Medication-related osteonecrosis of the lower jaw without osteolysis on computed tomography images.

INTRODUCTION: Surgery is the standard treatment for medication-related osteonecrosis of the jaw (MRONJ). This study reviewed patients with mandibular MRONJ who underwent surgical treatment, and in particular the characteristics of non-osteolytic MRONJ with no evidence of osteolysis on CT were described. MATERIALS AND METHODS: We conducted a retrospective study of patients with mandibular MRONJ who underwent surgery between January 2016 and September 2022. Various clinical and imaging factors regarding treatment outcomes were investigated and analyzed. Additionally, the disease course of non-osteolytic MRONJ was examined in detail. RESULTS: This study included 55 patients (66 surgeries) with a mean age of 74.7. The primary disease was osteoporosis (24 patients) and malignancy (31 patients); the type of antiresorptive agent was bisphosphonate (BP) in 21 patients and denosumab (DMB) in 26. BP was initially administered; however, it was changed to DMB in eight patients. Preoperatively, the cumulative cure rates for all 66 surgeries were 72.8% at 1 year and 77.3% at 2 years. Cure rates were significantly lower in patients with malignancy, those without osteolysis, and those who underwent sequestrum removal or marginal mandibulectomy than those with osteoporosis, osteolysis, and segmental mandibulectomy. Non-osteolytic MRONJ was observed in eight patients, all with malignancy and receiving high-dose DMB. Only two patients were cured after the initial surgery, and most patients ultimately underwent segmental mandibulectomy. CONCLUSIONS: Surgical treatment yielded good treatment outcomes in most patients with mandibular MRONJ; however, the cure rate was lower in patients with malignancy who showed no osteolysis on CT images.

Association between dental extraction after radiotherapy and osteoradionecrosis: A multi-centre retrospective study.

OBJECTIVE: Radiotherapy (RT) carries a substantial risk for the development of osteoradionecrosis (ORN) of the jaw. This study was performed to investigate the relationship between dental extractions after RT and the development of ORN. MATERIAL AND METHODS: Thirty-two patients with head and neck cancer who underwent tooth extraction after RT were investigated for correlations between the development of ORN and various factors. RESULTS: Postextraction ORN was diagnosed in 12 (12.1%) teeth of 9 patients. The RT dose against the site of tooth extraction was 62.0 and 37.4 Gy in the ORN and Non-ORN groups, respectively (p < .001). The duration from RT to tooth extraction was 41.2 and 28.2 months in the ORN and Non-ORN groups, respectively (p = .025). Tooth extraction was significantly associated with ORN in patients with a high RT dose against the site (odds ratio = 1.231) and a longer duration of time from RT (odds ratio = 1.084). CONCLUSIONS: Extraction of non-restorable teeth and those with a poor prognosis should not necessarily be postponed even when patients are undergoing RT. However, clinicians should pay special attention to postoperative management after tooth extraction in patients with a high RT dose and longer time from RT.

Effect of periosteal reaction in medication-related osteonecrosis of the jaw on treatment outcome after surgery.

INTRODUCTION: Surgical treatment in patients with medication-related osteonecrosis of the jaw (MRONJ) is superior to conservative treatment. However, treatment outcome in patients with periosteal reaction (PR) was significantly poorer than that of those without PR. The purpose of this retrospective study was to analyze the pathophysiology and clinical significance of PR in MRONJ. MATERIALS AND METHODS: Out of 181 patients with MRONJ undergoing surgery, 38 patients with PR were enrolled in the study. CT examinations, histological examinations, and bacteriological examinations using real-time polymerase chain reaction were performed, and the relationship among the opted surgical method, CT findings, and treatment outcome was investigated. RESULTS: The pattern of PR was classified into three types: type 1, new bone is formed parallel to the mandible, and no gap was evident between the mandible and new bone; type 2, new bone is formed parallel to the mandible, and a gap was evident between them; type 3, an irregular shape. Histological examinations revealed inflammatory tissue in the area visualized as a gap on CT. Bacteriological examination showed the presence of bacteria in the type 2 or type 3 PR. Complete cure was observed in 21 of 38 (55.3%) patients, which was lower than the cure rate of 73.4% in 143 patients without PR. The cure rate was significantly lower in cases with type 3 PR or with persistent osteolysis. CONCLUSIONS: It seems that complete resection of both osteolytic area and type 3 PR is necessary to obtain complete healing in patients undergoing marginal mandibulectomy.

Periosteal reaction of medication-related osteonecrosis of the jaw (MRONJ): clinical significance and changes during conservative therapy.

PURPOSE: We previously reported that the periosteal reaction (PR) in medication-related osteonecrosis of the jaw (MRONJ) is a poor prognostic factor in surgical cases, but it is not clear how PR changes during conservative therapy. The purpose of this retrospective study was to compare computed tomography (CT) findings at the first visit and during follow-up visits in MRONJ patients subjected to conservative therapy and to investigate factors associated with the exacerbation of PR during conservative therapy. METHODS: Sixteen patients with MRONJ of the lower jaw who underwent conservative therapy and experienced a PR on CT images at the first visit and underwent CT examination again after 6 months or more were enrolled in the study. Clinical features and CT findings (extent of osteolytic lesion, extent of PR, type of PR, and changes during conservative treatment) were investigated. RESULTS: On the second CT scan, the osteolytic lesion improved in 4 patients, had not changed in 5, and deteriorated in 7, whereas the PR improved in 5 patients, had not changed in 4, and deteriorated in 7 patients. PR was significantly deteriorated in patients who continued to receive antiresorptive agents during conservative treatment and in patients with deteriorated osteolytic lesions. CONCLUSION: PR in MRONJ often expands during conservative therapy and the PR type progresses from the attached type to the gap type, and the irregular type, but discontinuation of antiresorptive agent may improve PR as well as osteolytic lesions.

Drug holiday clinical relevance verification for antiresorptive agents in medication-related osteonecrosis cases of the jaw.

Treatment strategies of medication-related osteonecrosis of the jaw (MRONJ) are controversial. Recently, surgical treatment has been reported as superior to nonsurgical treatment, but the contribution discontinued antiresorptive agent use during MRONJ treatment remains unclear. This study aimed to evaluate the efficacy of drug holidays and treatment strategies in MRONJ cases. Four-hundred and twenty-seven patients with MRONJ treated at nine hospitals from 2009 to 2017 were included in this multicenter retrospective study. Multivariate Cox regression analysis showed that the primary disease (osteoporosis or malignant tumor), diabetes, serum albumin, and treatment method (surgical or nonsurgical) were significantly correlated with the cure rate. The cumulative 1-year cure rates in the surgical and nonsurgical treatment groups were 64.7% and 18.2%, respectively. However, discontinuing antiresorptive agents did not influence the treatment outcome in the cohort overall, or in 230 patients after performing propensity score matching among the discontinuation and continuation groups. When stratifying by treatment method, antiresorptive agent discontinuation significantly increased the cure rate in patients with osteoporosis who underwent nonsurgical treatment. In patients with malignant tumors undergoing nonsurgical therapy, discontinuing the antiresorptive agent was associated with a better treatment outcome, but not with statistical significance. In contrast, drug holidays showed no effect on improving outcomes in patients with both osteoporosis and malignant tumors who underwent surgical therapy. Thus, regardless of the primary disease, discontinuing antiresorptive agents during treatment for MRONJ may not be necessary and may be helpful in some cases. Future prospective trials should examine this question further.

Clinical significance of periosteal reaction as a predictive factor for treatment outcome of medication-related osteonecrosis of the jaw.

Regarding treatment strategies for medication-related osteonecrosis of the jaw (MRONJ), surgical therapy has recently been reported to be more effective than conservative therapy. However, some patients did not achieve complete healing, even when extensive surgery was performed. Periosteal reaction in MRONJ patients is often observed by the CT examination. Tssshe purpose of this study was to investigate the relationship between periosteal reaction and treatment outcome of MRONJ. A total of 164 surgeries in 136 patients with MRONJ at two hospitals were included in the study. Correlations between various clinical and radiographic factors and treatment outcome were examined with Cox regression analysis. The results showed that the presence of periosteal reaction, as well as primary disease involving malignant tumor, were independent risk factors related to poor outcome. Furthermore, we examined factors related to the occurrence of the periosteal reaction and found that 4 variables were significantly correlated with periosteal reaction by multivariate analysis: gender (female), site (lower jaw), primary disease (malignant tumor), and osteosclerosis (severe). The present study clarified that the cure rate after surgical treatment decreased in cases with periosteal reaction, suggesting that it is necessary to review the treatment method.

Multicenter Retrospective Study of the Risk Factors of Hemorrhage After Tooth Extraction in Patients Receiving Antiplatelet Therapy.

PURPOSE: To identify the risk factors affecting hemorrhage after tooth extraction in patients receiving antiplatelet therapy, this study investigated the relation between various factors and hemorrhage events after tooth extraction. PATIENTS AND METHODS: The records of 264 patients receiving antiplatelet therapy who underwent tooth extraction were retrospectively reviewed from 6 institutions belonging to the Japanese Study Group of Cooperative Dentistry with Medicine. Demographic information, hemorrhage events after tooth extraction, the presence or absence of comorbidities, antiplatelet agent, the use of preoperative antibiotics or nonsteroidal anti-inflammatory drugs, number of teeth extracted, serum creatinine level, estimated glomerular filtration rate, and alanine transaminase level were assessed. Risk factors for hemorrhage after tooth extraction were evaluated by univariate and multivariate analyses. RESULTS: The study population of 264 patients consisted of 153 men and 111 women with a mean age of 73.6 years (range, 24 to 96 yr). Six hundred ninety-four teeth were extracted (mean, 2.6 ± 2.3 teeth per patient). In patients receiving antiplatelet therapy, the frequency of hemorrhage after tooth extraction, including mild and self-controlled hemorrhages, was 17.4%. Univariate analysis showed that serum creatinine level and dual antiplatelet therapy were correlated with hemorrhage after tooth extraction (P = .001 and P = .049, respectively). Only serum creatinine was identified as an independent risk factor for hemorrhage after tooth extraction in patients receiving antiplatelet therapy (P = .037). CONCLUSIONS: The risk of hemorrhage after tooth extraction is increased in patients receiving dual antiplatelet therapy with or without chronic kidney disease. Local hemostatic treatments, such as at least suturing, are recommended.

A Lytic Polysaccharide Monooxygenase with Broad Xyloglucan Specificity from the Brown-Rot Fungus Gloeophyllum trabeum and Its Action on Cellulose-Xyloglucan Complexes.

Fungi secrete a set of glycoside hydrolases and lytic polysaccharide monooxygenases (LPMOs) to degrade plant polysaccharides. Brown-rot fungi, such as Gloeophyllum trabeum, tend to have few LPMOs, and information on these enzymes is scarce. The genome of G. trabeum encodes four auxiliary activity 9 (AA9) LPMOs (GtLPMO9s), whose coding sequences were amplified from cDNA. Due to alternative splicing, two variants of GtLPMO9A seem to be produced, a single-domain variant, GtLPMO9A-1, and a longer variant, GtLPMO9A-2, which contains a C-terminal domain comprising approximately 55 residues without a predicted function. We have overexpressed the phylogenetically distinct GtLPMO9A-2 in Pichia pastoris and investigated its properties. Standard analyses using high-performance anion-exchange chromatography-pulsed amperometric detection (HPAEC-PAD) and mass spectrometry (MS) showed that GtLPMO9A-2 is active on cellulose, carboxymethyl cellulose, and xyloglucan. Importantly, compared to other known xyloglucan-active LPMOs, GtLPMO9A-2 has broad specificity, cleaving at any position along the ß-glucan backbone of xyloglucan, regardless of substitutions. Using dynamic viscosity measurements to compare the hemicellulolytic action of GtLPMO9A-2 to that of a well-characterized hemicellulolytic LPMO, NcLPMO9C from Neurospora crassa revealed that GtLPMO9A-2 is more efficient in depolymerizing xyloglucan. These measurements also revealed minor activity on glucomannan that could not be detected by the analysis of soluble products by HPAEC-PAD and MS and that was lower than the activity of NcLPMO9C. Experiments with copolymeric substrates showed an inhibitory effect of hemicellulose coating on cellulolytic LPMO activity and did not reveal additional activities of GtLPMO9A-2. These results provide insight into the LPMO potential of G. trabeum and provide a novel sensitive method, a measurement of dynamic viscosity, for monitoring LPMO activity. IMPORTANCE: Currently, there are only a few methods available to analyze end products of lytic polysaccharide monooxygenase (LPMO) activity, the most common ones being liquid chromatography and mass spectrometry. Here, we present an alternative and sensitive method based on measurement of dynamic viscosity for real-time continuous monitoring of LPMO activity in the presence of water-soluble hemicelluloses, such as xyloglucan. We have used both these novel and existing analytical methods to characterize a xyloglucan-active LPMO from a brown-rot fungus. This enzyme, GtLPMO9A-2, differs from previously characterized LPMOs in having broad substrate specificity, enabling almost random cleavage of the xyloglucan backbone. GtLPMO9A-2 acts preferentially on free xyloglucan, suggesting a preference for xyloglucan chains that tether cellulose fibers together. The xyloglucan-degrading potential of GtLPMO9A-2 suggests a role in decreasing wood strength at the initial stage of brown rot through degradation of the primary cell wall.

Pathogenesis of Medication-Related Osteonecrosis of the Jaw: Odontogenic Infection-Preceding Type and Osteonecrosis-Preceding Type.

Introduction Medication-related osteonecrosis of the jaw (MRONJ) develops from odontogenic infection. However, there are also some cases of MRONJ developing from sites with no teeth, no root canal lesions, or no periodontal disease. This study aimed to retrospectively review radiographic images of MRONJ cases and examine the differences in characteristics between MRONJ suspected to be related to dental infection (odontogenic MRONJ) and MRONJ that occurred without dental involvement or of unknown cause (non-odontogenic MRONJ). Materials and methods One hundred and forty-five patients were diagnosed with MRONJ at Kansai Medical University Hospital and Kansai Medical University Medical Center. The following variables were investigated: sex, age, primary disease, MRONJ site, body mass index, smoking habit, diabetes, corticosteroids, type of antiresorptive agent, administration period, CT findings (separation of sequestrum, osteolysis, periosteal reaction, and osteosclerosis), trigger, leukocytes, neutrocytes, neutrophil-lymphocyte ratio, serum albumin, and serum creatinine levels. Results In the univariate analysis, significant differences between odontogenic and non-odontogenic MRONJs were found in patients whose primary disease was malignancy, receiving denosumab (DMB), and with short administration period of antiresorptive agent, no osteolysis, periosteal reaction, and serum creatinine level. In multivariate analysis, non-odontogenic MRONJ was significantly more common in patients with no osteolysis and with periosteal reaction. Conclusion Non-odontogenic MRONJ tends to occur more frequently in patients treated with high-dose DMB, and there were significantly more cases of non-osteolytic MRONJ without radiographic evidence of osteolysis or with periosteal reactions.

Postoperative Recurrence of Medication-Related Osteonecrosis of the Jaw: A Retrospective Study of 150 Patients Undergoing Surgery.

Introduction Surgery is the recommended treatment for medication-related osteonecrosis of the jaw (MRONJ). However, the disease may recur postoperatively. We reviewed imaging findings in patients undergoing three or more surgeries. Patients and methods One hundred fifty patients with MRONJ underwent surgery at our hospital. Here, we present the characteristics of 34 surgeries in nine patients (two men and seven women; mean age, 73.9 years) who underwent surgery at least three times. Results Three and six patients had maxillary and mandibular lesions, respectively. The primary disease was malignancy in eight patients, and denosumab was used in seven patients. All patients initially underwent either partial maxillectomy or marginal mandibulectomy, and segmental mandibulectomy was not performed. The number of surgeries ranged from three to six (average, 3.8). Healing was eventually achieved in seven cases, but not in two cases. Of the 27 unsuccessful surgeries, postoperative cone-beam computed tomography revealed no residual osteolysis, periosteal reaction, or osteosclerosis after seven surgeries and some residual lesions after 19 surgeries; imaging was not performed after one surgery. In contrast, among the seven successful surgeries, no residual osteolysis, periosteal reaction, or osteosclerosis was observed in all six cases in which postoperative computed tomography was performed. Conclusion Recurrence is more common in patients with residual areas of osteolysis, periosteal reactions, or mixed-type osteosclerosis, and including these areas in the resection is desirable.

Effect of oral function and postoperative eating patterns on salivary bacterial counts in gastrointestinal tract surgery patients: A preliminary study.

Background/purpose: Perioperative oral care is widely provided to prevent postoperative pneumonia and surgical site infections in patients undergoing surgery under general anesthesia. However, there is a lack of clarity regarding the kind of oral care that should be provided for different patients. The purpose of this study was to clarify the factors that influence the increase in salivary bacterial counts before and after gastrointestinal surgery to identify patients with a particular need for oral care. Materials and methods: Twenty patients undergoing gastrointestinal surgery were examined before surgery for denture use, number of remaining teeth, regular dental care, Oral Hygiene Index-Simplfied tongue coating, tongue pressure, bite pressure, masticatory efficiency, and dry mouth. Saliva samples were collected before surgery, in the fasting period after surgery, and in the oral feeding period. Total bacterial counts were determined by real-time PCR, and factors associated with bacterial counts were investigated. Results: Patients with decreased oral functions, such as tongue pressure, bite pressure, and masticatory efficiency, tended to have higher salivary bacterial counts in the preoperative, fasting, and oral feeding periods. Regarding the pre- and postoperative changes, salivary bacterial counts increased in the fasting period compared to the pre-operative period and returned to preoperative values in the oral feeding period. Conclusion: Perioperative oral care is important for patients with reduced oral function because the number of bacteria in saliva tends to be higher in such patients. As the number of bacteria in saliva increases during the fasting period, oral care is important, and oral feeding should be restarted as soon as possible.

Efficacy of perioperative oral care management in the prevention of surgical complications in 503 patients after pancreaticoduodenectomy for resectable malignant tumor: A multicenter retrospective analysis using propensity score matching.

BACKGROUND: Pancreaticoduodenectomy has been associated with a high mortality rate and significant postoperative morbidity. Recently, perioperative oral care management has been reported to be effective in preventing postoperative pneumonia and surgical site infection. In this study, we examined the effect of perioperative oral care management in reducing complications after pancreaticoduodenectomy, including surgical site infection. METHODS: This retrospective multicenter study included 503 patients who underwent pancreaticoduodenectomy at 8 facilities between January 2014 and December 2016. Among these, 144 received perioperative oral management by dentists and dental hygienists (oral management group), whereas the remaining 359 did not (control group). The oral care management program included oral health instructions, removal of dental calculus, professional mechanical tooth cleaning, removal of tongue coating, denture cleaning, instructions for gargling, and tooth extraction. The participants were matched using propensity scores to reduce background bias. Various factors were examined for correlation with the development of complications. RESULTS: The incidence of organ/space surgical site infection was significantly lower in the oral management group than in the control group (8.0% vs 19.6%, P = .005). Multivariable logistic regression analysis revealed that hypertension and lack of perioperative oral management were independent risk factors for organ/space surgical site infection. Lack of perioperative oral management had an odds ratio of 2.847 (95% confidence interval 1.335-6.071, P = .007). CONCLUSION: Perioperative oral care management reduces the occurrence of surgical site infections after pancreaticoduodenectomy and should be recommended as a strategy to prevent infections in addition to antibiotic use.

Medication-related osteonecrosis of the jaw without osteolysis on computed tomography: a retrospective and observational study.

Medication-related osteonecrosis of the jaw (MRONJ) is a refractory osteonecrosis caused by antiresorptive agents such as bisphosphonate and denosumab (DMB). In MRONJ surgery, computed tomography (CT) is generally used to determine the extent of bone resection. However, in some recent MRONJ cases, no abnormal findings were detected on CT. Therefore, we aimed to clarify the characteristics of MRONJ without osteolysis. This retrospective and observational study included 18 patients diagnosed with MRONJ between October 2020 and October 2022 at Department of Dentistry and Oral Surgery, Kansai Medical University Medical Center. In four of 18 patients with MRONJ, no abnormal findings such as osteolysis, separation of sequestrum, and periosteal reaction were observed on CT images at the first visit. All four patients with non-osteolytic MRONJ had malignant tumors and received high-dose DMB, and in the four patients there were no preceding dental infections such as apical lesions or periodontal disease and the trigger of MRONJ was unknown. Surgery was performed in three of the four patients. The extent of bone resection was determined using magnetic resonance imaging and intraoperative gross findings. In the future, it is necessary to establish a method for diagnosing non osteolytic MRONJ and determining the extent of bone resection.

Drug holiday of high-dose denosumab and recovery from osteoclast inhibition using immunohistochemical investigation of 7 patients with medication-related osteonecrosis of the jaw undergoing segmental mandibulectomy.

Background/purpose: Denosumab is used to treat bone metastases from malignant tumors. Unlike bisphosphonates, denosumab is not deposited in the bone; thus, withdrawal for a relatively short period would help recovery from osteoclast suppression. This study investigated the relationship between drug holidays and recovery from osteoclast suppression. Materials and methods: Seven patients who received high-dose denosumab and underwent segmental mandibulectomy for medication-related osteonecrosis of the jaw were enrolled in this study. Osteoclast suppression (+) was defined as the absence of cathepsin K-positive cells or cathepsin K-positive mononuclear or small multinucleated cells observed on the bone surface of both mesial and distal specimens. When normal osteoclasts were found, osteoclast suppression was defined as (-); when both suppressed cathepsin K-positive cells and normal morphological osteoclasts were found, it was defined as (±). Results: Osteoclast suppression was: (+) in four patients, three without a drug holiday and one with a 9-month drug holiday; (±) in one patient with an 8-month drug holiday, and (-) in two patients with drug holidays for 13 and 20 months. Conclusion: These findings suggest that a long-term drug holiday, such as 12 months, is required for recovery from osteoclast suppression in patients with cancer receiving high-dose denosumab.

Adenoid Ameloblastoma with BRAF p.V600E Mutation Revealing Ameloblastomatous Origin: A First Case Report.

BACKGROUND: Adenoid ameloblastoma (AdAM) is a frequently recurrent tumor that shows hybrid histological features of both ameloblastoma and adenomatoid odontogenic tumor (AOT). AdAM is expected to be classified as a new subtype of ameloblastoma in the next revision of the World Health Organization (WHO) odontogenic tumor classification. However, whether AdAM is a histologic variant of ameloblastoma or AOT remains unclear. To establish a new category, genetic evidence indicating the tumor category is necessary. METHODS: We present a case of a 23-year-old Japanese woman with AdAM who underwent genetic/DNA analysis for ameloblastoma-related mutation using immunohistochemical staining, Sanger sequencing, and next-generation sequencing (NGS) analyses with reliable clinicopathological evidence. RESULTS: Immunohistochemical expression of BRAF p.V600E was diffusely positive for both ameloblastoma- and AOT-like components. Sanger sequencing and NGS analyses showed missense mutations in BRAF p.V600E (c.1799T > A), a gene that is commonly altered in ameloblastomas but not in KRAS, another gene associated with AOT. CONCLUSION: This case report is the first to provide genetic evidence on the ameloblastomatous origin of AdAM with a BRAF p.V600E mutation. A larger series of AdAM groups' molecular testing is needed to aptly classify them and prognosticate the best treatment.

Number of Bacteria in Saliva in the Perioperative Period and Factors Associated with Increased Numbers.

Perioperative oral management is performed to prevent postoperative complications, but its indication and management method are unclear. This study aimed to investigate salivary bacterial counts pre-and postoperatively, and factors related to increased bacterial count postoperatively. We included 121 patients who underwent surgery under general anesthesia and perioperative oral management. The bacterial count in saliva was determined preoperatively, and first and seventh days postoperatively using the dielectrophoresis and impedance measurement methods. The relationships between salivary bacterial count and various variables were analyzed using one-way analysis of variance, Spearman's rank correlation coefficient, and multiple regression analysis. The salivary bacterial count increased significantly on the first day postoperatively but decreased on the seventh day. Multivariate analysis showed that age (p = 0.004, standardized coefficient ß = 0.283) and xerostomia (p = 0.034, standardized coefficient ß = 0.192) were significantly correlated with increased salivary bacterial count preoperatively. Salivary bacterial count on the day after surgery was significantly increased in patients with a large number of bacterial counts on the day before surgery after preoperative oral care (p = 0.007, standardized coefficient ß = 0.241) and postoperative fasting (p = 0.001, standardized coefficient ß = -0.329). Establishing good oral hygiene before surgery and decreasing salivary bacterial count are necessary in patients with a high risk of postoperative surgical site infection or pneumonia, especially in older adults or postoperative fasting.

Factors Exacerbating Clinical Symptoms and CT Findings in Patients with Medication-Related Osteonecrosis of the Jaw Receiving Conservative Therapy: A Multicenter Retrospective Study of 53 Cases.

Recent reports have shown that better treatment outcomes are obtained with surgical therapy in patients with medication-related osteonecrosis of the jaw (MRONJ) than with conservative therapy. However, conservative treatment is selected due to factors such as old age and poor general condition. Conservative therapy aims to relieve symptoms and prevent lesion exacerbation; however, the lesion may expand rapidly in some cases. This study investigated the clinical and imaging findings of 53 MRONJ patients undergoing conservative therapy, and the changes in the clinical findings and the lesion enlargement on CT imaging were examined. Improved clinical findings and no worsening of the imaging findings were considered overall comprehensive treatment successes. Among the 53 patients, the clinical symptoms disappeared or improved in 15 patients, whereas they worsened in 6. In contrast, osteolytic lesion enlargement occurred in 17 patients. The comprehensive treatment outcome of conservative therapy was successful in 12 patients and unsuccessful in 41 patients. The periosteal reaction was significantly correlated with poor comprehensive treatment outcomes (p = 0.038). MRONJ lesions may advance, even if they appear to improve clinically while undergoing conservative treatments. Patients, especially those with periosteal reactions, must be closely followed up with CT examinations, regardless of the clinical findings.

Effect of decreased tongue pressure on dysphagia and survival rate in elderly people requiring long-term care.

Background/purpose: Tongue pressure plays an important role in swallowing function. The purpose of this study is to investigate whether decreased tongue pressure is associated with dysphagia and the development of pneumonia in the elderly requiring long-term care. Materials and methods: Tongue pressure measurement and swallowing videoendoscopic (VE) examination were performed in 60 hospitalized elderly people (33 males and 27 females, with an average age of 84.3 years) to investigate the relationship with the clinical course. Factors related with dysphagia was analyzed by Fisher's exact test and one-way ANOVA, followed by multivariate logistic regression. The relationship between each variable and survival were analyzed by cox regression. Results: Twenty-one patients had dysphagia by VE examination. Multivariate analysis showed that smaller BMI and reduced tongue pressure were significantly correlated with dysphagia. Smaller number of remaining teeth and dysphagia were significantly related to pneumonia-related death. No patients with tongue pressure of larger than 20 kpa died by pneumonia within one year, while in those with tongue pressure of smaller than 20 kpa, one-year cumulative survival rate by pneumonia was 44.3%. Conclusion: Decreased tongue pressure was significantly associated with dysphagia and may increase the risk of pneumonia-related death in the elderly requiring long-term care.

Risk factors for osteoradionecrosis of the jaw in patients with oral or oropharyngeal cancer: Verification of the effect of tooth extraction before radiotherapy using propensity score matching analysis.

Background/purpose: Osteoradionecrosis of the jaw (ORN) often occurs in patients with head and neck cancer undergoing radiotherapy (RT). It has been recommended to extract the tooth before RT that may become source of infection, but in recent years, some investigators have reported that tooth extraction before RT increase the risk of developing ORN and therefore should be avoided. The purpose of the study is to evaluate the risk factors for ORN including tooth extraction before RT. Materials and methods: This was a retrospective study of 366 patients with oral or oropharyngeal cancer who underwent RT of 50 Gy or more at six university hospitals, with follow-up of at least six months post-RT. The relationship between each factor and ORN incidence was analyzed using the Cox proportional hazard model. Results: Periapical lesions, more than 50% loss of alveolar bone, and tooth extraction after RT significantly correlated with ORN. Intensity-modulated RT showed a lower incidence than three-dimensional conformal RT, although not statistically different. Tooth extraction before RT significantly reduced ORN incidence, after adjusting the background factors using propensity score matching. Conclusion: In patients with oral or oropharyngeal cancer who underwent RT, periapical lesions, more than 50% loss of alveolar bone, and tooth extraction after RT significantly increased the risk for ORN. Infected tooth extraction before RT significantly reduced the risk.

Relationship between Drug Holidays of Antiresorptive Agents and Surgical Outcomes in Cancer Patients with Medication-Related Osteonecrosis of the Jaw.

It is controversial as to whether the withdrawal of antiresorptive (AR) agents is necessary while treating medication-related osteonecrosis of the jaw (MRONJ). In this study, we investigated whether a drug holiday promoted sequestrum separation and improved the surgical outcomes of MRONJ patients with malignant tumors, who were undergoing high-dose AR therapy. In total, we included 103 MRONJ patients with malignant tumors as their primary disease who underwent surgery at Nagasaki University Hospital or Kansai Medical University Hospital from January 2009 to December 2020. We recorded the patients' age, sex, primary disease, MRONJ stage, type and administration period of the AR agent, presence of diabetes, corticosteroid use, drug holiday period, white blood cell count, serum albumin, serum creatinine, outcomes, and computed tomography findings. The relationships between a drug holiday and sequestrum separation, and between a drug holiday and outcome, were analyzed. Drug holidays of 60, 90, and 120 days were not significant factors of sequestrum separation and did not influence patients' surgical outcomes as per the univariate and multivariate analyses. MRONJ patients with cancer as their primary disease should be operated upon immediately and without drug holidays if their general condition permits surgery.