Mandibular bone structure, bone mineral density, and clinical variables as fracture predictors: a 15-year follow-up of female patients in a dental clinic

Mandibular trabecular bone pattern before and two years after medical or surgical obesity treatment in young Swedish women

OBJECTIVE

To investigate if changes in body mass index (BMI) result in changes of the mandibular trabecular bone structure.

MATERIALS AND METHODS

Females (18-35 years at baseline, mean BMI 42,3) were followed from before (n = 117) until two years (n = 66) after obesity treatment (medical or surgical). The mandibular bone trabeculation was classified as sparse, dense, or mixed on intraoral radiographs (Lindh's index). A digitized method (Jaw-X) assessed the size and intensities of intertrabecular spaces. The main predictor variable was BMI reduction over the period.

RESULTS

Before treatment, the group with a high BMI (≥ 45) had a significantly denser bone than those with a lower BMI (p = 0.035). Two years after treatment, fewer were classified with sparse bone (Lindh's index p = 0.001, Jaw-X p = 0.009). The physical activity increased with fewer having a sedentary lifestyle (40% before, 17% after treatment). The association between BMI reduction and the difference in Jaw-X was significant in regression models and not influenced by obesity treatment method but by baseline factors as age, trabecular bone pattern and level of ionized calcium.

CONCLUSIONS

Before obesity treatment, high BMI was associated with dense bone trabeculation in the jaw. The group with sparse bone had decreased at follow-up. The association between BMI reduction and bone trabeculation was influenced by individual and medical factors.

CLINICAL RELEVANCE

Bone trabeculation in the mandible was maintained during the first years after obesity treatment but new health habits should be encouraged, and patients need to be monitored and followed up further.

Evaluating trabecular microstructure of mandible and axis in osteoporosis, diabetes and chronic kidney disease using cone beam computed tomography

OBJECTIVES

Like other bones, the mandible and cervical vertebrae are affected by several systemic diseases. The aim of this study is to evaluate the effects of osteoporosis (OP), diabetes mellitus (DM), and dialysis-indicated advanced chronic kidney disease (CKD), which are the most effective systemic diseases on the bone metabolism, on the trabecular microstructure of the mandible and cervical vertebrae using cone beam computed tomography (CBCT).

METHODS

81 patients who signed our informed consent form are involved in the study. 18 of them were diagnosed with osteoporosis, 18 of them with diabetes mellitus, 18 of the patients had dialysis-indicated CKD, and 27 of them were in the control group without any systemic diseases. Nine patients in the control group, patients with CKD and patients with DM were men, and nine were women. All patients with osteoporosis and 18 of the patients in the control group were women. Using CBCT images, microstructural parameters of trabecular thickness (Tb.Th), trabecular spacing (Tb.Sp) and volume fraction (bone volume/total volume, BV/TV) were measured.

RESULTS

Tb.Th and BV/TV values were higher in the control group, while Tb.Sp was higher in the osteoporosis group. The difference in BV/TV parameters was statistically significant (p = 0.02). In the DM group, Tb.Th and BV/TV values were lower and Tb.Sp values were significantly higher than in the control group (p = 0.001). In patients with advanced CKD, Tb.Th and BV/TV values were lower, while Tb.Sp values were higher than in the control group. Differences in Tb.Sp parameters were statistically significant (0.004).

CONCLUSION

Systemic diseases affect bone tissue at different levels, and to evaluate these effects, cortical and trabecular bone parts must be investigated separately, and findings must be combined with patients' clinical symptoms. CBCT is suitable for microstructural evaluation of trabecular bone and the mandible carries valuable data for this purpose.

Potential of Health Insurance Claims Data to Predict Fractures in Older Adults: A Prospective Cohort Study

Purpose

In older adults, fractures are associated with mortality, disability, loss of independence and high costs. Knowledge on their predictors can help to identify persons at high risk who may benefit from measures to prevent fractures. We aimed to assess the potential of German claims data to predict fractures in older adults.

Patients and Methods

Using the German Pharmacoepidemiological Research Database (short GePaRD; claims data from ~20% of the German population), we included persons aged ≥65 years with at least one year of continuous insurance coverage and no fractures prior to January 1, 2017 (baseline). We randomly divided the study population into a training (80%) and a test sample (20%) and used logistic regression and random forest models to predict the risk of fractures within one year after baseline based on different combinations of potential predictors.

Results

Among 2,997,872 persons (56% female), the incidence per 10,000 person years of any fracture in women increased from 133 in age group 65–74 years (men: 71) to 583 in age group 85+ (men: 332). The maximum predictive performance as measured by the area under the curve (AUC) across models was 0.63 in men and 0.60 in women and was achieved by combining information on drugs and morbidities. AUCs were lowest in age group 85+.

Conclusion

Our study showed that the performance of models using German claims data to predict the risk of fractures in older adults is moderate. Given that the models used data readily available to health insurance providers in Germany, it may still be worthwhile to explore the cost–benefit ratio of interventions aiming to reduce the risk of fractures based on such prediction models in certain risk groups.

Hydrogel: A Potential Material for Bone Tissue Engineering Repairing the Segmental Mandibular Defect

Free flap surgery is currently the only successful method used by surgeons to reconstruct critical-sized defects of the jaw, and is commonly used in patients who have had bony lesions excised due to oral cancer, trauma, infection or necrosis. However, donor site morbidity remains a significant flaw of this strategy. Various biomaterials have been under investigation in search of a suitable alternative for segmental mandibular defect reconstruction. Hydrogels are group of biomaterials that have shown their potential in various tissue engineering applications, including bone regeneration, both through in vitro and in vivo pre-clinical animal trials. This review discusses different types of hydrogels, their fabrication techniques, 3D printing, their potential for bone regeneration, outcomes, and the limitations of various hydrogels in preclinical models for bone tissue engineering. This review also proposes a modified technique utilizing the potential of hydrogels combined with scaffolds and cells for efficient reconstruction of mandibular segmental defects.

The outcome of an automated assessment of trabecular pattern in intraoral radiographs as a fracture risk predictor

OBJECTIVES

This study aims to investigate if automated analyses of the trabecular pattern in intraoral radiographs independently contribute to fracture risk assessment when other risk factors incorporated in the Fracture Risk Assessment Tool (FRAX) are taken into account. A secondary aim is to explore the correlation between the automated trabecular pattern assessment in intraoral radiographs and Trabecular Bone Score (TBS).

METHODS

A total of 567 intraoral radiographs from older females participating in a large population-based study (SUPERB) based in Gothenburg, Sweden, were selected to analyse trabecular pattern using semi-automated and fully automated software. Associations between trabecular pattern analysis and incident fractures were studied using Cox proportional hazard model, unadjusted and adjusted for FRAX risk factors (previous fracture, family history of hip fracture, smoking, corticosteroids, rheumatoid arthritis, without and with bone mineral density (BMD) of the femoral neck). In addition, the correlation between trabecular pattern analysis and TBS of the lumbar spine was investigated using Pearson correlation analysis.

RESULTS

Neither the unadjusted nor the adjusted trabecular pattern analysis in intraoral radiographs was significantly associated with any fracture or major osteoporotic fracture (MOF). A weak correlation was found between semi-automated trabecular pattern analysis and TBS. No correlation was found between the fully automated trabecular pattern analysis and TBS.

CONCLUSIONS

The present study shows that semi-automated and fully automated digital analyses of the trabecular pattern in intraoral radiographs do not contribute to fracture risk prediction. Furthermore, the study shows a weak correlation between semi-automated trabecular pattern analysis and TBS.

The challenge of applying digital image processing software on intraoral radiographs for osteoporosis risk assessment

OBJECTIVES

The purpose of this study was to evaluate rater agreement and the accuracy of a semi-automated software and its fully automated tool for osteoporosis risk assessment in intraoral radiographs.

METHODS

A total of 567 intraoral radiographs was selected retrospectively from women aged 75-80 years participating in a large population-based study (SUPERB) based in Gothenburg, Sweden. Five raters assessed participants' risk of osteoporosis in the intraoral radiographs using a semi-automated software. Assessments were repeated after 4 weeks on 121 radiographs (20%) randomly selected from the original 567. Radiographs were also assessed by the softwares' fully automated tool for analysis.

RESULTS

Overall interrater agreement for the five raters was 0.37 (95% CI 0.32-0.41), and for the five raters with the fully automated tool included as 'sixth rater' the overall Kappa was 0.34 (0.30-0.38). Intrarater agreement varied from moderate to substantial according to the Landis and Koch interpretation scale. Diagnostic accuracy was calculated in relation to reference standard for osteoporosis diagnosis which is T-score values for spine, total hip and femoral neck and presented in form of sensitivities, specificities, predictive values, likelihood ratios and odds ratios. All raters' mean sensitivity, including the fully automated tool, was 40,4% (range 14,3%-57,6%). Corresponding values for specificity was 69,5% (range 59,7%-90,4%). The diagnostic odds ratios ranged between 1 and 2.7.

CONCLUSION

The low diagnostic odds ratio and agreement between raters in osteoporosis risk assessment using the software for analysis of the trabecular pattern in intraoral radiographs shows that more work needs to be done to optimise the automation of trabecular pattern analysis in intraoral radiographs.

Trabecular bone patterns as a fracture risk predictor: a systematic review

BACKGROUND

The aim of this systematic review was to evaluate the assessment of trabecular bone patterns in dental radiographs, for fracture risk prediction, compared with the current diagnostic methods.

METHODS

The PRISMA guidelines were followed. According to predefined inclusion criteria (PICO), literature searches were focussed on published studies with analyses of trabecular bone patterns on intraoral and/or in panoramic radiographs, compared with Dual X-ray Absorptiometry (DXA) and/or Fracture Risk Assessment Tool (FRAX), with the outcomes; fracture and/or sensitivity and specificity for osteoporosis prediction. The included studies were quality-assessed using the QUADAS-2 tool and the certainties of evidence was assessed using the GRADE approach.

RESULTS

The literature searches identified 2913 articles, whereas three were found to meet the inclusion criteria. Two longitudinal cohort studies evaluated the use of trabecular bone patterns to predict bone fractures. In one of the studies, the relative risk of fracture was significantly higher for women with sparse bone pattern, identified by visual assessment of dental radiographs, and in the other study by digital software assessment. Visual assessment in the second study did not show significant results. The cross-sectional study of digital analyses of trabecular bone patterns in relation to osteoporosis reported a sensitivity of 0.70 and a specificity of 0.69.

CONCLUSION

Based on low certainty of evidence, trabecular bone evaluation on dental radiographs may predict fractures in adults without a prior diagnosis of osteoporosis, and based on very low certainty of evidence, it is uncertain whether digital image analyses of trabecular bone can predict osteoporosis.

Two methods of evaluating mandibular trabecular pattern in intraoral radiographs and the association to fragility fractures during a 47-year follow up

In this longitudinal cohort study, we explored the association of fragility fractures to sparse trabecular bone pattern in intraoral radiographs using two methods, a visual and a semi-automated. Our aim was to study both sexes and to include younger age-groups, during a follow-up time of 47 years. The cohort consisted of 837 men and women aged 18-65 years, with intraoral radiographs from 1970-1971. The trabecular pattern was assessed in the mandibular premolar region with a visual and a semi-automated method. Data on fragility fractures were acquired from the Swedish National Patient Register for 47 years of follow-up time. Sparse trabecular pattern was found in 2.2% of the cohort using the visual method, and 18% were deemed at 'risk of osteoporosis' using the semi-automated method. A total of 132 individuals suffered at least one fragility fracture during the follow-up period. We found no significant association between fractures and sparse trabecular pattern using either method. This study shows that visual assessment, as a predictor of future fractures, may not be a suitable method for individuals of all ages and sexes. As for the semi-automated method, there is still very limited evidence for its fracture predictive ability.

The rise and fall of the alveolar process: Dependency of teeth and metabolic aspects

The alveolar bone has a unique capacity to follow the teeth's movements. It is formed around erupting teeth and their periodontal ligaments: the more the teeth have erupted, the larger the alveolar process. Throughout life the teeth erupt and migrate in an occlusal and mesial direction to compensate for attrition, an evolutionary trait. After tooth extraction, the alveolar process is resorbed to varying degrees. The mandibular alveolar bone mirrors skeletal bone condition. Due to fast bone turnover (which is the fastest in the whole skeleton), low bone mass and increased fracture risk may first be seen here. If a periapical radiograph of the mandibular premolars shows a dense trabeculation with well-mineralized trabeculae and small intertrabecular spaces, it is a reliable sign of normal skeletal bone density (BMD) and low skeletal fracture risk, whereas a sparse trabecular pattern indicates osteopenia and high fracture risk. The bone turnover rate in the mandible is twice that of the maxilla, and may, hypothetically, play a role in the development of osteonecrosis of the jaw (ONJ), which has been found mainly in the mandibular alveolar process?

Comparison of mandibular cortical thickness and QCT-derived bone mineral density (BMD) in survivors of childhood acute lymphoblastic leukemia: a retrospective study

OBJECTIVE

To examine whether panoramic radiograph-determined mandibular cortical thickness correlated with quantitative computed tomography-derived bone mineral density (BMD) in survivors of childhood acute lymphoblastic leukemia (ALL).

METHODS

We identified patients treated for ALL at St. Jude Children's Research Hospital, seen in the After Completion of Therapy (ACT) Clinic between January of 2006 and January of 2014 who had QCT-derived BMD and panoramic radiographs obtained within 1 month of each other. Panoramic radiographs were independently scored by a pediatric radiologist, two pediatric dentists, and a general dentist using the Klemetti technique. We used the Spearman's rank correlation test and the multivariate regression model to investigate the effect of evaluator experience on results.

RESULTS

The study cohort comprised 181 patients with 320 paired studies: 112 (62%) male, 112 (71%) were white. Median age at ALL diagnosis was 6.4 (range, 0-18.8) years. Median age at study was 11.9 (range, 3.3 to 29.4) years. The median average BMD was 154.6 (range, 0.73-256) mg/cc; median QCT Z-score (age and gender adjusted) was -0.875 (range, -5.04 to 3.2). We found very weak association between panoramic radiograph score and both QCT-BMD average (P = 0.53) and QCT Z-score (P = 0.39). Results were not influenced by level of reader experience.

CONCLUSIONS

The Klemetti technique of estimating BMD does not predict BMD deficits in children and young adult survivors of ALL, regardless of reviewer expertise. Alternative methods are needed whereby dental healthcare providers can identify and refer patients at risk for BMD deficits for detailed assessment and intervention.

Predicting Trabecular Bone Stiffness from Clinical Cone-Beam CT and HR-pQCT Data; an In Vitro Study Using Finite Element Analysis

Stiffness and shear moduli of human trabecular bone may be analyzed in vivo by finite element (FE) analysis from image data obtained by clinical imaging equipment such as high resolution peripheral quantitative computed tomography (HR-pQCT). In clinical practice today, this is done in the peripheral skeleton like the wrist and heel. In this cadaveric bone study, fourteen bone specimens from the wrist were imaged by two dental cone beam computed tomography (CBCT) devices and one HR-pQCT device as well as by dual energy X-ray absorptiometry (DXA). Histomorphometric measurements from micro-CT data were used as gold standard. The image processing was done with an in-house developed code based on the automated region growing (ARG) algorithm. Evaluation of how well stiffness (Young's modulus E3) and minimum shear modulus from the 12, 13, or 23 could be predicted from the CBCT and HR-pQCT imaging data was studied and compared to FE analysis from the micro-CT imaging data. Strong correlations were found between the clinical machines and micro-CT regarding trabecular bone structure parameters, such as bone volume over total volume, trabecular thickness, trabecular number and trabecular nodes (varying from 0.79 to 0.96). The two CBCT devices as well as the HR-pQCT showed the ability to predict stiffness and shear, with adjusted R2-values between 0.78 and 0.92, based on data derived through our in-house developed code based on the ARG algorithm. These findings indicate that clinically used CBCT may be a feasible method for clinical studies of bone structure and mechanical properties in future osteoporosis research.

Alveolar bone loss in osteoporosis: a loaded and cellular affair?

Maxillary and mandibular bone mirror skeletal bone conditions. Bone remodeling happens at endosteal surfaces where the osteoclasts and osteoblasts are situated. More surfaces means more cells and remodeling. The bone turnover rate in the mandibular alveolar process is probably the fastest in the body; thus, the first signs of osteoporosis may be revealed here. Hormones, osteoporosis, and aging influence the alveolar process and the skeletal bones similarly, but differences in loading between loaded, half-loaded, and unloaded bones are important to consider. Bone mass is redistributed from one location to another where strength is needed. A sparse trabeculation in the mandibular premolar region (large intertrabecular spaces and thin trabeculae) is a reliable sign of osteopenia and a high skeletal fracture risk. Having dense trabeculation (small intertrabecular spaces and well-mineralized trabeculae) is generally advantageous to the individual because of the low fracture risk, but may imply some problems for the clinician.

Technologies for assessment of bone reflecting bone strength and bone mineral density in elderly women: an update

Reduced bone mineral density is a strong risk factor for fracture. The WHO's definition of osteoporosis is based on bone mineral density measurements assessed by dual x-ray absorptiometry. Several on other techniques than dual x-ray absorptiometry have been developed for quantitative assessment of bone, for example, quantitative ultrasound and digital x-ray radiogrammetry. Some of these techniques may also capture other bone properties than bone mass that contribute to bone strength, for example, bone porosity and microarchitecture. In this article we give an update on technologies which are available for evaluation primarily of bone mass and bone density, but also describe methods which currently are validated or are under development for quantitative assessment of other bone properties.

Five-year alveolar bone level changes in women of varying skeletal bone mineral density and bone trabeculation

OBJECTIVES

To investigate alveolar bone level changes in women with varying skeletal bone mineral density (BMD) and bone trabeculation.

STUDY DESIGN

In a prospective, longitudinal study of 128 women (22-75 years of age), BMD (dual x-ray absorptiometry), and periapical radiography were performed in 1996 and 2001. The mandibular trabecular bone was assessed as dense, mixed, or sparse. Mandibular alveolar bone level was measured with a Schei ruler and related to BMD (osteoporotic, osteopenic, or normal) and trabeculation.

RESULTS

After 5 years, the total bone level score was significantly decreased (P = .001). No significant differences were found in the total bone level scores between the different BMD groups. The greatest decreased total bone level score in 1996 was found in the group with dense trabeculation (0.71 in the dense group vs. 0.31 in the nondense group, P = .005), and similarly in 2001 (0.75 in the dense group vs. 0.39 in the nondense group, P = .020). Five-year changes in the total bone level scores did not differ between trabeculation groups (P = .37).

CONCLUSIONS

The small group of women with dense mandibular trabecular bone seems to suffer a greater decrease in alveolar bone height compared with other women, including women with osteoporosis.