Lateral Approach With a Mouth Corner Incision for the Molar Part of Mandibulectomy.

OBJECTIVES: The aim of the present study was to evaluate the functional and esthetic results of marginal mandibulectomy for mandibular cancer using a lateral approach with a simple, straightforward mouth corner incision. STUDY DESIGN: Six mandibular cancer patients (2 men, 4 women; age range: 65-80 years; mean age, 73.1 years; all stage I) were treated using this approach. With this approach, the surgical field was widely exposed, and mandibulectomy was performed with sufficient surgical margins. Intraoperative frozen specimens of remaining tissues showed no malignancy in all cases. In all 6 patients, follow-up imaging assessments were obtained, with no local recurrence after 12 to 78 months. RESULTS AND CONCLUSIONS: An overall functional, physical, and esthetic assessment of oral behavior and oral appearance was made of all patients by the FACT-H&N questionnaire, which showed that functional lip behavior and esthetic lip appearance were not much affected by the present surgical approach, and good quality of life was maintained. Thus, the lateral approach with the mouth corner incision is an effective and useful alternative for the molar part of mandibulectomy.

Roles of Olfactomedin 1 in Muscle and Bone Alterations Induced by Gravity Change in Mice.

Microgravity causes both muscle and bone loss. Although we previously revealed that gravity change influences muscle and bone through the vestibular system in mice, its detailed mechanism has not been elucidated. In this study, we investigated the roles of olfactomedin 1 (OLFM1), whose expression was upregulated during hypergravity in the soleus muscle, in mouse bone cells. Vestibular lesion significantly blunted OLFM1 expression in the soleus muscle and serum OLFM1 levels enhanced by hypergravity in mice. Moreover, a phosphatidylinositol 3-kinase inhibitor antagonized shear stress-enhanced OLFM1 expression in C2C12 myotubes. As for the effects of OLFM1 on bone cells, OLFM1 inhibited osteoclast formation from mouse bone marrow cells and mouse preosteoclastic RAW264.7 cells. Moreover, OLFM1 suppressed RANKL expression and nuclear factor-κB signaling in mouse osteoblasts. Serum OLFM1 levels were positively related to OLFM1 mRNA levels in the soleus muscle and trabecular bone mineral density of mice. In conclusion, we first showed that OLFM1 suppresses osteoclast formation and RANKL expression in mouse cells.

Role of plasminogen activator inhibitor-1 in glucocorticoid-induced muscle change in mice.

We recently revealed that plasminogen activator inhibitor-1 (PAI-1), a serine protease inhibitor, is involved in diabetes, osteoporosis and muscle wasting induced by glucocorticoid (GC) treatment in mice. In the present study, we investigated the detailed mechanisms by which GC induces muscle wasting through PAI-1 in vivo and in vitro. PAI-1 deficiency suppressed the mRNA levels of atrogin1 and muscle RING-Finger Protein 1 (MuRF1), ubiquitin ligases leading to muscle degradation, elevated by GC treatment in the gastrocnemius muscle of mice. In vitro study revealed that active PAI-1 treatment augmented the increase in atrogin1 mRNA levels enhanced by dexamethasone (Dex) in mouse myoblastic C2C12 cells. Moreover, a reduction in endogenous PAI-1 level by siRNA suppressed the mRNA levels of atrogin1 and MuRF1 enhanced by Dex in C2C12 cells. In contrast, a reduction in endogenous PAI-1 levels and active PAI-1 did not affect the phosphorylations of Akt and p70S6 kinase nor myogenic differentiation with or without Dex in C2C12 cells. In addition, PAI-1 deficiency blunted IGF-1 mRNA levels decreased by GC treatment in the gastrocnemius muscle of mice, although neither active PAI-1 nor a reduction in endogenous PAI-1 levels affected the levels of IGF-1 mRNA in C2C12 cells in the presence of Dex. In conclusion, our data suggest that paracrine PAI-1 is involved in GC-induced muscle wasting through the enhancement of muscle degradation in mice.

Effectiveness of an Interdisciplinary Medical Hospital Admission Center: The Role of the Dental Section in the Interdisciplinary System for Perioperative Management of Patients Awaiting Surgery.

Perioperative oral functional management (POFM) involves total oral management of a patient before surgery. Considerable benefits have been reported, but POFM remains scarce in medical settings. An interdisciplinary Medical Hospital Admission Center (MHAC) opened in our hospital in December 2014, and has since provided unified perioperative management for patients. This study reports on the clinical system and contributions of the systematized, standardized POFM applied through the MHAC. Patients awaiting surgery undergo oral screening before admission, with patients classified into three groups: red, needing surgical oral management (tooth extraction or other oral surgery) before surgery; yellow, needing non-surgical oral management before surgery, due to the planned surgery or the risk of tooth injury in connection with general anesthesia; or green, patients with good oral hygiene considered capable of suitable oral self-management. Patients categorized as red or yellow undergo POFM in the dental section of the MHAC before surgery. Almost all patients (88.8%) awaiting surgery now undergo preoperative oral screening, excluding emergent surgeries. In addition, oral screening is important for preventing tooth injury during endotracheal intubation for general anesthesia, and a need for preventive measures was identified in 6.1% of patients. No traumatic injuries of the teeth in connection with general anesthesia have occurred since the opening of the MHAC. Standardized POFM through an interdisciplinary MHAC thus seems extremely useful.

Novel roles of FKBP5 in muscle alteration induced by gravity change in mice.

Skeletal muscle hypertrophy and wasting are induced by hypergravity and microgravity, respectively. However, the mechanisms by which gravity change regulates muscle mass still remain unclear. We previously reported that hypergravity increases muscle mass via the vestibular system in mice. In this study, we performed comparative DNA microarray analysis of the soleus muscle from mice kept in 1 or 3 g environments with or without vestibular lesions. Mice were kept in 1 g or 3 g environment for 4 weeks by using a centrifuge 14 days after surgical bilateral vestibular lesions. FKBP5 was extracted as a gene whose expression was enhanced by hypergravity through the vestibular system. Stable FKBP5 overexpression increased the phosphorylations of Akt and p70 S6 kinase (muscle protein synthesis pathway) and myosin heavy chain, a myotube gene, mRNA level in mouse myoblastic C2C12 cells, although it reduced the mRNA levels of atrogin-1 and MuRF1, muscle protein degradation-related genes. In conclusion, we first showed that FKBP5 is induced by hypergravity through the vestibular system in anti-gravity muscle of mice. Our data suggest that FKBP5 might increase muscle mass through the enhancements of muscle protein synthesis and myotube differentiation as well as an inhibition of muscle protein degradation in mice.

Tongue cancer with mental retardation due to microcephaly: a clinical report.

Oral cancer in patients with mental retardation has not been reported in detail, although the literature on clinical management of oral malignancies in the general population is extensive. No clear consensus has been established regarding the management of oral cancer in patients with mental retardation. We present herein the case of a 32-year-old Japanese man with mental retardation due to microcephaly who presented with advanced tongue cancer. He was treated with three courses of chemotherapy using superselective intra-arterial infusion of cisplatin at 100 mg/m2 via the femoral artery (Seldinger method). No major complications were encountered, and complete response was achieved. The patient has shown no clinical or radiological evidence of local recurrence or distant metastases as of 22 months after the end of treatment. This case provides a basis for the future appropriate management of oral cancer in patients with mental retardation.

Association between Toothbrushing and Cancer Risk.

Background: Most cancers are lifestyle-related and are thus preventable. Lifestyle habits can be improved by individual efforts; for example, because oral health is suggested to play a preventive role in cancer risk, toothbrushing is considered a critical and fundamental measure for controlling oral health. This study aimed to investigate the association between toothbrushing and cancer risk. Methods: Cross-sectional data from the Japan COVID-19 and Society Internet Survey, a large-scale (n = 32,000) online survey conducted in 2022, were used. From September 12 to October 19, 2022, questionnaires were distributed to candidates selected by simple random sampling from a Japanese Internet research company's panelists to represent the Japanese population. The association between toothbrushing and cancer risk according to cancer prevalence was then analyzed. Results: Among all 32,000 participants, 2,495 (7.8%) who had any cancer previously were analyzed. Multivariable logistic regression analysis revealed a significant association between toothbrushing habit and cancer risk. Conclusion: The findings of this study suggest that daily toothbrushing is essential for maintaining oral health and preventing cancer.

Is discontinuation of dental treatment related to exacerbation of systemic medical diseases in Japan?

Aims Since it is known that oral problems affect various medical diseases, the effects of restrictions on visits for dental treatment on exacerbations of various systemic medical diseases were examined.Method and materials The data were used from the Japan COVID-19 and Society Internet Survey, a large-scale internet survey conducted in 2021 (n = 28,175). The questionnaires were distributed to 33,081 candidates who were selected to represent the Japanese population regarding age, sex and residential prefecture using a simple random sampling procedure. Patients currently undergoing treatment for diabetes mellitus, hypertension, asthma, cardiocerebrovascular disease, hyperlipidemia, atopic dermatitis, and mental illness, such as depression, were extracted from the total participants. Then, whether discontinuation of dental treatment affected the exacerbation of their systemic disease was examined.Results Overall, 50-60% of patients with each systemic disease had continued to receive dental treatment, and 4-8% of them had discontinued dental treatment. On univariate and multivariate analyses, discontinuation of dental treatment is a risk factor in the exacerbation of diabetes mellitus, hypertensive conditions, asthma, cardiocerebrovascular disease and hyperlipidemia.Conclusion The present epidemiological study showed the relationship between oral health and systemic health, which can provide meaningful insights regarding future medical-dental collaboration in Japan.

Automatic identification of individuals using deep learning method on panoramic radiographs.

Abstract Background/purpose: The dentition shows individual characteristics and dental structures are stable with respect to postmortem decomposition, allowing the dentition to be used as an effective tool in forensic dentistry. We developed an automatic identification system using panoramic radiographs (PRs) with a deep learning method. Materials and methods: In total, 4966 PRs from 1663 individuals with various changes in image characteristics due to various dental treatments were collected. In total, 3303 images were included in the data set used for model training. Vgg16, Vgg19, ResNet50, ResNet101, and EfficientNet models were applied for identification. The precision curves were evaluated. Results: The matching precision rates of all models (Vgg16, Vgg19, ResNet50, ResNet101, and EfficientNet) were examined. Vgg16 was the best model, with a precision of around 80-90% on 200 epochs, using the Top-N metrics concept with 5-15 candidate labels. The model can successfully identify the individual even with low quantities of dental features in 5-10 s. Conclusion: This identification system with PRs using a deep learning method appears useful. This identification system could prove useful not only for unidentified bodies, but also for unidentified wandering elderly people. This project will be beneficial for police departments and government offices and support disaster responses.

Role of Macrophages and Plasminogen Activator Inhibitor-1 in Delayed Bone Repair in Diabetic Female Mice.

Delayed fracture healing is a clinical problem in diabetic patients. However, the mechanisms of diabetic delayed bone repair remain unknown. Here, we investigate the role of macrophages in diabetic delayed bone repair after femoral bone injury in streptozotocin (STZ)-treated and plasminogen activator inhibitor-1 (PAI-1)-deficient female mice. STZ treatment significantly decreased the numbers of F4/80-positive cells (macrophages) but not granulocyte-differentiation antigen-1-positive cells (neutrophils) at the damaged site on day 2 after femoral bone injury in mice. It significantly decreased the messenger RNA (mRNA) levels of macrophage colony-stimulating factor, inducible nitric oxide synthase (iNOS), interleukin (IL)-6, and CD206 at the damaged site on day 2 after bone injury. Moreover, STZ treatment attenuated a decrease in the number of hematopoietic stem cells in bone marrow induced by bone injury. On the other hand, PAI-1 deficiency significantly attenuated a decrease in the number of F4/80-positive cells induced by STZ treatment at the damaged site on day 2 after bone injury in mice. PAI-1 deficiency did not affect the mRNA levels of iNOS and IL-6 in F4/80- and CD11b-double-positive cells from the bone marrow of the damaged femurs decreased by diabetes in mice. PAI-1 deficiency significantly attenuated the phagocytosis of macrophages at the damaged site suppressed by diabetes. In conclusion, we demonstrated that type 1 diabetes decreases accumulation and phagocytosis of macrophages at the damaged site during early bone repair after femoral bone injury through PAI-1 in female mice.