Brain metastasis in a patient with BRCA2-mutated treatment-related neuroendocrine prostate carcinoma and long-term response to radiotherapy and Olaparib: A case report and literature review.

BACKGROUND: A new subtype of prostate cancer called treatment-related neuroendocrine prostate carcinoma (t-NEPC) was added to the revised World Health Organization classification of prostate cancer in 2022. t-NEPC cases are increasing, and there is no established standard treatment. METHODS: A 49-year-old male patient was referred to our department for dysuria. A rectal examination and a prostate biopsy revealed stony hardness and prostate adenocarcinoma, respectively. Imaging studies confirmed the presence of multiple bone and lymph node metastases. The patient was started on upfront treatment with androgen deprivation therapy and an androgen receptor signaling inhibitor, which resulted in a significant (>90%) decrease in prostate-specific antigen (PSA) levels. The patient experienced postrenal failure 6 months later, attributable to local disease progression. Concurrently, there was an elevation in neuron-specific enolase (NSE) levels and an enlargement of pelvic lymph node metastases, without PSA progression. RESULTS: Biopsy specimen for cancer genome profiling revealed deletion of BRCA 2 and PTEN, AR amplification, and the presence of the TMPRSS2-ERG fusion gene. Based on increased NSE and BRCA2 mutations, a diagnosis of t-NEPC with BRCA2 mutation was eventually made. The patient received docetaxel chemotherapy and pelvic radiotherapy. Subsequently, he was treated with olaparib. His NSE levels decreased, and he achieved a complete response (CR). However, 18 months following the olaparib administration, brain metastases appeared despite the absence of pelvic tumor relapse, and the patient's PSA levels remained low. Consequently, the patient underwent resection of the brain metastases using gamma knife and whole-brain radiotherapy but died approximately 3 months later. CONCLUSION SUBSECTIONS: Platinum-based chemotherapy is often administered for the treatment of t-NEPC, but there are few reports on the effectiveness of olaparib in patients with BRCA2 mutations. In a literature review, this case demonstrated the longest duration of effectiveness with olaparib alone without platinum-based chemotherapy. Additionally, the occurrence of relatively rare, fatal brain metastases in prostate cancer after a long period of CR suggests the necessity of regular brain imaging examinations.

Initial experience with prostatic urethral lift versus enucleation of the prostate: a retrospective comparative study.

BACKGROUND: This study aimed to assess initial results and patient characteristics of prostatic urethral lift (PUL) compared with those of bipolar transurethral enucleation of the prostate (TUEB) in the treatment of benign prostatic hyperplasia (BPH) in older patients. METHODS: This retrospective study was conducted at a single institution and involved 25 consecutive patients with BPH who underwent PUL between April 2022 and May 2023. Patient characteristics, operative details, and pre- and postoperative symptom scores were evaluated. The results were compared with those of a previously reported TUEB group (n = 55). RESULTS: The mean age of the patients in the PUL group was 74.6 years, and the mean prostate volume was 47.5 ml. The PUL procedure significantly improved urinary symptoms, particularly incomplete emptying (p = 0.041), intermittency (p = 0.005), and weak stream (p = 0.001). The PUL group had higher comorbidity scores (p = 0.048) and included older patients (p = 0.002) than the TUEB group. TUEB showed better improvements in some symptoms and maximum flow rate (p = 0.01) than PUL; however, PUL had a shorter operative time and fewer complications than TUEB (p < 0.001). CONCLUSION: The initial results demonstrate the efficacy and safety of PUL in older patients with BPH. Despite TUEB showing better outcomes in certain aspects than PUL, PUL offers advantages such as shorter operative time and fewer complications. Therefore, PUL can be considered a viable option for high-risk older patients with BPH.

Rezum water vapor thermal therapy in patients with benign prostatic hyperplasia: Initial real-world data from Japan.

Benign prostatic hyperplasia (BPH) is prevalent in older men. As surgery can be high risk in this group, minimally invasive procedures are preferrable. This study aimed to assess the initial results of minimally invasive Rezum water vapor thermal therapy (WVTT) in patients with BPH. This single-center retrospective study included 25 consecutive patients with BPH who underwent WVTT between September 2022 and July 2023. Parameters including age, Charlson Comorbidity Index and Geriatric 8 (G8) scores, operative time, and number of vapor injections were evaluated. The International Prostate Symptom Score (IPSS), Overactive Bladder Symptom Score, and Core Lower Urinary Tract Symptom Score (CLSS) were used to assess symptoms before the procedure, and at 1 and 3 months after it. Urinary function indicators such as single voiding volume, maximum flow rate (MFR), and post-void residual volume were assessed at the same time points. The mean patient age was 76.0 years and the mean prostate volume was 54.8 mL. The mean G8 score was 14.4 and the Charlson Comorbidity Index score averaged 1.2. The mean operative time was 6.84 min, and included a mean of 4.8 vapor injections. Three months after WVTT, significant improvements were observed in the maximum flow rate (P = .02), post-void residual volume (P = .001), and urine volume (P < .001), as well as in the IPSS incomplete emptying (P = .01) and weak stream (P = .01) domains. No significant changes were observed in the remaining IPSS domains or in the Overactive Bladder Symptom Score or CLSS. This study provides the first report on Rezum WVTT outcomes in Japan using the CLSS assessment tool. The initial results indicate a promising experience with this new treatment method. With a rapidly aging population, the incidence of BPH is expected to increase, making the minimally invasive Rezum system a valuable addition to BPH treatment options.

Clinical characteristics of patients with metastatic castration-resistant prostate cancer after treatment with combined androgen blockade.

BACKGROUND: Although the second-generation androgen receptor inhibitors and taxanes have recently been recommended for the initial treatment of metastatic prostate cancer, bicalutamide and flutamide are still used in a large number of cases. Therefore, it is important to elucidate the clinical characteristics of these treated CRPC cases and their sensitivity to the currently used therapeutic agents. We aimed to examine the outcomes of metastatic castration-resistant prostate cancer following combined androgen blockade as initial therapy at our institution. METHODS: Ninety-four patients who developed metastatic castration-resistant prostate cancer after hormonal treatment with combined nonsteroidal androgen receptor antagonists and continuous androgen deprivation therapy between January 2015 and December 2020 were included. The presence of visceral metastases, duration of efficacy of each treatment, and overall survival after castration-resistant prostate cancer were evaluated. RESULTS: Patients with a longer duration of castration-resistant prostate cancer tended to have a longer response duration to subsequent enzalutamide administration (p = 0.003). Patients who achieved a 90% reduction in prostate-specific antigen levels with enzalutamide had a significantly better castration-resistant prostate cancer prognosis (p = 0.002). Meanwhile, those with visceral metastases at the time of castration-resistant prostate cancer diagnosis had a significantly poorer prognosis (p < 0.001). A positive correlation was observed between the treatment efficacy of abiraterone and taxanes for castration-resistant prostate cancer. CONCLUSION: The study provides scientific evidence to support that patients with longer time to castration-resistant prostate cancer are more sensitive to enzalutamide, and the use of abiraterone between docetaxel and cabazitaxel has favorable prognostic impact. These findings provide instrumental evidence that can enable better treatment selection for prostate cancer patients.

Implant Placement Using the Bone Ring Technique With and Without Membrane Placement: A Preclinical 12-Month Study in Dogs.

The bone ring technique is applied for vertical augmentation, in which the dental implant and autogenous block bone graft are simultaneously inserted. We investigated the healing of bone around implants placed simultaneously using the bone ring technique with and without membrane placement after a 12-month healing period. Vertical bone defects were created on both sides of the mandible of Beagle dogs. Implants were inserted into the defects through bone rings and fixed with membrane screws as healing caps. The augmented sites on one side of the mandible were covered with a collagen membrane. Samples were harvested 12 months after implantation and assessed histologically and by microcomputed tomography analysis. All implants remained throughout the healing period; however, except for 1 implant, they showed lost caps and/or exposure to the oral cavity. The implants had contact with newly formed bone despite frequent bone resorption. The surrounding bone appeared mature. The medians of bone volume and percentages of total bone area and bone-to-implant contact within the bone ring were slightly higher in the group with membrane placement than in that without membrane placement. Nevertheless, none of the evaluated parameters were significantly affected by the membrane placement. In the present model, soft tissue complication was frequent, and the membrane application did not reveal the effect at 12 months after implant placement using the bone ring technique. Sustained osseointegration and maturation of surrounding bone were observed in both groups after a 12-month healing period.

Prophylaxis of Antifungal Drugs against Systemic Fungemia induced by Oral Candidiasis in Mice.

Oral mucositis is highly prevalent among the elderly, for whom oral care is often difficult. Oral mucositis, such as candidiasis, can induce systemic fungemia. Antifungal prophylaxis may be useful in such cases to prevent systemic fungemia; however, studies on this are limited. The objective of this study was to demonstrate the effectiveness of antifungal prophylaxis to prevent systemic Candida dissemination compared to oral care using a mice model. Oral candidiasis was induced using chemotherapy and inoculation with C. albicans in 8-week-old male mice. Group A was given oral care, Group B was orally administered an antifungal drug, Group C was intravenously administered an antifungal drug, and Group D was used as the negative control group. Macroscopic features of the tongue surface, colony forming units (CFU) on the tongue, and blood culture for C. albicans were evaluated. CFU was significantly higher in Group A than in Groups B and C. The oral care group, but not the groups administered antifungal agents, showed significantly higher positive numbers of animals with C. albicans in the blood as compared to the control group, indicating the effectiveness of antifungal prophylaxis over oral care. Antifungal prophylaxis may be an option for the prevention of systemic fungemia in individuals with difficulty in oral care.

Characteristics of prostate biopsy in patients under the dutasteride treatment.

We performed a retrospective study to clarify the characteristics of prostate biopsies in patients treated with dutasteride, a benign prostate hyperplasia treatment drug that inhibits 5α-reductase. We studied the digital clinical data of 677 patients, including 96 cases treated with dutasteride, with suspected localized prostate cancer. All patients underwent transrectal ultrasonography-guided prostate biopsy between 2014 and 2017 in our department. A propensity score matching analysis was performed based on prostate-specific antigen (PSA) (calculated as double the PSA value for the dutasteride group) and age. Ninety-six patients in each of the dutasteride and control groups were assessed and their characteristics were compared. The characteristics of the patients in the dutasteride and control groups were well balanced by matching. There were fewer prostate cancer-positive patients in the dutasteride group. When comparing only the prostate cancer-positive patients in each group, there were significantly more cases of high-grade cancers and abnormal magnetic resonance imaging (MRI) findings in the dutasteride group. In the dutasteride group, abnormal MRI findings and advanced age were significant predictors of high grade cancer. This study shows the characteristics of prostate biopsies in patients treated with dutasteride and indicates that patients on dutasteride with advanced age and abnormal MRI findings should undergo prostate biopsy.

Pumping the Periosteum: A Feasibility Study.

PURPOSE: Gradual elevation of periosteum from the bone surface is known to promote the adaptation of soft tissues and the formation of hard tissues. The aim of our study was to estimate the benefit of periosteal distraction osteogenesis (PDO) on de novo bone formation in a rat model. MATERIALS AND METHODS: After device placement, animals were allowed for a latency period of 7 days. Animals in the PDO group were subjected to distraction at a rate of 0.1 mm/d for 10 days. In the periosteal pumping (PP) group, the animals were subjected to distraction at a rate of 0.1 mm/d. The direction of distraction was alternated every 2 days. The animals were euthanized at 17, 31, and 45 days after surgery, and the samples were analyzed histologically and by microcomputed tomography. RESULTS: In both groups, the new bone was characterized as primary woven bone that was located at the leading edge of bone apposition. Bone volumes significantly increased throughout the observation period both in the PP group ( P = 0.018) and in the PDO group ( P < 0.001). The new bone was denser and more mature in the PP group than in the PDO group, and the difference was significant at the 31-day time point ( P = 0.024). However, the volume of the new bone was higher in the PDO at the 45-day time point ( P < 0.001). CONCLUSIONS: We propose that the PP may be applied to enhance the osteogenic capacity of periosteum without plate elevation. Because this is only a proof-of-principle study, the alternated protocol of periosteal distraction warrants evaluation in the future studies.

CBCT imaging and histopathological characteristics of osteoradionecrosis and medication-related osteonecrosis of the jaw.

PURPOSE: The purpose of this study was to evaluate the cone-beam computed tomographic (CBCT) imaging and histopathological characteristics of osteoradionecrosis (ORN) and medication-related osteonecrosis of the jaw (MRONJ). MATERIALS AND METHODS: Ten surgical specimens from segmental mandibulectomy (3 ORN and 7 MRONJ) were analyzed using CBCT. The CBCT parameters were as follows: high-resolution mode (tube voltage, 90.0 kV; tube current, 4.00 mA; rotation time, 16.8 s; field of view, 56 mm×56 mm; thickness, 0.099 mm). Histopathological characteristics were evaluated using histological slides of the surgical specimens. The Pearson chi-square test was used to compare ORN and MRONJ in terms of CBCT findings (internal texture, sequestrum, periosteal reaction and cortical perforation) and histopathological characteristics (necrotic bone, inflammatory cells, reactive bone formation, bacteria, Actinomyces, and osteoclasts). A P value less than 0.05 was considered to indicate statistical significance. RESULTS: MRONJ showed periosteal reaction on CBCT more frequently than ORN (7 of 7 [100%] vs. 0 of 3 [0%], P<0.05). Regarding histopathological characteristics, MRONJ showed osteoclasts more frequently than ORN (6 of 7 [85.7%] vs. 0 of 3 [0%], P<0.05). CONCLUSION: This study evaluated the CBCT imaging and histopathological characteristics of ORN and MRONJ, and the findings suggest that CBCT could be useful for the evaluation of ORN and MRONJ.

A Case of Low-Grade Oncocytic Tumor/Chromophobe Renal Cell Carcinoma (Oncocytic Variant) of the Kidney.

The oncocytic variant of chromophobe renal cell carcinoma (oChRCC) and low-grade oncocytic tumor (LOT) is introduced as new renal disease entity. Both of these tumors are low-grade malignancies consisting of cells with eosinophilic cytoplasm. Distinguishing between eosinophilic variant of chromophobe renal cell carcinoma (eCRCC) and oncocytoma is often a diagnostic challenge in routine surgical pathology. However, oChRCC and LOT might be independent disease entities that might not fit completely into any of these categories. Histologically, these tumors have greater morphological similarity with oncocytoma than with ChRCC. However, immunohistochemically, they exhibit diffuse and dense positivity for CK7 and are negative for CD117. In the present case, we initially had difficulty distinguishing among oncocytoma, eCRCC, and type 2 papillary renal cell carcinoma (2-pRCC). However, after learning about new disease entities such as oChRCC and LOT, we were able to diagnose this tumor.

Prominent luminescence of silicon-vacancy defects created in bulk silicon carbide p-n junction diodes.

We investigate fluorescent defect centers in 4H silicon carbide p-n junction diodes fabricated via aluminum-ion implantation into an n-type bulk substrate without the use of an epitaxial growth process. At room temperature, electron-irradiated p-n junction diodes exhibit electroluminescence originating from silicon-vacancy defects. For a diode exposed to an electron dose of [Formula: see text] at [Formula: see text], the electroluminescence intensity of these defects is most prominent within a wavelength range of 400-[Formula: see text]. The commonly observed [Formula: see text] emission was sufficiently suppressed in the electroluminescence spectra of all the fabricated diodes, while it was detected in the photoluminescence measurements. The photoluminescence spectra also displayed emission lines from silicon-vacancy defects.

Formation of quantum dots in GaN/AlGaN FETs.

GaN and the heterostructures are attractive in condensed matter science and applications for electronic devices. We measure the electron transport in GaN/AlGaN field-effect transistors (FETs) at cryogenic temperature. We observe formation of quantum dots in the conduction channel near the depletion of the 2-dimensional electron gas (2DEG). Multiple quantum dots are formed in the disordered potential induced by impurities in the FET conduction channel. We also measure the gate insulator dependence of the transport properties. These results can be utilized for the development of quantum dot devices utilizing GaN/AlGaN heterostructures and evaluation of the impurities in GaN/AlGaN FET channels.

Temperature Dependence on Tensile Mechanical Properties of Sintered Silver Film.

This paper investigates the influence of temperature on tensile mechanical properties of sintered silver (s-Ag) films with 8-10 µm in thickness for fundamental reliability design of semiconductor systems. The s-Ag film sintered under a pressure of 60 MPa possesses the porosity (p) around 5% determined from cross-sectional scanning electron microscope (SEM) images. The stress-strain (S-S) curves of s-Ag and pure silver (p-Ag) films are obtained using originally designed uniaxial tensile tester at temperatures from 25 °C to 150 °C. The S-S curves of p-Ag indicate ductile behavior irrespective of temperature, whereas those of s-Ag indicate brittle-ductile transition at 120 °C. Compared with p-Ag, s-Ag possesses low Young's modulus (E) and high ultimate tensile strength (UTS) below 80 °C. The mechanism of brittle-ductile transition is discussed based on fracture surface observation results.

Investigating the effect of antiseptic solution on the release of interleukin-6 and transforming growth factor beta 1 from human gingival fibroblasts using wound healing assays.

This in vitro study evaluated the effect of different antiseptics and different concentrations thereof in a model of wound healing using human gingival fibroblasts. The fibroblasts were rinsed with four different antiseptic solutions: sodium hypochlorite (HYP), hydrogen peroxide (H2O2), chlorhexidine digluconate (CHX), and benzalkonium chloride (BC). The effect on the release of interleukin-6 (IL-6) and transforming growth factor beta 1 (TGF-ß1) was investigated using enzyme-linked immunosorbent assays (ELISAs). In addition, the effects of the antiseptics on wound healing at 1, 12, 24, and 48 h were assessed through a wound healing assay. The viability of the fibroblasts rinsed with antiseptics was investigated with respect to the concentrations inhibiting cell growth by 50% (IC50), 25% (IC25), and ≤2% (IC2). A statistically significant increased release of IL-6 was obtained with BC IC25 and IC2 after 12, 24, and 48 h (P < 0.01). For TGF-ß1, no significant release was found for CHX IC2 after 24 and 48 h or for IC50 and IC25 after 12 h. There was no significant effect on wound healing capacity for CHX or for BC IC25 and IC2. This study demonstrated that antiseptic rinses of human gingival fibroblasts alter the release of IL-6 and TGF-ß1 and impact wound healing capacity, with both BC and CHX conferring neutral effects.

Single-staged implant placement using the bone ring technique with and without membrane placement: Micro-CT analysis in a preclinical in vivo study.

OBJECTIVES: To assess the impact of collagen membrane application on bone formation surrounding implants placed simultaneously with the bone ring technique. MATERIAL AND METHODS: Dental implants were inserted simultaneously with the bone ring technique in standardized, vertical alveolar bony defects in the mandible of dogs. On one side of the mandible, the augmented sites were covered with a collagen membrane (M-Group). On the contralateral side, no membranes were used (NM-Group). Implants were left to heal with osseointegration for three and six months. The harvested samples were analyzed by means of micro-CT. RESULTS: A nonparametric analysis of data revealed that the membranes were not a significant negative factor for bone volume (BV), but for bone-to-implant contact (BIC, p = .04). Absence of healing caps impaired BV (p = .04) and BIC (p = .02) as well. Furthermore, loss of healing caps and exposure to the oral environment significantly and negatively affected BV (p < .001) and bone mineral density (p < .05) within 2 mm below the implant shoulder. Implant exposure and healing time had a negative interaction effect on both BV (p = .01) and BIC (p = .01). CONCLUSIONS: Within its limitations, the present study revealed no benefit of membrane application to implant placement simultaneous with the bone ring technique. Disruption of soft tissue healing was identified as a risk factor for decrease in BV and BIC.

Quantitative SPECT/CT imaging for medication-related osteonecrosis of the jaw: a preliminary study using volume-based parameters, comparison with chronic osteomyelitis.

OBJECTIVE: To investigate the quantitative SPECT/CT imaging for medication-related osteonecrosis of the jaw (MRONJ) using volume-based parameters. METHODS: Thirteen patients with mandibular lesions (nine MRONJ and four chronic osteomyelitis) underwent SPECT/CT acquisition at 4 h after injection of technetium 99m hydroxymethylene diphosphonate. Then, reconstruction of the acquired data and underwent voxel-based quantitative analysis using GI-BONE software. The parameters of the quantitative manner, such as maximum standardized uptake value (SUVmax), peak SUV (SUVpeak), mean SUV (SUVmean), metabolic bone volume (MBV) and total bone uptake (TBU), were compared for the mandibular lesions. Statistical analyses for the quantitative parameters of mandibular lesions were performed by Mann-Whitney U test. A p value lower than 0.05 was considered as statistically significant. RESULTS: Then, reconstruction of these quantitative parameters, SUVmax (10.16 ± 0.96), SUVpeak (7.95 ± 0.88), SUVmean (5.90 ± 0.86) and TBU (94.22 ± 57.44) for chronic osteomyelitis were significantly higher than those for MRONJ [5.50 ± 2.47 (p = 0.020), 4.10 ± 1.85 (p = 0.011), 2.74 ± 1.07 (p = 0.006) and 29.88 ± 15.46 (p = 0.034), respectively]. CONCLUSIONS: SUVmax, SUVpeak, SUVmean and TBU derived from bone SPECT/CT and voxel-based quantitative parameters may be useful for the evaluation of mandibular lesions, such as MRONJ and chronic osteomyelitis.

Diffusion-weighted Magnetic Resonance Imaging in Odontogenic Keratocysts: Preliminary Study on Usefulness of Apparent Diffusion Coefficient Maps for Characterization of Normal Structures and Lesions.

OBJECTIVE: To investigate the usefulness of diffusion-weighted magnetic resonance imaging (DWI) in odontogenic keratocysts, especially apparent diffusion coefficient (ADC) maps for the characterisation of normal structures and cystic lesions in the jaw. METHODS: Sixteen patients who underwent magnetic resonance imaging (MRI) for the diagnosis of a cystic lesion in the jaw were included in this prospective study. DWI was performed on a 1.5 T unit with b factor of 0 and 800 s/mm2, and ADC maps were generated. ADC values were measured for the normal structures in the upper neck area and for the cystic lesion in the jaw. RESULTS: The mean ADC value of the cerebrospinal fluid (3.66 ± 0.47 × 10-3 mm2/s) in the upper neck area was higher than that of the nasal mucosa (1.80 ± 0.19 × 10-3 mm2/s), Waldeyer's ring (0.75 ± 0.11 × 10-3 mm2/s) and the spinal cord (0.71 ± 0.20 × 10-3 mm2/s). The mean ADC value of the five odontogenic keratocysts (1.03 ± 0.31 × 10-3 mm2/s) was lower than that of the one simple bone cyst (2.79 × 10-3 mm2/s), three nasopalatine duct cysts (2.28 ± 0.12 × 10-3 mm2/s), three radicular cysts (1.82 ± 0.71 × 10-3 mm2/s) and four dentigerous cysts (1.67 ± 1.06 × 10-3 mm2/s). CONCLUSION: This study suggested the usefulness of DWI in odontogenic keratocysts, especially ADC maps for the characterization of normal structures and cystic lesions in the jaw.

Computer programme to assess mandibular cortex morphology in cases of medication-related osteonecrosis of the jaw with osteoporosis or bone metastases.

PURPOSE: The purpose of this study was to evaluate the morphology of the mandibular cortex in cases of medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis or bone metastases using a computer programme. MATERIALS AND METHODS: Fifty-four patients with MRONJ (35 with osteoporosis and 19 with bone metastases) were examined using panoramic radiography. The morphology of the mandibular cortex was evaluated using a computer programme that scanned the mandibular inferior cortex and automatically assessed the mandibular cortical index (MCI) according to the thickness and roughness of the mandibular cortex, as follows: normal (class 1), mildly to moderately eroded (class 2), or severely eroded (class 3). The MCI classifications of MRONJ patients with osteoporosis or bone metastases were evaluated with the Pearson chi-square test. In these analyses, a 5% significance level was used. RESULTS: The MCI of MRONJ patients with osteoporosis (class 1: 6, class 2: 15, class 3: 14) tended to be higher than that of patients with bone metastases (class 1: 14, class 2: 5, class 3: 0) (P=0.000). CONCLUSION: The use of a computer programme to assess mandibular cortex morphology may be an effective technique for the objective and quantitative evaluation of the MCI in MRONJ patients with osteoporosis or bone metastases.

Usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases.

PURPOSE: To evaluate the usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases. MATERIALS AND METHODS: Ten patients with oral and maxillofacial diseases and 28 volunteers drawn from our student doctors were examined by shear wave elastography with a 14-MHz linear transducer using an Aplio 300 apparatus (Canon Medical Systems, Otawara, Japan). A statistical analysis of the shear elastic modulus (kPa) of healthy tissue (the sublingual gland, submandibular gland, anterior belly of the digastric muscle, and geniohyoid muscle) in the 28 volunteers was performed using 1-way repeated measures analysis of variance with the Tukey honest significant difference test. The maximum shear elastic modulus (kPa) of 8 patients with squamous cell carcinoma (SCC) and 2 patients with benign lesions was evaluated with the Mann-Whitney U test. The analysis used a 5% significance level. RESULTS: The mean shear elastic modulus of the sublingual gland (9.4±3.7 kPa) was lower than that of the geniohyoid muscle (19.2±9.2 kPa, P=.000) and the anterior belly of the digastric muscle (15.3±6.1 kPa, P=.004). The maximum shear elastic modulus of the SCCs (109.6±14.4 kPa) was higher than that of the benign lesions (46.4±26.8 kPa, P=.044). CONCLUSION: Our results demonstrated the usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases. Shear wave elastography has the potential to be an effective technique for the objective and quantitative diagnosis of oral and maxillofacial diseases.

Hard and soft tissue responses to implant made of three different materials with microgrooved collar in a dog model.

The objective of the present study was to assess hard and soft tissue around dental implants made of three different materials with microgrooves on the collar surface. Microgrooved implants were inserted in the mandibles of five male beagles. Implants were made of three kinds of material; titanium (Ti), yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) and ceria partially stabilized zirconia/alumina nanocomposite (Ce-TZP/Al2O3). The animals were euthanatized at three months after implantation, and harvested tissue was analyzed by means of histology. All kinds of implant were osseointegrated, and there were no significant differences in any histomorphometric parameters among the three groups of microgrooved implants made of different materials. Within the limitations of this study, implants with microgrooves integrated into the surrounding bone tissue, without statistically significant differences among the three tested materials, Ti, Y-TZP, and Ce-TZP/Al2O3.