Tokyo Dental College

Migraine is a disease that is difficult to be recognized by those around the patients, even though it causes significant hindrances. In this study, we conducted an exploratory comparison of the perceptions on migraine among patients, family members living with them, and physicians treating migraine patients. Patients and family members shared a common understanding on the pain of migraine, and hoped to spend more/better time together as a family. However, although family members felt compassion for the patients, lack of understanding by and patients’ concern for the surroundings led to feelings of resignation and endurance on the side of patients. Regarding physicians’ medical care, our results suggested the importance to understand the wishes and obstacles of each patient and to propose treatment accordingly. In order to reduce the burden of migraine, it is necessary to create an environment and raise awareness that allows people around the patients to understand and support the pain and hopes that each patient feels.

The endometrium during the sexual cycle undergoes detachment, tissue remodeling, and differentiation during the menstrual cycle. Localized and transient destruction and regeneration of endometrial tissue are also essential for pregnancy. It is possible to attribute many causes of failure in infertility treatment to the implantation stage. To improve the success rate of plateau fertility treatment, it is important to understand the regeneration mechanism of the endometrium, a unique regenerative tissue in the human body. In association with cell proliferation, tissue remodeling requires the relocation of proliferative cells, and the steady-state epithelial cells need to be motile for the relocation. Transient add-on motile activity in epithelial cells is mediated by epithelial to mesenchymal transition (EMT) and reversible mesenchymal to epithelial transition (MET). The destruction and regeneration of endometrial tissue over a period of days to weeks requires a system with a rapid and characteristic mechanism similar to that of wound healing. Here, I review the relationship between the well-known phenomenon of EMT in wound healing and endometrial tissue remodeling during the sexual cycle and pregnancy establishment, which are automatically triggered by menstruation and embryonal invasion.

Introduction Oral hypofunction comprises seven aspects of oral condition, including oral hygiene, oral dryness, bite strength, tongue‐lip motor function, tongue pressure, masticatory function, and swallowing function. Each of these seven has a single diagnostic criterion; however, the use of a single indicator without consideration of sex, age, or other factors is controversial. The purpose of this study was to evaluate the association between the oral hypofunction test and sex, age, and number of remaining teeth. Methods The study was conducted at 12 facilities by the members of the Japanese Society of Geriatric Dentistry during April to December 2019. The participants comprised 181 healthy older adults aged 65 years and over (56.9% female; age range 65–95 years) who regularly visited these facilities. All tests of oral function and oral status available in Japan were performed on the participants, and the association between these tests and sex, age, and number of remaining teeth was examined. Results Sex differences were observed in masticatory function, bite force, lip closure force, jaw‐opening force, oral diadochokinesis “ka,” and tongue coating index ( p < .05). In men, age was weakly ( r = 0.20–0.40) associated with masticatory function, jaw‐opening force, maximum tongue pressure, oral diadochokinesis, and swallowing function. In women, the number of remaining teeth, masticatory function, jaw‐opening force, and oral diadochokinesis “ta” and “ka” was also weakly associated with age. Conclusions Performance on the oral hypofunction test differs by sex, age, and number of remaining teeth. This means that the current single criterion for evaluation requires caution in its interpretation.

Background During the COVID-19 pandemic, concerns emerged that vaccinated individuals might engage less in infection-preventive behaviors, potentially contributing to virus transmission. This study evaluates the causal effects of COVID-19 vaccination on such behaviors within Japan, highlighting the significance of understanding behavioral dynamics in public health strategies. Methods Utilizing Japan’s age-based vaccination priority for those born before April 1, 1957, this research employs a regression discontinuity design (RDD) to assess the vaccination’s impact. Data from the fourth round of a longitudinal online survey, conducted from July 20 to 27, 2021, served as the basis for analyzing 14 infection-protective behaviors, including mask usage, handwashing, and avoiding crowds. Results A total of 12067 participants completed the survey. The analyzed sample size varied by outcome variable, ranging from 1499 to 5233. The analysis revealed no significant differences in the 14 behaviors examined among fully vaccinated, partially vaccinated, and unvaccinated individuals. This consistency across groups suggests that vaccination status did not significantly alter engagement in protective behaviors during the observation period. Conclusions Empirical findings highlight the complexity of behavioral responses following vaccination, indicating that such responses may be influenced by various factors, rather than by vaccination status alone. Additionally, this result underscores the importance of crafting public health policies that account for the intricate interplay between vaccination and behavior. This study contributes to the broader discourse on managing responses to the pandemic and tailoring interventions to sustain or enhance protective health behaviors amid vaccination rollouts.

Background The prevalence of rejection is 10–30% in penetrating keratoplasty (PKP) case, and the rate is higher in cases of high-risk patients. Although using topical corticosteroids is a standard method for management the rejection of post-PKP patients, it may not be sufficiently potent in high-risk patients. Topical administration of tacrolimus (TAC) may be effective in suppression rejection after corneal transplantation. This study aimed to investigate the efficacy and safety of topical TAC in high-risk PKP patients in Japan. Methods This study was a single centre, single-blinded, randomized controlled trial. Patients with a history of PKP, graft rejection, atopic dermatitis, or deep corneal neovascularisation who underwent PKP were enrolled. They were randomly assigned to receive 0.1% TAC ophthalmic suspension or artificial tear (AT) up to week 52 after surgery. All participants received 0.1% betamethasone up to week 13 after surgery then they received 0.1% fluorometholone up to week 52. The incidence of immunological rejection during the observation period was the main outcome measure in this study. Results Thirty patients were enrolled in this study, and 12 eyes in the TAC group and 13 eyes in the AT group completed the study, respectively. Five out of 30 patients discontinued participation after providing informed consent. No serious adverse effects were developed in patients who received 0.1% TAC ophthalmic suspension. No rejection episodes occurred in the TAC group, while one eye in the AT group had rejection. Graft clarity, best spectacle-corrected visual acuity, intraocular pressure, and corneal endothelial cell density were not significantly different between the TAC and AT groups. Conclusion Our results demonstrated that good tolerability of 0.1% TAC ophthalmic suspension. However, we failed to demonstrate its efficacy in preventing immunological rejection in high-risk patients undergoing PKP. Trial registration This study was first registered in the University Hospital Medical Information Network (UMIN000029669, Date of registration: November 1, 2017). With the enforcement of the Clinical Trial Act in Japan, the study re-registered in the Japan Registry of Clinical Trials (jRCTs031180342, Date of registration: March 18, 2019).

Background Surgical planning for hemifacial microsomia (HFM) patients often involves planning the amount of maxillary movement and mandibular bone distraction from three-dimensional (3D) volumetric images constructed from computed tomography scans. By representing anatomical indicators for facial symmetry in X, Y, and Z coordinates, we identified the more challenging areas in correcting facial asymmetry. Methods The study included five HFM patients with a mean age of 22.2 years, all diagnosed with HFM (type IIB). We established measurement points with high reproducible 3D coordinates on the 3D volumetric images obtained from computed tomography scans for before surgery, treatment objectives, and after surgery. We assessed the symmetry of measurement points between the affected side and nonaffected side at each time point. Results In the before-surgery group, significant differences were observed between the affected side and nonaffected side in X,Y (excluding Palatine foramen, upper molar, canine) and Z coordinates for measurement items. In the treatment objectives group, no differences were observed between the affected side and nonaffected side in X, Y, and Z coordinates, resulting in facial symmetry. In the after-surgery group, significant differences were observed in Y coordinates in the mental foramen area, and significant differences were observed in z axis measurement items in the canine and mental foramen areas. Conclusions It is evident that relying solely on a front view assessment is insufficient to achieve facial symmetry. Particularly, both anterior–posterior and vertical improvements in the area near the mental foramen on the affected side are necessary.

Background The aim of this retrospective study was to assess the use and safety of cetuximab (C‐mab) monotherapy or combination therapy with various regimens for treating oral cancer in our hospital. Methods The study comprised 53 patients diagnosed with oral cancer who underwent chemotherapy with C‐mab between January 2013 and December 2022 at the Oral Cancer Center, Tokyo Dental College. In total, 68 regimens were analyzed. The cumulative rate was determined by analyzing the timing and incidence of adverse events (AEs) with each regimen using a Kaplan–Meier curve. Results The treatment regimens administered included the following: induction C‐mab + paclitaxel + carboplatin (ICT‐PCE, n = 7), C‐mab + radiotherapy (RT) ( n = 22), C‐mab + cisplatin + fluorouracil ( n = 7), C‐mab + paclitaxel + carboplatin ( n = 1), C‐mab + paclitaxel ( n = 16), C‐mab maintenance ( n = 11), and four other cases. The total number of doses administered was 895. Conclusions This retrospective study investigated the effectiveness of treatment regimens containing C‐mab for oral cancer and adverse reactions to these regimens. C‐mab is a crucial component of oral cancer treatment when used in multidrug therapy. C‐mab containing regimens may result in direct or indirect AEs. Ongoing, rigorous monitoring is essential to mitigate these events. Partnering with other departments can help to limit their severity.

Nicotinamide adenine dinucleotide (NAD) is involved in renal physiology and is synthesized by nicotinamide mononucleotide adenylyltransferase (NMNAT). NMNAT exists as three isoforms, namely, NMNAT1, NMNAT2, and NMNAT3, encoded by Nmnat1, Nmnat2, and Nmnat3, respectively. In diabetic nephropathy (DN), NAD levels decrease, aggravating renal fibrosis. Conversely, sodium–glucose cotransporter-2 inhibitors increase NAD levels, mitigating renal fibrosis. In this regard, renal NAD synthesis has recently gained attention. However, the renal role of Nmnat in DN remains uncertain. Therefore, we investigated the role of Nmnat by establishing genetically engineered mice. Among the three isoforms, NMNAT1 levels were markedly reduced in the proximal tubules (PTs) of db/db mice. We examined the phenotypic changes in PT-specific Nmnat1 conditional knockout (CKO) mice. In CKO mice, Nmnat1 expression in PTs was downregulated when the tubules exhibited albuminuria, peritubular type IV collagen deposition, and mitochondrial ribosome (mitoribosome) excess. In CKO mice, Nmnat1 deficiency-induced mitoribosome excess hindered mitoribosomal translation of mitochondrial inner membrane-associated oxidative phosphorylation complex I (CI), CIII, CIV, and CV proteins and mitoribosomal dysfunction. Furthermore, the expression of hypermethylated in cancer 1, a transcription repressor, was downregulated in CKO mice, causing mitoribosome excess. Nmnat1 overexpression preserved mitoribosomal function, suggesting its protective role in DN.

Objectives To establish an analysis pipeline for the volumetric evaluation of the osteotomy site after bilateral sagittal split osteotomy (BSSO). Patients and methods Cone-beam computed tomography (CBCT) was performed before, directly after BSSO, and 6–12 months after surgery. Image segmentations of each osteotomy gap data set were performed manually by four physicians and were compared to a semi-automatic segmentation approach. Results Five patients with a total of ten osteotomy gaps were included. The mean interclass correlation coefficient (ICC) of individual patients was 0.782 and the standard deviation 0.080 when using the manual segmentation approach. However, the mean ICC of the evaluation of anatomical sites and time points separately was 0.214, suggesting a large range of deviation within the manual segmentation of each rater. The standard deviation was 0.355, further highlighting the extent of the variation. In contrast, the semi-automatic approach had a mean ICC of 0.491 and a standard deviation of 0.365, which suggests a relatively higher agreement among the operators compared to the manual segmentation approach. Furthermore, the volume of the osteotomy gap in the semi-automatic approach showed the same tendency in every site as the manual segmentation approach, but with less deviation. Conclusion The semi-automatic approach developed in the present study proved to be valid as a standardised method with high repeatability. Such image analysis methods could help to quantify the progression of bone healing after BSSO and beyond, eventually facilitating the earlier identification of patients with retarded healing.

Fibrocartilaginous entheses consist of tendons, unmineralized and mineralized fibrocartilage, and subchondral bone, each exhibiting varying stiffness. Here we examined the functional role of sclerostin, expressed in mature mineralized fibrochondrocytes. Following rapid mineralization of unmineralized fibrocartilage and concurrent replacement of epiphyseal hyaline cartilage by bone, unmineralized fibrocartilage reexpanded after a decline in alkaline phosphatase activity at the mineralization front. Sclerostin was co-expressed with osteocalcin at the base of mineralized fibrocartilage adjacent to subchondral bone. In Scx-deficient mice with less mechanical loading due to defects of the Achilles tendon, sclerostin⁺ fibrochondrocyte count significantly decreased in the defective enthesis where chondrocyte maturation was markedly impaired in both fibrocartilage and hyaline cartilage. Loss of the Sost gene, encoding sclerostin, elevated mineral density in mineralized zones of fibrocartilaginous entheses. Atomic force microscopy analysis revealed increased fibrocartilage stiffness. These lines of evidence suggest that sclerostin in mature mineralized fibrochondrocytes acts as a modulator for mechanical tissue integrity of fibrocartilaginous entheses.

Study Design Retrospective multicenter study. Objectives To investigate surgical outcomes following posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL) when performed by board-certified spine (BCS) or non-BCS (NBCS) surgeons. Methods We included 203 patients with cervical OPLL who were followed for a minimum of 1 year after surgery. Demographic information, medical history, and imaging findings were collected. Clinical outcomes were assessed preoperatively and at the final follow-up using the Japanese Orthopedic Association (JOA) score and the visual analog scale (VAS) for the neck. We compared outcomes between BCS surgeons, who must meet several requirements, including experience in more than 300 spinal surgeries, and NBCS surgeons. Results BCS surgeons performed 124 out of 203 cases, while NBCS surgeons were primary in 79 cases, with 73.4% were directly supervised by a BCS surgeon. There was no statistically significant difference in surgical duration, estimated blood loss, and perioperative complication rates between the BCS and NBCS groups. Moreover, no statistically significant group differences were observed in each position of the C2-7 angle and cervical range of motion at preoperation and the final follow-up. Preoperative and final follow-up JOA scores, VAS for the neck, and JOA score recovery rate were comparable between the two groups. Conclusions Surgical outcomes, including functional recovery, complication rates, and cervical dynamics, were comparable between the BCS and NBCS groups. Consequently, posterior decompression for cervical OPLL is considered safe and effective when conducted by junior surgeons who have undergone training and supervision by experienced spine surgeons.

The temporomandibular joint (TMJ) is a complex structure that plays a vital role in the movement of the jaw. Some anatomy and dental textbooks show that, at the medial margin, the TMJ capsule attaches to a suture between the sphenoid ala major and the temporal bone squamosa. In near‐term fetuses, the ala major extends posterolaterally to approach the TMJ. In this study, we aimed to investigate the contribution of the sphenoid ala major to the socket of the TMJ in near‐term fetuses. We examined histological sections from 22 human fetuses (approximately 15–40 weeks). At midterm, the lateral and superior walls of the TMJ cavity were formed by the temporal bone squamosa, whereas the ala major was distant from the joint. However, at near‐term, the ala major formed the medial wall of almost the entire part of the joint cavity. The top of the TMJ was attached to both the squamosa and ala major, with the condylar head consistently separated from the sphenoid by the joint disk. We observed a significant descent of the middle cranial fossa in near‐term fetuses, which brought the ala major close to the TMJ. This transient position of the TMJ near the sphenoid is likely due to brain enlargement and posterolateral growth of the ala major. After birth, occlusion causes the anterior growth of the mandibular fossa of the squamosa, which moves the ala major away from the TMJ. Similarly, the lateral growth of the sphenoid toward the squamosa suture may also stop in children.

We assessed the effect of non-protein thiols (NPSH), reduced glutathione (GSH) and n-acetylcysteine (NAC), on resin shear bond strength (SBS) to hydrogen peroxide (H2O2)-treated dentin, and their effects on the characteristics of dentin in comparison to ascorbic acid (AA) and sodium thiosulfate (STS). H2O2-treated dentin was conditioned with 5% AA, GSH, NAC, or STS applied for 1 or 5 min. The positive control group received H2O2 without antioxidant application, and the first negative control group received distilled water (DW). The specimens received resin bonding immediately after treatment except for the second negative control group (delayed bonding). Microhardness, roughness, and topography were studied. The SBS values of all antioxidants were statistically greater than the positive control group (p < 0.05); however, NAC and AA applied for 1 min demonstrated the highest values, which were comparable to delayed bonding. All treatments removed the smear layer except DW, H2O2, and STS. The negative effect of H2O2 on resin–dentin bonding was mitigated by the application of the antioxidants; however, their efficiencies were dependent on the antioxidant type and time of application. NAC was more effective in optimizing resin bonding to bleached dentin compared to GSH at 1 min application and STS at both application times but was comparable to AA. Negligible negative effects on the substrate’s roughness and microhardness were detected. The antioxidant properties of the agent and its capacity to remove the smear layer are the processes underpinning the ability of a certain antioxidant to reverse the effect of H2O2 on bonding.

Background Hyalinizing clear cell carcinoma (HCCC) is a rare, typically low‐grade malignant salivary gland tumor. We present a case of HCCC with multiple metastasis. Case Presentation The patient was a 34‐year‐old woman with a tumor at the base of tongue. HCCC was diagnosed by FISH analysis for EWSR1‐ATF1 rearrangement after surgery. Systematic metastasis was identified at a three‐year follow‐up. Signs of Rouviere lymph metastasis and distant metastases (i.e., pleura, mediastinum, and gluteus maximus) were identified. The patient died because her condition deteriorated with multiple metastases. Conclusion The potential for aggressive HCCC should be considered while offering treatment.

In recent years, a wide variety of materials have been used in dental implant treatment. In selecting the superstructures and abutments to be used it is important to consider their potential effect on the stability and durability of the planned implant. Excessive force applied to an implant during maintenance commonly results in complications, such as fracture of the superstructure or abutment, and loosening or fracture of the screws. This report describes a case of implant treatment for a 23-year-old man with esthetic disturbance due to trauma to the maxillary anterior teeth. The left maxillary central incisor could not be conserved due to this trauma, which had been caused by a traffic accident. After extraction, the tooth was restored with an anterior bridge. The crown of the left maxillary lateral incisor was fractured at the crown margin and, at the patient’s request, implant treatment was selected as the restorative treatment for the missing tooth. A thorough preoperative examination was performed using placement simulation software. One titanium screw-type implant was placed in the maxillary left central incisor under local anesthesia. An all-ceramic crown with a zirconia frame was placed as a screw-fixed direct superstructure. At one year postoperatively, however, the superstructure and abutment became detached due to trauma. The fractured zirconia abutment was removed and replaced with a remanufactured abutment and superstructure. The patient has reported no subsequent dental complaint over the last 11 years. In this case, a surface analysis of the fractured zirconia abutment was performed. The scanned images revealed a difference in the fracture surfaces between the tensile and compressive sides, and electron probe microanalysis demonstrated the presence of titanium on the fracture surface. It was inferred that the hard zirconia abutment had scraped the titanium from the internal surface of the implant.

Although the working environment may play a role in dental acid erosion, few studies have been conducted on this in Japanese workers in recent years. The purpose of this study was to investigate oral health status, including dental erosion, in workers who may have been exposed to an acidic environment. The study participants were recruited by an online research company. Oral examinations and questionnaire surveys were conducted on this cohort in January 2023. A total of 144 participants were finally included. Workers exposed to an acidic environment showed more use of protective equipment and underwent more dental examinations at the workplace (p<0.001). Possible dental erosion was observed in only 3 out of the total of 144 participants (2.1%), however. No significant difference was observed in the number of teeth, caries experience, or dental erosion according to the number of years of acid exposure in the workplace. The results of this study suggest that acid exposure exerts a relatively small effect on the oral health status of workers in Japan.

Objectives The aim of the study was to evaluate the mechanical properties and impact absorption capacity of prototype materials comprising ethylene vinyl acetate (EVA) of different hardness reinforced using different amounts of glass fibers (GFs), considering a buffer space. Materials and Methods Six prototype materials were made by adding E-GFs (5 and 10 wt%) to EVA with vinyl acetate (VA) contents of 9.4 wt% (“hard” or HA) and 27.5 wt% (“soft” or SO). Durometer hardness and tensile strength tests were performed to evaluate the mechanical properties of the materials. Moreover, an impact test was conducted using a customized pendulum impact tester to assess the impact absorption capacity (with or without a buffer space) of the specimens. Results The mechanical properties of the prototypes, namely, durometer hardness, Young's modulus, and tensile strength, were significantly higher in the HA group than in the SO group, regardless of the presence or added amount of GFs. The addition of GFs, particularly in a large amount (10 wt%), significantly increased these values. In terms of the impact absorption capacity, the original hardness of the EVA material, that is, its VA content, had a more substantial effect than the presence or absence of GFs and the added amount of GFs. Interestingly, the HA specimens with the buffer space exhibited significantly higher impact absorption capacities than the SO specimens. Meanwhile, the SO specimens without the buffer space exhibited significantly higher impact absorption capacities than the HA specimens. Moreover, regardless of the sample material and impact distance, the buffer space significantly improved impact absorption. In particular, with the buffer space, the impact absorption capacity increased with the added amount of GFs. Conclusion The basic mechanical properties, including durometer hardness, Young's modulus, and tensile strength, of the EVA prototype were significantly increased by reducing the amount of VA regardless of the presence or added amount of GFs. Adding GFs, particularly in large amounts, significantly increased the values of aforementioned mechanical properties. Impact absorption was significantly affected by the hardness of the original EVA material and enhanced by the addition of the buffer space. The HA specimen had a high shock absorption capacity with the buffer space, and the SO specimen had a high shock absorption capacity without the buffer space. With the buffer space, impact absorption improved with the amount of added GFs.