resulting DICOM (Digital Imaging and Communications in Medicine) files were converted into Standard Tessellation Language (STL) models that were used for bone volume and area measurements in the predefined orbital region to assess the validity of each CBCT protocol for virtual surgical planning. The highest CBCT bone volume and area of the STL models were obtained using normal dose protocol (F2) and ultra-low dose protocol (J13), which resulted in 48% and 96% of the mean STL bone volume and 48% and 95% of the bone area measured on CT scanners, respectively. The normal dose CBCT protocol "F2" offered optimal bone area and volume balance for STL. The optimal CBCT protocol can be defined using contrast-to-noise ratio and modulation transfer function values that were similar to those of the reference CT scanners'. CBCT scanners with selected protocols can offer a viable alternative to CT scanners for acquiring STL models for virtual surgical planning at a lower effective dose.

Assessment of the intrasinusidal volume before and after maxillary sinus augmentation using mri – a pilot study of eight patients

PurposeThe purpose of this study was to evaluate the suitability, accuracy, and reliability of a non-invasive 3-Tesla magnetic resonance imaging technique (3 T-MRI) for the visualization of maxillary sinus grafts in comparison to conventional, X-ray-based, established standard imaging techniques.MethodsA total of eight patients with alveolar bone atrophy who required surgical sinus floor augmentation in the course of dental implantation were included in this pilot study. Alongside pre-operative cone-beam computed tomography (CBCT), 3 T-MRI was performed before and 6 months after sinus floor augmentation. Two investigators measured the maxillary sinus volume preoperatively and after bone augmentation.ResultsIn all cases, MRI demonstrated accurately the volumes of the maxillary sinus grafts. Following surgery, the bony structures suitable for an implant placement increased at an average of 4.89 cm3, corresponding with the decrease of the intrasinusidal volumes. In general, interexaminer discrepancies were low and without statistical significance.ConclusionIn this preliminary study, we could demonstrate the feasibility of MRI bone volume measurement as a radiation-free alternative with comparable accuracy to CT/CBCT before procedures like sinus floor augmentation. Nevertheless, costs and artifacts, also present in MRI, have to be taken into account. Larger studies will be necessary to justify the practicability of MRI bone volume evaluation.

Melatonin promotes osteogenesis of bone marrow mesenchymal stem cells by improving the inflammatory state in ovariectomized rats

To investigate the effects of melatonin (MT) on bone mass and serum inflammatory factors in rats received ovariectomy (OVX) and to investigate the effects of MT on the levels of inflammatory factors in culture medium and osteogenic ability of bone marrow mesenchymal stem cells (BMSCs) stimulated by lipopolysaccharide. Fifteen 12-week-old Sprague Dawley (SD) rats were randomly divided into 3 groups. The rats in Sham group only received bilateral lateral abdominal incision and suture, the rats in OVX group received bilateral OVX, and the rats in OVX+MT group received 100 mg/(kg·d) MT oral intervention after bilateral OVX. After 8 weeks, the levels of serum inflammatory factors [interleukin-1β (IL-1β), IL-6, and tumor necrosis factor α (TNF-α)] were detected using ELISA assay. Besides, the distal femurs were detected by Micro-CT to observe changes in bone mass and microstructure, and quantitatively measured bone volume fraction, trabecular thickness, and trabecular number. The BMSCs were extracted from the femurs of three 3-week-old SD rats using whole bone marrow culture method and passaged. The 3rd-5th passage BMSCs were cultured with different concentrations of MT (0, 1, 10, 100, 1 000 µmol/L), and the cell viability was then detected using cell counting kit 8 (CCK-8) to select the optimal concentration of MT for subsequent experiments. Cells were devided into osteogenic induction group (group A) and osteogenic induction+1/5/10 μg/mL lipopolysaccharide group (group B-D). The levels of inflammatory factors (IL-1β, IL-6 and TNF-α) in cell culture medium were detected using ELISA assay after corresponding intervention. According to the results of CCK-8 method and ELISA detection, the cells were intervened with the most significant concentration of lipopolysaccharide for stimulating inflammation and the optimal concentration of MT with osteogenic induction, defining as group E, and the cell culture medium was collected to detect the levels of inflammatory factors by ELISA assay. After that, alkaline phosphatase (ALP) staining and alizarin red staining were performed respectively in groups A, D, and E, and the expression levels of osteogenic related genes [collagen type Ⅰ alpha 1 chain (Col1a1) and RUNX family transcription factor 2 (Runx2)] were also detected by real time fluorescence quantitative PCR (RT-qPCR). ELISA and Micro-CT assays showed that compared with Sham group, the bone mass of the rats in the OVX group significantly decreased, and the expression levels of serum inflammatory factors (IL-1β, IL-6, and TNF-α) in OVX group significantly increased (P<0.05). Significantly, the above indicators in OVX+MT group were all improved (P<0.05). Rat BMSCs were successfully extracted, and CCK-8 assay showed that 100 µmol/L was the maximum concentration of MT that did not cause a decrease in cell viability, and it was used in subsequent experiments. ELISA assays showed that compared with group A, the expression levels of inflammatory factors (IL-1β, IL-6, and TNF-α) in the cell culture medium of groups B-D were significantly increased after lipopolysaccharide stimulation (P<0.05), and in a concentration-dependent manner. Moreover, the expression levels of inflammatory factors in group D were significantly higher than those in groups B and C (P<0.05). After MT intervention, the expression levels of inflammatory factors in group E were significantly lower than those in group D (P<0.05). ALP staining, alizarin red staining, and RT-qPCR assays showed that compared with group A, the percentage of positive area of ALP and alizarin red and the relative mRNA expressions of Col1a1 and Runx2 in group D significantly decreased, while the above indicators in group E significantly improved after MT intervention (P<0.05). MT may affect the bone mass of postmenopausal osteoporosis by reducing inflammation in rats; MT can reduce the inflammation of BMSCs stimulated by lipopolysaccharide and weaken its inhibition of osteogenic differentiation of BMSCs.

Quantitative analysis of bone regeneration efficacy as shape conformity of scaffold: Evidence for importance of additive-manufacturing precision in tissue engineering

Additive manufacturing (AM) of customized scaffolds has been actively studied in tissue engineering. Most studies have focused on the functionalization of scaffolds for osteoinduction and osteoconduction for bone regeneration. However, in our previous study, we found that shape conformity between a defect and the scaffold was also a major factor with regard to enhancing bone regeneration. Thus, in this study, we performed a quantitative analysis of the shape conformity between the defect and scaffold using several novel experimental scaffolds. Employing several scaffolds with different conformities that increased linearly, the degree of bone regeneration was analyzed through new bone volume measurements and a histological analysis in conjunction with an in vivo experiment using rat calvaria. For the quantitative analysis, we compared the new bone volume reconstructed from a three-dimensional model based on CT data. New bone maturation was analyzed with respect to shape conformity through a histological analysis. Proliferation, maturation, and new bone formation were promoted by scaffold shape conformity. Thus, for bone regeneration, the AM precision and the fabrication technique are critical as the shape conformity of the scaffold to the bone defect is highly dependent on AM fabrication errors.

Three-dimensional (3D) quantitative evaluation of the morphological changes of the upper anterior alveolar bone after retraction of a maxillary incisor

BackgroundThe purpose of this study was to assess morphological changes of the upper anterior alveolus after retraction of a maxillary incisor by applying three-dimensional (3D) superimposition of pretreatment (T1) and posttreatment (T2) cone-beam computed tomography (CBCT) data.MethodsThe study group was comprised of 28 patients with skeletal Class II malocclusion who underwent incisor retraction. CBCT data were acquired before (T1) and after (T2) orthodontic treatment. Labial and palatal alveolar thickness were assessed at the crestal, midroot and apical levels of the retracted incisors. Following three-dimensional (3D) cranial base superimposition, we performed surface modeling and inner remodeling of the labial and palatal alveolar cortex of the maxillary incisors. Paired t-tests were used to compare T0 and T1 bone thickness and volume measurements. Comparisons between labial and palatal surface modeling, inner remodeling and outer surface modeling were performed with paired t-tests in SPSS 20.0 version.ResultsWe observed controlled tipping retraction of the upper incisor. After treatment, the alveolar thickness on the labial sides increased and the palatal alveolar thickness decreased. The labial cortex showed a wider range of modeling area with a larger bending height and a smaller bending angle than the palatal side. The extent of inner remodeling was more prominent than the outer surface on both the labial and palatal sides.ConclusionsAdaptive alveolar surface modeling occurred in response to incisor tipping retraction on both the lingual and labial sides although these changes occurred in an uncoordinated manner. Tipping retraction of the maxillary incisors led to a reduction in alveolar volume.

The clinical efficacy of periodontally accelerated osteogenic orthodontics in patients with bone fenestration and dehiscence: a retrospective study

PurposeThe objective of the study was to explore the effect of periodontally accelerated osteogenic orthodontics (PAOO) in orthodontic patients with bone dehiscence and fenestration in the anterior alveolar region of the mandible.MethodsA retrospective study was performed in 42 patients with bone dehiscence and fenestrations in the anterior alveolar region of the mandible who underwent the PAOO technique. The bleeding index (BI), probing depth (PD), keratinized gingiva width (KGW), gingival recession level (GRL), and gingival phenotype were recorded and assessed at baseline and 6 and 12 months postoperatively. Cone-beam computerized tomography was used to measure bone volume in terms of root length (RL), horizontal bone thickness at different levels, and vertical bone height at baseline and 6 months and 12 months after surgery.ResultsThe sample was composed of 42 patients (22 males and 20 females; mean age, aged 25.6 ± 4.8 years) with 81 teeth showing dehiscence/fenestrations and 36 sites presenting gingival recessions. There was no significant difference in BI, PD, or KGW (between baseline and 6 or 12 months postoperatively) based on the clinical evaluations (P > 0.05). Gingival recession sites demonstrated a significant reduction in the GRL after surgery (P < 0.05). Furthermore, the proportion of teeth with a thick gingival phenotype increased from 33.61% at baseline to 53.13% at the end of the follow-up. In addition, the bone thickness measurements at the mid-root and crestal levels were markedly increased compared with the baseline values (P < 0.05), although the increase in thickness at the apical level was not statistically significant (P > 0.05).ConclusionsWithin the limitations of the study, the results show that the PAOO technique is beneficial to periodontal conditions in terms of soft and hard tissue augmentation. The PAOO procedure may represent a safe and efficient treatment for orthodontic patients with bone dehiscence and fenestration.Trial registrationThis study was approved by the ethics committee of the stomatological hospital affiliated with Xi'an Jiaotong University (xjkqll [2019] No. 016) and registered in the Chinese Clinical Trial Registry (ChiCTR2100053092).

Informational content of two-dimensional panoramic radiographs and lateral cephalometric radiographs with respect to the bone volume of intraoral donor regions considering CBCT imaging

BackgroundTo test the hypothesis that cephalometric parameters in two-dimensional routine dental radiographs correlate with the bone volume of intraoral bone donor sites.MethodsOne-hundred and eight radiographs [36 panoramic radiographs (PRs), 36 lateral cephalometric radiographs (LCRs), and 36 cone-beam computed tomography scans (CBCT)] of 36 patients (all three imaging techniques applied according to the needs of treatment planning), were analyzed individually. Cephalometric parameters (PR and LCR) were correlated with the bone volume measurement in three-dimensional CBCT scans in three intraoral donor sites (chin, mandibular retromolar region, and zygomatic alveolar crest).ResultsThe mean bone volumes measured for the chin were (3.10 ± 1.11 cm³ SD), the mandibular retromolar region (1.66 ± 0.54 cm³ SD), and the zygomatic alveolar crest (0.17 ± 0.04 cm³ SD). Cephalometric parameters were significantly correlated (all p-values < 0.05) with the bone volume in the chin and the mandibular retromolar region. The bone volume of the zygomatic alveolar crest exhibited no correlations (p > 0.05) with cephalometric parameters. However, it was significantly correlated (p < 0.01) with the mandibular retromolar bone volume. No gender-specific differences (p > 0.05) were observed concerning bone volumes in all bone harvesting regions. Nevertheless, the male population’s interforaminal distance in the chin region was significantly higher (p = 0.001).ConclusionsPRs and LCRs can be used at the initial stage of peri-implant augmentation planning to deduce conclusions about the bone volume in different intraoral bone donor sites. It can help describe indications and justify additional diagnostic options, such as three-dimensional radiologic techniques.

EVALUATION OF MINERALIZED PLASMATIC MATRIX DURING SINUS LIFT WITH THE SIMULTANEOUS PLACEMENT OF DENTAL IMPLANTS

Objectives:Mineralized plasmatic matrix is reported to improve the quality of the bone/fibrin mixture, creating a stable and easy to handle homogeneous material. However, few studies evaluate the use of the mineralized plasmatic matrix during sinus lift with the simultaneous placement of dental implants. Purpose: This study evaluated the efficiency or not of MPM compared to the xenograft bone grafting in the maxillary sinus lift. Patients and methods:This study was conducted randomly on patients selected for treatment with a total of sixteen lateral windows sinus lift with simultaneous implant placement. Their ages ranged between 20 and 60 years old. Participating patients were divided into two groups equally and randomly The control group: eightsinus floor elevation was performed using simultaneous implant placement. As a grafting material, Xenograft was used. The study group: eight Sinus floor elevation was achieved with simultaneous implant placement. Xenograft has been used in the form of MPM as a grafting material. CBCT taken before and after sinus augmentation to measure bone volume and height after 1 week of baseline (T0), after 6 months (T1), and after 12 months of baseline (T0) (T2). The Osstell(PT) was used for assessment implant stability at implant insertion (PT0) as well as for loading visit (PT1). Result:A significant difference was observed between the two groups in bone volume (p=0.049). No significant difference was observed between the two groups (p=0.129) in height of graft. Conclusion:MPM eliminated the need for barrier membranes when a guided bone regeneration procedure is considered.The useofMPM as a grafting bone offered greater graft stability and handling.

Micro-Computed Tomography Analysis on Administration of Mesenchymal Stem Cells - Bovine Teeth Scaffold Composites for Alveolar Bone Tissue Engineering

The tissue engineering approach for periodontal tissue regeneration using a combination of stem cells and scaffold has been vastly developed. Mesenchymal Stem Cells (MSCs) seeded with Bovine Teeth Scaffold (BTSc) can repair alveolar bone damage in periodontitis cases. The alveolar bone regeneration process was analyzed by micro-computed tomography (µ-CT) to observe the structure of bone growth and to visualize the scaffold in 3-Dimensional (3D). The purpose of this study is to analyze alveolar bone regeneration by µ-CT following the combination of MSCs and bovine teeth scaffold (MSCs-BTSc) implantation in the Wistar rat periodontitis model. Methods. MSCs were cultured from adipose-derived mesenchymal stem cells of rats. BTSc was taken from bovine teeth and freeze-dried with a particle size of 150-355 µm. MSCs were seeded on BTSc for 24 hours and transplanted in a rat model of periodontitis. Thirty-five Wistar rats were made as periodontitis models with LPS induction fromP. gingivalisinjected to the buccal section of interproximal gingiva between the first and the second mandibular right-molar teeth for six weeks. There were seven groups (control group, BTSc group on day 7, BTSc group on day 14, BTSc group on day 28, MSCs-BTSc group on day 7, MSCs-BTSc group on day 14, MSCs-BTSc group on day 28). The mandibular alveolar bone was analyzed and visualized in 3D with µ-CT to observe any new bone growth. Statistical Analysis. Group data were subjected to the Kruskal Wallis test followed by the Mann-Whitney (p &lt;0.05). The µ-CT qualitative analysis shows a fibrous structure, which indicates the existence of new bone regeneration. Quantitative analysis of the periodontitis model showed a significant difference between the control model and the model with the alveolar bone resorption (p &lt;0.05). The bone volume and density measurements revealed that the MSCs-BTSc group on day 28 formed new bone compared to other groups (p &lt;0.05). Administration of MSCs-BTSc combination has the potential to form new alveolar bone.

Outcome of Using Medical Grade Calcium Sulfate Hemihydrate (DentoGen) in Unilateral Alveolar Cleft Repair

Objectives: The aim of this prospective study was to evaluate the efficacy of fast setting (DentoGen) bonesubstitute for secondary alveolar cleft repair.Materials and Methods: Ten patients with complete unilateral cleft lip and palate were included for alveolarcleft repair with fast setting (DentoGen) without autogenous bone graft in 2017 and 2018. Pre-operation and6 months post-operation CBCT were used for measurement of bone density and bone volume in cleft site.The data was analyzed by using Pearson’s correlation coefficient test and paired sample t-test via SPSSsoftware version 24.Results: The mean age of patients in this study was 10.4±2.657 years. The pre-operative mean alveolar cleftvolume was 0.8996±0.117cm3. Six months after grafting with fast setting (DentoGen) graft, satisfactorybone formation was observed in all patients except two patients. The mean bone density of cleft site was303±42.843 HU which was significantly lower than the non-cleft side, and the mean percentage of new boneformation was 64.74±10.290% compared with original cleft volume.Conclusion: Calcium sulfate hemihydrate (DentoGen) can represent a promising alternative to autogenousbone graft in repairing small unilateral alveolar cleft during mixed dentition.

A Novel Bone Substitute Based on Recombinant Type I Collagen for Reconstruction of Alveolar Cleft.

This study aimed to examine the optimal cross-link density of recombinant peptide (RCP) particles, based on human collagen type I, for bone reconstruction in human alveolar cleft. Low- (group 1), medium- (group 2), and high- (group 3) cross-linked RCP particles were prepared by altering the duration of the heat-dependent dehydration reaction. Rat palatine fissures (n = 45), analogous to human congenital bone defects, were examined to evaluate the potential of bone formation by the three different RCP particles. Microcomputed tomography images were obtained to measure bone volume and bone mineral density at 4, 8, 12, and 16 weeks post grafting. Specimens were obtained for histological analysis at 16 weeks after grafting. Additionally, alkaline phosphatase and tartrate acid phosphatase staining were performed to visualize the presence of osteoblasts and osteoclasts. At 16 weeks, bone volume, bone mineral density, and new bone area measurements in group 2 were significantly higher than in any other group. In addition, the number of osteoblasts and osteoclasts on the new bone surface in group 2 was significantly higher than in any other group. Our results demonstrated that medium cross-linking was more suitable for bone formation—and could be useful in human alveolar cleft repairs as well.

The impact of the primary canine premature extraction on the sagittal, vertical and transversal dimensions of the bone tissue

Relevance. The article studies the primary canine premature extraction as the cause of three-dimensional (sagittal, transversal, vertical) bone underdevelopment in the area of the extracted tooth. The research is relevant as there are insufficient data in the scientific literature on this topic and the prevalence of premature primary canine extraction for therapeutic and orthodontic indications is high.Materials and methods. The present case study developed a special technique for bone volume measurement in all planes by CBCT.Results. Several CBCTs of one patient over the period of three years were analyzed according to the suggested technique. The calculations demonstrated significant sagittal and vertical bone loss.Conclusions. The results of the research allowed us to conclude that premature extraction of the primary canines leads to the significant sagittal and vertical bone loss. Besides, no increase in the intercanine distance was detected despite the patient’s growth spurt.

Ibandronate Reduces the Surface Bone Resorption of Mandibular Bone Grafts: A Randomized Trial With Internal Controls.

ABSTRACTAutologous bone grafts are considered the gold standard for reconstruction of the edentulous alveolar ridges. However, this procedure is associated with unpredictable bone loss caused by physiological bone resorption. Bisphosphonates are antiresorptive drugs that act specifically on osteoclasts, thereby maintaining bone density, volume, and strength. It was hypothesized that the resorption of bone grafts treated with an ibandronate solution would be less advanced than bone grafts treated with saline. Ten patients who underwent bilateral sagittal split osteotomy were included in a randomized double‐blind trial with internal controls. Each patient received a bone graft treated with a solution of ibandronate on one side and a graft treated with saline (controls) contralaterally. Radiographs for the measurement of bone volume were obtained at 2 weeks and at 6 months after surgery. The primary endpoint was the difference in the change of bone volume between the control and the ibandronate bone grafts 6 months after surgery. All of the bone grafts healed without complications. One patient was excluded because of reoperation. In eight of the nine patients, the ibandronate bone grafts showed an increase in bone volume compared with baseline, with an average gain of 126 mm3 (40% more than baseline) with a range of +27 to +218 mm3. Only one ibandronate‐treated graft had a decrease in bone volume (8%). In the controls, an average bone volume loss of −146 mm3 (58% of baseline) with a range of −29 to −301 mm3 was seen. In the maxillofacial field, the reconstructions of atrophic alveolar ridges, especially in the esthetical zones, are challenging. These results show that bone grafts locally treated with ibandronate solution increases the remaining bone volume. This might lead to new possibilities for the maxillofacial surgeons in the preservation of bone graft volumes and for dental implant installations. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Intra- and Interobserver Reliability of Bone Volume Estimation Using OsiriX Software in Patients with Cleft Lip and Palate Using Cone Beam Computed Tomography.

The objective of the current study was to evaluate intra- and interobserver bone volume measurements and effect of orientation on the reliability of bone volume evaluation in as-acquired vis-à-vis oriented cone beam computed tomography scans using Osirix software and possible correlation between gender, age, and bone volume required. For this, 31 cone beam computed tomography (CBCT) scans of 14 girls and 17 boys (aged 9–13) with unilateral cleft lip and/or palate who met the inclusion criteria were analyzed. Efficacy and reliability of third party software Osirix for bone volume calculation was assessed using as acquired and oriented volumes by three specialists (a radiologist, an orthodontist, and an oral maxillofacial surgeon). The dataset and readings were anonymized to prevent any bias. Two-way mixed model analysis on as-acquired and oriented observations exhibited intra-class coefficient (ICC) values ≥ 0.90. Wilcoxon signed rank test (p = 0.10) and Kruskal–Wallis ANOVA (p = 0.46) indicated that although a clinical difference in volume assessment was seen between as-acquired and oriented observations (inter-observer and intra-observer), it was statistically insignificant. Spearman’s bi-variate correlation analysis revealed a significant relation between the type (side) of cleft and bone volume required to fill the defect (p < 0.05). Although there was clinical difference in bone volume measurement by the three observers, it was insignificant statistically. Clefts on the left side in the patients had significantly more bone required than the right side, whereas age and gender had no relation with bone needed to fill the defect. OsiriX software provided good reliability in measurements of bone volume.

Measuring Bone Volume at Multiple Densities by Micro-computed Tomography.

Bone strength is controlled by both bone mass, and the organization and quality of the bone material. The current standard method for measuring bone mass in mouse and rat studies is micro-computed tomography. This method typically uses a single threshold to identify bone material in the cortical and trabecular regions. However, this single threshold method obscures information about the mineral content of the bone material and depends on normal morphology to separately analyze cortical and trabecular structures. To extend this method to identify bone mass at multiple density levels, we have established a protocol for unbiased selection and application of multiple thresholds using a standard laboratory-based micro-computed tomography instrument. This non-invasive method can be applied to longitudinal studies and archived samples and provides additional information about bone structure and strength.

Trabecular Bone Assessment Using Magnetic-Resonance Imaging: A Pilot Study.

The aim of this study was to assess trabecular bone morphology via magnetic-resonance imaging (MRI) using microcomputed tomography (µCT) as the control group. Porcine bone samples were scanned with T1-weighted turbo spin echo sequence imaging, using TR 25 ms, TE 3.5 ms, FOV 100 × 100 × 90, voxel size 0.22 × 0.22 × 0.50 mm, and scan time of 11:18. µCT was used as the control group with 80 kV, 125 mA, and a voxel size of 16 µm. The trabecular bone was segmented on the basis of a reference threshold value and morphological parameters. Bone volume (BV), Bone-volume fraction (BvTv), Bone specific surface (BsBv), trabecular thickness (TbTh), and trabecular separation (TbSp) were evaluated. Paired t-test and Pearson correlation test were performed at p = 0.05. MRI overestimated BV, BvTv, TbTh, and TbSp values. BsBv was the only parameter that was underestimated by MRI. High statistical correlation (r = 0.826; p < 0.05) was found for BV measurements. Within the limitations of this study, MRI overestimated trabecular bone parameters, but with a statistically significant fixed linear offset.