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.

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.

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.

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.

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.

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.

Single-staged implant placement using bone ring technique with and without membrane placement: An experimental study in the Beagle dog.

AIM: To evaluate the impact of a collagen membrane on bone remodeling and osseointegration of implants placed simultaneously with a bone ring technique. MATERIAL AND METHODS: Standardized, vertical alveolar bone defects in the mandibles of six dogs were created. Tapered dental implants designed for two-stage subcrestal placement were inserted simultaneously with a bone ring technique. On one side of the mandible, the augmented sites were covered with a collagenous membrane. Implants with (M Group) and without membranes (NM Group) were left for an osseointegration period of 3 and 6 months, respectively. Block biopsies of the implants with surrounding bone were harvested and analyzed histologically. RESULTS: Implant exposure was a common finding (2/3) concomitantly with loss of healing caps. It appeared to be related to advanced bone loss around the implants. Exposure of implants was more frequent in M Group, however, without significant differences when compared to NM Group. The total bone area within the region of the bone ring was greater in the NM Group compared to the M Group. Moreover, in the region of the pristine bone of the M Group, the total bone was greater than at the corresponding NM Group sites at both observation periods. A nonparametric analysis of variance (ANOVA) revealed no significant effects of membrane placement or healing period on the total area of the bone. The total bone-to-implant contact (BIC) for the two groups was similar at each observation time point. However, BIC increased significantly at 6-month compared with 3-month observation period (p = .0088) in both groups. CONCLUSIONS: In vertical bone augmentation applying the bone ring technique, the disruption of soft tissue was a frequent complication. Membrane placement yielded no significant advantage on the osseointegration (BIC) of implants or bone characteristics.

Effect of Irrigation Time of Antiseptic Solutions on Bone Cell Viability and Growth Factor Release.

Antiseptic solutions are commonly utilized to treat local infection in the oral and maxillofacial region. However, surrounding vital bone is also exposed to antiseptic agents during irrigation and may have a potential negative impact on bone survival. The aim of the present study was therefore to investigate the effect of rinsing time with various antiseptic solutions on bone cell viability, as well as their subsequent release of growth factors important for bone regeneration. The bone samples collected from porcine mandible were rinsed in the following commonly utilized antiseptic solutions; povidone-iodine (0.5%), chlorhexidine digluconate (CHX, 0.2%), hydrogen peroxide (1%), and sodium hypochlorite (0.25%) for 1, 5, 10, 20, 30, or 60 minutes and assessed for cell viability and release of growth factors including vascular endothelial growth factor, transforming growth factor beta 1, bone morphogenetic protein 2, receptor activator of nuclear factor kappa-B ligand, and interleukin-1 beta by enzyme-linked immunosorbent assay. It was found in all the tested groups that the long exposure of any of the tested antiseptic solutions drastically promoted higher cell death. Sodium hypochlorite demonstrated the significantly highest cell death and at all time points. Interestingly, bone cell viability was highest in the CHX group post short-term rinsing of 1, 5, or 10 minutes when compared with the other 4 tested groups. A similar trend was also observed in subsequent growth factor release. The present study demonstrated that of the 4 tested antiseptic solutions, short-term CHX rinsing (ideally within 1 minute) favored bone cell viability and growth factor release. Clinical protocols should be adapted accordingly.

Comparison of three block bone substitutes for bone regeneration: long-term observation in the beagle dog.

This study aimed to evaluate the impact of three types of block bone substitute material on bone formation and graft resorption in vivo. Standardized bone defects (n = 4 defects/animal) were created in the calvaria of nine dogs. Block bone substitutes made of deproteinized bovine bone mineral (DBBM), beta-tricalcium phosphate (ß-TCP) and a mixture alpha-TCP and hydroxyapatite (α-TCP/HA) were inserted into the bone defects. A fourth defect was left untreated (empty). All sites were covered with a collagenous membrane. Block biopsies were harvested at 3, 6 and 12 months post-implantation and analyzed by micro-CT and histology. Biomaterial absorption was minimal and incorporation within the defect margin was good for all biomaterials. However, ß-TCP demonstrated a relatively greater volume of new bone formation and less residual material volume when compared with DBBM and α-TCP/HA. Conversely, α-TCP/HA showed higher osteoconductive potential and a greater new bone area compared with the other two biomaterials. The block bone substitutes used in the present in vivo study showed advantageous in terms of maintenance of their original form in bony defect. However, the positive impact of all biomaterials on new bone formation and replacement of bone was minor even at 12 months. These findings indicate that block bone substitutes are not well suited to vertical bone augmentation. Further investigations are required to improve the insufficient new bone volume for promising clinical results.

Single-staged vs. two-staged implant placement in vertically deficient alveolar ridges using bone ring technique - Part 2: implant osseointegration.

OBJECTIVES: The aim of this study was to evaluate the osseointegration of implants placed in a single-staged compared to two-staged procedure using bone ring technique. MATERIAL AND METHODS: In this study were used standardized, vertical alveolar bone defects in dogs. In the test group, dental implants (Straumann BL® , Basel, Switzerland) were inserted simultaneously with bone ring technique. As control group served implants inserted 6 months following grafting. Implants of both groups were left for an osseointegration period of 3 and 6 months. The peri-implant bone loss and bone-to-implant contact within the bone ring and native bone were analyzed morphometrically. An explorative statistical analysis was performed. RESULTS: The peri-implant bone level remained relatively stable within groups and between groups per given time period. Most of bone apposite on the implant surface in two groups was composed of newly formed bone. A nonparametric analysis of variance (ANOVA) revealed no significant advantage for two-staged implant placement for new and total bone, except for residual bone (P = .0084). Furthermore, two groups of implants performed similarly in bone ring and in native bone throughout the observation period. CONCLUSIONS: In terms of osseointegration, both techniques are likely equally efficient in the present defect model. The single-staged implant placement with cortical bone grafts warrants further documentation in clinical studies.

Single-staged vs. two-staged implant placement using bone ring technique in vertically deficient alveolar ridges - Part 1: histomorphometric and micro-CT analysis.

BACKGROUND: Simultaneous implant placement with bone grafting shortens the overall treatment period, but might lead to the peri-implant bone loss or even implant failure. The aim of this study was to compare the single-staged to two-staged implant placement using the bone ring technique. MATERIAL AND METHODS: Four standardized alveolar bone defects were made in the mandibles of nine dogs. Dental implants (Straumann BL® , Basel, Switzerland) were inserted simultaneously with bone ring technique in test group and after 6 months of healing period in control group. Animals of both groups were euthanized at 3 and 6 months of osseointegration period. The harvested samples were analyzed by means of histology and micro-CT. RESULTS: The amount of residual bone decreased while the amount of new bone increased up to 9 months of healing period. All morphometric parameters remained stable between 3 and 6 months of osseointegration period within groups. Per a given time point, median area of residual bone graft was higher in test group and area of new bone in control group. The volume of bone ring was greater in test than in control group, reaching the significance at 6 months of osseointegration period (P = 0.002). CONCLUSIONS: In the present type of bone defect, single-staged implant placement may be potentially useful to shorten an overall treatment period.

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.

Evaluation of cortical bone thickness and root proximity at maxillary interradicular sites for mini-implant placement.

OBJECTIVES: The purpose of this study was to evaluate the interradicular cortical bone thickness, alveolar process width and root proximity for planning mini-implant placement in the maxillary alveolar process. MATERIAL AND METHODS: Eighty maxillae (right and left sides) of 40 Japanese adult skulls were examined. The samples were imaged and measured using a micro-CT system. Buccal and palatal interradicular cortical bone thickness, alveolar process width, and root proximity were measured in six interradicular sites from distal of central incisor to mesial of second molar. Buccal and palatal interradicular cortical bone thickness and alveolar process width were measured at 10 different vertical levels. Root proximity was measured at four different vertical levels. RESULTS: Buccal and palatal interradicular cortical bone thickness and alveolar process width tended to increase from crest to base of alveolar process. The buccal interradicular cortical bone thickness between canine and first premolar or between first premolar and second premolar was the greatest, and between central incisor and lateral incisor was the least. The palatal interradicular cortical bone was significantly thicker than the buccal. The root proximity between second premolar and first molar or first premolar and second premolar was the widest and between central incisor and lateral incisor it was the narrowest. CONCLUSIONS: The findings of this study suggest that recommendations when low dose 3D multislice CT or low dose cone beam imaging is not available, the results of this research may be useful in providing indicators for selecting the design of the placement site.

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.

Evaluation of the palatal bone for placement of orthodontic mini-implants in Japanese adults.

Mini-implants are increasingly being used for orthodontic anchorage in the palate. The anatomical structure of the jaw must be properly evaluated prior to use; however, there are a few research reports providing basic data regarding the palate. Bone thickness was measured and bone morphology evaluated in the palates of Japanese people. The palates of five Japanese adult cadavers and 15 skulls were examined. The samples were imaged and measured using the micro-CT system. In the mid-palatine suture region, the cortical bone had a complex mesh-like structure and was thicker than surrounding areas. Cortical bone thickness varied depending on the site. The mid-palatine suture region is an ideal site for mini-implant insertion; however, because bone and cortical bone thickness markedly decrease in the lateral region, careful attention should be paid when inserting mini-implants in the mid-palatine suture.

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.

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.

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.

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.

Biomechanical role of peri-implant trabecular structures during vertical loading.

The aim of this study was to identify the load transfer paths in cortical bone and trabecular structure of cancellous bone in the jawbones for loads from endosseous implants. Maxillae were resected from beagle dogs 6 months after implant surgery and imaged using micro-computed tomography (micro-CT). A three-dimensional structure was produced based on the CT data and peri-implant trabecular structure was observed. Load transfer paths were analyzed from the results of three-dimensional finite element analysis. Furthermore, buffer actions in bone trabeculae when strain increased during stress analysis and when loads were applied were observed. Peri-implant bone trabeculae were seen extending into the upper and lower cortical bone from the fixture. The direction of bone trabecular alignment corresponded with the load transfer paths. In addition, analysis with increased strain confirmed that trabecular structures could serve as load buffers. These results suggest that bone trabeculae supporting load transfer from implants undergo remodeling.