COVID-19 transmission in dental and oral/maxillofacial surgical practice during pandemic: questionnaire survey in 51 university hospitals in Japan.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has become a major public health problem. Dental procedures that generate aerosols are considered to impose a high risk of infection; therefore, dental professionals, such as dentists and dental hygienists, may be at high risk of viral transmission. However, few studies have reported COVID-19 clusters in dental care settings. AIM: To investigate whether dental and oral/maxillofacial procedures are associated with the occurrence of COVID-19 clusters and measures taken to prevent nosocomial infection in dental clinics. METHODS: An online questionnaire survey on clinical activities (administrative control), infection control measures (environmental/engineering control, personal protective equipment, etc.), and confirmed or probable COVID-19 cases among patients and clinical staff was administered to the faculties of the dental and oral/maxillofacial surgical departments of university hospitals. FINDINGS: Fifty-one faculty members completed the questionnaire. All members were engaged in the treatment of dental and oral surgical outpatients and actively implemented standard precautions. Fourteen faculty members treated patients with COVID-19, but no infections transmitted from the patients to the medical staff were observed. In seven facilities, patients were found to have the infection after treatment (medical staff came in close contact), but there was no transmission from patients to medical staff. Four facilities had medical staff with infections, but none of them exhibited disease transmission from staff to patients. CONCLUSION: COVID-19 clusters are unlikely to occur in dental and oral surgical care settings if appropriate protective measures are implemented.

Denosumab-related osteonecrosis of the jaw after tooth extraction and the effects of a short drug holiday in cancer patients: a multicenter retrospective study.

Pre-existing inflammation, corticosteroid therapy, periapical periodontitis, longer duration of denosumab therapy, and female sex were significantly associated with an increased risk of denosumab-related osteonecrosis of the jaw after tooth extraction in patients with cancer on oncologic doses of denosumab. A short drug holiday did not protect against this complication. INTRODUCTION: This study retrospectively investigated the relationship between various risk factors, including brief discontinuation of denosumab, and development of denosumab-related osteonecrosis of the jaw (DRONJ) after tooth extraction in patients with cancer who were receiving oncologic doses of this agent. METHODS: Data were collected on demographic characteristics, duration of denosumab therapy, whether or not denosumab was discontinued before tooth extraction (drug holiday), duration of discontinuation, presence of pre-existing inflammation, and whether or not additional surgical procedures were performed. Risk factors for DRONJ after tooth extraction were evaluated by univariate and multivariate analyses. RESULTS: A total of 136 dental extractions were performed in 72 patients (31 men, 41 women) with cancer who were receiving oncologic doses of denosumab. Post-extraction DRONJ was diagnosed in 39 teeth (28.7%) in 25 patients. Tooth extraction was significantly associated with development of DRONJ only in patients with pre-existing inflammation (odds ratio [OR] 243.77), those on corticosteroid therapy (OR 73.50), those with periapical periodontitis (OR 14.13), those who had been taking oncologic doses of denosumab for a longer period (OR 4.69), and in women (OR 1.04). There was no significant difference in the occurrence of DRONJ between patients who had a drug holiday before tooth extraction and those who did not. CONCLUSIONS: These findings suggest that inflamed teeth should be extracted immediately in patients with cancer who are receiving oncologic doses of denosumab. Drug holidays have no significant impact on the risk of DRONJ.

A clinical investigation of the association between perioperative oral management and prognostic nutritional index in patients with digestive and urinary cancers.

Background: The prognostic nutritional index (pni) is a simple metric calculated using serum albumin and the peripheral lymphocyte count. It was reported that a low pni score is significantly associated with major postoperative complications and poor prognosis. The purpose of the present study was to investigate the effects of perioperative oral management (pom) on the perioperative pni profiles of patients with digestive system or urinary cancers. Study Design: The medical records of 181 patients with cancer who underwent surgery and for whom a pni could be calculated were retrospectively reviewed. Results: The intervention rate with pom was 34.8%. The median preoperative pni score was 48.25 in all patients with a pom intervention [25% to 75% interquartile range (iqr): 44.38-54.13] and 47.25 in those without an intervention (iqr: 42.0-53.5). Compared with patients not receiving pom, those who received pom had significantly higher pni scores from the early postoperative period (p < 0.05). Notably, of patients who could resume oral intake within 3 days after surgery, those who received pom intervention, compared with those who did not, had significantly higher pni scores from the early postoperative period (p < 0.05). Conclusions: Perioperative oral management interventions might have positive effects on the postoperative pni scores of patients with cancer.

Postoperative adjuvant therapy for patients with loco-regionally advanced oral squamous cell carcinoma who are at high risk of recurrence.

Extranodal extension (ENE) of lymph node metastasis and the presence of a positive or close margin (PCM) are major risk factors for head and neck squamous cell carcinoma recurrence. This retrospective multicentre cohort study compared the prognostic impact of postoperative radiotherapy (RT) and concurrent chemoradiotherapy (CCRT) in oral squamous cell carcinoma (OSCC) patients at high risk of recurrence. One hundred and eighteen patients with PCM and/or ENE who underwent definitive surgery plus either adjuvant RT or CCRT using cisplatin for OSCC were investigated. The cohort-wide 5-year loco-regional control (LRC), disease-free survival (DFS), and overall survival (OS) rates (the main outcome measures) were 54.3%, 35.8%, and 43.2%, respectively. Multivariate analysis showed that age ≥64 years (hazard ratio (HR) 0.584), cT3-4 stage (HR 1.927), ≥4 metastatic lymph nodes (HR 1.912), and PCM (HR 2.014) were significant independent predictors of OS. Moreover, postoperative CCRT with cisplatin was associated with a significantly improved LRC rate, but not with improved DFS or OS rates, compared to postoperative RT (HR 0.360). Given that CCRT with cisplatin does not significantly improve survival, additional clinical trials will be required to validate new regimens that further improve the outcomes of patients with loco-regionally advanced OSCC going forward.

Nuclear protein of the testis midline carcinoma in the oral cavity: retrospective review of those initially diagnosed as poorly differentiated squamous cell carcinoma using an anti-C52B1 antibody.

Nuclear protein of the testis (NUT) midline carcinomas (NMC) are malignant epithelial tumours that have chromosomal rearrangements of the gene encoding NUT at 15q14. NMC is typically an aggressive fatal cancer, clinically overlaps with other carcinomas, and differential diagnosis is difficult. The purpose of this study was to investigate NMC in poorly differentiated oral squamous cell carcinoma (OSCC) with a retrospective analysis based on anti-C52B1 immunohistochemical staining. An anti-C52B1 antibody was used for immunohistochemical staining in all 27 primary tumours, and the prevalence and pathological features of NMC in the oral cavity were examined. Only two of 27 cases (7.4%) were C52B1 immunopositive. Both positive patients were women aged 38 and 43 years - younger than the other C52B1-negative patients, whose average age was 65.6 years (range 41-83). The primary sites were the right side of the floor of the mouth and the left side of the tongue. They had a poor prognosis and died within 8 months postoperation compared with the median overall survival time of 60.2 months for patients with other poorly differentiated squamous cell carcinoma. The pathological findings of their primary tumours were similar to typical poorly differentiated OSCC.

Effectiveness of a comprehensive oral management protocol for the prevention of severe oral mucositis in patients receiving radiotherapy with or without chemotherapy for oral cancer: a multicentre, phase II, randomized controlled trial.

The aim of this phase II, multicentre, randomized controlled trial was to evaluate the effectiveness of a comprehensive oral management protocol for the prevention of severe oral mucositis in patients with oral cancer receiving radiotherapy alone or chemoradiotherapy. In total, 124 patients with oral cancer were enrolled from five institutions. Of these, 37 patients undergoing radiotherapy were randomly divided into an intervention group (n=18) and a control group (n=19). The remaining 87 patients, who were undergoing chemoradiotherapy, were also randomized into an intervention group (n=42) and a control group (n=45). During radiotherapy, patients in the control group received only oral care, while those in the intervention group additionally received spacers to cover the entire dentition, pilocarpine hydrochloride, and topical dexamethasone ointment for oral mucositis. The primary endpoint was the incidence of severe oral mucositis. The intervention was significantly associated with a decreased incidence of severe oral mucositis in patients receiving radiotherapy alone (P=0.046), but not in those receiving chemoradiotherapy (P=0.815). These findings suggest that an oral management protocol can prevent severe oral mucositis in patients with oral cancer undergoing radiotherapy without concurrent chemotherapy.

Medication-related osteonecrosis of the jaw after tooth extraction in cancer patients: a multicenter retrospective study.

Root amputation, immunosuppressive therapy, mandibular tooth extraction, pre-existing inflammation, and longer duration of treatment with bone-modifying agents were significantly associated with an increased risk of medication-related osteonecrosis of the jaw. Hopeless teeth should be extracted without drug holiday before the development of inflammation in cancer patients receiving high-dose bone-modifying agents. INTRODUCTION: No studies have comprehensively analyzed the influence of pre-existing inflammation, surgical procedure-related factors such as primary wound closure, demographic factors, and drug holiday on the incidence of medication-related osteonecrosis of the jaw (MRONJ). The purpose of this study was to retrospectively investigate the relationships between these various factors and the development of MRONJ after tooth extraction in cancer patients receiving high-dose bone-modifying agents (BMAs) such as bisphosphonates or denosumab. METHODS: Risk factors for MRONJ after tooth extraction were evaluated with univariate and multivariate analyses. The following parameters were investigated in all patients: demographics, type and duration of BMA use, whether BMA use was discontinued before tooth extraction (drug holiday), the duration of such discontinuation, the presence of pre-existing inflammation, and whether additional surgical procedures (e.g., incision, removal of bone edges, root amputation) were performed. RESULTS: We found that root amputation (OR = 22.62), immunosuppressive therapy (OR = 16.61), extraction of mandibular teeth (OR = 12.14), extraction of teeth with pre-existing inflammation, and longer duration (≥ 8 months) of high-dose BMA (OR = 7.85) were all significantly associated with MRONJ. CONCLUSIONS: Tooth extraction should not necessarily be postponed in cancer patients receiving high-dose BMA. The effectiveness of a short-term drug holiday was not confirmed, as drug holidays had no significant impact on MRONJ incidence. Tooth extraction may be acceptable during high-dose BMA therapy until 8 months after initiation.

Treatment modalities and risk factors associated with refractory neurosensory disturbances of the inferior alveolar nerve following oral surgery: a multicentre retrospective study.

Little research has been conducted into hypoesthesia, and no studies have elucidated the risk factors for refractory hypoesthesia and compared treatment modalities. The purpose of this multicentre retrospective cohort study was to investigate the relationships between various risk factors, treatment modalities, and refractory hypoesthesia. Risk factors for refractory hypoesthesia after oral surgery were evaluated using univariate and multivariate analysis. To minimize the selection bias associated with a retrospective data analysis, a propensity score analysis was performed between the medication and non-medication groups (65 sites in each group). Moderate or severe hypoesthesia (odds ratio 13.42) and no or late administration of ATP/vitamin B12 (odds ratio 2.28) were significantly associated with refractory hypoesthesia. In the propensity score analysis, the incidence rate of refractory hypoesthesia in the medication group was lower than that in the non-medication group (P<0.001). This study demonstrated the multivariate relationships between various risk factors, treatment modalities, and refractory hypoesthesia. Moderate or severe hypoesthesia and no or late administration of ATP/vitamin B12 were significantly associated with refractory hypoesthesia. Therefore, clinicians should consider these risk factors and initiate early oral administration of ATP/vitamin B12 in cases of hypoesthesia.

Natriuretic peptide receptor A is related to the expression of vascular endothelial growth factors A and C, and is associated with the invasion potential of tongue squamous cell carcinoma.

Natriuretic peptide receptor A (NPRA) is one of the natriuretic peptide receptors. NPRA has been reported to play a role in the carcinogenesis of various tumours, as well as functional roles in renal, cardiovascular, endocrine, and skeletal homeostasis. The clinicopathological significance of NPRA in tongue squamous cell carcinoma (TSCC) was examined in this study. The overexpression of NPRA was more frequent in TSCC (21/58, 36.2%) than in the normal oral epithelium (0/10, 0%) (P<0.05). It was also more frequently observed in cancers with higher grades according to the pattern of invasion (grades 1-2 vs. grades 3-4, P<0.01). Additionally, there was a tendency towards an association between the N classification and NPRA expression (N0 vs. N1-2, P=0.06). Significant correlations were also observed between the expression of NPRA and that of VEGF-A (P<0.001) and VEGF-C (P<0.001). The high-NPRA expression group had a significantly poorer prognosis, with a 5-year disease-specific survival rate of 39.7%, compared to 97.0% in the low-expression group (P<0.001). Multivariate analysis suggested that the overexpression of NPRA may also be an independent prognostic factor (P<0.05). In conclusion, NPRA is associated with VEGF expression levels, invasion, and metastasis, and may be a prognostic factor in TSCC patients.

A multicenter retrospective study of the risk factors associated with medication-related osteonecrosis of the jaw after tooth extraction in patients receiving oral bisphosphonate therapy: can primary wound closure and a drug holiday really prevent MRONJ?

Root amputation, extraction of a single tooth, bone loss or severe tooth mobility, and an unclosed wound were significantly associated with increased risk of developing medication-related osteonecrosis of the jaw (MRONJ). We recommend a minimally traumatic extraction technique, removal of any bone edges, and mucosal wound closure as standard procedures in patients receiving bisphosphonates. INTRODUCTION: Osteonecrosis of the jaws can occur following tooth extraction in patients receiving bisphosphonate drugs. Various strategies for minimizing the risk of MRONJ have been advanced, but no studies have comprehensively analyzed the efficacy of factors such as primary wound closure, demographics, and drug holidays in reducing its incidence. The purpose of this study was to retrospectively investigate the relationships between these various risk factors after tooth extraction in patients receiving oral bisphosphonate therapy. METHODS: Risk factors for MRONJ after tooth extraction were evaluated using univariate and multivariate analysis. All patients were investigated with regard to demographics; type and duration of oral bisphosphonate use; whether they underwent a discontinuation of oral bisphosphonates before tooth extraction (drug holiday), and the duration of such discontinuation; and whether any additional surgical procedures (e.g., incision, removal of bone edges, root amputation) were performed. RESULTS: We found that root amputation (OR = 6.64), extraction of a single tooth (OR = 3.70), bone loss or severe tooth mobility (OR = 3.60), and an unclosed wound (OR = 2.51) were significantly associated with increased risk of developing MRONJ. CONCLUSIONS: We recommend a minimally traumatic extraction technique, removal of any bone edges, and mucosal wound closure as standard procedures in patients receiving bisphosphonates. We find no evidence supporting the efficacy of a pre-extraction short-term drug holiday from oral bisphosphonates in reducing the risk of MRONJ.

Estimation of the width of free margin with a significant impact on local recurrence in surgical resection of oral squamous cell carcinoma.

The purpose of this study was to estimate the width of free margin with a significant impact on local recurrence in surgical resection of oral squamous cell carcinoma (OSCC). Clinical and pathological data of 127 consecutive patients who underwent radical resection of OSCC were analyzed retrospectively. The local control rate was compared between patients with clear, close, and involved surgical margins, changing the required width of free margin for the definition of 'close surgical margin' (from 1 to 5mm). If a free margin of within 1, 2, or 4mm was judged a close margin, the risk of local recurrence was significantly different among the patients with clear, close, and involved surgical margins. If the definition of close margin was within 5mm of the resection margin, the difference between clear and close margin did not reach statistical significance. The results of this study suggest that 5mm of clearance at the surgical resection margin should be the index of oncological surgery. More than 5mm of histological free margin around OSCC is not justified in terms of the risk management of local recurrence and the resultant morbidity.

Evaluation of the level of progression of extracapsular spread for cervical lymph node metastasis in oral squamous cell carcinoma.

Only a few reports on the level of progression of extracapsular spread (ECS) have been published. The aim of this study was to evaluate the efficacy of the level of progression of ECS in identifying those patients with oral squamous cell carcinoma (OSCC) at a high risk of recurrence who would benefit most from the intensification of adjuvant therapy. The level of progression of ECS for cervical lymph node metastasis in OSCC was divided into three types (A-C), and their relationships with patient prognosis were examined. ECS was observed in 87 of 441 patients with OSCC. The recurrence rate in patients with type C, which was defined as macroscopic tumour invasion into perinodal fat or muscle tissue, was high (69.8%), with 13 cases of death due to distant metastasis. The 3-year disease-specific survival rate for patients with type C was 49.0% and these patients also had a significantly poorer prognosis (P<0.01). The results of the multivariate analysis suggested that the prognosis of ECS in OSCC patients was associated with the level of progression of ECS, especially type C (P<0.01). Overall, the results of this study suggest that the level of progression of ECS is a useful prognostic factor in OSCC patients.

Note: practical monitoring system using characteristic impedance measurement during plasma processing.

A method for characteristic impedance monitoring (CIM) is developed for anomaly detection during plasma processing. Advantages of the method include high-sensitivity and real-time monitoring, as well as structural simplicity to install the measurement system in the mass production equipment. To obtain real-time monitoring without time delay, our CIM system consists of a directional coupler and a newly developed vector processing system instead of the conventional high voltage and current probes. The system can measure the time variations of characteristic and load impedances even while the plasma is generated.

Functional dissociation between Kana and Kanji: agraphia following a thalamic hemorrhage.

We report the case of a 61-year-old woman with a left thalamic hemorrhage causing agraphia of Kanji (morphograms). Single-photon emission computed tomography (SPECT) showed a decrease in the blood flow in the left thalamus from the superior temporal convolution to the parietal lobe, as well as in the frontal lobe while computed tomography showed no remarkable lesions in the cortex. The agraphia in this case may be due to the thalamic lesion itself, but the SPECT findings strongly suggest that a secondary cortical lesion may be involved in producing the higher cognitive disorder.

Baseline clinical and radiographic features are associated with long-term (8 years) signs/symptoms for subjects with diseased temporomandibular joint.

OBJECTIVES: The purpose of this study was to determine the extent to which baseline clinical and radiographic features were associated with long-term outcomes in patients with temporomandibular joint disorder (TMJD). METHODS: 49 patients with unilateral radiographically proven TMJD were available in this study. Self-reported long-term (mean 96.2 months) outcomes (current joint pain, maximum mouth opening and joint noise) after TMJD treatments were assessed by questionnaire. The impact of multiple initial clinical/radiographic findings (gender, age at first visit, time interval between first visit and questionnaire survey, treatment method, disc displacement, disc morphology, disc mobility, condylar bony change and morphology of the articular eminence) on the long-term outcomes was assessed using stepwise multiple regression and logistic regression analysis. RESULTS: Patient age at the first visit was significantly correlated with current joint pain. Disc mobility and morphology of the articular eminence were significantly correlated with current range of maximal mouth opening. CONCLUSIONS: The results of this study suggest that patients who appeared symptomatic at a younger age or who initially had a fixed disc were the most likely to have recurrent or persisting clinical signs/symptoms of TMJD after 8 years.