Three-dimensional imaging evaluation of facial swelling after orthognathic surgery with compression and Kinesio taping therapy: a randomized clinical trial.

Background: Postoperative swelling is a common complication of orthognathic surgery. The authors used three-dimensional (3D) image analysis and body surface temperature to determine the effects of compression taping (CT) and Kinesio taping (KT) by the epidermis, dermis, and fascia method (EDF-KT) on postoperative swelling. Materials and methods: The authors conducted a prospective, parallel-group, randomized controlled trial. Among the 162 patients diagnosed with jaw deformity and who underwent orthognathic surgery from August 2020 to October 2022, 105 patients (men: 36, women: 69, mean age: 28.27±8.92) underwent Le Fort type I + sagittal split ramus osteotomy (SSRO) or SSRO and were included in this study. Patients were randomly divided into three groups: EDF-KT group (n=31), CT group (n=41), and no tape group (control group, n=30). All taping was performed immediately postoperatively and removed on postoperative day (POD) 5. Three-dimensional images of the participants' faces were obtained preoperatively and at PODs 3, 7, 30, and 90 using a hand-held 3D imaging system and infrared thermography. Results: No significant difference was observed in postoperative swelling and postoperative body surface temperature between the groups at each time point. The CT group showed a trend towards reduced swelling on PODs 3 and 7 and a trend toward residual swelling on POD 90. The EDF-KT group showed a trend towards an increase in postoperative body surface temperature. Conclusion: CT taping may not be appropriate for postoperative swelling control, suggesting that EDF-KT may affect body surface temperature. Further validation of the efficacy of KT for jaw deformities is needed.

Novel frameshift variant of WNT10A in a Japanese patient with hypodontia.

Congenital tooth agenesis is caused by the impairment of crucial genes related to tooth development, such as Wnt signaling pathway genes. Here, we investigated the genetic causes of sporadic congenital tooth agenesis. Exome sequencing, followed by Sanger sequencing, identified a novel single-nucleotide deletion in WNT10A (NC_000002.12(NM_025216.3):c.802del), which was not found in the healthy parents of the patient. Thus, we concluded that the variant was the genetic cause of the patient's agenesis.

Factors affecting progressive facial swelling immediately after orthognathic surgery: A retrospective cohort study.

The aim of this study was to identify clinical factors associated with progressive facial swelling after orthognathic surgery. Patients diagnosed with jaw deformities and undergoing orthognathic surgery were retrospectively evaluated, and those with surgical site infection, Le Fort I osteotomy, or genioplasty only were excluded. Facial swelling volume was calculated by comparing facial volume preoperatively and three days postoperatively using 3D images and image analysis software (VECTRA H2). FXIII was measured within three days after surgery in only patients with unexplained postoperative bleeding or hematoma. The correlation between facial swelling volume and clinical factors was statistically analyzed. Facial swelling volume was examined in 78 patients. Univariate analysis showed a significant difference between facial swelling volume (mean = 41.6 cm3) and operation time (mean = 209.3 min, r = 0.283, p = 0.012), ΔHb level (mean = 1.18 g/dL, r = 0.235, p = 0.039), as well as decreased factor XIII activity (mean = 75.3%, p = 0.012). Multivariate analysis showed a significant difference between facial swelling volume and FXIII deficiency (standard error = 6.44, p = 0.031).Progressive facial swelling immediately after orthognathic surgery may be due to factor XIII deficiency.

In Vitro Study of Zirconia Surface Modification for Dental Implants by Atomic Layer Deposition.

Zirconia is a promising material for dental implants; however, an appropriate surface modification procedure has not yet been identified. Atomic layer deposition (ALD) is a nanotechnology that deposits thin films of metal oxides or metals on materials. The aim of this study was to deposit thin films of titanium dioxide (TiO2), aluminum oxide (Al2O3), silicon dioxide (SiO2), and zinc oxide (ZnO) on zirconia disks (ZR-Ti, ZR-Al, ZR-Si, and ZR-Zn, respectively) using ALD and evaluate the cell proliferation abilities of mouse fibroblasts (L929) and mouse osteoblastic cells (MC3T3-E1) on each sample. Zirconia disks (ZR; diameter 10 mm) were fabricated using a computer-aided design/computer-aided manufacturing system. Following the ALD of TiO2, Al2O3, SiO2, or ZnO thin film, the thin-film thickness, elemental distribution, contact angle, adhesion strength, and elemental elution were determined. The L929 and MC3T3-E1 cell proliferation and morphologies on each sample were observed on days 1, 3, and 5 (L929) and days 1, 4, and 7 (MC3T3-E1). The ZR-Ti, ZR-Al, ZR-Si, and ZR-Zn thin-film thicknesses were 41.97, 42.36, 62.50, and 61.11 nm, respectively, and their average adhesion strengths were 163.5, 140.9, 157.3, and 161.6 mN, respectively. The contact angle on ZR-Si was significantly lower than that on all the other specimens. The eluted Zr, Ti, and Al amounts were below the detection limits, whereas the total Si and Zn elution amounts over two weeks were 0.019 and 0.695 ppm, respectively. For both L929 and MC3T3-E1, the cell numbers increased over time on ZR, ZR-Ti, ZR-Al, and ZR-Si. Particularly, cell proliferation in ZR-Ti exceeded that in the other samples. These results suggest that ALD application to zirconia, particularly for TiO2 deposition, could be a new surface modification procedure for zirconia dental implants.

Effects of heated tobacco products and conventional cigarettes on dental implant wound healing: experimental research.

Smoking affects wound healing and is associated with dental implant failure. Heated tobacco products (HTPs) appear to be less harmful than conventional cigarettes (CCs); however, there is limited analytical data to support this claim. This study aimed to compare HTPs and CCs for their impact on wound healing using L929 mouse fibroblast cells and evaluate whether HTPs also lead to failure in implant therapy. Materials and methods: Cigarette smoke extract (CSE) was obtained from CCs (Marlboro, Philip Morris) and HTPs (Marlboro Heat Sticks Regular for IQOS, Philip Morris) and initiated a wound-healing assay with a cell-free area created in the centre of a titanium plate by sticking a 2-mm-width line tape. The L929 mouse fibroblast cells were exposed with 2.5 and 5% CSE from HTPs and CCs and then seeded in the titanium plate. A scratch wound-healing assay was initiated when all samples were at 80% confluence. The number of cells migrating to the wound site was counted after 12, 24, and 48 h. Results: Cell migration decreased after CSE exposure from both CCs and HTPs. At each time-point with 2.5% CSE, cell migration in the HTP group was less than that of the CC group. There were significant differences between the 2.5% CC and 2.5% HTP groups and the 5% CC and 5% HTP groups after 24 h. HTPs and CCs had similar effects in the wound-healing assay. Conclusion: Therefore, HTP use may be a risk factor for poor dental implant healing.

Synthesis of nucleoside oligophosphates by electrophilic activation of phosphorothioate.

We herein report a new synthetic method for nucleoside oligophosphates based on electrophilic activation of 5'-phosphorothioate nucleotides. The treatment of phosphorothioate with 2,4-dinitrochlorobenzene (DNCB) efficiently afforded the key activated species, electrophilic thioester nucleotides (EPT-Ns), which were coupled with various phosphate reagents to afford the target nucleoside oligophosphates, including an mRNA cap analog.

Cytotoxic, genotoxic, and toxicogenomic effects of heated tobacco products and cigarette smoke in human primary keratinocytes.

INTRODUCTION: Heated tobacco products (HTPs) appear to be less harmful to health than conventional cigarettes (CCs). However, limited analytical data are available to support this claim. This study aimed to compare the cytotoxic, genotoxic, and toxicogenomic effects of HTPs and CCs in carcinogenesis via multistep gene mutations in the oral mucosal cells. METHODS: Cigarette smoke extract (CSE) was obtained from HTPs and CCs. Primary human oral keratinocytes (HOKs) were treated with 5% and 20% CSE from HTPs and CCs. Cell survival rate assays were performed after 6, 12, and 24 h. After 6 h, DNA double-strand breaks (DSBs) were evaluated using anti-γH2AX antibodies with immunohistochemistry. mRNAs expressions of mediator of DNA damage checkpoint 1 (MDC1) and ataxia telangiectasia and Rad3-related protein (ATR), were analyzed. Expressions of miR-22 and miR-185 were analyzed because miR-22 targets MDC1 and miR-185, ATR. RESULTS: The HOKs had equivalent survival rates after exposure to the same concentrations of CSE from CCs and HTPs. HTPs increased foci formation of γH2AX in HOKs, as did CCs (without CSE vs 20% HTP, p<0.05; without CSE vs 20% CC, p<0.05). Expressions of MDC1 and ATR decreased in cells exposed to CSE from CCs and HTPs (MDC1: without CSE vs 20% HTP, p<0.05; without CSE vs 20% CC, p<0.05; ATR: without CSE vs 20% HTP, p<0.05; without CSE vs 20% CC, p<0.05). Expressions of miR-22 and miR-185 were not significantly increased when exposed to CSE from CCs or HTPs. CONCLUSIONS: HTPs and CCs had similar cytotoxic effects. HTPs are genotoxic, can cause DSBs, and have toxicogenomic damage because they inhibit the MDC1 and ATR-CHK1 DNA repair pathways in the oral mucosa. The miRNA-mRNA axis was not related to these inhibitions.

Oral hygiene status and factors related to oral health in hospitalized patients with schizophrenia.

OBJECTIVE: This study aimed to elucidate the oral hygiene status and the factors associated with poor oral hygiene among patients with schizophrenia. METHODS: The relationships of oral hygiene status (calculus index [CI], debris index [DI]), the mean number of decayed-missing-filled teeth (mean DMFT), and Revised Oral Assessment Guide (ROAG) with related factors (hospitalization, chlorpromazine equivalents [CPZE], age, Barthel Index [BI], frequency of cleaning teeth, and self-oral hygiene ability) among 249 hospitalized schizophrenic patients were investigated. RESULTS: The results for oral hygiene status were as follows: median (range); CI 0.5 (0-6.0), DI 1.7 (0-6.0), ROAG 10.0 (7.0-15.0); and mean DMFT 21.7 ± 7.3. The average CPZE was 524.4 ± 353.6 mg (mean ± SD), and the BI was 76.4 ± 30.7. There was a negative correlation between BI and DI (r = -0.34), and a positive correlation between age and mean DMFT (r = 0.57). Male patients tended to have worse oral conditions (ROAG) than females. The least-squares multiple regression analysis revealed that BI for DI, age for mean DMFT, sex for ROAG, and self-oral hygiene ability for CI, DI, and mean DMFT were factors related to oral health status. CONCLUSION: Patients with schizophrenia tended to have poor oral hygiene. BI, being male, and low activities of daily living were associated with poor oral hygiene. Furthermore, advanced age was associated with an increased risk of dental caries.

Salivary gland polymorphous adenocarcinoma: Clinicopathological features and gene alterations in 36 Japanese patients.

BACKGROUND: Polymorphous adenocarcinoma is a common intraoral minor salivary gland carcinoma in Western countries but is extremely rare in Japan. The current study aimed to characterize the clinicopathological features and status of molecular alterations of polymorphous adenocarcinoma-associated genes, such as PRKD1/2/3, ARID1A, and DDX3X, in a large cohort of Japanese patients with polymorphous adenocarcinoma. METHODS: We examined the cases of 36 Japanese patients with salivary gland polymorphous adenocarcinoma and 26 cases involving histopathological mimics. To detect gene splits, fluorescence in situ hybridization was carried out for polymorphous adenocarcinoma-associated genes. Additionally, we applied a SNaPshot multiplex assay to identify PRKD1 hotspot mutations. RESULTS: This study revealed the indolent clinical course of polymorphous adenocarcinoma with a high 10-year overall survival rate (92.9%), accompanied by occasional local recurrences and cervical lymph node metastasis (23.3%). Twenty cases (55.6%) of polymorphous adenocarcinoma (but none of the mimics) exhibited alterations in at least one polymorphous adenocarcinoma-associated gene. Rearrangement of polymorphous adenocarcinoma-associated genes and PRKD1 E710D were identified in 17 (47.2%) and 4 (11.1%) cases, respectively; one case showed coexisting PRKD3 split and PRKD1 E710D. In the multivariate analysis, high clinical stage (p = 0.0005), the presence of prominent nucleoli (p = 0.0003), and ARID1A split positivity (p = 0.004) were independent risk factors for disease-free survival. CONCLUSION: Japanese patients with polymorphous adenocarcinoma showed clinicopathological features similar to those reported in Western countries. This study disclosed that polymorphous adenocarcinoma-associated genetic alterations were common and specific findings in polymorphous adenocarcinomas. The diagnostic role and possible prognostic significance of polymorphous adenocarcinoma-associated genetic alterations in polymorphous adenocarcinomas were suggested.

Active Peripheral Osteoma in the Mandibular Notch: A Longitudinal Clinical Report.

Osteomas are benign osteogenic tumors composed of mature compact or cancellous bone and are characterized by slow, painless growth. A peripheral osteoma located in the mandibular notch is extremely rare. Here, we describe the case of a 38-year-old woman with an active peripheral osteoma in the mandibular notch for long-term follow up. Surgical resection of the lesion was performed, which resulted in the improvement of the mandibular function and temporomandibular dysfunction. This is the first report of resection surgery after confirming the activity of peripheral osteoma by bone scintigraphy. Creating a three-dimensional model of the mandible promises an accurate surgical plan.

Salivary CCL20 Level as a Biomarker for Oral Squamous Cell Carcinoma.

BACKGROUND/AIM: This study investigated the utility of C-C motif chemokine ligand 20 (CCL20) expression in saliva as a biomarker for oral squamous cell carcinoma (OSCC) and also examined the associated microbiome. MATERIALS AND METHODS: The study group included patients with OSCC or oral potentially malignant disorder (OPMD), and healthy volunteers (HVs). microarray and qRT-PCR were used to compare salivary CCL20 expression levels among groups. Data on CCL20 levels in oral cancer tissues and normal tissues were retrieved from a public database and examined. Furthermore, next-generation sequencing was used to investigate the salivary microbiome. RESULTS: A significant increase in the expression level of CCL20 was observed in both OSCC tissues and saliva from patients with oral cancer. Fusobacterium was identified as the predominant bacteria in OSCC and correlated with CCL20 expression level. OSCC screening based on salivary CCL20 expression enabled successful differentiation between patients with OSCC and HVs. CONCLUSION: CCL20 expression may be a useful biomarker for OSCC.

Relationship between age and sex and the numbers of ingestions and swallows for foods of different textures among healthy adults.

BACKGROUND: The number of swallows needed per single ingestion of food is an important index when assisting a patient with dysphagia in eating. While providing meal assistance, the caregiver may assume that one ingestion is completed with one swallow and then may administer the next ingestion even if the individual's mouth still has remaining food from the previous ingestions, increasing the risk for aspiration and choking. OBJECTIVE: The objective of this pilot study was to clarify the differences in foods ingested and swallowed because of influencing factors such as age and gender among healthy adults. METHODS: The study enrolled 110 healthy adults (47.4 ± 15.8 years; 57 males, 53 females). The numbers of ingestions and swallows were counted and evaluated by food type (pilaf, 100 g; yogurt 80 g; and sponge cake, 35 g) and participant age and sex and analyzed by least-squares multiple regression analysis. RESULTS: The mean numbers of ingestion/swallows were pilaf, 12.5 ± 3.2/13.4 ± 4.2; yogurt, 8.8 ± 2.1/10.8 ± 2.1; and sponge cake, 5.8 ± 2.1/7.0 ± 2.1. The mean number of ingestions and swallows for all foods were higher for female participants compared with male participants. Statistical analysis identified sex as a significant influencing factor for the number of ingestion for all foods. For the number of swallows, the significant influencing factors were sex for sponge cake and age for pilaf and yogurt. CONCLUSION: For the test foods of different textures, sex and age were significant influencing factors for the numbers of ingestions and swallows. Further research is needed to elucidate the problem areas in this pilot study.

Salivary NUS1 and RCN1 Levels as Biomarkers for Oral Squamous Cell Carcinoma Diagnosis.

BACKGROUND/AIM: Oral cancer may become advanced because of delay in diagnosis. In order to promote oral cancer screening, simple and highly reliable screening methods that can be implemented at general dental clinics are required. Herein we investigated differential salivary gene expression between oral squamous cell carcinoma (OSCC) patients and healthy volunteers (HV) to identify new biomarkers for OSCC detection. MATERIALS AND METHODS: Candidate genes were selected by microarrays, nuclear undecaprenyl pyrophosphate synthase 1 (NUS1) and reticulocalbin 1 (RCN1) were selected for further investigation. We used real-time quantitative reverse transcription PCR (qRT-PCR) to determine NUS1 and RCN1 expression levels in saliva and tissues. RESULTS: qRT-PCR analysis of clinical samples revealed that OSCC patients had significantly higher expression of salivary NUS1 and RCN1 than HV. CONCLUSION: A combination of NUS1 and RCN1 accurately distinguished patients from controls, and this combination can be implemented as a screening test for OSCC.

Relationship between facial asymmetry and positional plagiocephaly analyzed by three-dimensional computed tomography.

PURPOSE: A relationship between positional cranial deformation and facial asymmetry has been suggested; however, details regarding this relationship remain to be clarified. This study aimed to elucidate the relationship between facial asymmetry and positional plagiocephaly using three-dimensional computed tomography (3D-CT). METHODS: One-hundred-and-twenty-nine patients were included, and cranial vault asymmetry index (CVAI) and cephalic index (CI) were used as indicators of positional cranial deformation. Temporal muscle was constructed using 3D-CT data, and its volume was measured. VRL, Me (vertical reference line (VRL)-anterior nasal spine (ANS) and menton (Me) line) angle and the frontal occlusal plane (FOP) angle were measured. RESULTS: CVAI and VRL, Me angle (R2 = 0.31, P < 0.0001), VRL, Me angle and temporal muscle volume (R2 = 0.13, P < 0.0001), and FOP angle and VRL, Me angle were significantly correlated (R2 = 0.32, P < 0.0001), but CVAI and FOP angle were not (R2 = 0.08). Multiple linear regression analysis indicated that CVAI, FOP angle, and variable temporal muscle volume were significant predictors of VRL, Me angle [(F (5, 123) = 14.94, P < .0001, R2 = 0.38)]. CONCLUSIONS: Our results revealed that mandibular deviation was associated with contralateral head slant and ipsilateral increase in temporal muscle volume. Positional plagiocephaly may be a cause of facial asymmetry, and such deviations may occur in the temporal muscle.

A small number of residual teeth after the mandibular resection of oral cancer is associated with titanium reconstruction plate exposure.

Objective: Reconstruction plates are used to treat patients with a segmental mandibular defect after oral cancer surgery. Reconstruction plate failure analysis has rarely focused on occlusion, which conducts a mechanical force to the mandible and the plate. To determine the prognostic factors, we retrospectively evaluated patients who underwent reconstruction of a mandibular segmental defect with a reconstruction plate and assessed the number of residual paired teeth. Material and Methods: From among 390 patients with oral cancer who visited University of Tsukuba Hospital (Tsukuba, Japan) between 2007 and 2017, we selected and analyzed the data of 37 patients who underwent segmental resection of the mandible and reconstruction with reconstruction plates. Prognostic factors evaluated were patient age, sex, TNM classification, plate manufacturer, treatment with radiotherapy or chemotherapy, whether the patient had diabetes or smoked, and whether the patient had a small number of residual paired teeth, plate length, and use of a fibular-free flap. Among these 37 patients, eight reconstruction plates had intraoral or extraoral exposure and were removed in 5 years. Results: Kaplan-Meier and log-rank analyses revealed that the prognosis for the 5-year plate exposure-free rate was significantly poorer for patients with a small number of residual teeth than for patients with no teeth or those with a large number of residual teeth (.01). Univariate Cox regression analysis revealed that a small number of residual teeth was a significant prognostic factor in the loss of a reconstruction plate (hazard ratio: 5.63; 95% confidence interval [1.10, 25.85]; .04). Conclusions: A small number of residual teeth after the segmental resection of oral cancer is significantly involved in reconstruction plate survival and may be important in predicting reconstruction plate prognosis.

Association between p62 expression and clinicopathological characteristics in oral leukoplakia.

Objective: Oral leukoplakia is keratinized lesions in the buccal mucosa, tongue, and gingiva. It is the most common oral precancerous lesion; oxidative stresses and irrelevant autophagy have been reported to be the cause of oncogenesis. p62, a cytoplasmic protein induced by oxidative stress, is an adaptor protein involved in the formation of protein aggregates and induction and inhibition of autophagy. The inhibition of autophagy induces p62 overexpression and promotes oncogenesis via the oncogenic signaling pathway. The aim of the present study was to elucidate the involvement of intracellular expression of p62 in oral leukoplakia and to address its potential clinical implementation as a biomarker to predict malignant transformation. Material and Methods: Fifty samples from subjects with confirmed oral leukoplakia were evaluated by immunohistochemical staining for the expression of p62, 8-hydroxy-2'-deoxyguanosine (8-OHdG), Ki67, and p53. Univariate and multivariate logistic regression analyses were performed to evaluate the association between p62, 8-OHdG, Ki67, and p53 and clinical characteristics, including epithelial dysplasia. Results: Significant associations were observed between p62 expression in the nucleus, p62 aggregation, and epithelial dysplasia (adjusted odds ratio [OR] = 5.75; 95% confidence interval [CI]: [1.28, 26.2]; .024 and OR = 6.16; 95% CI: [1.01, 37.4]; .048, respectively). The expression of p62 in the cytoplasm and the levels of 8-OHdG, Ki67, and p53 were not significantly associated with epithelial dysplasia. A significant relationship was found between p62 expression in the nucleus and p53 expression (OR = 3.94; 95% CI: [1.14, 13.6]; .031). Conclusions: The results suggested that p62 expression in the nucleus and p62 aggregation can be potential markers to predict the malignant transformation of oral leukoplakia.

MicroRNA-205-5p suppresses the invasiveness of oral squamous cell carcinoma by inhibiting TIMP­2 expression.

MicroRNAs (miRNAs or miRs) play important roles in carcinogenesis. The miRNA, miR-205-5p, has been reported to suppress the growth of various types of tumor; however, its functional contribution to oral squamous cell carcinoma (OSCC) is not yet clear. Thus, this study was conducted to determine the miRNA expression signatures in OSCC and to investigate the functional role of miR­205­5p in OSCC cells. We measured miR­205­5p expression by RT-qPCR, and examined the function of miR­205­5p by transfecting a miR­205­5p mimic or inhibitor into OSCC cells and measuring cell proliferation, migration and invasiveness. Genes targeted by miR­205­5p were identified using the TargetScan database and verified by western blot analysis, luciferase reporter assay and ELISA. We found that miR­205­5p was significantly downregulated in OSCC cell lines and tissue specimens. Following transfection of miR­205­5p mimic or inhibitor into the cancer cell lines, miR­205­5p overexpression significantly suppressed cancer cell migration and invasion. We further demonstrated that miR­205­5p directly targeted and regulated the tissue inhibitor of metalloproteinases­2 (TIMP­2) gene. The silencing of TIMP­2 suppressed cancer cell invasion and the activation of pro­matrix metalloproteinase­2 (pro­MMP­2). These results suggest that TIMP­2 promotes tumor progression, and that miR­205­5p directly regulates TIMP­2, thereby suppressing pro­MMP­2 activation and inhibiting OSCC cell invasiveness. Our data describing the pathways regulated by miR­205­5p provide new insight into the mechanisms responsible for OSCC development and metastasis.

Expression of autophagy-related markers at the surgical margin of oral squamous cell carcinoma correlates with poor prognosis and tumor recurrence.

Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide, and is associated with poor prognosis. Autophagy is a programmed cell survival mechanism involved in physiologic processes and various diseases including cancer. However, the relationship between autophagy and cancer is controversial. Several studies have claimed that the expression of autophagy-related proteins, namely microtubule-associated protein light chain3 (LC3) and p62/SQSTM1 (p62), is associated with poor prognosis in OSCC. In this study, we evaluated the expression of the autophagy-related markers LC3A/B and p62 by immunohistochemistry in 71 OSCC patient samples, especially focusing on surgical margins. Results were correlated with clinical characteristics. The expression of LC3A and LC3B was correlated with tumor recurrence and poor overall survival based on multivariate analysis, whereas the expression of p62 was correlated with only tumor recurrence and not prognosis. Thus, we suggest that the expression of autophagy-related markers at the surgical margins might be an indicator of local recurrence and poor prognosis in human OSCC. These results will aid in the development of new therapeutics and diagnostics for OSCC.

Usefulness of esophagogastroduodenoscopy and 18F-fluorodeoxyglucose positron-emission tomography in detecting synchronous multiple primary cancers with oral cancer.

PURPOSE: The purpose of this study is to compare the value of screening for synchronous multiple primary cancers in other organs by esophagogastroduodenoscopy (EGD) or 18F-fluorodeoxyglucose positron-emission tomography (PET-CT) in patients newly diagnosed with oral cancer. METHODS: We retrospectively examined consecutive Japanese patients who were diagnosed with oral squamous cell carcinoma (OSCC) and were screened for synchronous multiple primary cancers in other organs by EGD and/or PET-CT between January 2010 and December 2015 at our institution. The study included 190 patients (106 males and 84 females) from 36 to 93 years of age (median age 68.8 years). The patients were screened by EGD, PET-CT, or both before beginning treatment for OSCC. RESULTS: Of 190 Japanese patients with OSCC, 15 had multiple primary cancers: 13 patients had double cancer and two had triple cancers. The sites of the 17 multiple primary cancers were gastric (6), esophageal (4), and lung (3), and ovarian, colon, liver, and thyroid (1 each). All of the gastric and esophageal cancers were found by EGD and were not detected by PET-CT. For three patients, the detection of multiple cancers affected the treatment modality or order of treatment selected for the OSCC. In two cases, the oral cancer and multiple primary cancer(s) in another organ were resected simultaneously by joint surgical teams. CONCLUSIONS: PET-CT for oral cancer patients is an effective supporting diagnostic tool. However, the ability of PET-CT has some limitations. Especially for early detection of the upper gastrointestinal cancers, it is necessary to be supplemented by EGD.