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.

Abstract Aim Oral cGVHD is one of the phenotypes of organ involvement of cGVHD and is a complex, frequent, and highly impactful complication of allogeneic hematopoietic cell transplantation (HSCT). Few studies have compared the incidences and risk factors of oral cGVHD, and they have not been discussed. We performed to evaluate the risk factors for oral cGVHD after allogeneic HSCT in a single center. Methods A retrospective study of clinical hematological data of all consecutive patients who underwent HSCT for malignant hematologic disease and then developed oral chronic graft versus host disease (cGVHD) in a single center from 2012 to the present was performed to evaluate the risk factors for oral cGVHD. Allogeneic HSCT was performed for 179 patients. Assessment of individual risk factors (age, sex, primary diagnosis, stem cell source, human leukocyte antigen [HLA] matching, regimen, donor age, and status after remission induction therapy) was completed to identify the effects of covariates of the independent variables. Results Seventy‐two (40.2%) patients were considered to have oral cGVHD within 36 months after HSCT. Statistical analysis showed that age, sex, stem cell source, HLA matching, regimen, donor age, and status after remission induction therapy were not significant factors related to oral cGVHD, whereas the primary disease was significant. Conclusion The primary disease was a significant risk factor for oral cGVHD. The oral cGVHD was more common in myeloid neoplasms (MNs) patients than in lymphoid neoplasms (LNs) patients.

PURPOSE: During the Coronavirus Disease 2019 (COVID-19) pandemic, there has been concern about nosocomial infections acquired through dental practice, where machines - such as air turbines - that generate aerosols are used, and where there are many opportunities to come into contact with saliva and blood. Because there is no report to date on whether dental treatment is associated with a risk of SARS-CoV-2 infection in Japan, the aim of the present cross-sectional study was to examine the risk of SARS-CoV-2 infection associated with dental treatment. MATERIALS AND METHODS: Cross-sectional data were gathered from the Japan COVID-19 and Society Internet Survey (JACSIS), a large-scale internet survey conducted in 2021 (n=28,175). From September 27, 2021, to October 30, 2021, the questionnaires were distributed to candidates selected from the panelists of a Japanese Internet research company to represent the Japanese population regarding age, sex, and residential prefecture using a simple random sampling procedure. The risk of SARS-CoV-2 infection related to dental treatment was examined and analysed. RESULTS: Multivariable logistic regression analysis showed that younger age, male sex and living alone were statistically significant factors positively associated with SARS-CoV-2 infection, whereas the presence or absence of dental treatment was not statistically significantly correlated with SARS-CoV-2 infection. CONCLUSION: The present epidemiological study showed that dental treatment is not a positive risk factor for SARS-CoV-2 infection 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.

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.

Atypical lipomatous tumor (ALT), one of the histologic subtypes of liposarcoma, is locally aggressive with intermediate malignant potential and is categorized as a synonymous entity with well-differentiated liposarcoma (ALT/WDLPS). Although ALT/WDLPS is the most common subtype of liposarcoma in the oral and maxillofacial region, its occurrence is extremely rare, and asymptomatic clinical behavior often delays definitive diagnosis and treatment. We present an extremely rare case of ALT/WDLPS in the buccal mucosa of an elderly Japanese woman. A provisional diagnosis of benign tumor was made from clinical symptoms that involved findings on magnetic resonance imaging. Microscopic examination revealed mature adipocytes with substantial variation in cell size, fewer multivacuolated lipoblasts, and positive stain with MDM-2 and P16, which resulted in a definitive diagnosis of ALT/WDLPS. Conservative surgical resection resulted in locoregional recurrence; however, no evidence of dedifferentiation was detected, and repeat conservative resection finally allowed the patient to avoid esthetic and functional disorder and to obtain an uneventful clinical prognosis over the long-term follow-up period. We also review previous reports of cases of ALT/WDLPS arising from the cheek/buccal mucosa. (C) 2020 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved.

症例は46歳女性で、右頬部の腫脹を主訴とした。腫脹は無痛性であり、また頸部のリンパ節は触知しなかった。CT検査では右咬筋内に透過領域が描出されたが、その領域の内部には約2cm大で円形の不透亮病変が存在していた。MRI所見も合わせ、右咬筋内の血管奇形と診断した。同腫瘍の大きさと局在を勘案し、手術は下顎下縁上位アプローチ(high perimandibular approach)で行うこととした。広頸筋を切開することで咬筋に到達し、本腫瘍を明瞭に直視しつつ筋組織と共に切除した。本腫瘍には白色で石灰化した物質が含まれており、病理検査にて咬筋内に発生した静脈結石を伴う静脈奇形と最終診断された。顔面麻痺や開口障害などの術後合併症は発生せず経過は良好であった。患者は整容性にも満足しており、手術から12ヵ月間に亘り再発はみられなかった。

BACKGROUND: Heterotopic gastrointestinal cysts have gastrointestinal epithelium in the cyst wall and rarely occur in the oral cavity. Most are found in the neonatal period. However, heterotopic gastrointestinal cysts that are diagnosed as a congenital tongue cyst by routine ultrasonography are extremely rare. CASE SUMMARY: A 12-day-old female presented with swelling of the anterior tongue. The obstetrician had detected significant tongue swelling on fetal ultrasonography in the 35th gestational week. The female was born by cesarean delivery at gestational week 39. She soon became dyspneic, and the cyst was aspirated. After the aspiration, her breathing recovered and she started breastfeeding. The cyst was excised under general anesthesia on the 67th day. Histopathologic examination showed that that cyst wall consisted of a lining of columnar gastrointestinal-type epithelium and pseudostratified ciliated epithelium. The patient restarted breastfeeding 3 h after surgery. The postoperative course was uneventful. CONCLUSION: Airway distress and feeding difficulty were successfully avoided by cyst aspiration, and surgical resection was performed with no perioperative complications.

A 60-year-old woman presented with a painless swelling in the right preauricular region. Physical examination revealed a soft, nontender, oval-shaped lump in this location. Computed tomography indicated an anterolateral cystic lesion that was attached to the condyle of the mandible and to the accessory parotid gland. Differential diagnoses included ganglion cyst, synovial cyst of the temporomandibular joint, and accessory parotid gland cyst. Surgical removal of the cyst was performed with the patient under general anesthesia. The specimen was 18 × 20 × 18 mm in size; it contained fluid that was clear, slightly yellow, and amylase positive. Hematoxylin and eosin staining revealed that a bilayer cuboidal epithelium lined the cyst wall. Immunohistochemical analyses of the cyst wall showed strong expression of cytokeratin and weak expression of vimentin. The final diagnosis was a salivary duct cyst. The postoperative course was uneventful except for a transient facial motor paresis.

25歳女。約5年前から舌後方部に腫瘤が出現し、徐々に増大傾向を認めた。また、左側上顎歯肉部より排膿症状が出現した。口腔内所見では左側舌後方部で有郭乳頭前方部に長径8mm大、表面粘膜正常の腫瘤を認めた。パノラマX線写真では上顎左345根尖部に残留嚢胞を疑う長径10mm大のX線透過性病変を認めたが、舌背部の病変を確認することはできなかった。CT写真では舌背後方部に8×5mm大の類球形の石灰化病変を認めた。初診から1ヵ月後、全身麻酔下に左側舌腫瘍切除術、左側上顎嚢胞摘出術を行った。切除標本のデンタルX線写真では、内部に硬組織が存在していることが判明した。病理組織学的所見では非薄な粘膜上皮下に存在し、周囲を薄い結合組織で囲まれている骨組織を認めた。病理診断は舌骨性分離腫であった。術後半年を経過するも再発なく、良好に経過している。

Lymph node (LN) metastasis has been suggested as a major prognostic factor for oral cancer. Knockdown of the growth factors and receptors involved in these metastatic mechanisms could significantly reduce LN metastasis and improve the survival of oral cancer patients after treatment. The present study, therefore, aimed to evaluate the expression levels of the following growth factors and receptors in squamous cell carcinoma (SCC) of the tongue: the vascular endothelial growth factor (VEGF)‑C and VEGF‑D, which bind to the cell surface tyrosine kinase receptor VEGF receptor‑3 (VEGFR‑3); C‑C motif chemokine receptor 7 (CCR7); neuropilin (NRP)1 and NRP2; and semaphorin 3E (SEMA3E). Furthermore, we assessed microvessel density (MVD) and lymphatic vessel density (LVD) to demonstrate the correlation between these factors and regional LN metastasis, with respect to the clinicopathological features. Finally, we analyzed the correlation between these proteins and overall or disease‑free survival, in order to demonstrate their prognostic value. Univariate analysis revealed a significant association between LN metastasis and the expression levels of VEGF‑C, VEGFR‑3, CCR7, NRP1, and SEMA3E, as well as LVD, in SCC cells. In contrast, multivariate analysis identified associations between LN metastasis and NRP1 expression, as well as between LN metastasis and LVD; however, no correlation was found between LN metastasis and the expression levels of the other proteins. The expression levels of VEGF‑C, VEGFR‑3, NRP1, and SEMA3E, as well as LVD, were correlated with disease‑free survival time. These results indicate that LN metastasis is associated with poor survival in SCC. This study suggests that NRP1 expression and LVD are independent factors that are likely to predict the risk of LN metastasis in SCC of the tongue, whereas the expression of VEGF‑C, VEGFR‑3, CCR7, and SEMA3E are non‑independent predictive factors.

症例は62歳女性で、ハチミツをハチの巣ごと食べようとした際に、右側頬粘膜の疼痛を自覚した。その後間もなく、ミツバチが口腔内から出てきたためミツバチに刺されたことを自覚した。約2週間後より右側頬粘膜が徐々に腫脹してきた。頬粘膜腫瘍を疑い、局所麻酔下に切除術を施行した。術後2ヵ月での再診時に再発は認めず、その後も良好に経過した。病理組織学的所見では、上皮下に著明な好中球浸潤を伴う肉芽組織の形成を認め、その中心にハチの針を認めた。病理組織学的診断は異物肉芽腫であった。

Fatty acid binding proteins (FABPs) are a family of small and highly conserved lipid chaperone molecules with highly varied functions. Among them, fatty acid binding protein 4 (FABP4, also known as aP2) is highly expressed by adipocytes, macrophages and dendritic cells. Although the role of FABP4 in cancer is still unclear, it has been reported to be highly expressed by human tumors such as ovarian and bladder cancers. In the present study, we investigated the expression and role of FABP4 in oral squamous cell carcinoma (SCC) and its expression in oral SCC tissues. Immunohistochemical staining revealed that FABP4 expression in the tumor tissue was much higher than that in the non-tumor area of the same specimen. In the in vitro studies, an FABP4-knockdown SCC cell line (established through FABP4-specific siRNA) showed inhibited growth, and inhibited expression and activation of mitogen-activated protein kinase (MAPK). These results indicate that expression of FABP4 plays an important role in the cell growth of oral SCC through the MAPK pathway.

Iatrogenic tooth displacement is a rare complication during extraction of impacted molars, but displacement of a maxillary third molar into the maxillary sinus, infratemporal fossa, buccal space, pterygomandibular space, and lateral pharyngeal space has been reported. Currently, 6 published reports describe third molar displacement into the lateral pharyngeal space, only 1 of which involved the loss of a maxillary third molar into this area, which occurred after an attempted self-extraction by the patient. There have been no reported cases of iatrogenic displacement of the maxillary third molar during an extraction procedure. This article describes the recovery, under general anesthesia, of a maxillary third molar from the lateral pharyngeal space after an iatrogenic displacement.