The efficacy of ultrasonography in monitoring the healing of jaw lesions.

PURPOSE: This study aimed to assess the reliability of ultrasonography (US) in comparison with cone-beam computed tomography (CBCT) as a tool for monitoring the healing of jaw lesions. MATERIALS AND METHODS: Twenty-one radiolucent lesions in jaws referred to the Oral Surgery Department at our institution were selected for this study. All lesions underwent CBCT and US examinations. The anteroposterior, superoinferior, and mesiodistal dimensions of the lesions were measured on CBCT and US images before surgery and at 6 months after surgery. The dimensions were compared between the US and CBCT images. Blood-flow velocity around the lesions was measured by color Doppler before surgery and at 1 week and 6 months after surgery to assess the capability of US to show changes in blood-flow velocity around the lesion. RESULTS: Before surgery, there were no significant differences between US and CBCT in the mesiodistal and anteroposterior dimensions, although a significant difference was found in the superoinferior dimension (P<.05). However, at 6 months after surgery, significant differences were found between US and CBCT in all dimensions, and it is likely that the US measurements more accurately reflected the extent of healing. The average blood-flow velocity increased at 1 week after surgery (5.84 cm/s) compared with the velocity before surgery (4 cm/s) (P<.05). Then, at 6 months after surgery, the blood-flow velocity significantly decreased (3.53 cm/s) compared to the velocity measured at 1 week after surgery (P<.05). CONCLUSION: US with color Doppler was confirmed to be a more efficient tool than CBCT for monitoring bone healing.

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

PURPOSE: The goal of this study was to develop a new index as an objective reference for evaluating current and newly developed indices used for osteoporosis screening based on dental images. Its name; IDIOS, stands for Index of Dental-imaging Indices of Osteoporosis Screening. MATERIALS AND METHODS: A comprehensive PubMed search was conducted to retrieve studies on dental imaging-based indices for osteoporosis screening. The results of the eligible studies, along with other relevant criteria, were used to develop IDIOS, which has scores ranging from 0 (0%) to 15 (100%). The indices presented in the studies we included were then evaluated using IDIOS. RESULTS: The 104 studies that were included utilized 24, 4, and 9 indices derived from panoramic, periapical, and computed tomographic/cone-beam computed tomographic techniques, respectively. The IDIOS scores for these indices ranged from 0 (0%) to 11.75 (78.32%). CONCLUSION: IDIOS is a valuable reference index that facilitates the evaluation of other dental imaging-based osteoporosis screening indices. Furthermore, IDIOS can be utilized to evaluate the accuracy of newly developed indices.

Assessment of jawbone trabecular bone structure amongst osteoporotic women by cone-beam computed tomography: the OSTEOSYR project.

OBJECTIVE: To assess the trabecular bone structure of jawbones and the dens (the odontoid process of the second cervical vertebra) amongst osteoporotic and nonosteoporotic women using cone-beam computed tomography (CBCT). Analysis of the dens trabecular bone structure aimed to test the validity of CBCT in such analysis. METHODS: Thirty-eight women who went under dual-energy X-ray absorptiometry (DXA) examination were scanned by CBCT. Cuboids from different areas of jawbones and the dens were extracted from each scan. Trabecular thickness (Tb.Th), trabecular separation (Tb.S), bone volume fraction (BV/TV), specific bone surface (BS/TV) and connectivity density were calculated. Student's t-test, Pearson correlation, and logistic regression analysis were used to explore differences in these measures between groups. RESULTS: Jawbone-derived measures showed insignificant differences (P > 0.05) between osteoporotic and non-osteoporotic groups, and weak correlations with femoral neck and lumbar vertebrae T-scores (r ≤ 0.4). Dens-derived measures, however, resulted in the opposite (r = 0.34-0.38 [P value = 0.02-0.036] and r = 0.48-0.61 [P value ≤ 0.003]) and the highest accuracy of osteoporosis prediction: 84.2% and 78.9% respectively. CONCLUSION: Trabecular bone structure of the mandible and maxilla is not affected in osteoporosis as assessed by CBCT. Dens trabecular bone analysis revealed the opposite, so some trabecular bone measures may be assessed by CBCT, which may aid in predicting osteoporosis.

Osteoporosis prediction from the mandible using cone-beam computed tomography.

PURPOSE: This study aimed to evaluate the use of dental cone-beam computed tomography (CBCT) in the diagnosis of osteoporosis among menopausal and postmenopausal women by using only a CBCT viewer program. MATERIALS AND METHODS: Thirty-eight menopausal and postmenopausal women who underwent dual-energy X-ray absorptiometry (DXA) examination for hip and lumbar vertebrae were scanned using CBCT (field of view: 13 cm×15 cm; voxel size: 0.25 mm). Slices from the body of the mandible as well as the ramus were selected and some CBCT-derived variables, such as radiographic density (RD) as gray values, were calculated as gray values. Pearson's correlation, one-way analysis of variance (ANOVA), and accuracy (sensitivity and specificity) evaluation based on linear and logistic regression were performed to choose the variable that best correlated with the lumbar and femoral neck T-scores. RESULTS: RD of the whole bone area of the mandible was the variable that best correlated with and predicted both the femoral neck and the lumbar vertebrae T-scores; further, Pearson's correlation coefficients were 0.5/0.6 (p value=0.037/0.009). The sensitivity, specificity, and accuracy based on the logistic regression were 50%, 88.9%, and 78.4%, respectively, for the femoral neck, and 46.2%, 91.3%, and 75%, respectively, for the lumbar vertebrae. CONCLUSION: Lumbar vertebrae and femoral neck osteoporosis can be predicted with high accuracy from the RD value of the body of the mandible by using a CBCT viewer program.

Experimental evaluation of bone quality measuring speed of sound in cadaver mandibles.

OBJECTIVES: To demonstrate in vitro the feasibility of speed of sound (SOS) measurements through the mandible and to investigate the relationships between mandibular SOS, local bone mineral density (BMD), and the ratio between trabecular and cortical thicknesses (Tb.Th/Cort.Th). The long-term goal is to find a safe, simple test for bone quality in sites for dental implant placement. METHODS: Excised human mandibles (N = 23) were used for the measurement of sound transmission with two 1.6 MHz transducers. Three regions of interest (ROIs) were selected in each of the specimens, namely incisor, premolar, and molar regions. To determine short-term precision, 10 measurements (with repositioning between measures) were performed for each ROI. Local BMD and mandibular cross-sectional morphological characteristics were determined by dual x-ray absorptiometry (DXA) and computed tomography (CT). RESULTS: The coefficient of variation for SOS was found to be 1%. SOS measurements at different sites were significantly different. A significant linear relationship was found between SOS and BMD (r2 = 0.62; P < .0001), whereas a nonlinear relationship was found between SOS and Tb.Th/Cort.Th (r2 = 0.53; P < .0001). CONCLUSION: This in vitro study demonstrated the feasibility of SOS measurement through the mandible. Mandibular SOS reflects local BMD and Tb.Th/Cort.Th. In vivo studies are now required to confirm the predictive power of SOS measurement for bone quality assessment and its potential usefulness as a clinical diagnostic technique.

[MR-Imaging of lower leg muscle perfusion]. / Magnetresonanztomographische Diagnostik der peripheren Durchblutung.

PURPOSE: This article describes the potential of dynamic contrast- enhanced magnetic resonance tomography (DCE-MRT) for the visualization and quantification of blood flow of lower leg muscles at rest and after individually adjusted muscular exercise. PATIENTS AND METHODS: Five cases were chosen to exemplify the qualitative and semi-quantitative blood flow evaluation in the lower leg muscles. The crural muscle state was determined with an isometric maximal strength measurement from a female patient with peripheral arterial occlusive disease (pAVK), a male patient with coronary heart disease (KHK) without clinical signs of a pAVK, a volunteer with sufficient physical activity in accordance with the Freiburg Questionnaire of Physical Activity and two professional athletes. After calibration of the plantarflexion ergometer MR-PEDALO (Figures 2a and 2b) for the execution of auxotonic muscle work a 1- minute alternating foot extension and flexion exercise on MRPEDALO was performed in the MR machine. Instead of the lower leg splint shown in Figures 2a and 2b the MR coil fits exactly in MR-PEDALO used for DCE-MRT. Mechanical work performed during the 1-minute exercise ranged from 52 watt seconds (Ws) to 244 Ws (0.65 W to 4.07 W), indicating similar interindividual work loads in relation to the individual maximum isometric strength. DCE-MRT was performed at rest and immediately after auxotonic exercise test (T1w 2DFLASH- GE sequence with TR/TE/alpha: 100 ms/6 ms/70 degrees; field of view: 400; matrix: 81 x 256; slice thickness: 10 mm; acquisitions: 73 at 8.3 s each; total examination time: 9.24 min; bolus application of Magnevist, Schering, 0.02 ml/kg kg, 20 ml bolus NaCl, flow 2 ml/s, 22G cannula in a cubital vein). Signal intensity (SI) curves were analyzed with DynaVision (MeVis gGmbH, Bremen, Germany). RESULTS: Measuring peripheral blood flow needs appropriate muscular stress tests. The SI-curves of the region of interest (ROI) representing the peroneus, tibialis anterior and gastrocnemius muscle run almost parallel at rest. Workloads between 52 Ws and 244 Ws (0.65 W and 4.07 W), similar in relation to the individual maximum isometric strength, induce distinctive changes of the upslope, wash-in, peak and washout of SI-curves preferably for the peroneus muscle and less predominant also for the tibialis anterior muscle and gastrocnemius muscle respectively. The first case, a 55-year-old female patient with peripheral arterial occlusive disease (pAVK) stage Fontaine IIb before (Figure 3a) and after (Figure 3b) percutaneous transluminal angioplasty (PTA) of a right femoral artery stenosis shows after interventional treatment a rapid post-exercise SI-increase in the peroneus muscle. The steeper SI-curve indicates a better contrast medium inflow due to an improved perfusion. The second case, a 65-year-old man suffering from coronary heart disease without clinical signs of pAVK (Figure 4) exercised with a workload of 92 Ws. After stress test the ROI for the peroneus muscle shows a clear intensity increase. After exercise the SI-curve for the tibialis anterior muscle shows a similar, but less predominant change while the shape of the SI-curve of the gastrocnemius muscle remains mainly identical. A 23-year-old male person with average physical activity (Figure 5) performed DCE-MRT of the left lower leg after stress test with 172 Ws demonstrating a rapid signal increase in the peroneus muscle while the synergistic tibialis anterior muscle and antagonistic gastrocnemius muscle show a comparatively slow contrast-medium wash-in. A 26-year-old male athlete (Figure 6) exercised with 196 Ws showing a rapid contrast medium inflow in the peroneus muscle and initially also in the synergistic tibialis anterior muscle. A contrast-medium wash-out appears in both muscles, while the shape of the gastrocnemius muscle SI-curve remains substantially unchanged. A 26-year-old female athlete (Figure 7) exercised with 244 Ws. Post exercise SI-curves show a distinctive and rapid increase of contrast medium wash-in with a sharp peak particularly in the peroneus muscle and similarly in the tibialis anterior and gastrocnemius muscle. After exercise all SI-curves show a wash-out phase. CONCLUSION: SI-curves show relative increase in correlation with Time-to-Peak (TTP) decrease and Mean-Intensity to Time Ratio (MITR) increase indicating blood flow reserve mobilization after exercise. Individual muscle state seems to be linked to muscle recruitment and muscle coordination reflected by post-exercise SI-curves. The gastrocnemius muscle shows comparatively low SI-curve changes after muscular load test. Further methodological standardization and optimization of the stress test is mandatory to assure intra- and interindividual comparisons. Due to direct visualization and quantitative evaluation of the peripheral microcirculation DCE-MRT has a diagnostic potential for monitoring therapeutic response in peripheral circulation disorders and sports medicine.