Osteoclasts are also found on the external surface of the alveolar bone, interfacing the oral barrier tissue. Osteoclasts in the oral barrier region are not coupled with osteoblastic bone formation and often remain active long after the completion of wound healing, leading to a net decrease in the alveolar bone structure.

The novel concept of oral barrier osteoclasts may provide important clues for future clinical strategies to maintain residual ridges for successful prosthodontic and restorative therapies.

The novel concept of oral barrier osteoclasts may provide important clues for future clinical strategies to maintain residual ridges for successful prosthodontic and restorative therapies.

The involvement of oral mucosa cells in mechanical stress-induced bone resorption is unclear. The aim of this study was to investigate the effects of cyclic pressure-induced cytokines from oral mucosal cells (human gingival fibroblasts hGFs) on osteoclast activity in vitro.

Cyclic pressure at 50 kPa, which represents high physiologic occlusal force of dentures on the molar area, was applied to hGFs. NFAT-reporter stable RAW264.7 preosteoclasts (NFAT/Luc-RAW cells) were cultured in conditioned medium collected from hGF cultures under cyclic pressure or static conditions. NFAT activity and osteoclast formation were determined by luciferase reporter assay and TRAP staining, respectively. Cyclic pressure-induced cytokines in hGF culture were detected by ELISA, real-time RT-PCR, and cytokine array analyses.

Conditioned media from hGFs treated with 48 hours of cyclic pressure significantly induced NFAT activity and increased multinucleated osteoclast formation. Furthermore, the cyclic pressure significantly i-regulation of OPG. These findings introduce the possible involvement of GFs in mechanical stress-induced alveolar ridge resorption, such as in denture wearers.

This literature review aimed to investigate predictability of re-establishment of the occlusion following placement of restorations at an increased OVD, duration and to assess the quality of the available evidence.

An electronic search of articles using MEDLINE (1946-01/2019), EMBASE (1974-01/2019) and the Cochrane databases was undertaken. Search terms included dental restoration, vertical dimension and time. Studies involving placement of restorations at an increased OVD and recorded the time taken for the occlusion to re-establish were included. Eligibility assessments were carried out independently by two reviewers who also undertook independent extraction of predefined data fields, including study quality indicators.

The search provided 61 results with 11 being relevant. A further 5 papers were identified for full text analysis. 4 papers used similar data from previous studies and 3 were excluded after full text assessment.. A final total of 9 papers were included in the review. It was indicated that the technique of placing restorations at an increased OVD appears to be clinically predictable in terms of re-establishment of occlusion and appears to occur most rapidly in younger patients.

The time taken for the occlusion to re-establish was between 15 days to 24 months. However, there is a need for prospective studies to evaluate the process in terms of success, predictive variables and specifically how long the process takes and this information would be helpful for both clinicians and patients, so that they know what to expect before embarking on a treatment.

The time taken for the occlusion to re-establish was between 15 days to 24 months. However, there is a need for prospective studies to evaluate the process in terms of success, predictive variables and specifically how long the process takes and this information would be helpful for both clinicians and patients, so that they know what to expect before embarking on a treatment.

Secular trends in the risk of recurrent stroke have been reported in several epidemiological studies worldwide, but this issue has not been investigated in general Japanese populations. We examined the trends in the 5-year risk of recurrent stroke over a half century using community-based prospective data in Japan.

We established 4 cohort studies in 1961, 1974, 1988, and 2002. To examine the risk of recurrent stroke, participants who developed stroke during a 10-year follow-up period in each cohort were followed-up for 5 years from the date of first onset. A total of 154 (first sub-cohort 1961-1971), 144 (second sub-cohort 1974-1984), 172 (third sub-cohort 1988-1998), and 146 (fourth sub-cohort 2002-2012) participants from each cohort were enrolled in the present study. The 5-year cumulative risk of recurrent stroke was compared among the sub-cohorts using the Kaplan-Meier method and the age- and sex-adjusted Cox proportional hazards model.

The risks of recurrent stroke after any stroke and ischemic stroke decreased significantly from the first to the third sub-cohort, but they did not clearly change from the third to the fourth sub-cohort. The risk of recurrent stroke after hemorrhagic stroke decreased mainly from the first to the second sub-cohort and there was no apparent decrease from the second to the fourth sub-cohort. These trends were substantially unchanged after adjusting for age and sex.

In the Japanese community, the risk of recurrent stroke decreased mainly from the 1960s to 1990s, but there was no apparent decrease in recent years.

In the Japanese community, the risk of recurrent stroke decreased mainly from the 1960s to 1990s, but there was no apparent decrease in recent years.

The aperture shape controller (ASC) is a tool on a radiation therapy planning system to reduce complexity by increasing the aperture size of multileaf collimator (MLC). The purposes of this study were to clarify the effect of the dose index on the treatment plan when the intensity of ASC is changed and then to clarify the effect on the verification result in the individual patient-specific quality assurance (QA) using the verification phantom.

For four types of mock structures presented at AAPM TG-119, volumetric modulated arc therapy (VMAT) treatment plans with three dose levels were set without using the ASC for each of these four types. ASC settings were changed to very low, low, moderate, high and very high for the treatment plan, and the treatment plan was recreated without changing the planning target volume (PTV) and/or OAR dose constraints. The dose index of the treatment plan was then evaluated. The plan was also transferred by the true composite method to the assessment phantom, and patient-specthe PTV and/or organ at risk (OAR). In particular, the improvement was notable for the case where the evaluation result of patient-specific QA was 95% or less when the ASC was not used.In this study, we verified the targeting time and coordinates of stereotactic vacuum-assisted biopsy (STVAB) and digital breast tomosynthesis-guided vacuum-assisted biopsy (DBTVAB). We used 23 fabricated phantom samples that consisted of small round, amorphous, and pleomorphic clustered microcalcifications, and two types of image reconstruction methods filtered back projection (FBP) and iterative super-resolution reconstruction (ISR). Regarding targeting time, DBTVAB tended to be shorter than STVAB in the two image reconstruction methods and the targeting time was significantly shorter for the amorphous and pleomorphic calcifications using DBTVAB with FBP compared to that using STVAB (p=0.022 for amorphous, p=0.041 for pleomorphic). The targeting time for small round calcifications was longer using DBTVAB with ISR compared to that using STVAB (p=0.013). For targeting coordinates, using DBTVAB with FBP showed a significant difference only for pleomorphic calcifications but using DBTVAB with ISR showed no significance. The findings of this study suggest that FBP is more suitable than ISR to be used as an image reconstruction method, and DBTVAB can shorten the targeting time compared to STVAB.The bone mineral density (BMD) measurement of the lumbar spine with dual-energy X-ray absorptiometry (DXA) has the advantage of being able to detect early changes in BMD, which is usually used for the evaluation of drug therapy. However, DXA is not considered suitable for spinal deformity because it is a two-dimensional measurement. The aims of this study were to compare frontal and lateral measurements with a phantom and to examine the possibility of the evaluation of lumbar spine BMD in spinal deformity. The values of frontal and lateral measurements were compared when the lumbar phantom was tilted by 10 degrees from 0 to 40 degrees, assuming kyphosis, and when it was tilted by 5 degrees from 0 to 10 degrees to the right and left, assuming scoliosis. We revealed that in the case of kyphosis, the frontal is more accurate, and in the case of scoliosis, the lateral is more accurate; small rotation of subjects on the plane parallel to the image receiving surface could be acceptable. In general, the two-directional BMD measurement is useful for the improvement of the accuracy and may have a potential to measure patients with spinal deformity, which was previously thought to be impossible.

Contrast-to-noise ratio (CNR) of four X-ray beams (90 kV with 0.15-mm Cu filter, 90 kV with 0.2-mm Cu filter, 120 kV without filter and 120 kV with 0.2-mm Cu filter) in CsI-flat panel detector (FPD) radiography for lung cancer diagnosis was investigated using Monte Carlo simulation.

Two billion photons were injected to the chest phantom model (width 300 mm, length 300 mm, thickness 200 mm) with imitated lung nodules (10 mm diameter, CT value +30 Hounsfield unit (HU), -375 HU, and -620 HU). Individual primary and secondary photon’s process (absorption, scattering and penetration) in the phantom and CsI-detector was recorded by Monte Carlo simulation. CNR was calculated using primary and secondary absorbed photon’s number in the CsI-detector.

CNR of 90 kV X-ray beam with 0.15 mm and 0.2 mm Cu filters was higher to 120 kV X-ray beam because of higher primary object contrast and photon’s contribution, and high photon’s absorption to CsI.

By Monte Carlo calculation, it was verified that 90 kV X-ray beam with 0.15 mm and 0.2 mm Cu filters yielded higher CNR to 120 kV X-ray beam.

By Monte Carlo calculation, it was verified that 90 kV X-ray beam with 0.15 mm and 0.2 mm Cu filters yielded higher CNR to 120 kV X-ray beam.It is not easy to measure the half-value layer (HVL) of CT because it is necessary to place the X-ray tube position fixed. The aim of this study was to experiment the new methods of HVL measuring of CT using a custom-made lead slit. The custom-made lead slit method allowed the HVL measuring of CT while the rotation of the X-ray tube. The error of HVL value using the custom-made lead slit method compared to the conventional method was within 6%. The custom-made lead slit method can enable to measure the HVL of CT easily without the X-ray tube position fixed.

During computed tomography (CT) examinations, it may be necessary to assist the patient to maintain an appropriate body position. However, there is little protective equipment available for caregivers who approach the gantry. This study aimed to evaluate the effectiveness of novel radiation protective curtains in reducing radiation exposure to caregivers while assisting patients, especially during CT examinations of the head.

The absorbed dose in air around the gantry during CT examinations of the head was measured using glass dosimeters. The measurement points from the center of the gantry were 40 to 120 cm in the front, 0 to 100 cm for each side in the right and left, and 60 to 180 cm from the floor. Measurements were performed at each 20-cm interval, and all points were accumulated 10 times. The absorbed dose in air in a CT room was compared with and without the protective curtains. Next, we assumed the height of the caregiver to be 170 cm, and measured the points for the crystalline lens, chest, and abdomen.