Changes in mandibular cortical width measurements with age in men and women

Radiographical Diagnostic Evaluation of Mandibular Cortical Index Classification and Mandibular Cortical Width in Female Patients Prescribed Antiosteoporosis Medication: A Retrospective Cohort Study

Osteoporosis is often detected late and becomes severe because of a lack of subjective symptoms. Digital panoramic radiography (DPR) has been reported to be useful for osteoporosis screening based on the morphological classification of the mandibular inferior cortex. The purpose of this study was to evaluate the sensitivity and specificity of the mandibular cortical index (MCI) in the diagnosis of osteoporosis in a group of patients who were and were not using antiosteoporosis medication (AOM). Three hundred and fifty female patients aged 40 years or older who had DPR imaging performed during a 6-year period from December 2015 to February 2022 met the selection criteria. Two examiners recorded mandibular cortical width and MCI from the images. These results were statistically examined together with the patients' demographic data. Forty-nine patients were using AOM (13 nonbisphosphonate/denosumab and 36 bisphosphonate/denosumab). MCI type 3 was the most common in the AOM group. In the MCI classification, DPR imaging among the AOM group was more sensitive (0.95) than that of the control group. This method of estimating osteoporosis based on MCI classification using DPR images has high sensitivity, especially in patients using AOM, suggesting that this method is useful as a screening test.

General and local predictors of mandibular cortical bone morphology in adult females and males: the seventh survey of the Tromsø Study

OBJECTIVES

To analyze factors predicting mandibular cortical width (MCW) and mandibular cortical index (MCI) in adult females and males.

MATERIAL AND METHODS

Data on 427 females and 335 males aged 40-84 from The Tromsø study: Tromsø7 were used. T-score, age, menopausal status (for females), remaining teeth, and periodontal status were analyzed in linear and logistic regression analyses as predictors of MCW and MCI, respectively.

RESULTS

T-score, age, and the number of remaining teeth significantly predicted MCW in females but not males. Standardized β coefficients were 0.286, -0.231, and 0.131, respectively. The linear regression model explained 24% of MCW variation in females. MCI in females was significantly predicted by T-score, age, and remaining teeth with the Wald values of 9.65, 6.17, and 5.83, respectively. The logistic regression model explained 16.3-23% of the variation in MCI in females. In males, T-score was the only significant predictor of the eroded cortex, and the logistic model explained only 4.3-5.8% of the variation in MCI.

CONCLUSIONS

The T-score demonstrated a stronger relationship with MCW and MCI than other factors in females, which supports the usefulness of those indices for osteoporosis screening. Conversely, the T-score exhibited no association with MCW and remained the only significant predictor of MCI in males, yet to a lesser extent than in females.

CLINICAL RELEVANCE

Understanding factors affecting mandibular cortical morphology is essential for further investigations of MCW and MCI usefulness for osteoporosis screening in females and males.

Radiographic changes of mandibular cortical bone in bisphosphonate drug holiday

Objectives

There have been few studies to date on the residual effect of bisphosphonate. This study investigated the radiographic changes of mandibular cortical thickness upon bisphosphonate drug holiday.

Materials and Methods

This retrospective study includes 36 patients diagnosed with MRONJ (medication-related osteonecrosis of the jaw) at Ajou University Dental Hospital in 2010-2021. All patients stopped taking bisphosphonate under consultation with the prescribing physicians. Panoramic radiographs were taken at the start of discontinuation (T₀), 12 months after (T₁), and 18 months after (T₂) discontinuation of bisphosphonate, respectively. Mental index and panoramic mandibular index were calculated using Ledgerton’s method. Paired t-tests were used to analyze differences over time.

Results

The difference in indices (mental index and panoramic mandibular index) between T₀ and T₁ was not statistically significant (paired t-test, P>0.05). However, the difference in these indices between T₁ and T₂ was statistically significant (paired t-test, P<0.05).

Conclusion

The cortical thickness of the mandible decreased in the late stage (after 18 months) as observed by panoramic radiograph.

Decreased mandibular cortical bone quality after botulinum toxin injections in masticatory muscles in female adults

This study aimed to clarify how masticatory muscle atrophy induced by botulinum toxin (BTX) injection affects cortical bone quality of the mandible using 3D modeling technology. A total of 39 young (26.9 ± 6.0 years) and 38 post-menopausal (55.3 ± 6.3 years) females were included. Computed tomography (CT) images were obtained before and after 12 months of treatment. Predictor variables were application of a stabilization splint, and/or two times of BTX injection in the bilateral temporalis and masseter muscles within a six-month interval. Outcome variables were changes in average Hounsfield units (HU) and cortical thickness of region of interest (ROI). 3D mandibular models were reconstructed using CT images, and models were used to calculate average HU and cortical thickness of ROIs, including inferior half of the lateral surface of ascending ramus, coronoid process, and temporomandibular joint condyle. Cortical bone quality at muscle insertion site was influenced by decreased muscle thickness but seemed not to be affected by decreased functional loading. Reduced functional loading seemed to influence cortical bone quality of the condyles. These effects were more remarkable in post-menopausal females. Hence, decreased masticatory muscle thickness may lead to alterations of the mandibular cortical structures, especially in post-menopausal females.

Dental Panoramic Radiographic Indices as a Predictor of Osteoporosis in Postmenopausal Saudi Women

Background

Many oral presentations of osteoporosis-a bone metabolic disease-were recorded. Thus, we aimed to assess panoramic radiomorphometric indices with bone mineral density (BMD) values among Saudi postmenopausal women and its importance in the prediction of osteoporosis.

Methods

A total of 431 Saudi women were enrolled in this study. Panoramic radiographs were obtained at the time of BMD measurement. Subjects were fatherly classified into; normal BMD, osteopenia, and osteoporosis groups. Serum follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E2), 25-hydroxy-vitamin D (25[OH]D) and intact-parathyroid hormone were measured. Moreover, serum creatinine, calcium, and phosphate, together with serum osteocalcin (s-OC), procollagen type I N-terminal propeptide (s-PINP) and cross-linked C-terminal telopeptide of type 1 collagen (s-CTX) were measured. Receiver-operator curve (ROC) curve analysis for use of mandibular cortical width (MCW), panoramic mandibular index (PMI), and maxillary-mandibular ratio (M/M ratio) to differentiate women with osteoporosis or osteopenia from normal subjects was calculated. Cut off values of 4.6 at T score <−1 and 4.1 at T score ≤−2.5 were used.

Results

Body mass index is significantly low in the osteoporotic group. There is no significant difference in serum levels of LH, E2, calcium, phosphate, and 25(OH)D between the studied groups. Moreover, s-OC, C-terminal propeptide of procollagen type I, s-PINP, s-CTX, and urinary-CTX are significantly higher in osteoporosis than normal and osteopenia groups. ROC curve analysis revealed that MCW and PMI showed significant data while M/M ratio is non-significant.

Conclusions

It could be concluded that MCW as an important panoramic radiographic parameter can be used for prediction and diagnosis of osteoporosis in postmenopausal Saudi women with low BMD.

Comparison of fractal dimension analysis and panoramic-based radiomorphometric indices in the assessment of mandibular bone changes in patients with type 1 and type 2 diabetes mellitus

OBJECTIVES

This study compared the fractal dimension (FD) and radiomorphometric indices in the assessment of mandibular bone of patients with type 1 (T1 DM) and type 2 diabetes mellitus (T2 DM).

STUDY DESIGN

Panoramic radiographs of 104 patients were evaluated to calculate FD, mandibular cortical width (MCW), panoramic mandibular index (PMI), and mandibular cortical index (MCI) in the mandible.

RESULTS

No statistically significant differences were found in FD when T1 DM and T2 DM groups were compared with controls (P ≥ .168). Patients with T1 DM had significantly lower MCW (P < .001) and PMI (P = .030) compared with controls. Patients with T2 DM had no significant differences in MCW (P = .228) or PMI (P = .137) compared with controls. No significant differences were observed between patients with T1 DM and those with T2 DM for FD, MCW, and PMI (P > .05). In the T1 DM and T2 DM groups, there was a significant correlation between MCW and FD (P ≤ .011). No correlation was observed between FD and PMI in either the T1 DM group or the T2 DM group (P ≥ .142). No significant differences in MCI were observed between the DM groups and controls (P = .740) or between the T1 DM and T2 DM groups (P = 1.000).

CONCLUSIONS

The cortical and trabecular bone architectures of patients with T1 DM and T2 DM were not different. Patients with T1 DM had lower cortical measurements compared with controls.

Detecting the earliest radiological signs of bisphosphonate-related osteonecrosis

Introduction Oral bisphosphonates are the most commonly prescribed anti-resorptive drugs used in the treatment of osteoporosis, but osteonecrosis of the jaw is a serious complication. The early diagnosis of this destructive side effect is crucial in preventing excessive bone loss, pain and infection.Objective To aid dental practitioners in the early identification of bisphosphonate-related osteonecrosis of the jaw.Method A scoping review was carried out.Data sources We searched MEDLINE via OVID, EMBASE via OVID, Dentistry and Oral Sciences Source (DOSS), Proquest Dissertation and Theses Search, to identify references that described clinical and radiological findings in medication-related osteonecrosis of the jaw (MRONJ).Data selection Nineteen references mentioned the earliest radiological changes in MRONJ with a description of the observations and were included in the analysis.Data synthesis The radiographic signs included osteosclerosis/lysis, widening of the periodontal ligament and thickening of the lamina dura and cortex. To assess the quality of original data on which recommendations had been made, these 19 studies were subjected to a quality appraisal.Conclusion Using bone exposure as a criterion for diagnosis of MRONJ, leads to delayed diagnosis and a poor response to treatment. In those patients at risk of bone exposure with MRONJ, insufficient information is present in the literature to allow the general dental practitioner to reliably identify the radiographic features indicating imminent bone exposure. A well-designed prospective study is needed.

Is the panoramic mandibular index useful for bone quality evaluation?

Purpose

The aim of this study was to determine whether the panoramic mandibular index (PMI) is useful for assessing bone mineral density. We also analyzed the potential correlations between PMI parameters and patient age.

Materials and Methods

Four observers measured the PMI of both sides of the mental foramen using a picture archiving and communication system and images in the Digital Imaging and Communications in Medicine format. They studied 300 panoramic radiographic images of patients belonging to the following age groups: 40–49 years, 50–59 years, 60–69 years, 70–79 years, and 80–89 years. The observers were allowed to zoom in or out and to adjust the contrast of the images. Further, they were instructed to record the reasons for any measurements that could not be made. Then, we conducted a reliability analysis of the measured PMI and assessed the correlations between different patient age groups and the 3 parameters used for determining the PMI from the available data.

Results

Among the 600 data items collected, 23 items were considered unmeasurable by at least 1 observer for the following 4 reasons: postoperative state, lesion, unidentified mental foramen, and alveolar bone loss. The intraobserver reproducibility of the measurable data was 0.611-0.752. The mandibular cortical width (MCW) decreased significantly as patient age increased.

Conclusion

PMI had limited usability when the margin of the mental foramen was not clear. In contrast, MCW, a parameter used for determining the PMI, had fewer drawbacks than the PMI with respect to bone mineral density measurements and exhibited a significant correlation with patient age.

Distributional Variations in the Quantitative Cortical and Trabecular Bone Radiographic Measurements of Mandible, between Male and Female Populations of Korea, and its Utilization

It is important to investigate the irregularities in aging-associated changes in bone, between men and women for bone strength and osteoporosis. The purpose of this study was to characterize the changes and associations of mandibular cortical and trabecular bone measures of men and women based on age and to the evaluation of cortical shape categories, in a large Korean population. Panoramic radiographs of 1047 subjects (603 women and 444 men) aged between 15 to 90 years were used. Mandibular cortical width (MCW), mandibular cortical index (MCI), and fractal dimensions (FD) of the molar, premolar, and anterior regions of the mandibular trabecular bone were measured. Study subjects were grouped into six 10-years age groups. A local linear regression smoothing with bootstrap resampling for robust fitting of data was used to estimate the relationship between radiographic mandibular variables and age groups as well as genders. The mean age of women (49.56 ± 19.5 years) was significantly higher than that of men (45.57 ± 19.6 years). The MCW of men and women (3.17mm and 2.91mm, respectively, p < 0.0001) was strongly associated with age and MCI. Indeed, trabecular measures also correlated with age in men (r > −0.140, p = 0.003), though not as strongly as in women (r > −0.210, p < 0.0001). In men aged over 55 years, only MCW was significantly associated (r = −0.412, p < 0.0001). Furthermore, by comparison of mandibular variables from different age groups and MCI categories, the results suggest that MCW was detected to be strongly associated in both men and women for the detection of bone strength and osteoporosis. The FD measures revealed relatively higher association with age among women than men, but not as strong as MCW.

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.

Dental panoramic indices and fractal dimension measurements in osteogenesis imperfecta children under pamidronate treatment

OBJECTIVES

To verify radiomorphometric indices and fractal dimension (FD) in dental panoramic radiographs (DPRs) of children with different types of osteogenesis imperfecta (OI) and also to verify the effect of pamidronate (PAM) treatment in such panoramic analyses.

METHODS

In this retrospective study, 197 DPRs of 62 children with OI Types I, III and IV who were in treatment with a comparable dosage of intravenous PAM were selected. The mandibular cortical width (MCW), mandibular cortical index, visual estimation of the cortical width and FD of three standardized trabecular and cortical mandibular regions of interest were obtained from the radiographs. Factorial analysis of variance and Fisher test were used to compare FD and MCW measurements in children with different types of OI for different PAM cycles.

RESULTS

Children with all types of OI have thinner and more porous mandibular cortices at the beginning of treatment. There were significant differences between MCW and FD of the cortical bone, regarding different types of OI and number of PAM cycles (p = 0.037 and p = 0.044, respectively). FD measurements of the trabecular bone were not statistically different among OI types nor were PAM cycles (p > 0.05).

CONCLUSIONS

Children with OI presented cortical bone alterations after PAM treatment. Both MCW and the FD of the cortical bone were higher in children with OI after PAM treatment. It is argued that cortical bone should be considered for analyzing patients with OI, as well as to monitor the progress of PAM treatment.

Osteoporotic Fracture: 2015 Position Statement of the Korean Society for Bone and Mineral Research

Osteoporotic fractures are one of the most common causes of disability and a major contributor to medical care costs worldwide. Prior osteoporotic fracture at any site is one of the strongest risk factors for a new fracture, which occurs very soon after the first fracture. Bone mineral density (BMD) scan, a conventional diagnostic tool for osteoporosis, has clear limitations in diagnosing osteoporotic fractures and identifying the risk of subsequent fractures. Therefore, early and accurate diagnosis of osteoporotic fractures using the clinical definition which is applicable practically and independent of BMD, is essential for preventing subsequent fractures and reducing the socioeconomic burden of these fractures. Fractures caused by low-level trauma equivalent to a fall from a standing height or less at major (hip, spine, distal radius, and proximal humerus) or minor (pelvis, sacrum, ribs, distal femur and humerus, and ankle) sites in adults over age 50, should be first regarded as osteoporotic. In addition, if osteoporotic fractures are strongly suspected on history and physical examination even though there are no positive findings on conventional X-rays, more advanced imaging techniques such as computed tomography, bone scan, and magnetic resonance imaging are necessary as soon as possible.

Osteoporosis and jawbones in women

Osteoporosis is a major health problem affecting one in three women over the age of 50 and may not be detected until fractures occur. Since osteoporotic fractures are a health burden worldwide, identifying subjects with a high risk of osteoporosis and preventing osteoporosis-related mortality and morbidity are a very important health strategy. Women show an estrogen-related bone loss starting at menopause, predominantly occurring in trabecular bone. Diagnosis of osteoporosis is usually based on the bone mineral density measurement, but this is not a practical and economical technique for early detection. Therefore, investigators are interested in the possibility of detecting osteoporosis from the panoramic radiographs. Mandibular cortical bone undergoes resorptive activity in osteoporotic patients, leading to a decreased thickness and more porous inferior border. Therefore, studies have demonstrated the usefulness of cortical width and shape, determined from panoramic radiographs, in identifying elderly individuals with undetected osteoporosis, especially postmenopausal women. In conclusion, postmenopausal women with C3 category, Mental Index (MI) <3 mm, and panoramic mandibular index (PMI) <0.3 may be considered for further osteoporosis investigation.

Detecting low bone mineral density from dental radiographs: a mini-review

Over a number of years researchers have reported associations between osteoporosis or low bone mineral density and signs that can be detected on dental radiographs, particularly in the width of the inferior mandibular cortex and the texture of the trabecular bone. As patients visit the dentist more regularly than they visit their doctor, there is the possibility that such signs could be used as a means of identifying individuals at risk of developing osteoporosis or suffering from consequent fracture. This paper reviews the historical background behind this research and the current status, including recent developments in automation of measurement using computer image analysis.

Osteoporosis prediction from the mandible using cone-beam computed tomography

PURPOSE

This study aimed to evaluate the use of dental cone-beam computed tomography (CBCT) in the diagnosis of osteoporosis among menopausal and postmenopausal women by using only a CBCT viewer program.

MATERIALS AND METHODS

Thirty-eight menopausal and postmenopausal women who underwent dual-energy X-ray absorptiometry (DXA) examination for hip and lumbar vertebrae were scanned using CBCT (field of view: 13 cm×15 cm; voxel size: 0.25 mm). Slices from the body of the mandible as well as the ramus were selected and some CBCT-derived variables, such as radiographic density (RD) as gray values, were calculated as gray values. Pearson's correlation, one-way analysis of variance (ANOVA), and accuracy (sensitivity and specificity) evaluation based on linear and logistic regression were performed to choose the variable that best correlated with the lumbar and femoral neck T-scores.

RESULTS

RD of the whole bone area of the mandible was the variable that best correlated with and predicted both the femoral neck and the lumbar vertebrae T-scores; further, Pearson's correlation coefficients were 0.5/0.6 (p value=0.037/0.009). The sensitivity, specificity, and accuracy based on the logistic regression were 50%, 88.9%, and 78.4%, respectively, for the femoral neck, and 46.2%, 91.3%, and 75%, respectively, for the lumbar vertebrae.

CONCLUSION

Lumbar vertebrae and femoral neck osteoporosis can be predicted with high accuracy from the RD value of the body of the mandible by using a CBCT viewer program.

Fractal dimension and mandibular cortical width in normal and osteoporotic men and women

OBJECTIVE

To verify whether fractal dimensions (FD) on the mandibular trabecular and cortical bone and mandibular cortical width (MCW) differ between patients with normal bone mineral density (BMD) and osteoporosis.

STUDY DESIGN

In this retrospective study, 133 dental panoramic radiographs from men aged >60 years and postmenopausal women with a bone densitometry report of the lumbar spine and hip classified as either normal or osteoporotic were selected. Fractal dimensions of five standardized trabecular and cortical mandibular regions of interest and mandibular cortical width were measured on the panoramic radiographs by an experienced oral radiologist, blinded to the densitometric diagnosis. The following statistical analyses were performed: ANOVA and a forward logistic stepwise regression to verify associations between dental panoramic measurements and the densitometric diagnosis. P values less than .05 indicated statistical significance.

MAIN OUTCOME MEASURES

Fractal dimension and mandibular cortical width.

RESULTS

Differences were found in the FD values on mandibular cortical bone and MCW between patients with normal BMD and with osteoporosis, but not in the FD values of trabecular bone. The odds of having lower mean values of MCW and FD on cortical bone were 2.16, 3125 and 1005 times in osteoporotic patients, respectively, compared with patients with normal BMD.

CONCLUSION

The values of FD analysis on mandibular cortical bone and MCW were lower in women with osteoporosis. A well-adjusted logistic regression model showed that cortical bone measurements might be considered as auxiliary tools to referring patients for DXA exam.

Can mandibular bone resorption predict hip fracture in elderly women? A systematic review of diagnostic test accuracy

OBJECTIVES

The aim of this systematic review was to determine the diagnostic accuracy of the mandibular cortical width measurements and porosity in detecting hip osteoporosis.

BACKGROUND

All of the included studies used measurements on panoramic radiographs.

MATERIALS AND METHODS

Studies were included if they compared the radiographic measurements (or index tests) with central dual energy X-ray absorptiometry (DXA) of the hip as the reference standard. A measure of diagnostic accuracy such as sensitivity and specificity or area under the receiver operating characteristic curve was also required for inclusion.

RESULTS

Seven studies were identified. Meta-analysis was not possible because of the heterogeneity of the studies. The studies all demonstrated moderate diagnostic accuracy.

CONCLUSION

If a patient with a thin or porous mandibular cortex is identified by a chance radiographic finding, additional clinical risk factors need to be considered and the patient referred for further investigation with DXA where necessary.

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.

Panoramic radiomorphometry and vertebral fractures in Spanish postmenopausal women

OBJECTIVE

To evaluate the relationship between panoramic radiomorphometric indexes, and the presence of osteoporotic fractures in a Spanish postmenopausal women.

METHODS

A sample of 120 women (60 with fragility spine fractures and 60 healthy), aged 55-70 years, with fragility spine fractures, were included in this cross-sectional study that was conducted from 2008 to 2011. All the women were referred to undergo a radiological spine examination, spinal densitometry and a panoramic radiograph for assessing osteoporosis using 3 radiomorphometric indexes: Panoramic Mandibular Index (PMI), Mental Index (MI) and Mandibular Cortical Index (MCI). According to mandibular cortical shape, in MCI, three groups were defined: C3 (osteoporosis), C2 (osteopenia), C1 (health).

RESULTS

Significant differences were found between all the MCI groups due to their composition between fractures and non-fractures. C1 group (healthy) has less fractures women than C2 (Bonferroni p<0.001), C1 has less fractures than C3 (Bonferroni p<0.001) and finally, C2 has less fractures than C3 (Bonferroni p<0.006). PMI and MI values were significantly lower in cases than in controls (U Mann-Whitney p<0.001).

CONCLUSIONS

Panoramic radiomorphometrics mandibular indexes such as MCI, PMI, and MI, may be useful for identifying the population at higher risk for fracture. The relationship between panoramic index and osteoporosis remains unclear and further studies using fragility fracture as a real marker of osteoporosis are warranted to clarify the exact role and effect of one condition on the other and the corresponding clinical implications.

Gender differences in the growing, abnormal, and aging jaw

Despite wide variations in the size and shape of the human face, head, and body, there is remarkable consistency for quantifiable gender-specific facial traits. The relationships between the growing jaws and tooth eruption are complex, but they show gender-specific trajectories in children and adolescents. Disturbances in genetic, endocrine, and nutritional regulatory controls result in gender-specific and nonspecific disorders. Gender-specific differences are also apparent in the aging jaw, with the acceleration of jawbone atrophy upon loss of teeth, especially in women.

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.

Growth changes of the mandibular body with eruption of mandibular third molars: analysis of anatomical morphometry and quantitative bone mineral content by using radiography

This study aimed to analyze growth changes in mandibular body morphology and quantitative bone mineral content (QBMC) with eruption of mandibular third molars (M3s) and the relationship between those variables and posterior mandibular body length. Linear and angular measurements were conducted using standard lateral radiographs of 37 dried mandibles in Hellman's dental developmental stages IVA (14 specimens) to VA (23 specimens). Cortical and trabecular basal bone mineral contents (CBMC and TBMC) in the mandible were expressed in millimeter titanium equivalent values using a titanium step wedge. The largest significant change in the mandibular body morphology was an increase in the horizontal dimension (M2DP'-Go': 7.59mm), followed by vertical dimension - total height of the mandibular body (THOMB: 4.96mm) and mandibular cortical width (MCW: 1.22mm). The gonial angle (GA) decreased significantly by 6.72° between stages IVA and VA. The mandibular cortical index (MCI) was classified only as C1 or C2 in each stage. Among 4 types of line profile, types 1 and 2 were most commonly observed in both stages. Mean values for CBMC and TBMC increased significantly between stages IVA and VA. Posterior mandibular body length (MeF'-Go') correlated positively with M2DP'-Go', THOM, MCW, and CBMC (r=0.816, 0.698, 0.595, and 0.507), respectively and negatively with GA (r=-0.582). These results demonstrated that the morphological changes in the posterior mandibular body and the QBMC increased significantly with M3 eruption, while the GA became significantly smaller. The posterior mandibular body length had a linear correlation with these variables.

Identification of the risk for osteoporosis in dental patients

This article describes how dentists can recognize osteoporosis before fractures develop, and discusses whether osteoporosis affects tooth loss or inhibits implant osseointegration. Some success in diagnosing osteoporosis has been obtained using clinical questionnaires that attempt to identify those who have strong risk factors for the disease, and analysis of the sparse trabeculation and thinning of the mandibular cortex often seen in dental panoramic radiographs. The role of osteoporosis in periodontal disease is unclear as there are many conflicting reports, but the evidence suggests that tooth loss may be more prevalent in patients with osteoporosis.