Measurement Of Bone Loss Research Articles

Objective Pre-Operative Measurement of Anterior Glenoid Bone Loss: A Novel and Simple Computer-Based Method using Unilateral 3-D CT (SS-22)

Arthroscopic measurement of glenoid bone loss relative to the bare spot is used currently for clinical decision-making with shoulder instability. It would be advantageous to precisely determine glenoid bone loss from imaging in order to make pre-operative decisions about soft tissue versus boney reconstruction. Previous methods describe comparison of the contralateral glenoid, which requires additional radiation exposure and expense. The purpose of this study was to evaluate the ease, reproducibility, and applicability of a novel method of unilateral CT measurement of glenoid surface area, based upon the typically circular geometry of the normal inferior glenoid.

An improved cost‐effective, reproducible method for evaluation of bone loss in a rodent model

This study was designed to investigate the utility of two "new" definitions for assessment of bone loss in a rodent model of periodontitis. Eighteen rats were divided into three groups. Group 1 was infected by Aggregatibacter actinomycetemcomitans (Aa), group 2 was infected with an Aa leukotoxin knock-out, and group 3 received no Aa (controls). Microbial sampling and antibody titres were determined. Initially, two examiners measured the distance from the cemento-enamel-junction to alveolar bone crest using the three following methods; (1) total area of bone loss by radiograph, (2) linear bone loss by radiograph, (3) a direct visual measurement (DVM) of horizontal bone loss. Two "new" definitions were adopted; (1) any site in infected animals showing bone loss >2 standard deviations above the mean seen at that site in control animals was recorded as bone loss, (2) any animal with two or more sites in any quadrant affected by bone loss was considered as diseased. Using the "new" definitions both evaluators independently found that infected animals had significantly more disease than controls (DVM system; p<0.05). The DVM method provides a simple, cost effective, and reproducible method for studying periodontal disease in rodents.

Validation of a dental image analyzer tool to measure alveolar bone loss in periodontitis patients

Radiographs are an essential adjunct to the clinical examination for periodontal diagnoses. Over the past few years, digital radiographs have become available for use in clinical practice. Therefore, the present study investigated whether measuring alveolar bone loss, using digital radiographs with a newly constructed dental image analyzer tool was comparable to the conventional method, using intra-oral radiographs on film, a light box and a Schei ruler. Alveolar bone loss of the mesial and distal sites of 60 randomly selected teeth from 12 patients with periodontitis was measured using the conventional method, and then using the dental image analyzer tool, by five dentists. The conventional method scored bone loss in categories of 10% increments relative to the total root length, whereas the software dental image analyzer tool calculated bone loss in 0.1% increments relative to the total root length after crucial landmarks were identified. Both methods showed a high interobserver reliability for bone loss measurements in nonmolar and molar sites (intraclass correlation coefficient > or = 0.88). Also, a high reliability between both methods was demonstrated (intraclass correlation coefficient nonmolar sites, 0.98; intraclass correlation coefficient molar sites, 0.95). In addition, the new dental image analyzer tool showed a high sensitivity (1.00) and a high specificity (0.91) in selecting teeth with > or = 50% or < 50% alveolar bone loss in comparison with the conventional method. This study provides evidence that, if digital radiographs are available, the dental image analyzer tool can reliably replace the conventional method for measuring alveolar bone loss in periodontitis patients.

Macrophage Inflammatory Protein‐1α: A Salivary Biomarker of Bone Loss in a Longitudinal Cohort Study of Children at Risk for Aggressive Periodontal Disease?

Periodontitis develops in a time-dependent manner. Cross-sectional studies document one moment in time but fail to capture the progressive nature of disease. Radiographic measures of bone loss are relatively insensitive but are reliable markers of irreversible disease. Longitudinal studies are needed to identify biomarkers that can precede radiographic evidence of bone loss and, thus, mark the period prior to clinical evidence of irreversible disease. A longitudinal study of students susceptible to localized aggressive periodontitis (LAgP) was conducted to evaluate chemokines/cytokines found in saliva derived from periodontally healthy children who subsequently developed alveolar bone loss. Students were screened, sampled for Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans [Aa]), and divided into a cohort of Aa+ and Aa- students. Ninety-six periodontally healthy Aa+ and Aa- students were recalled every 6 to 9 months following screening. Examinations, saliva collections, and radiographs were performed. After seven students developed bone loss, the levels of 21 cytokines were assessed and matched to saliva from seven Aa+ and seven Aa- students who remained healthy for > or =1 year. Subsequently, saliva from an additional 27 students who remained healthy was analyzed. Nineteen cytokines were not detected or were detected at low levels. Macrophage inflammatory protein (MIP)-1alpha was elevated 50-fold in seven Aa+ students who developed disease 6 to 9 months prior to radiographic detection of bone loss compared to levels in 21 Aa+ and 20 Aa- students who remained healthy (P <0.001). Interleukin (IL)-1beta was also elevated (P = 0.01). MIP-1alpha had a specificity of 96.8% and a sensitivity of 100%, whereas IL-1beta showed 90.3% specificity and 85.7% sensitivity relative to bone loss. MIP-1alpha levels were also related to increasing probing depth and the number of pockets >6 mm. The superior sensitivity and specificity of MIP-1alpha, which correlated well with probing depths and the onset of bone loss, suggested that it could be used as an early biomarker for LAgP.

Bone Mineral Density and Bone Turnover in Postmenopausal Women Treated for Breast Cancer

Chemotherapy and endocrine treatments for breast cancer are believed to increase risk of osteoporosis by causing early menopause in premenopausal women and by further depleting estrogen levels in postmenopausal women. Multivariate analyses were used to evaluate the contributions of 7 predictors (age, body mass index [BMI], family history of osteoporosis, months since menopause, past use of chemotherapy, and current use of tamoxifen or aromatase inhibitors) in explaining variability in bone mineral density (BMD) at the hip and the spine and bone turnover in 249 postmenopausal women who are breast cancer survivors. This report was an analysis of baseline data from a federally funded (1 R01 NR07743-01A1) intervention study on osteoporosis prevention. Mean age of the women was 58.5 years, and average BMI was 26.7 kg/m; 98% were white. All had measurable bone loss, 167 had chemotherapy, 76 were on tamoxifen, and 21 were on aromatase inhibitors. Women with higher BMI had higher BMD at the hip (P < .001) and the spine (P = .004). Women on tamoxifen had lower measures of bone formation (Alkphase B) (P < .001), suggesting less bone turnover, and higher BMD at the hip (P = .035). There was a trend for women who had received chemotherapy to have lower BMD at the spine (P = .06). The implications of these findings are discussed in the article.

Performance of Threaded Versus Sintered Porous‐Surfaced Dental Implants Using Open Window or Indirect Osteotome‐Mediated Sinus Elevation: A Retrospective Report

The purpose of this retrospective report was to evaluate the performance of dental implants placed in a teaching environment in patients requiring maxillary sinus elevation. Threaded (acid-washed or sand-blasted acid-etched) and sintered porous-surfaced (SPS) press-fit implants were used. Sinuses were managed using direct (open window) or indirect (osteotome-mediated) techniques. Records were available for 97 implants in 62 patients. Preoperative subantral bone heights were determined from radiographs, primarily panoramic. Of 69 threaded implants used, 40 and 29 were placed using direct (DTH) and indirect (ITH) techniques, respectively. Twenty-eight SPS implants were placed using the indirect technique. Implant failure rates using the Kaplan-Meier method of analysis and cumulative crestal bone loss (the latter based on bone levels seen in the most recent radiographs) were determined for both types of implants. The mean preoperative subantral bone height for DTH implants was 5.0 mm (range, 1 to 12 mm). Preoperative bone heights for ITH implants and SPS implants placed using the indirect approach were 7.2 mm (range, 4 to 12 mm) and 4.2 mm (range, 3 to 6 mm), respectively. Significant differences in preoperative bone height were seen between DTH and ITH implants (P <0.0001) and between ITH and SPS implants (P <0.0001). Average functional times were 18.7 months and 16.3 months for DTH and ITH implants, respectively, whereas the average functional time for SPS implants was 49.9 months. Time in function was significantly greater (P <0.0001) for SPS than DTH and ITH implants. Significant differences in implant length were also seen, with SPS implants significantly shorter than DTH or ITH implants. Three implants failed to integrate, one in each of the three treatment groups, giving initial survival rates of 97.5%, 96.6%, and 96.4% for DTH, ITH, and SPS implants, respectively. Mean cumulative crestal bone loss measurements were 1.84, 1.90, and 0.57 mm for DTH, ITH, and SPS implants, respectively. Bone loss was significantly less with SPS implants than with DTH or ITH implants. A second SPS implant failed after 7 years in function, likely because of prosthetic deficiencies. This late failure reduced the Kaplan-Meier survival rate to 80.4% for the SPS group. Results from this teaching clinic suggest that the use of dental implants with sinus elevation procedures is a predictable treatment for the resorbed posterior maxilla.

Measurement of Glenoid Bone Loss

Background Osteotomies at an angle of 45° to the long axis of the glenoid were originally used in a cadaveric model to simulate the bone loss that can occur clinically in anterior instability of the shoulder. However, this type of glenoid defect is not consistent with the usual clinical scenario, in which bone loss occurs nearly parallel (at 0°) to the long axis of the glenoid. Purpose Our objectives were to compare the amount of glenoid bone loss measured after a 45° glenoid osteotomy with that after a 0° osteotomy and to determine differences in bone loss measurement from 2 different posterior shoulder portals. Study Design Controlled laboratory study. Methods Glenoids of 14 embalmed cadaveric shoulders (mean age, 81 years; range, 56–90) were mounted in a custom shoulder holder, and 2 posterior portals (2 and 3 o'clock) were fixed into place. The area of a best-fit circle of the inferior portion of the glenoid was digitally calculated, and 2 sequential osteotomies of 12.5% and 25% of anteroinferior glenoid bone loss area were created. Two different types of osteotomies were created: group 1, “inverted-pear” bone loss (45° to the long axis of the glenoid); and group 2, “clinical” bone loss osteotomy (0° to the long axis of the glenoid). Measurements of bone loss were performed based on the bare spot method from 2 simulated posterior portals at 2 and 3 o'clock using a calibrated probe and digital calipers. The osteotomy was measured in 3 different locations (upper, middle, and lower thirds). Results In the 12.5% bone loss model, bone loss measurements for both groups were significantly higher than expected (22.2%–23.1 % in group 1,17.4%–17.9% in group 2; P = .031-.049). In the 25% bone loss model, the mean measured bone loss was 27.8% in group 1 and 27.5% in group 2; however, bone loss measurements varied significantly in group 1 based on measurement location along the osteotomy (upper third, 12.3%; middle third, 31.5%; lower third, 39.8% loss) (P = .01-.0001). In group 2, the bone loss measurements were less varied (23.5%–0.3%). There were no differences between the location of the posterior portal (2 vs 3 o'clock) in determination of glenoid bone loss for both the 12.5% and 25% osteotomies. Conclusion Glenoid bone loss determination in a 45° osteotomy model significantly overestimates the amount of true glenoid bone loss. However, in a 0° clinical bone loss simulation model, the arthroscopic bare spot method of bone loss determination was sufficiently accurate at all 3 areas (upper, middle, and lower third) of bone loss. Both the 2-o'clock and 3-o'clock posterior portals were accurate to determine the amount of glenoid bone loss as referenced from the bare spot. Clinical Relevance Arthroscopic determination of glenoid bone loss is more accurate than what has been previously described with the 45° simulation model. Measurement of glenoid bone loss from either the 2-o'clock or 3-o'clock posterior portal is accurate in a clinical bone loss model.

Dual-energy X-ray absorptiometry is a highly sensitive measure of bone loss in early RA

Dual-energy X-ray absorptiometry is a highly sensitive measure of bone loss in early RA

Quantitative analysis of glenoid bone loss in osteoarthritis using three-dimensional computed tomography scans

The 3-dimensional (3D) shape of the glenoid vault has been defined previously and shown to be a complex, yet consistent, shape in individuals without glenoid pathology. We proposed assessing whether this conserved shape could be used as a template to measure glenoid bone loss in subjects with glenohumeral osteoarthritis. Computed tomography (CT) scans of both shoulders were obtained from 12 subjects with unilateral glenohumeral osteoarthritis. The paired scapulae were reconstructed 3-dimensionally, using a previously developed graphic software package. Two methods of estimating glenoid bone loss were performed. First, using the software, a stereolithography model of the standardized vault shape was implanted into each glenoid and measurements made of the volume of the implant not contained within each vault. Second, direct measurements of the paired glenoid vault volumes were performed. The volume of the nonarthritic glenoid was used as a subject-specific template for normal glenoid vault volume for each pair. The glenoid bone volumes measured by each method were compared and Pearson's correlation coefficient determined. The average measurement of glenoid bone loss using the vault implant was within 0.8% (SD +/- 1.5%) of the measurement made using the contralateral, normal glenoid. For all patients, Pearson's correlation coefficient was .99, indicating a very high correlation between the two methods of measuring bone loss (P < .0001). The intricate, yet consistent 3D shape of the glenoid vault can be used as an accurate and reliable template to measure glenoid bone loss in glenohumeral osteoarthritis.

Comparison of the reproducibility of storage phosphor and film bitewings for assessment of alveolar bone loss

Objective. To compare bitewing storage phosphor images and a digital measuring method with bitewing films and an analog measuring method with regard to the reproducibility of measurements of alveolar bone loss. Material and methods. Nine participants randomly selected from an epidemiological study were radiographically examined using two modalities: bitewing SP images and bitewing films. A digital measuring method was used on the bitewing SP images and an analog measuring method on the bitewing films. Alveolar bone loss was measured at 12 index sites in the premolar/molar region per participant and modality. One hundred measured sites on each modality were assessed twice by three observers. Paired t-test values and intra-class correlation coefficient (ICC) were computed. Results. Comparison of the mean absolute difference of alveolar bone loss between the digital and analog measuring methods demonstrated comparable results (p=0.53). The absolute difference in millimetres between 1st and 2nd measurements was comparable for two observers and statistically different for one. Intra-observer performance between 1st and 2nd measurements was comparable for the digital (ICC=0.85) and analog (ICC=0.83) measuring methods. Inter-observer agreement for the digital measurements was higher (ICC=0.79) than for the analog measurements (ICC=0.64). Conclusions. The study demonstrates that digital and analog measuring methods are comparable with regard to absolute alveolar bone measurements and intra-observer agreement. Inter-observer comparison demonstrated significantly higher agreement for the digital measurements. Based on the overall results, the modalities with the measuring methods utilized are comparable when measuring minor alveolar bone loss.

Radiographic Alveolar Bone Loss in Patients Undergoing Periodontal Maintenance

The aim of the present cross-sectional investigation was to evaluate percentage of bone loss in patients who had been one year under periodontal maintenance at the Department of Periodontology, Faculty of Dentistry, University of São Paulo by radiographic analysis. Complete sets of periapical radiographs provided data regarding percentage of alveolar bone loss, which was correlated with arches, tooth group and proximal sites. The sample consisted of 27 men and 53 women ranging in age from 16 to 85 years (mean: 48.3 years). A total of 1,120 periapical radiographs (1,970 teeth) were digitized and analyzed with the Image Tool software (University of Texas Health Science Center). Bone loss was defined as when the distance between the cemento-enamel junction and the alveolar bone crest was greater than 2 mm. Two examiners (p<0.0001) performed radiographic measurements of bone loss. The Greenhouse-Geisser normality test and a univariate analysis of variance were used for statistical analysis. Mean bone loss was 20.60% (+/-12.12). The highest level of bone loss was observed on the distal surface and in the upper arch, as well as in the upper incisors and molars.

Use of Preoperative Three-Dimensional Computed Tomography to Quantify Glenoid Bone Loss in Shoulder Instability

The purpose of this study was to determine if three-dimensional computed tomography (3-D CT) scans of the glenoid can be used to accurately quantify, by means of a glenoid index, bone loss in patients with anterior glenohumeral instability, and to compare the results with arthroscopic measurements to determine if the 3-D CT scan can preoperatively predict which patients with anterior glenohumeral instability will benefit from a bone grafting procedure. From 2003 to 2006, 188 patients with anterior glenohumeral instability underwent arthroscopic evaluation and treatment by the senior author (S.S.B.). Of 188 total patients, there were 25 patients ranging in age from 15 to 43 years (median, 19 years) who underwent 3-D CT evaluations of both shoulders followed by arthroscopy of the unstable shoulder. For an arthroscopically measured bone loss of less than 25% of the inferior glenoid diameter, an arthroscopic Bankart repair was performed; for a glenoid bone loss of greater than or equal to 25%, an open Latarjet reconstruction was performed. We defined the glenoid index as the ratio of the maximum inferior diameter of the injured glenoid compared to the maximum inferior diameter of the uninjured contralateral glenoid as calculated from the 3-D CT scans. If the glenoid index was greater than 0.75, the patient was predicted to benefit from an arthroscopic Bankart repair (the need for surgery and the type of surgery having been determined on the basis of arthroscopic measurements). However, if the glenoid index was less than or equal to 0.75, the patient was predicted to benefit from an open Latarjet procedure. The results of each patient's glenoid index were compared with the arthroscopic decision to perform either an arthroscopic Bankart repair or an open Latarjet procedure. Of the 25 patients included in this study, 13 patients underwent an open Latarjet procedure and 12 patients underwent an arthroscopic Bankart repair. The 3-D CT scans accurately predicted the arthroscopic decisions to perform an arthroscopic Bankart repair or open Latarjet in 24 (96%) of 25 cases (Fisher exact test; P < .001). The glenoid index as calculated from the 3-D CT scan accurately predicted the requirement of a bone grafting procedure for 24 (96%) of 25 patients when the benchmark value of 0.75 was used. The 3-D CT scan can therefore be used by surgeons as an additional diagnostic tool for preoperative planning and patient counseling. Level III, development of diagnostic criteria with universally applied reference (nonconsecutive patients).

Comparison between inverted and unprocessed digitized radiographic imaging in periodontal bone loss measurements

The advances in digital imaging technology in dentistry have provided an alternative to film-based radiography and have given new options to detect periodontal bone loss. The purpose of this study was to compare inverted and unprocessed digitized radiographic imaging in periodontal bone loss measurements. Thirty-five film-based periapical radiographs of patients suffering from moderate to advanced untreated periodontal bone loss associated to lower premolar and molars was selected from the department files, with 40 bone loss areas. The film-based radiographs were digitized with a flatbed scanner with a transparency and radiograph adapter used for transilluminating the radiograph imaging. Digitization was performed at 600 dpi and in gray scale. The images were digitized using Image Tool software by applying image inversion, that is, transformation of radiopaque structures into radiolucent structures and vice-versa. The digital data were saved as JPEG files. The images were displayed on a 15-inch and 24-bit video monitor under reduced room lighting. One calibrated examiner performed all radiographic measurements, three times, from the cementoenamel junction to the most apical extension of the bone loss, in both types of image (inverted and unprocessed). Brightness and contrast were adjusted according to the examiner's individual demand. Intraclass correlation coefficient was used to compare the measurements from both types of images. The means of radiographic measurements, in mm, for inverted and unprocessed digitized imaging were 6.4485 and 6.3790, respectively. The intraclass correlation coefficient was significant (0.99) The inverted and unprocessed digitized radiographic images were reliable and there was no difference in the diagnostic accuracy between these images regarding periodontal bone loss measurements.

Retrospective Evaluation of 48 Consecutive Immediate Load Hybrid Cases Performed at the OSU OMFS Resident Clinic

Today patients are living longer and demanding more stable prostheses to replace teeth as they are lost. Replacing mandibular dentition with immediate load hybrid prostheses via the OSU protocol allows patients to have a definitive restorative solution immediately following surgery. In this retrospective evaluation we review the success rates of hybrid restorations regardless of success or failure of individual variables. The records of 60 patients that had implant surgery for hybrid restorations with immediate load between October 2001 and May 2006 were initially examined. These records were sorted based on the following five inclusion criteria: case performed in the resident clinic, restored with a mandibular hybrid, implant/hybrid complex immediately loaded, patients with a minimum follow-up time of 3 months and, lastly, complete records. Of the original cases reviewed 48 met all of the inclusion criteria. The variables examined for the implant fixture included the following: crestal bone loss, immobility, absence of symptoms (infection, pain and neurosensory disturbances), soft tissue free of inflammation and ability to maintain adequate hygiene. Variables examined for the hybrid prosthesis included the following: passive fit of framework, adequate occlusion, adequate function, esthetics, a design that enables adequate hygiene, and component integrity. Descriptive statistics. One patient (2.08%) had measurable crestal bone loss after one year, seven patients (14.58%) had mobility of at least one implant as established by Periotest (Bensheim an der Bergstrasse, Germany), five (10.41%) had continued symptoms after 3 months, nine (18.75%) had continued areas of soft tissue inflammation after 3 months of healing, and five (10.41%) were not able to adequately maintain hygiene secondary to the surgery. One prosthesis (2.08%) had a non-passive framework, one (2.08%) was found to have inadequate occlusion, eight (16.67%) were found to have inadequate function, and none were found to have poor esthetics. In eight patients (16.67%) the prosthesis inhibited adequate hygiene practices. Eighteen patients (37.5%) were found to have failed component integrity. We found multiple minor issues associated with the surgery as well as the prosthetic reconstruction. However, most of these individual issues were addressed and the patients went on to heal and function uneventfully. This shows that regardless of a number of failures in individual categories evaluated, the overall success rate of the implant/hybrid complex with immediate loading was 93.75% (44 cases). The clinical success rate of the immediate load mandibular hybrid prostheses following the OSU protocol in the resident clinic is very high. Healing time between implant placement and delivery of definitive prosthesis is decreased from 6-9 months to 2 days following the OSU immediate load protocol. This eliminates the need for an interim removable denture for esthetic or functional purposes. The fixed stability of the prosthesis allows the patient to function better and more naturally than any type of removable prosthesis. The anxiety of being seen without teeth is overcome with this treatment decreasing the amount of patient self-awareness.

Flat-Panel Detector—Based Volume Computed Tomography: A Novel 3D Imaging Technique to Monitor Osteolytic Bone Lesions in a Mouse Tumor Metastasis Model

Skeletal metastasis is an important cause of mortality in patients with breast cancer. Hence, animal models, in combination with various imaging techniques, are in high demand for preclinical assessment of novel therapies. We evaluated the applicability of flat-panel volume computed tomography (fpVCT) to noninvasive detection of osteolytic bone metastases that develop in severe immunodeficient mice after intracardial injection of MDA-MB-231 breast cancer cells. A single fpVCT scan at 200-wm isotropic resolution was employed to detect osteolysis within the entire skeleton. Osteolytic lesions identified by fpVCT correlated with Faxitron X-ray analysis and were subsequently confirmed by histopathological examination. Isotropic three-dimensional image data sets obtained by fpVCT were the basis for the precise visualization of the extent of the lesion within the cortical bone and for the measurement of bone loss. Furthermore, fpVCT imaging allows continuous monitoring of growth kinetics for each metastatic site and visualization of lesions in more complex regions of the skeleton, such as the skull. Our findings suggest that fpVCT is a powerful tool that can be used to monitor the occurrence and progression of osteolytic lesions in vivo and can be further developed to monitor responses to antimetastatic therapies over the course of the disease.

Sonography of periimplant buccal bone defects in periodontitis patients: A pilot study

The degree of marginal bone loss at buccal periimplant sites may now be measured noninvasively using sonography. The purpose of the present study was to assess the reproducibility and validity of linear measurements of periimplant buccal bone loss on sonographic images. In 25 patients with 29 buccal bone defects in the mandibular anterior region, the vertical distance between the upper thread of the implant and the most apical level of the marginal bone was evaluated sonographically by using a linear (B-scan) 12.5-MHz small-part transducer, and surgically by using a calibrated periodontal probe. For each subject, measurements were taken in 2 test settings, on the day of periodontal reevaluation ("test re-test"), and 2 weeks after periodontal re-evaluation on the day of periodontal surgery ("sonography versus surgery"). Statistical analysis consisted of univariate analysis of variance for repeated measurements. Data were analyzed for reliability by using the intraclass correlation coefficient (ICC) and the method error (ME). For the sonographic measurements, there was a significant "session"/"test setting"/"bone loss level" interaction (P = .024). Analysis of simple session-within-level effects revealed a significant difference between the measurements for advanced bone loss levels at the "sonography versus surgery" setting (P = .037). Measurements made at moderate bone loss levels were the most reliable (ICC = 0.76 to 0.81; ME = 4.2% to 6.6%). The results of this study indicate that sonography may be a reliable and valid method for assessment of marginal bone loss at buccal periimplant sites. The difference in defect assessment ability depends on defect depth.

Influence of Photodynamic Therapy on the Development of Ligature‐Induced Periodontitis in Rats

The purpose of this study was to evaluate, histologically and radiographically, the effect of photodynamic therapy on the progression of experimentally induced periodontal disease in rats. Ligatures were placed at the first mandibular molar in rats. The animals were divided into four groups: group 1 (C) received no treatment; group 2 was treated topically with methylene blue (MB; 100 microg/ml); group 3 was treated with low-level laser therapy (LLLT); and group 4 was treated topically with methylene blue followed by LLLT (4.5 J/cm(2)) (photodynamic therapy; PDT). Rats were sacrificed 5, 15, or 30 days postoperatively. Standardized radiographs were taken to measure bone loss around the mesial root surface of the first molar. Data were analyzed statistically (analysis of variance and Tukey test; P <0.05). A scoring system was used to evaluate the connective tissue, periodontal ligament, and alveolar bone histologically. Data were analyzed statistically (Kruskal-Wallis test; P <0.05). Radiographic examination showed that there was significantly less bone loss in Group PDT compared to Group C at 5 and 15 days postoperatively. There was no significant difference in bone loss at 30 days. At 15 days, the histologic results showed significant differences in the extent of inflammatory reaction in the gingival tissue, with a greater extent of chronic inflammatory reaction in Group LLLT. PDT transiently reduced the periodontal tissue destruction.

Measures of Renal Function, BMD, Bone Loss, and Osteoporotic Fracture in Older Adults: The Rancho Bernardo Study

The association between bone and renal function in healthy seniors is not well studied. In this cross-sectional and longitudinal study in 1713 older men and women, creatinine clearance was significantly associated with hip BMD. If confirmed, this may warrant adding mild to moderate renal dysfunction as an indication for osteoporosis screening. This study determined the cross-sectional and longitudinal association between measures of renal function and BMD, bone loss, and osteoporotic fracture in older adults. It determined which measure of renal function--creatinine clearance by the Cockcroft-Gault (CG) equation, estimated glomerular filtration rate by the Modification of Diet in Renal Disease (MDRD) equation, or serum creatinine--is most strongly associated with BMD and osteoporotic fracture. This was a cross-sectional and prospective study in older community-dwelling men and women. Between 1992 and 1995, 1713 participants (average age, 71.3 +/- 11.1 years) completed standardized questionnaires, physical examinations, laboratory testing, and bone densitometry; 1023 participants returned for a follow-up visit in 1997-1999, an average of 4.1 +/- 0.9 years later. Calculated renal function declined with age (p < 0.001). Renal function was categorized by Kidney Disease Outcomes Quality Initiative (K/DOQI) chronic kidney disease (CKD) stage. By the CG equation, at baseline, 5.5% of participants had stage 1 CKD (glomerular filtration rate > or = 90 ml/min/1.73 m(2)), 43.0% had stage 2 CKD (60-89 ml/min/1.73 m(2)), 48.8% had stage 3 CKD (30-59 ml/min/1.73 m(2)), and 2.7% had stages 4 and 5 CKD (<30 ml/min/1.73 m(2)). Using the MDRD equation, these percents were 7.0%, 61.7%, 30.9%, and 0.5%, respectively. In cross-sectional analyses, there was a significant linear association between creatinine clearance by CG or glomerular filtration rate by MDRD and hip BMD. In prospective analyses, there was an average annual bone loss of 0.6% and a significant association between baseline CG and 4-year hip bone loss. There was no association between baseline MDRD or serum creatinine and bone loss. At baseline, 180 of 1713 participants (11%) reported at least one clinical fracture of the hip, femur, forearm, or wrist; 79 (8%) reported new clinical fractures during follow-up. Baseline renal function by any measure was not significantly associated with prevalent or incident clinical fractures. Although renal function measured by both CG and MDRD was associated with BMD in cross-sectional analyses, only creatinine clearance by CG predicted 4-year bone loss. If confirmed, this should be the preferred method for assessing the association between renal function and BMD. Cross-sectional associations between renal function and BMD were strongest at higher CKD stage. None of the baseline renal function estimates was associated with prevalent or incident fractures, perhaps reflecting the multifactorial etiology of fractures beyond BMD. If further studies in the elderly confirm renal function as an important predictor of bone loss and fracture, this may warrant adding mild to moderate renal dysfunction as an indication for osteoporosis screening.

Influence of image filters on the reproducibility measurements of alveolar bone loss

The reproducibility of measurements of alveolar bone loss on radiographs may be a problem on epidemiologic studies, as they are based on comparisons of the diagnosis of various examiners. The aim of the present research paper was to assess the inter- and intra-examiner reproducibility of measurements of the interproximal alveolar bone loss on non-manipulated digital radiographs and after the application of image filters. Five Oral Radiologists measured the distance between the cementoenamel junction (CEJ) to the alveolar crest or to the deepest point of the bony defect on 12 interproximal digital radiographs of molars and bicuspids of a dry human skull. The digital manipulation and the linear measurements were obtained with the Trophy Windows software (Throphy®). For each image, six different versions were created: 1) non-manipulated; 2) bright-contrast adjustment; 3) negative; 4) negative with brightness-contrast adjustment; 5) pseudo-colored; 6) pseudo-colored with brightness-contrast adjustment. In order to prevent interpretation bias because of the repetition of measurements, the examiners measured the radiographs in a random sequence. The two-way ANOVA test at 5% level of significance to compare the means of readings of the same operator with each filter indicated p<0.05 for the majority of operators, while the comparison between the mean values of operators using the same filter indicated p>0.05 for all filters. Based on the results, we concluded that linear measurements of interproximal alveolar bone loss on digital radiographs are highly reproducible among examiners. Nevertheless, the application of image filters significantly influenced the degree of intra-examiner reproducibility. Some filters even reduced the reproducibility of intra-examiner readings.

T Lymphocyte–Deficient Mice Lose Trabecular Bone Mass With Ovariectomy

We examined OVX-induced bone loss in three TLD mouse models. In TLD mice, OVX caused trabecular bone loss equivalent to that of WT. In contrast, cortical bone loss with OVX was variable. We conclude that T lymphocytes do not influence OVX-induced trabecular bone loss. We examined ovariectomy (OVX)-induced bone loss in three T lymphocyte-deficient (TLD) mouse models: nude mice, recombination activating gene 2-deficient (RAG2 KO) mice, and T cell receptor alpha chain-deficient (TCRalpha KO) mice. Bone mass was examined by DXA, microCT, and histomorphometry. We also examined the effect of OVX on T lymphocytes in the bone marrow and spleens of wildtype (WT) mice and on in vitro osteoclastogenesis and colony forming unit-granulocyte macrophage (CFU-GM) activity in the bone marrow of WT and nude mice. In WT mice, OVX did not alter T lymphocyte number in the bone marrow but did increase T lymphocytes in the spleen. Comparison of bone mass in nude, RAG2 KO, and TCRalpha KO mice with WT as measured by DXA showed decreased femoral bone mass in nude mice and increased vertebral bone mass in RAG2 KO mice. In TCRalpha KO mice, femoral, tibial, and vertebral bone mass were decreased. In vertebrae and long bones, bone loss with OVX was consistently present in WT mice but variably present in TLD mice as measured by DXA. In contrast, microCT and histomorphometry showed similar trabecular bone loss after OVX in all mice. However, femoral cortical bone loss occurred only in WT and RAG2 KO mice. OVX produced similar trabecular bone loss in WT and TCRalpha KO mice and also induced cortical bone loss in both. Histomorphometry showed that TRACP(+) area in bones was increased by OVX in femurs from both WT and nude mice as was in vitro osteoclast-like cell formation and CFU-GM activity. These results show that OVX caused similar trabecular bone loss in both WT and TLD mice. The ability of DXA and measurement of cortical bone loss to show OVX-induced effects on bone mass was variable. It seems that T lymphocytes are not critical for OVX-induced trabecular bone loss in these mouse models.