Maxillary bone mineral density and its relationship to the bone mineral density of the lumbar spine and hip

The relationship between radiographic measurements of alveolar bone in posterior single-tooth edentulous regions and non-alveolar jawbones using multidetector computed tomography

OBJECTIVE

This study aimed to evaluate the relationship between radiographic measurements of the alveolar bone in posterior single-tooth edentulous regions and radiographic measurements of non-alveolar jawbones using multidetector computed tomography (MDCT).

METHODS

The sample consisted of 47 patients aged between 20 and 42 years who underwent MDCT. All patients had a posterior single-tooth edentulous region. Extraction was performed 1-8 years ago at the time of inclusion (mean = 3.2). The alveolar bone in the edentulous region and non-alveolar bone regions (maxillary tuberosity, condyles, inferior to the mandibular foramen, and mandibular angle) were studied radiographically (radiographic density, dimensions, and cortical bone ratio). Pearson correlation, independent sample t test, and linear regression analysis were used for the statistical analysis.

RESULTS

Radiographic density of the alveolar bone (measured in the axial or buccolingual directions) correlated significantly with that of the maxillary tuberosity (0.3 < r < 0.4; P value ≥ 0.001) and, to a lesser extent, with the radiographic density of the region inferior to the mental foramen (r ≈ 0.3). Based on these correlation coefficients, non-alveolar bone density could explain 10-16% of the alveolar bone density after extraction according to linear regression analysis.

CONCLUSIONS

This study revealed that alveolar bone radiographic density was correlated with that of the maxillary tuberosity and inferior to the mental foramen region. Accordingly, linear regression models were suggested to aid in predicting future alveolar bone density in areas where extraction is to be performed.

Comparative evaluation of bone density after implant placement using cone-beam CT analysis in augmented versus non-augmented

Introduction

Dental implants are the most popular alternative to rehabilitation of missing teeth and oro-facial structures. The outcome of such procedures depends on various factors and most-importantly on the osseo-integation with the surrounding bone. The evaluation needs better visualization and evaluation using CBCT anaylsis and determination of HU, using an appropriate software.

Materials and Methods

This prospective cohort study was conducted at a tertiary level teaching hospital. A total of 129 cases were considered for the study after applying the laid down inclusion and exclusion criteria. Implant placement was done by single operator for placement of the endosteal implant (AB implant system Inc). All implants were placed using a minimum insertion torque of 25 Ncm as assessed by the physio-dispenser (NSK). The HU numbers were obtained at specified areas after immediate and 24 weeks post-operative period. The cases were divided into Augmented cases (Group I) and non-augmented cases (Group II). The augmented cases utilised Novabone putty bone graft.

Results

The study showed homogenous distribution of skewness and kurtosis in both the groups. The initial increase in augmented cases was due to increased radio-opacity of the graft. The HU values reached to near normal in both groups with no significant difference. The statistical test needed to analyze equality of variances, Levene's test was considered to ascertain the level of significance. Although the variance of subjects in group I is significantly different from that of group II, the test concludes that equal variances are not assumed. This prompts us to reject the null hypothesis at hand.

Conclusion

The use of augmentation as in this case with a bone putty show no significant improvement in improved bone quality at accelerated time. The study may need to be further augmented with research.

Age estimation using postmortem computed tomography-based Hounsfield unit values of the palate and mandibular condyle and the Eichner classification

Age estimation is important in forensic investigations of unidentified human remains. This study assessed the correlation between age and Hounsfield unit (HU) values of the palate and mandibular condyle based on postmortem computed tomography (CT) and analyzed the influence of occlusal support in developing an age estimation method for Japanese individuals, including older adults. The sample consisted of a training dataset (357 cadavers) and a validation dataset (300 cadavers) that underwent postmortem CT. Three measurements were selected: the respective HU values of the palate and mandibular condyle and the Eichner classification. The correlation coefficients between age and HU values were also evaluated. Multiple stepwise regression analysis was performed to evaluate the significance of four parameters (sex, respective HU values of the palate and mandibular condyle, and the Eichner classification) for age estimation and to determine the best age estimation formula. In the validation tests, inaccuracy and bias were calculated for the groups aged ≥65 or <65 years. Significant correlations between age and HU values of the palate and mandibular condyle were observed, regardless of sex. In multiple stepwise regression analysis, all variables except sex were significantly correlated with age. The age estimation formula from the regression analysis was useful, and the validation test exhibited high accuracy, especially in older adults. The HU values of the palate and mandibular condyle and the Eichner classification are useful for age estimation in Japanese individuals.

Association between periodontitis and osteoporosis in United States adults from the National Health and Nutrition Examination Survey: a cross-sectional analysis

OBJECTIVE

This cross-sectional study aimed to investigate the association between periodontitis and osteoporosis among US adults as well as the subgroup of menopausal women.

BACKGROUND

Periodontitis and osteoporosis are both chronic inflammatory diseases characterized by local or systemic bone resorption. Since they share many risk factors, and the significant decrease in estrogen along with menopause is unfavorable for both diseases, it's reasonable to assume that there exists some links between the two diseases, especially during the menopause.

METHODS

We analyzed data from the National Health and Nutrition Examination Survey (NHANES) 2009-2010 and 2013-2014. Periodontitis (defined according to the CDC/AAP definition) and osteoporosis (assessed by the dual-energy radiation absorptiometry) data were available for 5736 participants, and 519 subjects were enrolled in the subgroup of menopausal women aged 45-60 years old. We used binary logistic regression analysis to examine the association between the two diseases both in crude and fully adjusted model.

RESULTS

In the fully adjusted model, osteoporosis was significantly associated with an increased risk of periodontal disease (OR:1.66, 95% CI: 1.00-2.77) in the whole population. As to the subgroup of menopausal women, osteoporosis group had an adjusted OR of 9.66 (95% CI: 1.13-82.38) for developing severe periodontitis in the fully adjusted model.

CONCLUSIONS

Osteoporosis is significantly associated with periodontitis and the association is even more pronounced in menopausal women with severe periodontitis.

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.

Osteoporosis and periodontal diseases - An update on their association and mechanistic links

Periodontitis and osteoporosis are prevalent inflammation-associated skeletal disorders that pose significant public health challenges to our aging population. Both periodontitis and osteoporosis are bone disorders closely associated with inflammation and aging. There has been consistent intrigue on whether a systemic skeletal disease such as osteoporosis will amplify the alveolar bone loss in periodontitis. A survey of the literature published in the past 25 years indicates that systemic low bone mineral density (BMD) is associated with alveolar bone loss, while recent evidence also suggests a correlation between clinical attachment loss and other parameters of periodontitis. Inflammation and its influence on bone remodeling play critical roles in the pathogenesis of both osteoporosis and periodontitis and could serve as the central mechanistic link between these disorders. Enhanced cytokine production and elevated inflammatory response exacerbate osteoclastic bone resorption while inhibiting osteoblastic bone formation, resulting in a net bone loss. With aging, accumulation of oxidative stress and cellular senescence drive the progression of osteoporosis and exacerbation of periodontitis. Vitamin D deficiency and smoking are shared risk factors and may mediate the connection between osteoporosis and periodontitis, through increasing oxidative stress and impairing host response to inflammation. With the connection between systemic and localized bone loss in mind, routine dental exams and intraoral radiographs may serve as a low-cost screening tool for low systemic BMD and increased fracture risk. Conversely, patients with fracture risk beyond the intervention threshold are at greater risk for developing severe periodontitis and undergo tooth loss. Various Food and Drug Administration-approved therapies for osteoporosis have shown promising results for treating periodontitis. Understanding the molecular mechanisms underlying their connection sheds light on potential therapeutic strategies that may facilitate co-management of systemic and localized bone loss.

The Effect of Under-Drilling and Osseodensification Drilling on Low-Density Bone: A Comparative Ex Vivo Study

The aim of this study is to identify a method that can maximize implant primary stability (IPS) and bone density under the controlled drilling conditions of the same diameter and length in low-density bones through an ex vivo study. A total of 87 dental implants were placed with standard drilling, under-drilling, and osseodensification drilling in 13 fresh porcine sternums. The Periotest value and the implant stability quotient were measured to evaluate the primary stability. The difference in the Hounsfield unit (HU) between the hole and peripheral bone up to a distance of 1 mm was measured. Osseodensification and under-drilling technique increased the IPS, compared with conventional drilling technique with statistical significance under the drilling conditions of the same diameter and length. Osseodensification technique with the counter-clockwise direction had higher HU gaps than the standard drilling and osseodensification technique with clockwise direction. Due to the effect of bone densification, the gap of HU was increased by a minimum of 43 HU and a maximum of 180 HU. Within the limitations of this ex vivo study, it was found that the osseodensification technique with counter-clockwise direction is effective to increase IPS and bone mineral density in low-density bone.

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.

The Use of Dual Energy X-Ray Bone Density Scan in Assessment of Alveolar Cleft Grafting Using Bone Marrow Stem Cells Concentrate/Platelet-Rich Fibrin Regenerative Technique

OBJECTIVES

To determine the densitometric quality of regenerated bone at the site of bone marrow and platelet-rich membrane grafting technique at unilateral alveolar cleft region using dual energy x-ray bone density scan (DEXA).

METHODS

The present prospective cohort study included 16 unilateral alveolar cleft patients who were selected randomly from the outpatient maxillofacial surgery clinic and suffered from unilateral alveolar cleft. Bone marrow aspirate and platelet-rich fibrin (PRF) (bone marrow stem cells + PRF) were used as the grafting material. Six months of follow-up have been conducted for all patients' including clinical and radiographic assessments with (DEXA scan).

RESULTS

Sixteen unilateral patients with a mean age of 12.56 ± 1.71 years were included in the sample and the majority of patients were females with a frequency of 56.2 percent. The current research revealed no infection or wound dehiscence. After surgery, the pain and edema scores were reasonable. Our findings showed that, after 6 months of regenerative graft, the average bone mineral density of the cleft side DEXA scan value was 1.56 ± 0.32 gm/cm2, compared to 1.51 ± 0.488 gm/cm2 on the normal side of the noncleft scan. There was no statistically significant difference in DEXA bone mineral content measurements between the cleft and standard sides (P = 0.461).

CONCLUSIONS

The bone marrow stem cells + PRF regenerative graft technique has been successfully integrated, and the DEXA scan approach for measuring regenerated grafted bone mineral content was found to be appropriate for simple and inexpensive follow-up of alveolar cleft lip patients.

Low bone mineral density is associated with severe periodontitis at the end of the second decade of life: A population-based study

AIM

To evaluate the association between low bone mineral density (BMD) and severe periodontitis at the end of the second decade of life.

MATERIALS AND METHODS

This population-based study analysed 2032 youngers (18-19 years old) of the RPS cohort. BMD of lumbar spine (BMD-LS) and of the whole body (BMD-WB) were assessed by dual x-ray emission densitometry. Low BMD-LS (Z-score ≤ -2) and low BMD-WB (Z-score ≤ -1.5) were correlated with severe periodontitis. The extent of periodontal disease was also evaluated as the following outcomes: proportions of teeth affected by clinical attachment loss ≥5 mm and probing depth ≥5 mm. Multivariate models by sex, education, family income, risk of alcohol dependence, smoking, plaque, bleeding index, and body mass index were estimated through logistic regression (binary outcomes) and Poisson regression (continuous outcomes).

RESULTS

The prevalence of severe periodontitis was 10.97%. Low BMD-LS (odds ratio [OR] = 2.08, confidence interval [CI] = 1.12-3.85, p = .01) and low BMD-WB (OR = 1.34, CI = 1.001-1.81, p = .04) were associated with severe periodontitis in the final multivariate models. Low BMD-LS and BMD-WB were also associated with a greater extent of periodontitis (p < .05).

CONCLUSIONS

Low BMD was found to be associated with the severity and extent of periodontitis in adolescents. Adolescents at peak bone mass age presenting low BMD are more likely to be affected by severe periodontitis.

Accuracy of bone segmentation and surface generation strategies analyzed by using synthetic CT volumes

Different kinds of bone measurements are commonly derived from computed-tomography (CT) volumes to answer a multitude of questions in biology and related fields. The underlying steps of bone segmentation and, optionally, polygon surface generation are crucial to keep the measurement error small. In this study, the performance of different, easily accessible segmentation techniques (global thresholding, automatic local thresholding, weighted random walk, neural network, and watershed) and surface generation approaches (different algorithms combined with varying degrees of simplification) was analyzed and recommendations for minimizing inaccuracies were derived. The different approaches were applied to synthetic CT volumes for which the correct segmentation and surface geometry were known. The most accurate segmentations of the synthetic volumes were achieved by setting a case-specific window to the gray value histogram and subsequently applying automatic local thresholding with appropriately chosen thresholding method and radius. Surfaces generated by the Amira® module Generate Lego Surface in combination with careful surface simplification were the most accurate. Surfaces with sub-voxel accuracy were obtained even for synthetic CT volumes with low contrast-to-noise ratios. Segmentation trials with real CT volumes supported the findings. Very accurate segmentations and surfaces can be derived from CT volumes by using readily accessible software packages. The presented results and derived recommendations will help to reduce the measurement error in future studies. Furthermore, the demonstrated strategies for assessing segmentation and surface qualities can be adopted to quantify the performance of new segmentation approaches in future studies.

Overcoming compact bone resistance to tooth movement

The general boundaries to tooth movement are within the adjacent compact and trabecular bones, gingiva, mucosa, and muscular envelope. Findings from finite element analysis of maxillary posterior teeth distalization against mini-implants suggest that stiff outer and interproximal compact bone resists tooth movement, regardless of bone thickness, and that teeth should be steered away from this bone during orthodontic treatment. However, individual variation in the tooth-bone interface dictates the course and outcome of treatment, offering the basis for inferences on the limits of mini-implant anchorage and the presumed influence of the regional acceleratory phenomenon through decortication and microperforation, 2 modalities advocated to effect faster tooth movement.

Fragility fractures and delayed wound healing after tooth extraction in Japanese older adults

INTRODUCTION

Fragility fractures can cause delayed wound healing after tooth extraction, which contributes to an increased risk of osteomyelitis of the jaw. We evaluated whether a history of fragility fracture was associated with increased risk of delayed wound healing after tooth extraction in older adults in Japan.

MATERIALS AND METHODS

Of 5352 people aged 50-89 years in the 2014 basic resident registry of the town of Obuse, the present study included 376 subjects (190 men and 186 women) who completed a structured questionnaire and measurement of the bone mineral densities (BMDs) of the bilateral femoral neck. Delayed wound healing after tooth extraction was self-reported. Fragility fractures were confirmed via examination of hospital medical records. Logistic regression analyses adjusted for age and gender were used to evaluate association of clinical variables with delayed would healing after tooth extractions. Odds ratios (ORs) and the 95% confidence intervals (CIs) of all possible associated variables for the presence of delayed wound healing were calculated.

RESULTS

Subjects with a history of fragility fractures had a significantly higher risk of delayed wound healing compared with those without previous fragility fractures (OR 2.68; 95% CI 1.11-6.46, p = 0.028). This association still remained after adjusted for all other variables (OR 2.70; 95% CI 1.10-6.60, p = 0.030). Delayed wound healing was not significantly associated with the BMD of the femoral neck.

CONCLUSIONS

History of fragility fracture may be associated with increased risk of delayed wound healing after tooth extraction in Japanese men and women aged 50-89 years.

Titanium implant surface properties enhance osseointegration in ovariectomy induced osteoporotic rats without pharmacologic intervention

OBJECTIVES

This study determined whether implant surfaces that promote osseointegration in normal rats can promote osseointegration in osteoporotic rats without pharmacologic intervention.

MATERIALS AND METHODS

Virgin female 8-month-old CD Sprague Dawley rats (N = 25) were ovariectomized. At 6 weeks, microstructured/non-nanostructured/hydrophobic, microstructured/nanostructured/hydrophobic, or microstructured/nanostructured/hydrophilic Ti implants (Ø2.5 × 3.5 mm; Institut Straumann AG, Basel, Switzerland) were placed in the distal metaphysis of each femur. At 28 days, bone quality and implant osseointegration were assessed using microCT, histomorphometrics, and removal torque values (RTVs). Calvarial osteoblasts were isolated and cultured for 7 days on Ø15 mm Ti disks processed to exhibit similar surface characteristics as the implants used for the in vivo studies. The phenotype was assessed by measuring the production of osteocalcin, osteoprotegerin, osteopontin, BMP2, VEGF, and RANKL.

RESULTS

Microstructured/nanostructured/hydrophilic implants promoted increased bone-to-implant contact and RTVs in vivo and increased osteoblastic marker production in vitro compared to microstructured/non-nanostructured/hydrophobic and microstructured/nanostructured/hydrophobic implants, suggesting that osseointegration occurs in osteoporotic animals, and implant surface properties improve its rate.

CONCLUSIONS

Although all modified implants were able to osseointegrate in rats with OVX-induced osteoporosis without pharmacologic intervention, the degree of osseointegration was greater around microstructured/nanostructured/hydrophilic implant surfaces. These results suggest that when appropriate microstructure is present, hydrophilicity has a greater influence on Ti implant osseointegration compared to nanostructures. Moreover, modified implant surfaces can exert their control over the altered bone turnover observed in osteoporotic patients to stimulate functional osseointegration. These results provide critical insight for developing implants with improved osseointegration in patients with metabolic disorders of bone remodeling.

Two distalization methods compared in a novel patient-specific finite element analysis

INTRODUCTION

Orthodontic mini-implants aid in the correction of distocclusions via direct anchorage (pull from mini-implant to teeth) and indirect anchorage (teeth pulled against other teeth anchored by the mini-implant). The aim of this study was to compare stress levels on the periodontal ligament (PDL) of maxillary buccal teeth in direct and indirect distalization against orthodontic mini-implants and accounting for individual variation in maxillary anatomy and biomechanical characteristics of the compact bone.

METHODS

A 3D model of the maxilla containing the different components (teeth, PDL, trabecular and cortical bones) was generated from a computed tomographic scan. Cortical bone was divided into several areas according to previously defined zones. Bone stiffness and thickness data, obtained from 11 and 12 cadavers, respectively, were incorporated into the initial model to simulate the individual cortical bone variation at the different locations. Subsequently, a finite element analysis was used to simulate the distalization modalities.

RESULTS

Stresses at the buccal, palatal, mesial, and distal surfaces were significantly different between adjacent teeth under stiffness but not thickness variation. In both distalization modalities, low or no significant correlations were found between stress values and corresponding cortical bone thicknesses. High significant and inverted correlations were observed at the first molar between stress amounts and cortical bone stiffness (direct modality: -0.68 < r < -0.72; indirect modality: -0.80 < r < -0.82; P <0.05).

CONCLUSIONS

With the use of a novel finite element approach that integrated human data on variations in bone properties, findings suggested that cortical bone stiffness may influence tooth movement more than bone thickness. Significant clinical implications could be related to these findings.

Relationship of gray values in cone beam computed tomography and bone mineral density obtained by dual energy X-ray absorptiometry

OBJECTIVES

The aim of this study was to assess the correlation between bone mineral density (BMD) determined with cone beam computed tomography (CBCT) gray values and BMD determined by dual energy X-ray absorptiometry (DEXA).

STUDY DESIGN

Women age greater than 50 years requiring CBCT for implant treatment were included in the study. BMD was determined by calculating the mean gray value of CBCT cross-sectional images of anterior, premolar, retromolar, and tuberosity areas of the mandible and maxilla. Patients were then subjected to DEXA of the femoral neck and lumbar spine. Independent t tests, analysis of variance (ANOVA), Pearson's correlation tests, and receiver operating characteristic (ROC) evaluation were used for data analysis.

RESULTS

Of 61 asymptomatic patients (mean age 64 years), 47.5% and 55.7% had abnormal BMD, based on the T-scores of the femoral neck and lumbar spine, respectively. Significant correlations were noted between the T-scores of the femoral neck and lumbar spine and the gray values of the maxillary incisor and tuberosity areas.

CONCLUSIONS

A strong correlation exists between the CBCT gray values at different sites in the maxilla and the results of DEXA. A gray value less than 298 at the maxillary tuberosity can help distinguish patients with osteoporosis from normal individuals, with 66% to 67% accuracy and suggests the need for DEXA analysis.

Antiosteoporotic Drugs to Promote Bone Regeneration Related to Titanium Implants: A Systematic Review and Meta-Analysis

IMPACT STATEMENT

This meta-analysis was to investigate literature on the administration of antiosteoporotic drugs as an effective adjunct therapy for implant osseointegration using in vivo animal models.

Preoperative evaluation of bone quality for dental implantation using an ultrasound axial transmission device in an ex vivo model

This study investigated the clinical utility of an ultrasound axial transmission device in preoperative evaluation of bone quality for dental implantation, by clarifying the relationship between cortical bone speed of sound (cSOS), insertion torque values (ITV), and implant stability quotient (ISQ) in porcine femur bone. Eleven fresh porcine femurs, without soft tissue, were prepared. The cSOS of these bones were measured using the axial transmission device. Bone mineral density (BMD) and porosity (Po) were measured in cortical bone samples obtained from the region of ultrasound measurements by X-ray microcomputed tomography. Thirty-three implants were inserted into these samples (three implants per bone sample), and ITV and ISQ were measured for all implants. Then, cortical bone thickness (CbTh) of the area for implantation was measured for all implants using a micrometer. The mean cSOS was 3962 m/s; mean BMD and Po were 0.822 g/cm2 and 0.185%, respectively. cSOS and BMD values were positively correlated, and cSOS values and Po values were negatively correlated. Mean ITV, ISQ, and CbTh were 37.95 Ncm, 71.172, and 2.869 mm, respectively. There was a positive correlation between cSOS values and ISQ values. The cSOS of each bone did not correlate with ITV for all of the bone samples. However, when the CbTh ranges from 3.0 to 3.5 mm, ITV are correlated with cSOS. These findings suggest that cSOS, which reflects the cortical bone quality, may be clinical utility as a preoperative diagnosis of the implant.

Evaluation of Extraction Site Dimensions and Density Using Computed Tomography Treated With Different Graft Materials: A Preliminary Study

PURPOSE

The preliminary human study was designed to evaluate extraction site changes using CT after socket preservation (SP) with different materials.

MATERIALS AND METHODS

Fifty-two sockets from 17 Turkish individuals (8 women and 9 men; mean age 44.70 ± 9.99 years) localized at the maxillary anterior area were treated with demineralized bone matrix + collagen membrane (CM) (N = 14), hydroxyapatite bone substitute (HBS) + CM (N = 14), CM (N = 13), or left empty (N = 11). CT scans were taken 10 and 120 days after the procedure. Horizontal and vertical socket dimensions and Hounsfield unit (HU) values were evaluated.

RESULTS

First 3 groups showed a significant horizontal decrease from day 10 to 120. No significant change was detected in vertical socket dimension. For both horizontal and vertical, no intergroup difference was detected at days 10 and 120. At days 10 and 120, HU values in HBS + CM group were significantly higher compared with others. Apical and coronal HU values were not different at any period.

CONCLUSION

Even if it did not provide better socket dimensions, HBS + CM treatment brought higher tissue density and thus, can be recommended to increase the bone quality and implant success after SP in upper anterior area.

Osteocyte morphology and orientation in relation to strain in the jaw bone

Bone mass is important for dental implant success and is regulated by mechanoresponsive osteocytes. We aimed to investigate the relationship between the levels and orientation of tensile strain and morphology and orientation of osteocytes at different dental implant positions in the maxillary bone. Bone biopsies were retrieved from eight patients who underwent maxillary sinus-floor elevation with β-tricalcium phosphate prior to implant placement. Gap versus free-ending locations were compared using 1) a three-dimensional finite-element model of the maxilla to predict the tensile strain magnitude and direction and 2) histology and histomorphometric analyses. The finite-element model predicted larger, differently directed tensile strains in the gap versus free-ending locations. The mean percentage of mineralised residual native-tissue volume, osteocyte number (mean ± standard deviations: 97 ± 40/region-of-interest), and osteocyte shape (~90% elongated, ~10% round) were similar for both locations. However, the osteocyte surface area was 1.5-times larger in the gap than in the free-ending locations, and the elongated osteocytes in these locations were more cranially caudally oriented. In conclusion, significant differences in the osteocyte surface area and orientation seem to exist locally in the maxillary bone, which may be related to the tensile strain magnitude and orientation. This might reflect local differences in the osteocyte mechanosensitivity and bone quality, suggesting differences in dental implant success based on the location in the maxilla.

Implant Survival between Endo-osseous Dental Implants in Immediate Loading, Delayed Loading, and Basal Immediate Loading Dental Implants a 3-Year Follow-up

Introduction:

With introduction of the term “ossteointegration of dental implant” by Branemark, advancement in implantology from 1957 to 2017 has come a long way with modification in implant type and in loading time. This study aims to evaluate the survival of endo-osseous immediate loading (IL) implant and basal IL implants in atrophic jaws with objective to compare implant survival in atrophic jaws for full mouth rehabilitation between endo-osseous IL versus endo-osseous delayed loading (DL) versus basal IL during 3-year follow-up.

Materials and Methods:

Fifty-two (34 endo-osseous and 18 basal) implants were placed in 4 patients requiring full mouth rehabilitation in atrophic jaws. Case 1: Endo-osseous DL implants in upper and lower arch, Case 2: Endo-osseous IL implants in upper and lower arch, Case 3: Basal IL implant in upper and lower arch, and Case 4: Endo-osseous DL in upper arch and basal IL implant in the lower arch. Intraoperative evaluation was done on the basis of pain (visual analog scale [VAS]), operative time, and initial primary implant stability. Postoperative evaluation was done on pain (VAS), infection, radiographically successful implant (orthopantomogram), and patient satisfaction (Grade 0–10).

Results:

All cases showed satisfactory results but more amount of intra- and post-operative pain was felt with immediate basal implants.

Conclusion:

We believe that clinicians should comply with patient requests, and for this reason, we agree with some authors to use minimally invasive techniques and to avoid when possible esthetic or functional problems associated with the use of removable prosthesis after teeth extractions.

Clinical and radiographic evaluation of effect of risedronate 5 mg as an adjunct to treatment of chronic periodontitis in postmenopausal women (12-month study)

Bisphosphonates are beneficial to women, after menopause, in treatment of gum diseases. In this study, significant improvement in the disease condition was found and that no further progress was noted, and no side effects were reported. Bisphosphonates can be safely and successfully be used to support oral health procedures.

INTRODUCTION

The purpose of this study was to evaluate host modulating effect of bisphosphonate adjunct with the treatment of chronic periodontitis in osteopenic and osteoporotic postmenopausal women.

METHODS

Twenty-two osteopenic and osteoporotic postmenopausal women with moderate to severe chronic periodontitis were selected for the study. On intraoral examination, periodontal parameters like probing depth (PD), clinical attachment level (CAL), Plaque Index (PI) and Gingival Index (GI) were recorded. Scaling and root planing were done. Intraoral periapical X-rays were taken, and alveolar bone density (ABD) was measured with cone beam computed tomography (CBCT), and then, medications (risedronate 5 mg once daily (OD), calcium citrate 250 mg OD, vitamin D 400 IU OD) were given. Patients were recalled for follow-up at 3, 6 and 12 months. Intraoral periapical (IOPA) X-rays were taken at 6 and 12 months and ABD was measured at baseline and 12 months.

RESULTS

There was a significant improvement in all the parameters. There was an increase of 0.02 ± 0.001 cm on CT scan and 0.38 ± 0.005 mm on IOPA in bone height over 12 months from baseline. Bone density increased by 118.56 ± 3.251 Hounsfield units (HU). There was no progress in the disease, and further bone loss was not noticed. This is in correlation with clinical parameters which showed highly significant gain in CAL (3.57 ± 0.234 mm) and reduction in PD (2.20 ± 0.229 mm)

CONCLUSIONS

Bisphosphonate therapy as an adjunct to scaling and root planing may have significant beneficial clinical effects on the periodontium of postmenopausal women with moderate to severe chronic periodontitis.

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.

Analysis of correlation between initial alveolar bone density and apical root resorption after 12 months of orthodontic treatment without extraction

OBJECTIVE

The aim of the present study was to investigate the correlation between initial alveolar bone density of upper central incisors (ABD-UI) and external apical root resorption (EARR) after 12 months of orthodontic movement in cases without extraction.

METHODS

A total of 47 orthodontic patients 11 years old or older were submitted to periapical radiography of upper incisors prior to treatment (T1) and after 12 months of treatment (T2). ABD-UI and EARR were measured by means of densitometry.

RESULTS

No statistically significant correlation was found between initial ABD-UI and EARR at T2 (r = 0.149; p = 0.157).

CONCLUSION

Based on the present findings, alveolar density assessed through periapical radiography is not predictive of root resorption after 12 months of orthodontic treatment in cases without extraction.

Key local and surgical factors related to implant failure

The concept of osseointegration has revolutionized the treatment options for the replacement of missing teeth in both partially and completely edentulous patients. Dental implants are widely used because clinical practice and studies have documented its successful outcomes. However, implants can occasionally fail, and such failures can be classified as early or late. Measures that can aid in the early recognition of failing osseointegrated implants are needed, as are measures that can facilitate appropriate treatment methods aimed at saving failing implants by determining the probable etiologic factors. This article summarizes our current understanding of the local factors that can be linked to implant failure.

Bone mineral density in cone beam computed tomography: Only a few shades of gray

Cone beam computed tomography (CBCT) has often been used to determine the quality of craniofacial bone structures through the determination of mineral density, which is based on gray scales of the images obtained. However, there is no consensus regarding the accuracy of the determination of the gray scales in these exams. This study aims to provide a literature review concerning the reliability of CBCT to determine bone mineral density. The gray values obtained with CBCT show a linear relationship with the attenuation coefficients of the materials, Hounsfield Units values obtained with medical computed tomography, and density values from dual energy X-ray absorciometry. However, errors are expected when CBCT images are used to define the quality of the scanned structures because these images show inconsistencies and arbitrariness in the gray values, particularly when related to abrupt change in the density of the object, X-ray beam hardening effect, scattered radiation, projection data discontinuity-related effect, differences between CBCT devices, changes in the volume of the field of view (FOV), and changes in the relationships of size and position between the FOV and the object evaluated. A few methods of mathematical correction of the gray scales in CBCT have been proposed; however, they do not generate consistent values that are independent of the devices and their configurations or of the scanned objects. Thus, CBCT should not be considered the examination of choice for the determination of bone and soft tissue mineral density at the current stage, particularly when values obtained are to be compared to predetermined standard values. Comparisons between symmetrically positioned structures inside the FOV and in relation to the exomass of the object, as it occurs with the right and left sides of the skull, seem to be viable because the effects on the gray scale in the regions of interest are the same.

Relation between Spongy Bone Density in the Maxilla and Skeletal Bone Density

BACKGROUND AND PURPOSE

Osteoporosis is a disease affecting more than 300 million people worldwide and is responsible for numerous medical complications. This study aimed to investigate the relation between skeletal and maxillary bone density.

MATERIALS AND METHODS

Seventy-three patients were recruited and divided between group A (osteoporosis), group B (healthy, control), and group C (osteopenia) on the basis of a dual-energy x-ray absorptiomery (DXA) scan. These patients also received a CT scan on which bone density measurements were performed at five sites: maxilla midline, retromolar tuberosities, incisor, premolars, and molar regions.

RESULTS

The bone density was lower in osteoporotic patients compared with the control patients. The bone mineral density (BMD) of the tuberosities showed the strongest correlations with the BMD of the hip and the spine (respectively, r = 0.50 and r = 0.61). The midline region showed moderate correlations with the hip (r = 0.47) and the spine (r = 0.46). For potential implant sites, the correlations with the BMD of the hip and spine were, however, small to insignificant. Based on measurements of bone density of the maxilla, it was possible to predict if the patient was osteoporotic or not with a sensitivity of 65% and a specificity of 83%.

CONCLUSIONS

The maxillary bone density of subjects with osteoporosis is significantly lower than that of healthy patients. Moreover, there is a direct correlation between the density of the skeleton and the density of some sites of the maxilla. Using measurements of maxillary bone density in order to predict skeletal bone density might be a useful tool for the screening of osteoporosis.

Clinical utility of dental cone-beam computed tomography: current perspectives

Panoramic radiography and computed tomography were the pillars of maxillofacial diagnosis. With the advent of cone-beam computed tomography, dental practice has seen a paradigm shift. This review article highlights the potential applications of cone-beam computed tomography in the fields of dental implantology and forensic dentistry, and its limitations in maxillofacial diagnosis.

Is there correlation between alveolar and systemic bone density?

OBJECTIVE: The present study assessed the correlation between maxillomandibular alveolar bone density and systemic bone mineral density (BMD). METHODS: Dual-energy X-ray absorptiometry of the anterior and posterior maxillomandibular alveolar bone, of the standard sites for the measurement of BMD (lumbar spine and femur) and the third cervical vertebra was performed on 23 middle-aged women. Periapical radiographs were also obtained, with an aluminum step-wedge as reference for the digital reading of apical bone density of the upper incisors. RESULTS: Spearman's correlations coefficients revealed that density in the apical region was correlated with that of the femoral neck (r = 0.433; p < 0.05); BMDs of the posterior regions of the mandible and maxilla were significantly correlated with that of the cervical vertebra (r = 0.554, p < 0.01 and r = 0.423, p < 0.05, respectively); and the anterior maxilla was correlated with the posterior mandible (r = 0.488, p < 0.05). CONCLUSION: Bone density of the maxillary alveolar bone was significantly correlated with that of the femoral neck. Among the bone densities of the alveolar regions, only the anterior maxilla and the posterior mandible were significantly correlated. The findings suggested that bone densitometry might be individually and locally evaluated.

Clinical and radiological classification of the jawbone anatomy in endosseous dental implant treatment

Objectives

The purpose of present article was to review the classifications suggested for assessment of the jawbone anatomy, to evaluate the diagnostic possibilities of mandibular canal identification and risk of inferior alveolar nerve injury, aesthetic considerations in aesthetic zone, as well as to suggest new classification system of the jawbone anatomy in endosseous dental implant treatment.

Material and Methods

Literature was selected through a search of PubMed, Embase and Cochrane electronic databases. The keywords used for search were mandible; mandibular canal; alveolar nerve, inferior; anatomy, cross-sectional; dental implants; classification. The search was restricted to English language articles, published from 1972 to March 2013. Additionally, a manual search in the major anatomy and oral surgery books were performed. The publications there selected by including clinical and human anatomy studies.

Results

In total 109 literature sources were obtained and reviewed. The classifications suggested for assessment of the jawbone anatomy, diagnostic possibilities of mandibular canal identification and risk of inferior alveolar nerve injury, aesthetic considerations in aesthetic zone were discussed. New classification system of the jawbone anatomy in endosseous dental implant treatment based on anatomical and radiologic findings and literature review results was suggested.

Conclusions

The classification system proposed here based on anatomical and radiological jawbone quantity and quality evaluation is a helpful tool for planning of treatment strategy and collaboration among specialists. Further clinical studies should be conducted for new classification validation and reliability evaluation.

The role of orthodontic tooth movement in bone and root mineral density: a study of patients submitted and not submitted to orthodontic treatment

Background

Orthodontic force application to the teeth is responsible for a series of biological responses in the bone and dentin, which lead to some alterations of the mineral density of the tissues. Our objective was determine, through cone-beam computed tomography (CBCT), the mineral density of the apical third of the roots of the upper central incisors and of the periapical bone portion surrounding these teeth, in patients submitted to orthodontic treated and untreated individuals.

Material/Methods

30 untreated individuals and 15 treated ones (treatment cessation at least 1 year before the study) underwent CBCT. Mineral density was assessed in the apical third of the root of the upper central incisors and in the alveolar bone in the periapical region of these teeth. In order to reduce CBCT-related mineral density variability, we standardized the cone-beam tomography device, the image-acquisition settings and the field of view positioning and size. Student’s t test was used for the analyses.

Results

bone mineral density (BMD) and root mineral density (RMD), in Hounsfield Units, were 674.84 and 1282.26 for the untreated group and 630.28 and 1370.29 for the treated group, respectively. The differences between the group means were statistically significant for RMD (p<0.05).

Conclusions

untreated individuals had a significant lower mean RMD in comparison with those submitted to orthodontic treatment.

Bone quality and quantity of the anterior maxillary trabecular bone in dental implant sites

OBJECTIVES

The aim of this study was to investigate the characteristics of implant sites on the edentulous alveolar ridge in the anterior maxilla. We studied the bone quantity and quality of implant sites at the anterior maxilla using CT images for the 33 implant sites on patients who underwent dental implant therapy in our Department since 2006.

MATERIALS AND METHODS

Computed tomography (CT) images of 33 patients (20 women: 13 men) encompassing 33 implant sites were chosen and examined. The recipient sites for implant placement were determined based on CT data using an implant planning software (Simplant 11.0). The mean bone density values in Hounsfield unit (HU) were recorded using Simplant for both the simulated implant areas and the trabecular bone width. We classified the edentulous alveolar ridge and bone quality according to a classification based on Lekholm and Zarb (1985).

RESULTS

Incisors had higher bone densities than canines. Women had lower bone densities than men. Canines displayed greater trabecular bone density and alveolar bone widths than incisors. No maxillary sites were judged to have a bone quality of 1 in this group. Quality 3 accounted for 69.7% of the total samples.

CONCLUSIONS

An assessment of bone quality in the anterior alveolar ridge may well reflect age-related systemic pathological conditions and should be used in dental implant treatment planning to avoid associated risk factors.

Histomorphometrical and molecular evaluation of endosseous dental implants sites in humans: correlation with clinical and radiographic aspects

OBJECTIVE

To evaluate the correlations between clinical-radiographical aspects and histomorphometric-molecular parameters of endosseous dental implant sites in humans.

MATERIAL AND METHODS

The study sample consisted of bone implant sites from the jawbones of 32 volunteers, which were classified according to two different systems: (1) based only on periapical and panoramic images (PP); (2) as proposed by Lekholm & Zarb (L&Z). Bone biopsies were removed using trephine during the first drilling for implant placement. Samples were stained with haematoxylin-eosin (HE), and histomorphometric analysis was performed to obtain the following parameters: trabecular thickness (Tb.Th), trabecular number, bone volume density (BV/TV), bone specific surface (BS/BV), bone surface density and trabecular separation (Tb.Sp). In addition, immunohistochemistry analysis was performed on bone tissue samples for the proteins, Receptor activator of nuclear factor kappa-B (RANK), RANK ligand (RANKL), osteoprotegerin (OPG) and Osteocalcin (OC). Also, the determination of the relative levels of gene expression was performed using Reverse transcription-real-time Polymerase Chain Reaction (RT-PCR).

RESULTS

PP and L&Z classification systems revealed a moderate correlation with BV/TV, BS/BV, Tb.Th and Tb.Sp. L&Z's system identified differences among bone types when BV/TV, BS/BV, Tb.Th and Tb.Sp were compared. A weak correlation between PP/L&Z classifications and the expression of bone metabolism regulators (RANK, RANKL, OPG e OC) was found. The analysis of mRNA expression showed no difference between the bone types evaluated.

CONCLUSIONS

Our results suggest that PP and L&Z subjective bone-type classification systems are related to histomorphometric aspects. These data may contribute to the validation of these classifications. Bone remodelling regulatory molecules do not seem to influence morphological aspects of the jawbone .

The correlation of bone mineral density and histologic data in the early grafted maxillary sinus: a preliminary report

PURPOSE

: Implant success in the grafted maxillary sinus is dependent on the formation of new vital autogenous bone and its mineral density. Different bone graft materials and graft combinations have been used in the sinus augmentation procedure to support dental implants under occlusal loads. The goal of this study was to determine whether it is possible to observe a direct correlation between bone mineral density and histologic data in the grafted maxillary sinus. Based on the observed histological findings, we propose a bone mineral density classification that has 3 rather than 4 types of bone.

MATERIALS AND METHODS

: A total of 15 patients participated in this study, all of which had only 1 sinus grafted. A total of 34 dental implants were placed in the grafted sinuses. In 7 patients, designated as group A, a 50:50 composite ratio of autogenous and allogeneic bone was used to graft the sinuses. Four patients had the sinuses grafted with a 50:50 composite ratio of a naturally occurring marine algae hydroxyapatite graft material and autogenous bone. One patient had the sinus grafted with 100% autogenous bone. In this group of patients, a total of 25 dental implants were surgically placed 14 to 20 weeks after sinus grafting. The implants were restored 12 weeks later. No implant failures were observed over a 52-week period. The last 3 patients, designated as group B, completed implant surgery beyond the 52-week end point of the study for various reasons. They provided a unique opportunity to histologically observe bone maturation at 68, 88, and 260 weeks, respectively. Using cone beam computed tomography (CT) technology and 3D-CT interactive software, bone mineral density in Hounsfield unit values were recorded during different healing time periods.

RESULTS

: In all 15 patients, bone mineral density was observed to steadily increase during the 52-week observation period and beyond, as evidenced by the increase in Hounsfield unit values and the formation of new, vital autogenous trabecular bone.

CONCLUSION

: Histologic and histomorphometric data demonstrate a definite correlation with the formation of new, vital autogenous trabecular bone and bone mineral density (quality) that permits early loading of implants in the grafted maxillary sinus.

Ambiguity in bone tissue characteristics as presented in studies on dental implant planning and placement: a systematic review

OBJECTIVES

To survey definitions of bone tissue characteristics and methods of assessing them in studies of dental implant planning and placement.

MATERIAL AND METHODOLOGY

Three databases were searched using specified indexing terms. Three reviewers selected from the titles and retrieved abstracts in accordance with inclusion and exclusion criteria. Descriptions of bone tissue characteristics (bone quality, density and quantity) used before or during dental implant placement were searched for and categorized.

RESULTS

The search yielded 488 titles. One hundred and fort-nine publications were selected and read in full text. One hundred and eight were considered relevant. There were many different definitions and classification systems for bone tissue characteristics and examination protocols. Approximately two-third of the included publications reported the Lekholm & Zarb classification system for bone quality and quantity. However, only four studies implemented the Lekholm & Zarb system as originally proposed. A few publications described bone quality in accordance with the Misch or Trisi and Rao classifications systems. Assessment methods were often described only briefly (or not at all in one-fifth of the publications). Only one study presented the diagnostic accuracy of the assessment method, while only two presented observer performance.

CONCLUSION

The differing definitions and classification systems applied to dental implant planning and placement make it impossible to compare the results of various studies, particularly with respect to whether bone quality or quantity affect treatment outcomes. A consistent classification system for bone tissue characteristics is needed, as well as an appropriate description of bone tissue assessment methods, their diagnostic accuracy and observer performance.

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.

Evaluation by quantitative magnetic resonance imaging of trabecular bone quality in mandible and cervical vertebrae

OBJECTIVE

The purpose of this study was to make a comparison between mandibular and cervical vertebral bone quality (BQ) using quantitative magnetic resonance imaging (MRI).

METHODS

The cervical MRI images included in this study belonged to 36 patients (23 women, 13 men; mean age 54 years) who had various clinical symptoms (e.g., headache, vertigo, imbalance). The mandible and cervical vertebrae BQ measurements were performed by the same investigator on these sections. Mandibular and cervical vertebral T2(*) axial cross sections were performed following receipt of consent from each patient. T2(*) relaxation time values were determined in the trabecular area.

RESULTS

The relationship between cervical vertebral and mandibular BQ was revealed by regression and correlation analysis. The correlation coefficient was r=0.04, r(2)=0.002, and P=0.818, which is not statistically significant. The relation between age and mandible BQ was very weak (r=0.001, r(2)=0.000001, and P=0.995), and the relation between age and cervical vertebrae BQ was correlated (r=-0.585, r(2)=0.342, and P<0.001).

CONCLUSIONS

There is a low correlation between the BQ measurements of cervical vertebrae and the mandible. Precise mandibular BQ measurement does not provide information that correlates with BQ in the other sites of the skeleton. Although an age-dependent decrease occurs in vertebral BQ, no significant alteration occurs in mandibular BQ.

Trabecular Bone Structures in the Edentulous Diastema of Osteoporotic Sheep

The edentulous ovine diastema represents a suitable region for implantological research. Due to distinctive embryonic origin and mechanical loading, the edentulous diastema may respond differently to osteoporosis than tooth-bearing areas. To test this assumption, we subjected geriatric sheep to ovariectomy, calcium-/vitamin-D-restricted diet, and methylprednisolone administration. Adult control sheep remained untreated. Structural parameters and bone mineral density were determined by microcomputed tomography and conventional computed tomography, respectively. We report that the trabecular microstructure in the diastema was preserved from catabolic changes. In contrast, the premolar maxillary region of osteoporotic sheep had diminished trabecular bone mineral density, with the corresponding structural deteriorations. These results suggest that maxillary trabecular bone of the edentulous diastema does not respond to catabolic changes which occur in the tooth-bearing area in osteoporosis. Our findings imply that regional anatomic domains must be considered in the planning of pre-clinical studies, taking osteoporotic changes into account.

The use of visual assessment of dental radiographs for identifying women at risk of having osteoporosis: the OSTEODENT project

OBJECTIVE

The objective of this study was to investigate the diagnostic accuracy of visual assessment of the trabecular pattern in intraoral periapical radiographs to identify female subjects at risk of having osteoporosis.

STUDY DESIGN

Six hundred female subjects underwent intraoral periapical radiography of the maxillary and mandibular premolar region. Five observers assessed the trabecular pattern as dense, heterogeneous, or sparse, with the aid of reference images. All patients received a central dual energy x-ray absorptiometry (DXA) examination of the hip and lumbar spine.

RESULTS

With sparse trabecular pattern as indicative of osteoporosis, mean specificity was high (91.6 for the upper jaw and 90.8 for the lower jaw) while the sensitivity was low (28.2 for the upper and lower jaw). The mean intraobserver agreement was comparable for radiographs of the upper and lower jaw (median kappa(w) 0.53 and 0.57, respectively).

CONCLUSION

Visual assessment of the trabecular pattern in intraoral periapical radiographs of premolar regions is a potential method to identify women at risk of having osteoporosis.

Assessments of trabecular bone density at implant sites on CT images

OBJECTIVES

To evaluate the association between trabecular bone density measurements of potential implant sites made on axial DICOM images (DentaCT software) and on the same images with eFilm workstation, to correlate bone densities in Hounsfield units (HU) with subjective classification, and to establish a quantitative scale for each bone quality class.

STUDY DESIGN

Twenty-seven maxillary and 27 mandibular computed tomographic (CT) examinations of 75 potential implant sites were selected. Trabecular bone density was evaluated with DentaCT and eFilm. Bone quality was subjectively evaluated by 2 examiners. Descriptive statistics, between- and within-group comparison, correlation analysis, and Bland-Altman plot were used for data analysis.

RESULTS

DentaCT measurements were higher than eFilm (P < .001). Bone type 2 was the most prevalent, and bone density was significantly reduced from bone types 1 to 4. Quantitative parameters ranged as follows: bone type 4 <200 HU, bone types 2 and 3 >200 to <400 HU, and bone type 1 >400 HU.

CONCLUSION

Different qualities of bone can be found in any of the anatomical regions studied (anterior and posterior sites of maxilla and mandible), which confirms the importance of a site-specific bone tissue evaluation prior to implant installation.

A comparison of bone mineral density in the spine, hip and jaws of edentulous subjects

OBJECTIVES

The aim was to investigate the relationship between bone mineral density (BMD) of the jaws (mandible and maxilla) and other skeletal sites. In addition, the influence of gender, smoking and the number of years without natural teeth were examined.

MATERIALS AND METHODS

18 edentulous patients (9 females, 9 males) with a mean age of 67.1 (sd 12.6) years had DXA scans to assess the BMD of the lumbar spine and hip, together with the ramus, body and symphysis of the mandible and the anterior of the maxilla.

RESULTS

BMD values for the ramus were similar to those for the femur but significantly lower than the lumbar spine. The body and anterior mandible had higher values and the anterior maxilla lower values than both the femur and ramus. The ramus BMD showed moderately strong relationships with the standard measures of BMD in the spine and hip, but the BMD of other areas of the jaws showed no relationship with skeletal sites. The BMD for both the hip and the ramus showed an inverse relationship with increasing age. There was no statistically significant relationship between BMD of hip, spine and jaw and either years edentulous or cigarette years. (207)

CONCLUSIONS

Although the ramus of the mandible may show correlation of BMD with skeletal sites, the areas of the jaws where implants may be placed do not. Therefore BMD of the skeletal sites could not be used to predict BMD of the jaws. The BMD of the jaws as measured by DXA showed no relationship with either years edentulous or cigarette smoking.

Pixel intensity and fractal analyses: detecting osteoporosis in perimenopausal and postmenopausal women by using digital panoramic images

OBJECTIVE

Pixel intensity values (PI) and fractal dimensions (FD) were compared in selected mandibular regions on digital panoramic images of normal, osteopenic, and osteoporotic perimenopausal and postmenopausal women to evaluate their relative efficacies in detecting osteoporotic-associated bone density changes.

STUDY DESIGN

Standardized mandibular angle, body, and canine/premolar (C/PM) regions on 54 charge-coupled device (CCD) digital panoramic images of normal and potentially osteoporotic postmenopausal women were analyzed for PI and FD. Lumbar spine and femoral neck dual-energy x-ray absorptiometry (DXA) on each patient served as the reference standard examination. Pearson correlation coefficients and analysis of variance (ANOVA) were performed.

RESULTS

There was significant correlation among PI measurements (P < 0.01), and no significant correlation between FD. C/PM had significantly lower PI than control C/PM (P = 0.049).

CONCLUSIONS

Osteoporotic changes in mandibular C/PM cancellous bone were detected in our study population on CCD digital panoramic images by using a robust image analysis paradigm. Future automated application of such image analysis could enable widespread, cost effective screening for osteoporosis in dental settings.

Change in mandibular trabecular pattern and hip fracture rate in elderly women

OBJECTIVES

To determine if alterations of trabecular pattern, or the rate of change of jaw trabeculae, are associated with rate of hip fracture.

METHODS

Participants in a population-based study of residents of a California retirement community (Leisure World Cohort Study) were asked for permission to obtain their dental radiographs. Periapical radiographs were retrieved on 598 women (average age at time of first radiograph=77 years). Several measurements of trabecular pattern (strut analysis), textural properties (run-length analysis) and Fourier analysis were made in several anatomical regions of the jaw. These trabecular features and clinical information self-reported by subjects in the early 1980s were examined for association with hip fracture rate using Cox proportional-hazard regression.

RESULTS

Rate of hip fracture increased with decreasing average length of node-to-terminus struts in the mandibular incisor region. Each 0.01 mm per year decrease in the average length of node-to-terminus struts increased hip fracture rate by a factor of 2.9 (P=0.02, accuracy=73%). Inclusion of clinical parameters improved the predictive model compared with use of the radiographic parameter alone (accuracy=79%). Similar results were seen for percent change per year in this parameter.

CONCLUSIONS

Changes in radiographic trabecular structure, augmented with clinical information, are predictive of hip fracture in elderly women. Further refinement of both the radiographic and clinical parameters may lead to a screening process accessible to a large number of women and to early diagnosis and treatment of osteoporosis.