Radiographic Bone Density Research Articles

Age- and Gender-Related Variations in Cortical Bone Density of the Mandible using Cone-Beam Computed Tomography in Central Indian Population

Abstract Background: “A radiographic imaging technique called cone-beam computed tomography (CBCT) enables precise three-dimensional (3D) visualization of hard tissue features. It is the most significant of the recently created dental diagnostic imaging modalities. There is, however, a lack of information on the correlation among mandibular cortical bone radiography density, including age and sex. Hence, the goal of this project was to use CBCT to estimate the cortical bone density of the mandible for age and sex variations in the population of central India. Materials and Methods: A retrospective research involving 300 patients was carried out. Patients arrived from the radiology and oral medicine divisions. The CBCT scans were divided into three age groups: those between the ages of 31–50, 51–70, and those older than 70.” The picture archiving and communication system was used to retrieve the images from the system. We determine the mandibular cortical bone radiography density on the CBCT using regions of interest. Results: The CBCT-measured cortical bone radiographic density was substantially linked by age. In addition, young males (1600 ± 129.63) had considerably higher cortical bone radiography density than young females (1366.95 ± 197.46), old men (1480.70 ± 189.59), and elderly females (962.38 ± 138.50). Conclusion: Mandibular cortical bone density is higher in males than females. Age-related alterations in the cortical bone of the jaw were examined using CBCT. In addition, CBCT analysis of the mandibular cortical bone could help recognize risk factors for declining bone mineral density. CBCT changes in the cortical bone of the mandible with aging. In addition, employing CBCT to assess the mandibular cortical bone could help identify risk factors for declining bone mineral density.

Autologous bone harvested during implant bed preparation: A randomized clinical trial comparing high-speed drilling with irrigation versus low-speed drilling without irrigation.

To compare collected bone weight and the frequency of autologous bone harvesting from the flutes of surgical drills used for implant bed preparation using two different drilling techniques. A comparative evaluation of radiographic bone density and bone quality was also made. A randomized clinical trial was made of 66 dental implants in patients with a single posterior edentulous site. The compared drilling techniques were high-speed drilling with irrigation (control group) and low-speed drilling without irrigation (test group). The bone collected in both groups was dried and weighed with a precise electronic balance. The frequency of harvesting was calculated. The median radiographic bone density of each implant site was measured using cone-beam computed tomography (CBCT) pixel values. Patient sex, age, implant position and dimensions, as well as the last drill diameter were analyzed as independent variables. The level of significance was 5%. The harvesting of bone chips from drill flutes proved possible in 51.5% of the procedures in the control group and in 100% in the test group (p < 0.001). There were also statistically significant differences in bone weight between the control group (6.7 ± 10.6 mg) and the test group (41.9 ± 30.3 mg) (p < 0.001). The CBCT pixel values were directly correlated with the collected bone weight in both groups. The median radiographic bone density, arch and last drill diameter were significantly associated with harvesting bone frequency and collected bone weight (p < 0.05). Our findings suggest that the frequency and weight of autologous bone harvested from drills are greater with low-speed drilling without irrigation than with high-speed drilling with irrigation. Radiographic bone density, arch and last drill diameter also significantly influenced the harvesting outcomes.

Effectiveness of Autologous Platelet Concentrates in the Sinus Lift Surgery: Findings from Systematic Reviews and Meta-Analyses.

Maxillary sinus augmentation is one of the most predictable procedures for the rehabilitation of the posterior maxilla. The current overview aimed to summarize the findings provided by systematic reviews (SRs) and meta-analyses on the effectiveness of autologous platelet concentrates (APCs) in sinus lift and to assess the methodological quality of the included SRs. Three electronic databases have been explored. SRs and meta-analyses addressing the effectiveness of APCs in sinus lift technique were included. Clinical, radiographic and histomorphometric findings were considered for APCs as solely grafting materials and APCs in combination with biomaterials. Outcomes were implant survival rate (ISR), implant stability (IS), implant failure (IF), postoperative complications, histomorphometric findings, radiographic bone gain, bone volume and bone density. The methodological quality of the included SRs was assessed using the updated version of "A Measurement Tool to Assess Systematic Review" (AMSTAR-2). Thirty SRs were included. The methodological quality of the included reviews ranged from critically low (3 studies) to high (9 studies). The included SRs showed favorable clinical outcomes, short-term new bone formation and no biological complications when APCs were used both as solely graft material or in combination with other biomaterials. However, no significant additional effects in the long-term period were observed. APCs did not add any further positive effects compared to the physiological healing derived by the natural blood clot. The current overview of SRs highlighted the need for high-quality SRs evaluating the role of APCs in sinus lift though network meta-analyses, in order to identify the most powerful material for sinus lift augmentation. The use of APCs improves the healing of soft tissues and the postoperative quality of life in the short-term period. Thus, its application can be recommended.

Can gait patterns be explained by joint structure in people with and without radiographic knee osteoarthritis? Data from the IMI-APPROACH cohort

ObjectiveTo determine the association between joint structure and gait in patients with knee osteoarthritis (OA).MethodsIMI-APPROACH recruited 297 clinical knee OA patients. Gait data was collected (GaitSmart®) and OA-related joint measures determined from knee radiographs (KIDA) and MRIs (qMRI/MOAKS). Patients were divided into those with/without radiographic OA (ROA). Principal component analyses (PCA) were performed on gait parameters; linear regression models were used to evaluate whether image-based structural and demographic parameters were associated with gait principal components.ResultsTwo hundred seventy-one patients (age median 68.0, BMI 27.0, 77% female) could be analyzed; 149 (55%) had ROA. PCA identified two components: upper leg (primarily walking speed, stride duration, hip range of motion [ROM], thigh ROM) and lower leg (calf ROM, knee ROM in swing and stance phases). Increased age, BMI, and radiographic subchondral bone density (sclerosis), decreased radiographic varus angle deviation, and female sex were statistically significantly associated with worse lower leg gait (i.e. reduced ROM) in patients without ROA (R2 = 0.24); in ROA patients, increased BMI, radiographic osteophytes, MRI meniscal extrusion and female sex showed significantly worse lower leg gait (R2 = 0.18). Higher BMI was significantly associated with reduced upper leg function for non-ROA patients (R2 = 0.05); ROA patients with male sex, higher BMI and less MRI synovitis showed significantly worse upper leg gait (R2 = 0.12).ConclusionStructural OA pathology was significantly associated with gait in patients with clinical knee OA, though BMI may be more important. While associations were not strong, these results provide a significant association between OA symptoms (gait) and joint structure.

Conventional Versus Osseodensification Drilling in the Narrow Alveolar Ridge: A Prospective Randomized Controlled Trial.

Background Conventionally, undersized osteotomies were used to increase initial bone-to-implant contact to achieve primary stability in implantology. This is particularly evident in regions with low bone density. The potential for severe bone compression and ischemia poses a challenge to secondary stability. Instead, lateral bone compaction is caused by the idea of osseodensification. Research on the potential benefits of this method for narrow ridges is lacking. This study aimed to determine if the osseodensification drilling technique affects primary stability and how much the alveolar ridge expands following implant site preparation. Methodology A total of 30 participants aged 20 to 80 years were included in this randomized controlled clinical investigation. Each participant was randomly assigned to one of the following two groups: one that received standard drill preparation, and another that received osseodensification drill preparation. Implant stability using implant stability quotient values, crest width, apical width (5 mm from crest), and bone density were assessed both before and after six months using cone-beam computed tomography. Results Osseodensification impacted the width at the apex (5 mm from the crest) and radiographic bone density, adding to the quality, but did not affect implant stability and crestal width after osseointegration. The mean difference in conventional and osseodensification groups was 0.46 and 0.68 mm, respectively, concerning the crestal width. Moreover, the mean difference was 0.74 and 0.58 mm for conventional and osseodensification groups, respectively, concerning the width at the apex (5 mm from the crest). Conclusions This study demonstratesthat the osseodensification process increased both the radiographic bone density and the width at the apex, demonstrating that osseodensification drilling techniques allow for the placement of implants with larger diameters innarrow alveolar ridges.

Evaluation of the efficacy of using dental pulp graft in the healing of the alveolar bone after impacted canine extraction: a prospective cohort study.

The purpose of this study was to evaluate the radiographic density of the alveolar bone of the maxilla after extraction of the impacted canines and using the pulp tissue as an autogenous graft. This prospective cohort study recruited 14 patients (8 females and 6 males) between 2021 and 2023, with an average age of 35 years. All participants had palatally impacted maxillary canines. The impacted teeth were extracted surgically. The extracted teeth were then used for autogenous grafting. The pulp tissue was removed, cut into small pieces, and placed on an absorbable gelatin sponge before being inserted into the extraction socket. The wound was subsequently closed meticulously. After 4 months, the bone density was assessed radiographically using the Hounsfield Scale on cone beam computed tomography scans. After 4 months, the mean radiographic bone density value in the extraction area was (652.77 ± 56.13 HU), while the average density of the original bone was (659.7 ± 39.6 HU). Within the limits of this study, dental pulp tissue can be used to restore bony defects of the alveolar bone in the maxilla. However, further research is needed to confirm these findings.

Effects of Date Palm Fruit (Phoenix Dactylifera L.) as a Dietary Additive on Some Physiological Parameters and Radiographic Bone Density in Heat Stressed Male Rats

Effects of Date Palm Fruit (Phoenix Dactylifera L.) as a Dietary Additive on Some Physiological Parameters and Radiographic Bone Density in Heat Stressed Male Rats

Radiographic evaluation of alveolar ridge preservation using a chitosan/polyvinyl alcohol nanofibrous matrix: A randomized clinical study

The objective of this randomized clinical trial (RCT) was to assess the effectiveness of electrospun chitosan/polyvinyl alcohol (CS/PVA) nanofibrous scaffolds in preserving the alveolar ridge and enhancing bone remodeling following tooth extraction when compared to a control group. In this split RCT, 24 human alveolar sockets were randomly assigned to two groups, with 12 sockets receiving CS/PVA nanofibrous scaffold grafts (test group) and 12 left to heal by secondary intention as the control group. Cone-beam computed tomography (CBCT) was performed at two different time points: immediately after extraction (T0) and 4 months post-extraction (T4). After 4 months, linear vertical and horizontal radiographic changes and bone density of extraction sockets were assessed in both the test and control groups. The RCT included 12 patients (4 male and 8 female) with a mean age of 24 ± 3.37 years. The test group had a significantly lower mean vertical resorption vs the control group, with a mean difference of 1.1 mm (P < 0.05). Similarly, the control group's mean horizontal bone resorption was −2.01 ± 1.04 mm, while the test group had a significantly lower mean of −0.69 ± 0.41 mm, resulting in a mean difference of 1.35 mm (P < 0.05). Furthermore, the study group exhibited a significant increase in bone density (722.03 ± 131.17 HU) after 4 months compared to the control group (448.73 ± 93.23 HU). In conclusion, we demonstrated within the limitations of this study that CS/PVA nanofibrous scaffold significantly limited alveolar bone resorption horizontally and vertically and enhanced bone density in alveolar sockets after 4 months when compared to results in the control group (TCTR20230526005).

Machine-learning predicted and actual 2-year structural progression in the IMI-APPROACH cohort.

In the Innovative Medicine's Initiative Applied Public-Private Research enabling OsteoArthritis Clinical Headway (IMI-APPROACH) knee osteoarthritis (OA) study, machine learning models were trained to predict the probability of structural progression (s-score), predefined as >0.3 mm/year joint space width (JSW) decrease and used as inclusion criterion. The current objective was to evaluate predicted and observed structural progression over 2 years according to different radiographic and magnetic resonance imaging (MRI)-based structural parameters. Radiographs and MRI scans were acquired at baseline and 2-year follow-up. Radiographic (JSW, subchondral bone density, osteophytes), MRI quantitative (cartilage thickness), and MRI semiquantitative [SQ; cartilage damage, bone marrow lesions (BMLs), osteophytes] measurements were obtained. The number of progressors was calculated based on a change exceeding the smallest detectable change (SDC) for quantitative measures or a full SQ-score increase in any feature. Prediction of structural progression based on baseline s-scores and Kellgren-Lawrence (KL) grades was analyzed using logistic regression. Among 237 participants, around 1 in 6 participants was a structural progressor based on the predefined JSW-threshold. The highest progression rate was seen for radiographic bone density (39%), MRI cartilage thickness (38%), and radiographic osteophyte size (35%). Baseline s-scores could only predict JSW progression parameters (most P>0.05), while KL grades could predict progression of most MRI-based and radiographic parameters (P<0.05). In conclusion, between 1/6 and 1/3 of participants showed structural progression during 2-year follow-up. KL scores were observed to outperform the machine-learning-based s-scores as progression predictor. The large amount of data collected, and the wide range of disease stage, can be used for further development of more sensitive and successful (whole joint) prediction models. Trial Registration: Clinicaltrials.gov number NCT03883568.

Longitudinal Radiographic Bone Density Measurement in Revision Hip Arthroplasty and Its Correlation with Clinical Outcome.

The subjective analysis of conventional radiography represents the principal method for bone diagnostics in endoprosthetics. Alternative objective quantitative methods are described but not commonly used. Therefore, semi-quantitative methods are tested using digital computation and artificial intelligence to standardize, simplify, and ultimately improve the assessment. This study aimed to evaluate the correlation between relative density progressions and clinical outcomes. Radiographs and clinical examinations before and 24 and 48 weeks after surgery were obtained from sixty-eight patients with a modular hip stem. For the calculation of the relative bone density, the modal gray values of the Gruen zones were measured using ImageJ and were normalized by gray values of the highest and lowest ROI. The clinical outcomes were measured according to the Harris hip score before evaluating them for correlations. Analyses were performed separately for subgroups and bone regions. The Harris hip score increased from 44.15 ± 15.00 pre-operatively to 66.20 ± 13.87 at the latest follow-up. The relative bone density adjustment of Gruen zone 7 showed a significant correlation to its clinical outcome. Other bone adaptations could be realistically reproduced and differences by regional zones and patients' histories visualized. Next to the simplicity and that no additional examination is required, the method provides good semi-quantitative results and visualizes adaptations, which make it suitable for use.

An Evaluation of the Effectiveness of Local Delivery of Zoledronic Acid in Accelerating Bone Healing After the Extraction of Mandibular Third Molars.

Background and objective Zoledronic acid (ZA) has been reported to aid with the formationof new bone, inhibit osteoclastic bone resorption, and improve osteoblast proliferation. This split-mouth randomized clinical research aimed to evaluate the effect of the local application of ZA on bone regeneration after the removal of bilateral mandibular third molars. Methods A randomized, split-mouth study involving 12 patients aged 19-35 yearsrequiring extraction of bilaterally mandibular third molars was conducted. The extraction ofmandibular third molars on both sides was conducted in one session for all patients. In each participant, a gelatin sponge (Gelfoam) soaked with ZA was randomly applied to one cavity of the extraction socket. A gelatin spongesoaked with normal saline wasapplied to the opposite cavity; all patients were blinded asto which socket the drug was applied to. The study was conducted over a period of two months. The changes in bone density (BD) in the socket were assessed through cone-beam CT (CBCT) images; two images were taken for each patient at two different time points: immediately after extraction (T0) and after two months (T1). Results BD values in the socket on both sides of extraction increased from T0 to T1. There were statistically significant differences when comparing the amount of change in radiographic BD from T0 to T1 between the two sides of the extraction (p<0.05); the increase in radial BD between the two different time points was more significant in the ZA group. Conclusions Within the limitation of this study, the local application of ZAradiographically improved bone healingin a statistically significant manner and could be a cost-effective and simple way to activate bone regeneration.

Clinical and radiographic evaluation of ozone therapy in odontectomy of impacted mandibular third molar

Introduction: Ozone can interact with blood components to have a positive impact on tissue microcirculation, oxygen metabolism, cell energy, immunomodulatory properties, and antioxidant defense systems. In dental surgery, ozone may be useful to promote hemostasis, enhance local oxygen supply, and inhibit bacterial growth. Ozone has been suggested for usage in dentistry due to its healing, antibacterial, and disinfecting qualities. Aim: To assess the influence of topical ozone administration on patient comfort after third molar surgery. Material and Methods: Two equal groups of the forty patients with lower impacted third molars who required surgical extraction were chosen at random. Patients in Group (I) had odontectomy for an impacted mandibular 3rd molar. Patients in Group (II) underwent odontectomy of the impacted mandibular 3rd molar, then ozone gel was injected into the socket. The follow-up visits were performed where the intensity of pain, the symptoms of trismus, swelling and radiographic bone density were evaluated. Results: Group II showed statistical significant difference of pain compared to group I while both groups showed no statistical significant difference with regard to swelling and trismus and radiographic bone density. Conclusion: After odontectomy of the mandibular third molar, ozone gel application therapy proved helpful for reducing postoperative discomfort and improving quality of life. Yet, in addition to bone density, it had no impact on either post-operative edema or trismus.

Radiological Comparative Study Between Conventional and Nano Hydroxyapatite With Platelet-Rich Fibrin (PRF) Membranes for Their Effects on Alveolar Bone Density.

The entry of the concept of nanotechnologies into the field of biomaterials has improved the results of their use in regenerative therapies based on the principles of tissue engineering, due to its improvement of the physical properties of materials manufactured in this way, so it has become possible to produce particles of hydroxyapatite in nano sizes. This study will evaluate the efficacy of applying nanohydroxyapatite paste and platelet-rich fibrin (PRF) as a barrier membrane in comparison with traditionalhydroxyapatite (a powder consisting of macro-sized particles) and PRF as a barrier membrane in symmetrically extracted alveoli of the mandible. The research sample consisted of 40 lower alveoli (symmetrical) of the extracted teeth. The study samples were divided randomly into two groups. Group 1: A paste of nanohydroxyapatite with PRF as a barrier membrane was applied to one side of the extraction. Group 2: Hydroxyapatite powder with PRF as a barrier membrane was applied to the alveolus from the opposite side of Group 1 (the opposite side of the extraction). Three radiographs were performed by cone beam conventional tomography (CBCT) in three consecutive periods to conduct the radiological study (T0: immediately after extraction and grafting, T1: after three months, T2: after six months). The mean of the radiographic bone density of the hydroxyapatite powder group at time T0 is 824.36 HU with a standard deviation of ±277.29 HU, and at time T1 is 1119.93 HU with a standard deviation of ±306.93 HU, and at time T2 is 1074.14 HUwith a standard deviation of ±223.62 HU, with statistically significant differences when comparing the amount of change in radiographic bone density at time T0 and T1 withP < 0.05, and at time T0 and T2 with P < 0.05, but there were no significant differences when comparing the amount of change in radiographic bone density in T1 and T2 times with P > 0.05. The mean radiographic bone density of the nanohydroxyapatite paste group at time T0 is 629.88 HU with a standard deviation of ±193.64 HU, and at time T1 is 960.67 HU with a standard deviation of ±256.88 HU, and at time T2 is 743.87 HU with a standard deviation of ±180.96 HU, and in the time T0 and T1 with P < 0.05, and in the time T0 and T2 with P < 0.05, and in the time T1 and T2 with P < 0.05. Statistically, significant differences have been found between bone density change T1, T2in the nanohydroxyapatite paste group and bone density change T1, T2in the hydroxyapatite powder group P<0.05, which expresses a greater loss of density in the nanohydroxyapatite group, and thus the resorption of the bone graft and the placement of new bone tissue. Within the limits of our study, the results demonstrated that the use of traditional hydroxyapatite powder and nanohydroxyapatite paste increases the radiographic bone density, nanohydroxyapatite paste has a greater absorbency after 3 months compared with traditional hydroxyapatite powder which helps replace it by natural bone tissue.

Clinical And Radiographic Assessment of Xenogenic Bone Graft with or Without Hyaluronic Acid for Post Extraction Socket Preservation (Randomized Clinical Trial)

Aim: hyaluronic acid shows osteogenic potentials which considered important property during bone regeneration. So, we aim to assess the efficiency of hyaluronic acid with xenograft mixture in post extraction alveolar sockets to decelerate resorption of dental alveolar ridge. Materials and Methods: A total of twelve patients with twenty nonrestorable maxillary premolars, which were extracted atraumatically are included in this study. Twenty extracted sockets were divided randomly into two equal groups. Sockets were grafted as follows: Group (I) sockets were grafted by xenograft mixed with hyaluronic acid; Group (II) sockets were grafted by xenograft alone. CBCT scans are made for each patient to measure bone density while pain assessment was done by VAS (visual analogue scale) for pain postoperatively. Results: All preserved sockets enrolled in this study received final crowns over the abutments and the Osseo integrated implants were in fully function position without any complication. According to VAS pain recorded a higher mean value (7.4±1.35) for Group (I), in comparison to Group (II) (4.2±1.48). The differences between study and control groups were statistically significant (p=0.00). While Radiographic bone density Group (I) recorded a higher mean value (879.09±118.76), in comparison to Group (II) (546.18±123.61). The differences between study and control groups were statistically significant (p=0.00) Conclusion: The results clearly concluded that both groups are successful in achieving clinical and radiographic socket preservation with superiority for xenograft mixed with hyaluronic acid

Development of an in vivo radiographic method with potential for use in improving bone quality and the welfare of laying hens through genetic selection

ABSTRACT 1. Genetic selection for bone quality can improve this, as it is heritable. A method was established using digital X-ray which took around 40 s in total and gave an image that allowed quantification of bone density from many appendicular bones. 2. The tibiotarsus measurement of bone density on the live hen across the different experiments had correlations with post-mortem whole bone radiographic density from 0.62 to 0.7, similar to that between density and material properties for example. Differences between groups of hens, where calcium and phosphorus in the diet were manipulated, were detected within 3 weeks of treatment using live hen measurement (P < 0.001, n = 24). 3. In a gage analysis, ‘hen’ explained more than 86% of the variance, demonstrating the ability to observe clear differences between hens. The effect of different operators’ analysis on the contribution to variance was very low as was the repeated measurement of the same hen. 4. The measurement of bone density on the live hen described in this paper represented major progress to a usable method for genetic selection to improve bone strength in laying hens. The method has the potential to reduce the number of animals needed to test nutritional and management interventions to improve bone health.

FlexMetric bone marrow aspirator yields laboratory and clinically improved results from mesenchymal stem and progenitor cells without centrifugation.

Several devices used to harvest stem/progenitor cells from bone marrow are available to clinicians. This study compared three devices measuring stem cell yields and correlating those yields to bone regeneration. A flexible forward aspirating system Marrow Marxman (MM), a straight needle aspirating on withdrawal system Marrow Cellutions (MC), and a straight needle aspirating on withdrawal and centrifuging the aspirate (BMAC) were compared in a side-to-side patient comparison, as well as tissue engineered bone grafts. The FlexMetric system (MM) produced greater CFU-f values compared to the straight needle (MC) Δ=1083/ml, p<0.001 and 1225/ml, p<0.001 than the BMAC system. This increased stem/progenitor cell yield also translated into a greater radiographic bone density at 6months Δ=88.3 Hu, p≤0.001 versus MC and Δ=116.7, p<0.001 versus BMAC at 6months and Δ=72.2, p<0.001 and Δ=93.3, p<0.001 at 9months respectively. The increased stem/progenitor cell yield of the MM system clinically translated into greater bone regeneration as measured by bone volume p<0.014 and p<0.001 respectively, trabecular thickness p<0.007 and p<0.002 respectively, and trabecular separation p=0.011 and p<0.001. A flexible bone marrow aspirator produces higher yields of stem/progenitor cells. Higher yields of stem/progenitor cells translate into greater bone regeneration in tissue engineering. Flexmetric technology produces better bone regeneration due to a forward aspiration concept reducing dilution from peripheral blood and its ability to target lining cells along the inner cortex. Centrifugation systems are not required in tissue engineering procedures involving stem/progenitor cells due to nonviability or functional loss from g-forces.

Effect of Osseodensification on Bone Density and Crestal Bone Levels: A Split-mouth Study

Dental implants have become a popular alternative in the oral and maxillofacial rehabilitation after the introduction of the concept of osseointegration. A poor density bone can negatively influence the bone to implant contact (BIC) and delay osseointegration. Various osteotomy techniques and drilling procedures have been used to increase stability in low-density bone. But they have been associated with limitations such as trauma to the surrounding bone and difficulty in controlling the technique. Osseodensification has recently been developed. Densifying burs are specifically designed burs which help in preserving the bone by condensing the bone by rotating in the noncutting direction. Split-mouth study was conducted on a total of 10 patients wherein implants were placed in the same patient bilaterally in maxillary posterior region where the left maxillary posterior region received implants through sequential osteotomy technique and the right maxillary posterior region received implants through a series of new multifluted tapered burs (Densah™). A cone-beam computed tomography (CBCT) was taken preoperatively, immediately after implant placement, and 3 and 6 months after implant placement. The bone density and crestal bone levels were measured. Results were analyzed by student's paired "t" test and Man-Whitney U test. There is no statistical difference between the levels of the crestal bone between an osseodensified site as compared to a conventional osteotomy site. The width of the residual bone increases after osseodensification and remains in the increased dimension for 3 months and continues at 6 months. Thus, it can be concluded that osseodensification leads to bone expansion. The radiographic bone density adjacent to the implant is significantly increased after ossedensification and the bone there remains relatively dense over a period of 6 months aiding in a primary stability and eventual good osseointegration.

Factors associated with root migration after lower third molar coronectomy - preliminary results

Objective: The aim of this prospective study, with preliminary results, was to evaluate factors related with rootmigration after lower third molar coronectomy, especially radiographic bone density. Material and Methods:Twenty-two patients were submitted to 31 lower third molar coronectomies. Clinical and radiographic evaluationof all patients were performed preoperatively and at 7, 90 and 365 days postoperatively. Sociodemographic,clinical and radiographic data were collected. The root migration was analyzed by the distance from the toothapex to the mandibular canal, and radiographic bone density above the remaining roots was obtained, both usingthe software Image J©. Results: After 1-year follow-up no patients showed paresthesia, symptoms or requiredreintervention, however all roots showed migration. The mean root migration was 2.66 mm at 90 days, and3.37 mm at 365 days (p = 0.0007). The rate of migration was higher at the early postoperative period. The simplelinear regression test between root migration and radiographic bone density was not significant (R=-0.173 andp=0.453; R=-0.045 and p=0.902; at 90 days and 365 days, respectively) as well as the analysis between rootmigration and other clinical and radiographic variables. Conclusion: It was possible to conclude, based on thesepreliminary results, that all roots showed migration during the follow-up period. The radiographic bone densityincreases and, consequently, the root migration rate diminishes within time, however none of the evaluatedfactors showed significant association with root migration.KEYWORDSBone density; Mandibular nerve; Third molar; Surgery oral.

ASSOCIATIONS BETWEEN PREDICTED AND ACTUAL STRUCTURAL PROGRESSION IN THE APPROACH COHORT

In the APPROACH study, machine learning models were trained to predict structural and pain progression of individual participants. Predicted progression was differentiated into a structural (S) and pain (P) progression score, where the score (range 0-1) reflected the likelihood of a participant being a progressor. Structural progression was defined as a decrease in minimum JSW of ≥0.3mm/year. Only participants with the estimated highest 75% combined (P+S) score after screening were included. To evaluate the associations between the predicted and actual structural progression according to different parameters over two years. 297 Participants were included at five European centers. Radiographs and 1.5T or 3T MRIs were acquired at baseline and two years. Minimum and mean medial and lateral tibiofemoral (TF) JSW, subchondral bone density, and osteophyte size were measured from radiographs. Medial and lateral cartilage thickness was measured from 3D SPGR MRI scans using manual, quality-controlled segmentations. Semi-quantitative MOAKS cartilage damage, bone marrow lesions (BML) and osteophytes scores were assessed from triplanar PDW and T1W sequences, summarized to overall medial and lateral scores. Progression was defined as two-year change greater than the smallest detectable change (SDC) for continuous measures or a change in ≥1 full MOAKS score, in the most affected compartment (MAC). For minimum JSW, progressors as predefined in the study protocol were analyzed as well. The association of S scores with progression was analyzed using logistic regression. Data was available for 237 participants. TF progression was seen most often in MRI cartilage thickness (38%) and radiographic bone density (39%) and osteophyte size (35%). S scores were not significantly associated with progression of any TF structural parameter besides minimum JSW, both based on the predefined progression criterion of ≤-0.6mm and on the SDC of <-0.49mm over two years. However, baseline minimum JSW was used for calculation of S scores, and after adjustment for baseline minimum JSW, the S scores were no longer associated with minimum JSW progression (both p>0.38). Selecting only participants with radiographic OA (KL grade ≥2, 53%) resulted in a higher percentage of progressors for all parameters (e.g. 50% MRI cartilage thickness) but this did not change results for S score association. Despite the use of machine learning models in the APPROACH cohort to only include participants that were predicted to show fast pain and/or structural progression, only around 1 in 6 participants was a structural progressor based on the predefined criterion. It is possible this number would have been lower without the model-based inclusion. Still, the S scores were generally not associated with progression. The machine learning model was trained using a different progression criterion than most criteria used in this validation; machine learning models trained on the actual criteria used for this analysis may have been more effective and is now possible with the data from the APPROACH cohort. EU/EFPIA Innovative Medicines Initiative Joint Undertaking (grant n° 115770) WW: Chondrometrics GmbH; FWR: Boston Imaging Core Lab, LLC IMI-APPROACH (NCT03883568) participants and investigators CORRESPONDENCE ADDRESS: m.p.jansen-36@umcutrecht.nl .

Radiographic predictive factors for 10-year survival of removable partial denture abutment teeth: Alveolar bone level and density.

To determine postoperative periodontal and radiographic factors that predict the survival rates of abutments of removable partial dentures (RPDs). Patients who wore RPDs for > 10 years and received supportive periodontal therapy were included. Periodontal examinations and radiographic assessments were conducted on 83 abutment teeth in 35 patients at baseline, and five years after RPD insertion. In addition to conventional factors, such as tooth mobility at 5 years, radiographic factors, such as the crown-root ratio (ΔCR ratio) and gray-level changes reflecting changes in alveolar bone density (ΔABD), were evaluated. The impact of the covariables on the 10-year survival of abutment teeth was estimated using a multivariate Cox regression model, considering multicollinearity. Patients were classified as having A2-B2 (45.7%) and B3-C2 (54.3%) tooth loss, according to the Eichner classification. A probing depth ≥ 4 mm, tooth mobility ≥ grade 1, and CR ratio ≥ 1 were found in 30.1%, 33.7%, and 51.8% of abutment teeth, respectively. The 10-year survival rate of abutment teeth was 86.7%. Multivariate analysis showed that the 10-year survival of abutment teeth was significantly associated with root canal treatment (P = 0.045, hazard ratio [HR] = 1.23), the 5-year ΔCR ratio (P = 0.022, HR = 3.20), and ΔABD on the edentulous side of the abutment teeth (P = 0.047, HR = 1.08). In addition to root canal treatment, changes in the CR ratio and radiographic alveolar bone density at five years predicted the long-term survival rate of RPD abutments.