Observer performance in diagnosing osteoporosis by dental panoramic radiographs: results from the osteoporosis screening project in dentistry (OSPD)

Radiomorphometric indices of the mandible as indicators of decreased bone mineral density and osteoporosis - meta-analysis and systematic review

This review aims to evaluate the accuracy of various mandibular radiomorphometric indices in comparison with DEXA BMD measurements in the diagnosis of osteopenia and osteoporosis based on a meta-analysis of the sensitivity and specificity of the indices. PRISMA statement was followed. The materials for analysis were collected in August 2023 by searching three databases: PubMed Central, Web of Science, and Scopus. The selection of studies consisted of three selection stages, and 64 articles were finally obtained. Quality assessment was performed with the QUADAS-2 tool, and the general methodological quality of retrieved studies was low. Statistical analysis was performed based on 2 × 2 tables and estimated sensitivity and specificity were obtained using SROC curves. The most used indices were MCI, MCW and PMI. The best results in detecting reduced BMD obtained for MCW ≤ 3 mm, estimated sensitivity and specificity were 0.712 (95% CI, 0.477-0.870) and 0.804 (95% CI, 0.589-0.921), respectively. The most prone to the risk of bias is the MCI due to the examiner's subjectivism. Radiomorphometric indices of the mandible can be useful as a screening tool to identify patients with low BMD, but should not be used as a diagnostic method. Further research needs to focus on analysing the ability of the indices to detect osteoporosis and also in combination the indices with clinical parameters.

Effectiveness of Orthopantomograms as a Screening Tool for Osteoporosis: A Case-Control Study

Introduction Osteoporosis is a disease that is characterised by low bone mineral density (BMD), and loss of structural and biomechanical properties that are essential in maintaining bone homeostasis. Osteoporosis is diagnosed by clinical measurement of BMD and is the best predictor of osteoporosis. The study was conducted with the aim of assessing the effectiveness of orthopantomogram (OPG) as a screening tool for osteoporosis in postmenopausal women and chronic drug users. Objectives The primary objective of the current study was to assess the mandibular cortical width and antegonial index in postmenopausal women and chronic drug users, the secondary objective was to compare the mandibular cortical width and antegonial index of postmenopausal women and chronic drug users with that of the control group (healthy individual). Methods Three groups were taken in this study with a sample size of 300 with 100 OPG in each group. The groups categorised in the study were postmenopausal women, patients under drugs (glucocorticoids, proton pump inhibitor, anti-epileptic drugs, selective serotonin reuptake inhibitor) and the control group and the parameters assessed were antegonial index and mandibular cortical width. Results Results were tabulated and analysed using Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 26.0, Armonk, NY). The normality tests Kolmogorov-Smirnov and Shapiro-Wilks test results reveal that the variables (both indices) follow the normal distribution. The mandibular cortical width was 3.44, 2.66 and 2.96 in the normal, postmenopausal women and women on drugs respectively. The antegonial index was 163.5, 157.2 and 158.8 in the normal, postmenopausal women and women on drugs respectively. Conclusion From the above results, it is evident that there is a statistically significant reduction in antegonial index and mandibular cortical width in postmenopausal women compared to normal individuals. Alterations of this value are suggestive that early pre-clinical changes of osteoporosis can be detected in the high-risk group using OPG.

Relation between panoramic mandibular index and disease activity in patients with rheumatoid arthritis

Background

DEXA scan could be unavailable at some health centers, and radiologic examination of the mandible and oral cavity is considered more commonly used radiologic test that can predict, diagnose, or even follow-up on any defect in bone mineralization. The aim of this study was to elucidate the ability of panoramic radiograph to detect osteoporosis in rheumatoid arthritis patients and correlate panoramic mandibular index with RA disease activity and severity parameters.

Results

The sensitivity of panoramic mandibular index for diagnosis of osteoporosis was 96% in group Ι (primary OP) and 70% in group ΙΙ (RA patients). The positive predictive value of PMI was 67% in group Ι and 55% in group ΙΙ. The negative predictive value of PMI was 34% in group Ι and was 46% in group ΙΙ. The cutoff value of PMI for diagnosis of OP was ≤ 0.31 in group Ι and ≤ 0.17 in group ΙΙ. In group I, there were significant correlations between panoramic mandibular index and patient’s ages, weights, T score at L1-4, T score at femoral neck, and T score at forearm while there were insignificant correlations between PMI and patients’ heights. In group ΙΙ, there were significant correlations between PMI, patients’ ages, weights, disease durations, SHARP score, ESR, RF, T score at L1-4, T score at femoral neck, and T score at forearm, while there were insignificant correlations between PMI and patients’ heights, DAS, and CRP.

Conclusions

Panoramic radiography could have a potential usability in the diagnosis of osteoporosis in rheumatoid arthritis patients regardless of displaying insignificant correlation with disease activity.

Panoramic radiography and patients with disability: a new simple breathing technique to reduce common airspace error

Patients with intellectual disabilities often fail to follow traditional tongue position instructions for panoramic radiographs resulting in missed pathology or unnecessary further radiation. This simple breathing technique is a new clinical instruction method for panoramic radiography developed to reduce the most common patient position error: patient failure to hold the tongue to the roof of the mouth. The technique is suitable for all patients including young patients and those with intellectual disabilities. The simple breathing technique uses 'tell-show-do' communication methods and does not mention the tongue but utilises the known tongue positions that occur during breathing and swallowing. This simple breathing technique instruction for panoramic radiography uses a demonstration of 'breathe-in, breathe-out, swallow, lips closed and hold still' to reduce the intensity of both the palatoglossal and pharyngeal airspaces on panoramic radiographs. This method, referred in this article as the simple breathing technique, can improve the diagnostic potential of panoramic radiographs and can be used with young children and patients with intellectual disabilities, and this slow breathing technique can help them further relax.

Mandibular cortical bone structure as risk indicator in fractured and non-fractured 80-year-old men and women

Objective

To investigate the association between mandibular cortex parameters and fracture in a group of 286 men and women, 79–80 years of age.

Study design

In a cross-sectional study, the mandibular cortex was evaluated with Klemetti’s index for cortical erosion. The cortical thickness was measured with a ruler adjusting for the magnification factor. The odds ratio (OR) for fracture when having a severely eroded cortex or a cortex thickness < 3 mm was calculated.

Results

A normal cortex was found in 65% of men, whereas only 7% had a severely eroded cortex. The OR for severely eroded cortex  as fracture risk predictor was significant (2.32; 95% CI 1.3–4.2), also when the female group was evaluated separately. A significant difference was found between the mean thickness for men (3.96 mm) and women (2.92 mm), respectively. The OR for cortical thickness < 3 mm was significant (2.00; 95% CI 1.1–3.6) in the total group, but not when men and women were evaluated separately.

Conclusions

Among old women, the cortical parameters were significantly associated with prevalent fracture. In old men, other circumstances may be more important.

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.

Clinical guidelines for the application of panoramic radiographs in screening for osteoporosis

Osteoporotic fractures are associated with an increased risk of subsequent fractures, a higher rate of mortality, and incremental medical costs. Incidental findings, which include some measurements related to the mandibular inferior cortex and the alveolar trabecular bone pattern of the mandible determined on panoramic radiographs, are considered to be a useful tool for identifying asymptomatic individuals at risk of having osteoporosis and/or fragility fractures. We undertook a worldwide literature survey and present the following clinical recommendations. Postmenopausal female dental patients with a mandibular inferior cortical width of less than 3 mm on panoramic radiographs may be at risk of having low skeletal bone mineral density (BMD) or osteoporosis, but not fragility fractures. In addition, those with a severely eroded mandibular inferior cortex may have an increased risk of having low skeletal BMD, osteoporosis, and fragility fractures. The alveolar trabecular bone pattern of the mandible might be useful for identifying female dental patients at risk of having fragility fractures, although further investigation is necessary to confirm this possibility. These incidental findings on panoramic radiographs, when used for identifying asymptomatic postmenopausal female patients at risk of having osteoporosis in general dental practice, may be helpful in reducing the incidence of first fractures, with a consequent reduction in the secondary fractures, medical costs, and mortality associated with osteoporotic fragility fractures, without incurring any additional cost.

How massed practice improves visual expertise in reading panoramic radiographs in dental students: An eye tracking study

The interpretation of medical images is an error-prone process that may yield severe consequences for patients. In dental medicine panoramic radiography (OPT) is a frequently used diagnostic procedure. OPTs typically contain multiple, diverse anomalies within one image making the diagnostic process very demanding, rendering students’ development of visual expertise a complex task. Radiograph interpretation is typically taught through massed practice; however, it is not known how effective this approach is nor how it changes students’ visual inspection of radiographs. Therefore, this study investigated how massed practice–an instructional method that entails massed learning of one type of material–affects processing of OPTs and the development of diagnostic performance. From 2017 to 2018, 47 dental students in their first clinical semester diagnosed 10 OPTs before and after their regular massed practice training, which is embedded in their curriculum. The OPTs contained between 3 to 26 to-be-identified anomalies. During massed practice they diagnosed 100 dental radiographs without receiving corrective feedback. The authors recorded students’ eye movements and assessed the number of correctly identified and falsely marked low- and high prevalence anomalies before and after massed practice. Massed practice had a positive effect on detecting anomalies especially with low prevalence (p < .001). After massed practice students covered a larger proportion of the OPTs (p < .001), which was positively related to the detection of low-prevalence anomalies (p = .04). Students also focused longer, more frequently, and earlier on low-prevalence anomalies after massed practice (p_s < .001). While massed practice improved visual expertise in dental students with limited prior knowledge, there is still substantial room for improvement. The results suggest integrating massed practice with more deliberate practice, where, for example, corrective feedback is provided, and support is adapted to students’ needs.

Computer-aided diagnosis system for osteoporosis based on quantitative evaluation of mandibular lower border porosity using panoramic radiographs

OBJECTIVES

A new computer-aided screening system for osteoporosis using panoramic radiographs was developed. The conventional system could detect porotic changes within the lower border of the mandible, but its severity could not be evaluated. Our aim was to enable the system to measure severity by implementing a linear bone resorption severity index (BRSI) based on the cortical bone shape.

METHODS

The participants were 68 females (>50 years) who underwent panoramic radiography and lumbar spine bone density measurements. The new system was designed to extract the lower border of the mandible as region of interests and convert them into morphological skeleton line images. The total perimeter length of the skeleton lines was defined as the BRSI. 40 images were visually evaluated for the presence of cortical bone porosity. The correlation between visual evaluation and BRSI of the participants, and the optimal threshold value of BRSI for new system were investigated through a receiver operator characteristic analysis. The diagnostic performance of the new system was evaluated by comparing the results from new system and lumbar bone density tests using 28 participants.

RESULTS

BRSI and lumbar bone density showed a strong negative correlation (p < 0.01). BRSI showed a strong correlation with visual evaluation. The new system showed high diagnostic efficacy with sensitivity of 90.9%, specificity of 64.7%, and accuracy of 75.0%.

CONCLUSIONS

The new screening system is able to quantitatively evaluate mandibular cortical porosity. This allows for preventive screening for osteoporosis thereby enhancing clinical prospects.

Mandibular Trabecular Bone Analysis Using Local Binary Pattern for Osteoporosis Diagnosis

BACKGROUND

Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and micro-architectural deterioration of bone tissue, leading to bone fragility and increased fracture risk. Since Panoramic image is a feasible and relatively routine imaging technique in dentistry; it could provide an opportunistic chance for screening osteoporosis. In this regard, numerous panoramic derived indices have been developed and suggested for osteoporosis screening. Jaw trabecular pattern is one of the main bone strength factors and trabecular bone pattern assessment is important factor in bone quality analysis. Texture analysis applied to trabecular bone images offers an ability to exploit the information present on conventional radiographs.

OBJECTIVE

The purpose of this study was to evaluate the relationship between Jaw trabecular pattern in panoramic image and osteoporosis based on image texture analyzing using local binary pattern.

MATERIAL AND METHODS

An experiment is evaluated in this paper based on a real hand-captured database of panoramic radiograph images from osteoporosis and non-osteoporosis person in Namazi Hospital, Shiraz, Iran .An approach is proposed for osteoporosis diagnosis consisting of two steps. First, modified version of local binary patterns is used to extract discriminative features from jaw panoramic radiograph images. Then, classification is done using different classifiers.

RESULTS

Comparative results show that the proposed approach provides classification accuracy about 99.6%, which is higher than many state-of-the-art methods.

CONCLUSION

High classification accuracy, low computational complexity, multi-resolution and rotation invariant are among advantages of our proposed approach.

Comparison of mandibular index values determined from standard panoramic versus cone beam computed tomography reconstructed images

OBJECTIVE

The aim of this study was to compare mandibular index values, including the mandibular cortical index (MCI), mental index (MI), and panoramic mandibular index (PMI), determined on the basis of cone beam computed tomography (CBCT) and panoramic reconstructed (PR) images.

STUDY DESIGN

PR and CBCT images of 182 patients were retrospectively analyzed. Cross-sectional (CS) and PR images were obtained from CBCT data. The MCI, MI, and PMI were assessed on CS, PR, and panoramic images and evaluated for intra- and interobserver agreements by κ-value or intraclass correlation coefficient (ICC) analysis. Agreement among measurement methods was assessed by using the Bland-Altman method, with CS images as the gold standard for linear measurements.

RESULTS

Measurements from PR and CS images agreed with those from panoramic images in 66.7% and 53.8% of C3 classifications of MCI (porous cortices forming many endosteal residues), respectively. Panoramic and CBCT images exhibited good agreement in MI findings (ICC 0.91) and moderate (PR and panoramic images: ICC 0.79) to good (CS and panoramic images: ICC 0.87) agreement in PMI findings.

CONCLUSIONS

Because of the overlapping of buccal and lingual cortices, panoramic images are especially inadequate for determining the C3 category of MCI. However, CS images obtained from available CBCT data provide better visibility compared with panoramic images and, therefore, can be used for evaluating mandibular indices.

Digital panoramic radiography and cone-beam CT as ancillary tools to detect low bone mineral density in post-menopausal women

OBJECTIVES

To evaluate the usefulness of the mandibular cortical index (MCI) obtained by digital panoramic radiography (DPR) and by panoramic reconstruction (PR) of cone-beam CT (CBCT) with three different slice thicknesses for the screening of low bone mineral density (BMD) in post-menopausal women.

METHODS

Two trained oral and maxillofacial radiologists assessed the MCI based on the morphology of the mandibular bone cortex (classified as C1, C2 or C3). The DPR and PR of CBCT with slice thicknesses of 5, 15 or 25 mm were compared to the BMD obtained by dual-energy X-ray absorptiometry (DXA) in post-menopausal women. Measures related to accuracy were calculated with MedCalc software. The confidence interval was set at 95%.

RESULTS

54 women (mean age 58.70 ± 7.35 years) participated in the study. The sensitivity and specificity values obtained for DPR were 52.6% and 56.2%, respectively, and values for PR of CBCT with 5, 15, and 25 mm slice thicknesses were 63.1% and 43.7%, 50.0% and 50.0%, and 52.6% and 62.5%, respectively. For the tools evaluated, the positive likelihood ratio ranged from 1.00 to 1.40 and negative likelihood ratio from 0.76 to 1.00. The positive predictive value (PPV) ranged from 70.4 to 76.9% and the negative predictive value (NPV) from 29.6 to 35.7%. Among the examinations, the highest value for area under the curve (AUC) was obtained for CBCT with 25 mm slice thickness (57.6%).

CONCLUSIONS

The MCI calculated by DPR and CBCT differed with regard to accuracy. Within the limitations of this study, the PR of CBCT with 25 mm slice thicknesses seems to be the most accurate among the examinations evaluated. Should the dentist be attentive, DPR and CBCT may be useful tools for the screening of low BMD in post-menopausal women, facilitating their timely referral for further assessment.

IDIOS: An innovative index for evaluating dental imaging-based osteoporosis screening indices

Purpose

The goal of this study was to develop a new index as an objective reference for evaluating current and newly developed indices used for osteoporosis screening based on dental images. Its name; IDIOS, stands for Index of Dental-imaging Indices of Osteoporosis Screening.

Materials and Methods

A comprehensive PubMed search was conducted to retrieve studies on dental imaging-based indices for osteoporosis screening. The results of the eligible studies, along with other relevant criteria, were used to develop IDIOS, which has scores ranging from 0 (0%) to 15 (100%). The indices presented in the studies we included were then evaluated using IDIOS.

Results

The 104 studies that were included utilized 24, 4, and 9 indices derived from panoramic, periapical, and computed tomographic/cone-beam computed tomographic techniques, respectively. The IDIOS scores for these indices ranged from 0 (0%) to 11.75 (78.32%).

Conclusion

IDIOS is a valuable reference index that facilitates the evaluation of other dental imaging-based osteoporosis screening indices. Furthermore, IDIOS can be utilized to evaluate the accuracy of newly developed indices.

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.

Quantitative assessment of mandibular cortical erosion on dental panoramic radiographs for screening osteoporosis

PURPOSE

Studies reported that the mandibular cortical width (MCW) measured on dental panoramic radiographs (DPRs) was significantly correlated with bone mineral density. However, MCW is not a perfect index by itself, and studies suggest the added utility of mandibular cortical index (MCI). In this study, we propose a method for computerized estimation of mandibular cortical degree (MCD), a new continuous measure of MCI, for osteoporotic risk assessment.

METHODS

The mandibular contour was automatically segmented using an active contour model. The regions of interest near mental foramen were extracted for MCW and MCD determination. The MCW was measured on the basis of residue-line detection results and pixel profiles. Image features including texture features based on gray-level co-occurrence matrices were determined. The MCD were estimated using support vector regression (SVR). The SVR was trained using previously collected 99 DPRs, including 26 osteoporotic cases, by a computed radiography system. The proposed scheme was tested using 99 DPRs obtained by a photon-counting system with data of bone mineral density at distal forearm. The number of osteoporotic, osteopenic, and control cases were 12, 18, and 69 cases, respectively. The subjective MCD by a dental radiologist was employed for training and evaluation.

RESULTS

The correlation coefficients with the subjective MCD were -0.549 for MCW alone, 0.609 for the MCD by the features without MCW, and 0.617 for the MCD by the features and MCW. The correlation coefficients with the BMD were 0.619, -0.608, and -0.670, respectively. The areas under the receiver operating characteristic curves for detecting osteoporotic cases were 0.830, 0.884, and 0.901, respectively, whereas those for detecting high-risk cases were 0.835, 0.833, and 0.880, respectively.

CONCLUSIONS

In conclusion, our scheme may have a potential to identify asymptomatic osteoporotic and osteopenic patients through dental examinations.

Identifying risk groups for osteoporosis by digital panoramic radiography

BACKGROUND

Osteoporosis is a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to bone fragility, and enhanced susceptibility to fractures. Dental radiographs, especially panoramic images, have been used to predict bone mineral density. A number of indices, (mandibular cortical index [MCI], mandibular cortical width [MCW], and panoramic mandibular index [PMI]) have been developed to assess and quantify the quality of mandibular bone mass and to observe the signs of resorption.

OBJECTIVES

The objectives of the study were to assess mental index (MI), MCW index, and PMI with bone density in identifying risk group for osteoporosis and also to investigate influence of age and gender on MI, MCI, and PMI.

MATERIALS AND METHODS

After obtaining consent, details regarding age, gender, systemic health status, and oral parafunctional habits were recorded in each patient. Then a digital panoramic radiograph was taken. The image thus obtained was subjected to calibrations and morphometric analysis using Digora version 2.7. The obtained values of indices were compared with the mean values of indices, to evaluate subjects whether they are prone to osteoporosis or not. The obtained information was subjected to statistical analysis for the significance of the parameters.

RESULTS

Data analysis showed that calibration indices were highly significant in the assessment of risk group for osteoporosis than noncalibration index. The subjects at a higher risk for development of osteoporosis were old-aged adults with higher prevalence being reported in women compared to male subjects.

CONCLUSION

In conclusion, our results suggest that higher percentage of subjects with undetected decreased bone mineral density may be identified based on trained general dental practitioners analyses of their panoramic radiographs using simple screening analytical calibration MI and MCI.

Radiomorphometric indices of mandibular bones in an 18th century population

OBJECTIVE

To estimate four radiomorphometric indices of mandibular bones in an 18th century population sample, and possibly associate the findings with bone mass loss related to sex, age, nutritional habits and pathologies reflecting on the bone.

DESIGN

Thirty-six sculls (31 males, 5 females), recovered from the crypt of Požega Cathedral in Croatia were analyzed. Age estimation was based on tooth wear, and Eichner class was determined according to the number of occlusal supporting zones. The parameters in recording analogue orthopantomographs were set to constant current of 16 mA, exposure time of 14.1s, and voltage between 62-78 kV. Films were processed in an automatic dark chamber processor for 12 min, and digitized at 8-bit, 300 dpi. The thickness of the mandibular cortex was assessed below the mental foramen (MI), at antegonion (AI), at gonion (GI). Qualitative mandibular cortical index (MCI) was assessed.

RESULTS

Average values of MI, AI and GI were 3.97 ± 0.94 mm, 2.98 ± 0.56 mm, and 1.99 ± 0.55 mm, respectively. Statistically significant differences between males and females were found for AI right (p=0.014), GI left (p=0.010) and GI average (p=0.006), and were in all cases higher in males. There were no statistically significant differences between age groups for either index (p>0.05). Considering Eichner classification the differences were not significant for MI (p=0.422), AI (p=0.516), and GI (p=0.443), but in Eichner classes II, MCI was significantly higher (p=0.02).

CONCLUSION

The obtained data does not suggest generalized malnutrition or calcium, phosphorus and vitamin D deprivation in the historic population studied.

Panoramic measures for oral bone mass in detecting osteoporosis: a systematic review and meta-analysis

Different quantitative and qualitative indices calculated on oral panoramic radiographs have been proposed as useful tools to screen for reduced skeletal bone mineral density (BMD). Our aim was to systematically review the literature on linear and qualitative panoramic measures and to assess the accuracy of these indices by performing a meta-analysis of their sensitivity and specificity. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement was followed. Fifty studies were included in the qualitative appraisal and 19 were considered for meta-analysis. The methodological quality of the retrieved studies, assessed with the QUADAS-2 tool, was on average low. Three indices were reported by most of the studies: mandibular cortical width, panoramic mandibular index, and the Klemetti index. Mandibular cortical width presented with a better accuracy in excluding osteopenia/osteoporosis (specificity), since patients with a cortical width more than 4 mm had a normal BMD in 90% of the cases. Almost all studies used a cutoff of 0.3 for the panoramic mandibular index, resulting in an estimated sensitivity and specificity in detecting reduced BMD, respectively, of 0.723 (SE 0.160; 95% confidence interval [CI], 0.352-0.926) and 0.733 (SE 0.066; 95% CI, 0.587-0.841). The presence of any kind of mandibular cortical erosion gave an estimated sensitivity and specificity in detecting reduced BMD, respectively, of 0.789 (SE 0.031; 95% CI, 0.721-0.843) and 0.562 (SE 0.047; 95% CI, 0.47-0.651) and a sensitivity and specificity in detecting osteoporosis, respectively, of 0.806 (SE 0.105; 95% CI, 0.528-0.9200) and 0.643 (SE 0.109; 95% CI, 0.417-0.820). The mandibular cortical width, panoramic mandibular index, and Klemetti index are overall useful tools that potentially could be used by dentists to screen for low BMD. Their limitations are mainly related to the experience/agreement between different operators and the different image quality and magnification of the panoramic radiographs.

Panoramic radiography measurements, osteoporosis diagnoses and fractures in Japanese men and women

OBJECTIVES

The purpose of this study was to investigate the association of the shape of the mandibular cortex on panoramic radiographs with the risk of an osteoporosis diagnosis without prevalent fractures and with the risk of osteoporotic fractures in Japanese men and women.

SUBJECTS AND METHODS

One thousand and twenty-one subjects aged 40-89 years, who visited our university hospital and underwent panoramic radiography between 2007 and 2013, participated in this study. Eighty-eight patients received a diagnosis of osteoporosis without prevalent fractures, and 55 were diagnosed with osteoporotic fractures. Blinded to the groupings, we classified the shape of the mandibular cortex on panoramic radiographs as normal, moderately eroded or severely eroded.

RESULTS

After adjustment for confounding factors, the odds ratios for an osteoporosis diagnosis associated with moderately eroded and severely eroded mandibular cortices were 1.4 (95% CI, 0.8-2.6) and 2.6 (95% CI, 1.4-5.0), respectively. The odds ratios for an osteoporotic fracture associated with moderately eroded and severely eroded cortices were 0.8 (95% CI, 0.4-1.7) and 1.1 (95% CI, 0.5-2.5), respectively.

CONCLUSIONS

Subjects in Japan with eroded mandibular cortices tended to be at increased risk of osteoporosis diagnoses but not of fractures.

A comparison of the mandibular index on panoramic and cross-sectional images from CBCT exams from osteoporosis risk group

Osteoporosis is a degenerative disease that primarily affects postmenopausal women. Based on panoramic radiographs, several assessment methods have been proposed for the diagnosis and evaluation of bone changes and as a predictor of osteoporosis for example the mandibular index.

INTRODUCTION

The purpose of this study is to compare the assessment of mandibular indices on panoramic and cross-sectional images.

METHODS

Forty-four cone beam computed tomography (CBCT) images from postmenopausal female subjects aged more than 45 years without systemic changes were selected for this study. From those images, cross-sectional and panoramic reconstruction images were assembled into a template for evaluation. The evaluation was conducted by observing the panoramic images and parasagittal sections. The appearance of the inferior cortex of the mandible was classified according to the mandibular index: C1, the endosteal margin of the cortex was even and sharp; C2, the endosteal margin presented semilunar defects or appeared to form endosteal cortical residues; or C3, the cortical layer formed heavy endosteal cortical residues and was clearly porous.

RESULTS

Based on Wilcoxon statistical test (p > 0.01), the data showed no statistically significant difference between the exams.

CONCLUSION

The mandibular index assigned in tomographic images is comparable to that obtained in panoramic images, indicating a valid use of the index in CBCT images, which can lead to the identification of patients with bone mass loss and a premature referral to further exams and treatment.

Relationship between findings of mandibular cortical bone in inferior border and bone mineral densities of lumbar vertebrae in postmenopausal women

It is important to assess the general bone condition in dental implant treatment. The relationships between the bone mineral densities (BMDs) of lumbar vertebrae and mandibular cortical bone condition in the inferior border using multi-slice computed tomography (CT) were assessed in postmenopausal women. If a strong correlation between them is obtained, the mandibular cortical bone condition may be useful to evaluate the general bone condition. Twenty-two postmenopausal women were enrolled in this investigation. The maximum CT value and width of the mandibular cortical bone (MCW-MSCT) were measured, and the mandibular cortical bone index (MCI-MSCT) was classified using multi-slice CT. BMDs of lumbar vertebrae were measured using dual energy X-ray absorptiometry (DXA), and then the percentage of the young adult mean (YAM) was analyzed. The correlations were investigated between the mandibular cortical bone condition and values of lumbar vertebrae. Weak correlations were observed between MCW-MSCT and the percentage of YAM. Also, significant differences in the percentage of YAM were noted between types of MCI-MSCT. The mandibular cortical bone index (MCI-MSCT) in the inferior border using multi-slice CT may be applicable to evaluate the influence of the general bone condition.

An assessment of intra- and interobserver agreement of reporting orthopaedic findings on presale radiographs of Thoroughbred yearlings

REASONS FOR PERFORMING STUDY

Radiography is commonly used in clinical practice but agreement of reporting of radiographically detected orthopaedic findings in horses has rarely been studied.

OBJECTIVES

To assess agreement within and between observers for reporting of orthopaedic findings on presale radiographs of Thoroughbred yearlings.

STUDY DESIGN

Retrospective analysis of archived radiographs.

METHODS

Four veterinary radiology specialists each twice examined 167 sets of radiographs for orthopaedic findings in the fore feet, fore and hind fetlocks, carpi, tarsi and stifles. There were 27 findings analysed for agreement. Kappa statistic (κ), percentage of positive agreement (Ppos) and percentage of negative agreement are reported.

RESULTS

An excellent percentage of negative agreement was observed for all findings, with the exception of regular vascular channels of the proximal sesamoid bones. Ppos and κ results were variable. The presence of extra carpal bones, osseous cyst-like lesions of the ulnar carpal bone, sagittal ridge defects of the third metacarpus, fracture of the fore and hind proximal sesamoid bones, regular vascular channels in the hind proximal sesamoids, osteochondrosis lesions of the distal intermediate ridge and/or medial malleoli of the tibia, and osseous cyst-like lesions in the medial femoral condyle was consistently observed with an intra- and interagreement κ≥0.5 and Ppos≥50%. Lucency within the proximal sesamoids consistently had an observed intra- and interagreement κ<0.4 and Ppos<40%.

CONCLUSIONS

Observation of orthopaedic findings on yearling repository radiographs showed generally excellent agreement on the absence of findings, but variable agreement on the presence of findings. Agreement was good for larger and easy to categorise radiographic findings. More accurate definitions and training need to be developed to improve agreement within and between observers for orthopaedic findings with poor or fair to good agreement.

The combination of a histogram-based clustering algorithm and support vector machine for the diagnosis of osteoporosis

Purpose

To prevent low bone mineral density (BMD), that is, osteoporosis, in postmenopausal women, it is essential to diagnose osteoporosis more precisely. This study presented an automatic approach utilizing a histogram-based automatic clustering (HAC) algorithm with a support vector machine (SVM) to analyse dental panoramic radiographs (DPRs) and thus improve diagnostic accuracy by identifying postmenopausal women with low BMD or osteoporosis.

Materials and Methods

We integrated our newly-proposed histogram-based automatic clustering (HAC) algorithm with our previously-designed computer-aided diagnosis system. The extracted moment-based features (mean, variance, skewness, and kurtosis) of the mandibular cortical width for the radial basis function (RBF) SVM classifier were employed. We also compared the diagnostic efficacy of the SVM model with the back propagation (BP) neural network model. In this study, DPRs and BMD measurements of 100 postmenopausal women patients (aged >50 years), with no previous record of osteoporosis, were randomly selected for inclusion.

Results

The accuracy, sensitivity, and specificity of the BMD measurements using our HAC-SVM model to identify women with low BMD were 93.0% (88.0%-98.0%), 95.8% (91.9%-99.7%) and 86.6% (79.9%-93.3%), respectively, at the lumbar spine; and 89.0% (82.9%-95.1%), 96.0% (92.2%-99.8%) and 84.0% (76.8%-91.2%), respectively, at the femoral neck.

Conclusion

Our experimental results predict that the proposed HAC-SVM model combination applied on DPRs could be useful to assist dentists in early diagnosis and help to reduce the morbidity and mortality associated with low BMD and osteoporosis.

Use of digital panoramic radiography as an auxiliary means of low bone mineral density detection in post-menopausal women

OBJECTIVES

To correlate the radiomorphometric indices obtained using digital panoramic radiography (DPR) with bone mineral densities, evaluated by the dual-energy X-ray absorptiometry test, in a population of post-menopausal females to identify patients with asymptomatic low bone mineral densities.

METHODS

The morphology of the mandibular cortex was evaluated using the mandibular cortical index (MCI) and the inferior mandibular cortex width was evaluated using the mental index (MI) in 64 female patients who had undergone dual-energy X-ray absorptiometry assessment. Of these patients, 21 were diagnosed with osteopaenia and 20 with osteoporosis, and 23 were normal. Three new indices for evaluating the inferior mandibular cortex width were designed: the mental posterior index 1 (MPI1), MPI2 and MPI3. Statistical analyses were performed using the χ(2) and Kruskal-Wallis tests and the receiver operating characteristic curve.

RESULTS

There were significant differences between the normal and lower bone mineral density groups (osteopaenia and osteoporosis) for MCI (p < 0.01). In the osteoporosis group, the MI, MPI1, MPI2 and MPI3 were significantly different from the normal and osteopaenia groups (p < 0.05). The MI, MPI1, MPI2 and MPI3 showed that there is an area in the mandibular cortex, located between the mental foramen and the antegonial region, which is valid for identifying females at high risk for osteoporosis.

CONCLUSIONS

The MCI, MI, MPI1, MPI2, and MPI3 radiomorphometric indices evaluated using DPR can be used to identify post-menopausal females with low bone densities and to provide adequate medical treatment for them.

Image texture in dental panoramic radiographs as a potential biomarker of osteoporosis

Previous studies have shown an association between osteoporosis and automatic measurements of mandibular cortical width on dental panoramic radiographs (DPRs). In this study, we show that additional image texture features increase this association and propose the combined features as a potential biomarker for osteoporosis. We used an existing dataset of 663 DPRs of female patients with bone mineral density (BMD) measurements. The mandibular cortex was located using a previously described computer algorithm. Texture features, based on co-occurrence matrices and fractal dimension, were measured in the bone within the cortex and also in the superior basal bone above the cortex. These, augmented by cortical width measurements, were used by a random forest classifier to identify osteoporosis at femoral neck, total hip, and lumbar spine. Classification performance was assessed by ROC analysis. Area-under-curve (AUC) values for identifying osteoporosis at femoral neck were 0.830, 0.824, and 0.872 using, respectively, cortical width alone, cortical texture (co-occurrence matrix features) alone, and combined width and texture. At 80% sensitivity, these classifiers produced specificity values of 74.4%, 73.6%, and 80.0%, respectively. Fractal dimension was a less effective texture feature. Prediction of osteoporosis at the lumbar spine was poorer, but a combined width and superior basal bone texture classifier gave a significant improvement in AUC at over the use of width alone.

Mandibular cortical shape index in non-standardised panoramic radiographs for identifying patients with osteoporosis as defined by the German Osteology Organization

The aim of this prospective controlled study was to determine the validity of the mandibular cortical shape index (CI) on panoramic radiographs in distinguishing patients with osteoporosis as defined by the German Osteology Organization (Dachverbands der Deutschsprachigen Osteologischen Fachgesellschaften, DVO). The study group contained 50 patients (33 female, 17 male, mean age: 74.9 years), who had a high risk of osteoporosis. 50 young patients (33 female, 17 male, mean age: 37.9 years) with no anamnestic evidence of osteoporosis served as control. Three blinded observers evaluated panoramic views of the study and the control group in a mixed manner regarding the mandibular cortical shape index. The study group underwent bone mineral density measurement using dual energy X-ray absorptiometry and received a diagnosis according to the Organization's guidelines (normal, osteopenia, osteoporosis). The CI showed a high sensitivity of 72.2% and a high specificity of 93.9% with a highly significant predictive value (Chi-square = 22.96, p < 0.001), while the observer's agreement was moderate (kappa = 0.47). We concluded that patients with a cortical shape index of the category assessed as "severe" on non-standardised panoramic radiographs have a higher risk of suffering systemic osteoporosis. The CI in panoramic radiographs is a good screening tool, which could be implemented in the routine assessment of panoramic radiographs in elder patients.

Computer-aided system for morphometric mandibular index computation. (Using dental panoramic radiographs)

OBJECTIVE

We propose and validate a computer-aided system to measure three different mandibular indexes: cortical width, panoramic mandibular index and, mandibular alveolar bone resorption index.

STUDY DESIGN

Repeatability and reproducibility of the measurements are analyzed and compared to the manual estimation of the same indexes.

RESULTS

The proposed computerized system exhibits superior repeatability and reproducibility rates compared to standard manual methods. Moreover, the time required to perform the measurements using the proposed method is negligible compared to perform the measurements manually.

CONCLUSIONS

We have proposed a very user friendly computerized method to measure three different morphometric mandibular indexes. From the results we can conclude that the system provides a practical manner to perform these measurements. It does not require an expert examiner and does not take more than 16 seconds per analysis. Thus, it may be suitable to diagnose osteoporosis using dental panoramic radiographs.

Mandibular bone changes in 24 years and skeletal fracture prediction

OBJECTIVES

The objectives of the investigation were to describe changes in mandibular bone structure with aging and to compare the usefulness of cortical and trabecular bone for fracture prediction.

MATERIALS AND METHODS

From 1968 to 1993, 1,003 women were examined. With the help of panoramic radiographs, cortex thickness was measured and cortex was categorized as: normal, moderately, or severely eroded. The trabeculation was assessed as sparse, mixed, or dense.

RESULTS

Visually, the mandibular compact and trabecular bone transformed gradually during the 24 years. The compact bone became more porous, the intertrabecular spaces increased, and the radiographic image of the trabeculae seemed less mineralized. Cortex thickness increased up to the age of 50 and decreased significantly thereafter. At all examinations, the sparse trabeculation group had more fractures (71-78 %) than the non-sparse group (27-31 %), whereas the severely eroded compact group showed more fractures than the less eroded groups only in 1992/1993, 24 years later. Sparse trabecular pattern was associated with future fractures both in perimenopausal and older women (relative risk (RR), 1.47-4.37) and cortical erosion in older women (RR, 1.35-1.55). RR for future fracture associated with a severely eroded cortex increased to 4.98 for cohort 1930 in 1992/1993. RR for future fracture associated with sparse trabeculation increased to 11.43 for cohort 1922 in 1992/1993.

CONCLUSION

Dental radiographs contain enough information to identify women most at risk of future fracture.

CLINICAL RELEVANCE

When observing sparse mandibular trabeculation, dentists can identify 40-69 % of women at risk for future fractures, depending on participant age at examination.

Osteoporosis and periodontitis in older subjects participating in the Swedish National Survey on Aging and Care (SNAC-Blekinge)

Abstract Objective. We assessed the relationships between (I) ultrasonography calcaneus T-scores (PIXI) and mandibular cortex characteristics on oral panoramic radiographs in older subjects; and (II) osteoporosis and periodontitis. Material and methods. We examined 778 subjects (53% women) aged 59-96 years. Periodontitis was defined by alveolar bone loss assessed from panoramic radiographs. Results. PIXI calcaneus T-values ≤-2.5 (osteoporosis) were found in 16.3% of women and in 8.1% of men. PIXI calcaneus T-values <-1.6 (osteoporosis, adjusted) were found in 34.2% of women and in 21.4% of men. The age of the subjects and PIXI T-values were significantly correlated in women (Pearson's r = 0.37, P < 0.001) and men (Pearson's r = 0.19, P < 0.001). Periodontitis was found in 18.7% of subjects defined by alveolar bone level ≥5 mm. Subjects with osteoporosis defined by adjusted PIXI T-values had fewer remaining teeth [mean difference 4.1, 95% confidence interval (CI) -1.1 to -6.5, P < 0.001]. The crude odds ratio (OR) of an association between the panoramic assessment of mandibular cortex erosions as a sign of osteoporosis and the adjusted T-value (T-value cut-off <-1.6) was 4.8 (95% CI 3.1-7.2, P < 0.001; Pearson χ(2) = 60.1, P < 0.001). A significant OR between osteoporosis and periodontitis was only found in women for the T-value cut-off ≤-2.5 (crude OR 1.8, 95% CI 1.1-3.3, P < 0.03). Conclusions. An association between osteoporosis and periodontitis was only confirmed in women. The likelihood that the mandibular cortex index agrees with adjusted PIXI T-values is significant.

Radiological and histologic studies of the mandibular cortex of ovariectomized monkeys

OBJECTIVE

The objective was to study the radiological and histologic changes in the mandibular cortices of ovariectomized monkeys.

STUDY DESIGN

Twelve female, adult, Cynomolgus monkeys (Macaca fascicularis) were used. Under anesthesia, 1 group was bilaterally ovariectomized (OVX), and the other (control group) underwent sham surgery. Seventy-six weeks after surgery, the monkeys were humanely killed, their mandibles were excised, and their mandibular inferior cortices (MIC) and adjacent cortices were examined histologically and with panoramic radiographs and micro computed tomography.

RESULTS

Striped shadows were seen on the endosteal side of the OVX cortices on panoramic radiographs. Histologic observation revealed many enlarged pores with eroded surfaces and calcein labeling (indicating osteon remodeling) in the OVX cortices.

CONCLUSIONS

In the MIC and adjacent cortices of OVX monkeys, enlarged Haversian canals were seen and there were indications of a high rate of bone turnover. The enlarged Haversian canals resulted in striped shadows and unclear endosteal margins on radiographic images.

Prediction of hip and hand fractures in older persons with or without a diagnosis of periodontitis

PURPOSE

In a prospective study, we assessed if a diagnosis of osteoporosis and periodontitis could predict hip and hand fractures in older persons.

MATERIALS AND METHODS

Bone density was assessed by a Densitometer. Periodontitis was defined by evidence of alveolar bone loss.

RESULTS

788 Caucasians (52.4% women, overall mean age: 76 years, S.D.± 9.0, range: 62 to 96) were enrolled and 7.4% had a hip/hand fracture in 3 years. Calcaneus PIXI T-values < -1.6 identified osteoporosis in 28.2% of the older persons predicting a hip/hand fracture with an odds ratio of 3.3:1 (95% CI: 1.9, 5.7, p < 0.001). Older persons with osteoporosis had more severe periodontitis (p < 0.01). Periodontitis defined by ≥ 30% of sites with ≥ 5 mm distance between the cemento-enamel junction (CEJ) and bone level (ABL) was found in 18.7% of the older persons predicting a hip/hand fracture with an odds ratio of 1.8:1 (95% CI: 1.0, 3.3, p < 0.05). Adjusted for age, the odds ratio of a hip/hand fracture in older persons with osteoporosis (PIXI T-value < -2.5) and periodontitis was 12.2:1 (95% CI: 3.5, 42.3, p < 0.001).

CONCLUSIONS

Older persons with osteoporosis and periodontitis have an increased risk for hip/hand fractures.

Assessment of bone mineral density in the jaws and its relationship to radiomorphometric indices

OBJECTIVES

The aim of this study was to evaluate maxillary, mandibular and femoral neck bone mineral density using dual energy X-ray absorptiometry (DXA) and to determine any correlation between the bone mineral density of the jaws and panoramic radiomorphometric indices.

METHODS

49 edentulous patients (18 males and 31 females) aged between 41 and 78 years (mean age 60.2 +/- 11.04) were examined by panoramic radiography. Bone mineral density (BMD) of the jaws and femoral neck was measured with a DXA; bone mineral density was calculated at the anterior, premolar and molar regions of the maxilla and mandible.

RESULTS

The mean maxillary molar BMD (0.45 g cm(-2)) was significantly greater than the maxillary anterior and premolar BMD (0.31 g cm(-2), P < 0.05). Furthermore, the mean mandibular anterior and premolar BMD (1.39 g cm(-2) and 1.28 g cm(-2), respectively) was significantly greater than the mean mandibular molar BMD (1.09 g cm(-2), P < 0.01). Although BMD in the maxillary anterior and premolar regions were correlated, BMD in all the mandibular regions were highly correlated. Maxillary and mandibular BMD were not correlated with femoral BMD. In addition, mandibular cortical index (MCI) classification, mental index (MI) or panoramic mandibular index (PMI) values were not significantly correlated with the maxillary and mandibular BMDs (P > 0.05).

CONCLUSIONS

The BMD in this study was highest in the mandibular anterior region and lowest in the maxillary anterior and premolar regions. The BMD of the jaws was not correlated with either femoral BMD or panoramic radiomorphometric indices.

Modern dental imaging: a review of the current technology and clinical applications in dental practice

A review of modern imaging techniques commonly used in dental practice and their clinical applications is presented. The current dental examinations consist of intraoral imaging with digital indirect and direct receptors, while extraoral imaging is divided into traditional tomographic/panoramic imaging and the more recently introduced cone beam computed tomography. Applications, limitations and current trends of these dental "in-office" radiographic techniques are discussed.

Assessment of trabecular pattern on periapical and panoramic radiographs: a pilot study

OBJECTIVE

This methodological study aimed to determine whether the mandibular trabecular bone assessment from panoramic radiographs, using a visual index, corresponds to the evaluation obtained from periapical radiographs.

MATERIAL AND METHODS

A panoramic radiograph and corresponding periapical radiographs of the region of the lower premolars and molars were collected from each of 32 patients (mean age 18.5 +/- 5.5 years). Two calibrated observers assessed randomly the interdental sites between the first molar and second premolar and between the two premolars on all the radiographs using a visual index. Evaluations were repeated with an interval of 60 days. The results of the repeated evaluations were used to assess intra- and inter-observer agreements, employing Kappa statistics. Spearman's correlation was used to determine the association between assessments of panoramic and periapical radiographs.

RESULTS

In total, 79 interdental sites were evaluated on the panoramic and periapical radiographs. The visual analysis of periapical radiographs revealed intra-observer agreements of 0.88 for observer 1 and 0.93 for observer 2, and an inter-observer agreement of 0.82. The intra-observer agreement for panoramic radiographs was 0.79 and 0.83 for observers 1 and 2, respectively, and the inter-observer agreement was 0.79. A substantial correlation was found between periapical and panoramic radiographs (rho = 0.737, p = 0.001).

CONCLUSIONS

Although panoramic radiographs are less reliable than periapical radiographs, they can be used for assessment of the trabecular bone pattern with the aid of a visual index. Training on the method is recommended to obtain results with a high reproducibility.

Triage screening for osteoporosis in dental clinics using panoramic radiographs

Many patients with osteoporosis go undiagnosed because typically no symptoms are present before a fracture. Triage screening to refer patients to appropriate medical professionals for further investigation would be useful to address the increase in the incidence of osteoporotic fractures. Dental clinics may offer a new triage screening pathway because dentists frequently take radiographs of bones in the course of dental treatment. A major premise for such triage screening in dental clinics is that dentists can readily use a screening tool in their dental practice. For example, cortical width and shape of the mandible detected on panoramic radiographs may be appropriate indices for triaging individuals with osteoporosis. To date, several investigators have demonstrated significant associations between cortical indices on panoramic radiographs and bone mineral density of the skeleton generally, such as the spine and femur, biochemical markers of bone turnover and risk of osteoporotic fractures. Further, in two recent Japanese clinical trials, approximately 95% of women who were identified by trained dentists in their clinics using cortical shape findings did have osteopenia or osteoporosis. These findings support the possibility that dental clinics may offer a new triage platform to identify individuals with otherwise undetected osteoporosis.