What Is the Appropriate Antibiotic Administration During Tooth Extractions in Patients Receiving High-Dose Denosumab?

PURPOSE: Medication-related osteonecrosis of the jaw (MRONJ) occasionally occurs following tooth extractions in cancer patients receiving denosumab (Dmab). However, there are currently no established guidelines for perioperative antibiotic administration during tooth extraction in these patients. The primary objective was to develop guidelines for the dose and frequency of antibiotics during tooth extraction by investigating the correlation between the current status of antibiotic administration and the development of MRONJ. METHODS: This study included 68 cancer patients receiving high-dose Dmab who had tooth extractions between 2012 and 2022 at 10 hospitals. The relationship between the way of perioperative antibiotic administration and the development of MRONJ was analyzed. A P-value < .05 was considered significant. RESULTS: There was considerable variability across hospitals and surgeons regarding the type, dosage, and duration of antibiotic administration. Amoxicillin (AMPC) was the most commonly used antibiotic. Focusing exclusively on teeth extracted under AMPC administration, MRONJ developed in 21 out of 123 teeth (17.0%). No significant relationship was found between the development of MRONJ and the dosage or duration of perioperative AMPC administration. CONCLUSION: Perioperative antibiotic administration alone may not be sufficient to prevent MRONJ. Therefore, a single preoperative dose is likely adequate for effective and appropriate AMPC administration.　.

Effect of Statins on Patients With Osteoradionecrosis of the Jaw.

BACKGROUND: Osteoradionecrosis of the jaw (ORN) is a late complication of radiation therapy. Radiation-induced fibrosis is the most likely mechanism for developing ORN, and statins are effective against radiation-induced fibrosis. However, no reports have indicated the direct effectiveness of statins in treating ORN. PURPOSE: This study aimed to measure the association between statin exposure and ORN disease resolution. STUDY DESIGN, SETTING, SAMPLE: This retrospective cohort study included patients with ORN diagnosed between January 2008 and December 2020 at the Hospital's Department of Oral and Maxillofacial Surgery. Patients who were immunocompromised or followed up for < 6 months were excluded. PREDICTOR VARIABLE: The predictor variable was statin exposure, which was defined as the use of statins for dyslipidemia. MAIN OUTCOME VARIABLE: The main outcome variable was ORN disease progression status (good prognosis). Patients who showed full recovery and improvement were included in the good prognosis group, and those who showed invariance and deterioration were included in the poor prognosis group. COVARIATES: We analyzed the clinicodemographic including the age of onset, sex, history of smoking, alcohol consumption, history of chemotherapy, tumor site, association with dental treatment, location (maxilla or mandible), the time to ORN onset from radiation therapy, and stage of ORN, and treatment characteristics including hyperbaric oxygen therapy, long-term macrolide administration, and sequestrectomy. ANALYSES: We analyzed the association between statin exposure or covariates and time to ORN improvement using bivariate and multivariate Cox regression. The significance level was set at P = .05. RESULTS: We analyzed 102 patients, and the improvement rate was 32.4%. The favorable prognostic factors were statin exposure (adjusted hazard ratio [HR], 3.71; 95% confidence interval [CI], 1.62 to 8.50; P = .002), onset in the maxilla (HR, 2.15; 95% CI, 1.02 to 4.55; P = .045), and stage 1 of ORN (HR, 2.65; 95% CI, 1.20 to 5.83; P = .016). CONCLUSION AND RELEVANCE: In this study, statin exposure, onset in the maxilla, and stage 1 of Lyons's classification were favorable prognostic factors for ORN. Although this study's findings were insufficient to recommend statin use for ORN, statins may be a novel and effective treatment for ORN.

Incidence of antiresorptive agent-related osteonecrosis of the jaw: A multicenter retrospective epidemiological study in Hyogo Prefecture, Japan.

Background/purpose: The incidence of medication-related osteonecrosis of the jaw is increasing worldwide, mostly due to the use of antiresorptive agents (ARAs) such as bisphosphonate (BP) and denosumab (Dmab). However, the proportion of BP-related osteonecrosis of the jaw (BRONJ) and Dmab-related osteonecrosis of the jaw (DRONJ) among all ARA-related osteonecrosis of the jaw (ARONJ) cases is not clear; this hinders appropriate treatment, recurrence-prevention planning, and avoidance of unnecessary Dmab withdrawal. Moreover, the causative drug administered at each disease stage remains unknown. Therefore, we conducted a retrospective study of patients with ARONJ who visited oral and maxillofacial surgery departments at hospitals in Hyogo Prefecture, Japan, over 3 years to classify and compare patient characteristics with those having BRONJ and DRONJ. We sought to identify the proportion of DRONJ in ARONJ. Materials and methods: After excluding stage 0 patients, 1021 patients were included (471 high-dose; 560 low-dose). ARA treatment for bone metastases of malignant tumors and multiple myeloma was considered high dose, while that for cancer treatment-induced bone loss and osteoporosis was low dose. Results: Low doses of BP and Dmab accounted for >50% patients; the results differed from those in other countries. DRONJ accounted for 58% and 35% of high-dose and low-dose cases, respectively. Stage 3 ARONJ cases comprised 92 (19.5%) low-dose BRONJ, 39 (20.1%) high-dose BRONJ, 24 (30%) low-dose DRONJ, and 68 (24.5%) high-dose DRONJ. Eighty-nine patients who received switch therapy were divided into BRONJ or DRONJ, but there was no difference in the ratio of each stage compared to the non-switch therapy. Conclusion: To the best of our knowledge, this is the first study to clarify the proportion of BRONJ and DRONJ cases, causative drug, and its doses by disease stages. DRONJ accounted for approximately 30% of the ARONJ, approximately 60% of which was due to high doses.

The characteristics of oro-cervical necrotizing fasciitis-Comparison with severe cellulitis of oro-cervical region and necrotizing fasciitis of other body regions.

BACKGROUND: Necrotizing fasciitis (NF) is an acute and life-threatening soft-tissue infection however rarely seen in oro-cervical region. Therefore, the details of oro-cervical NF (OCNF) are not well known. The purpose of this study was to investigate the characteristics of OCNF by comparing it with severe cellulitis of oro-cervical region (OCSC) or NF of other body regions (e.g., limb, perineum, and trunk) (BNF), respectively. MATERIALS AND METHODS: At first, various risk factors for OCNF in oro-cervical severe infection (OCSI; composed of OCNF and OCSC), including neutrophil-to-lymphocyte ratio (NLR) and Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score, were investigated by univariate and multivariate analyses. Next, the differences between OCNF and BNF, including inflammatory markers and mortality, were investigated. RESULTS: In the present study, 14 out of 231 OCSI patients had OCNF. Multivariate analyses of OCSI patients showed that NLR ≥15.3 and LRINEC score ≥6 points were significantly related to OCNF. During the same period, 17 patients had BNF. The OCNF group had significantly higher inflammatory markers than the BNF group when diagnosis, but significantly lower clinical stages at the time and mortality as outcomes. CONCLUSION: We found that compared to BNF, OCNF can be detected at lower clinical stage by using indexes, such as NLR and LRINEC score, besides clinical findings, which may help contributing to patient's relief.

Usefulness of Quantitative Bone SPECT/CT for Evaluating Treatment Response in a Patient with Mandibular Osteomyelitis.

We report here a case of mandibular osteomyelitis in a 63-year-old female in which quantitative values determined using bone SPECT/CT were useful to evaluate response to antibiotic therapy, hyperbaric oxygen therapy, and sequestomy. After finishing therapy, the chief complaints were well relieved, and posttreatment Tc-99m HMDP bone SPECT/CT examination showed decreased uptake. The maximum standardized uptake value (SUV), peak SUV, mean SUV, metabolic bone volume, and total bone uptake of the untreated lesion were 6.26, 5.16, 3.97, and 11.86 mL and 42.21, respectively, which were decreased to 4.65, 3.90, 2.77, and 9.67 mL and 26.80, respectively, following hyperbaric oxygen therapy and antibiotic administration, and were moreover decreased to 4.28, 3.67, 2.75, and 6.24 mL and 17.19, respectively, after sequestomy. In comparison with pretreatment situation, those parameters were decreased by -25.7, -24.4, -30.2, -18.5, and -36.5%, respectively, following hyperbaric oxygen therapy and antibiotic administration, and moreover by -31.6, -28.9, -30.7, -47.4, and -59.3, respectively, after sequestomy, likely reflecting treatment response. Quantitative bone SPECT/CT may be useful to evaluate bone inflammatory activity and treatment response in a patient with mandibular osteomyelitis.

Effect of educational intervention on the appropriate use of oral antimicrobials in oral and maxillofacial surgery: a retrospective secondary data analysis.

BACKGROUND: In Japan, oral third-generation cephalosporins with broad-spectrum activity are commonly prescribed in the practices of dentistry and oral surgery. However, there are few reports on the appropriate use of antibiotics in the field of oral surgery. This study aimed to evaluate the appropriateness of antibiotic use before and after an educational intervention in the Department of Oral and Maxillofacial Surgery, Kobe University Hospital. METHODS: The use of oral antibiotics was investigated among inpatients and outpatients before and after an educational intervention conducted by the antimicrobial stewardship team. Additionally, the frequency of surgical site infection after the surgical removal of an impacted third mandibular molar under general anesthesia and the prevalence of adverse effects of the prescribed antibiotics were comparatively evaluated between 2013 and 2018. RESULTS: After the educational intervention, a remarkable reduction was noted in the prescription of oral third-generation cephalosporins, but increased use of penicillins was noted among outpatients. There was reduced use of macrolides and quinolones in outpatients. Although a similar trend was seen for inpatients, the use of quinolones increased in this population. Despite the change in the pattern of antibiotic prescription, inpatients who underwent mandibular third molar extraction between 2013 and 2018 did not show a significant increase in the prevalence of surgical site infections (6.2% vs. 1.8%, p = .336) and adverse effects of drugs (2.1% vs. 0%, p = .466). CONCLUSIONS: This study suggests that the judicious use of oral antibiotics is possible through conscious and habitual practice of appropriate antibiotic use. However, further investigation is required to develop measures for appropriate use of oral antibiotics.

Antimicrobial susceptibility surveillance of bacterial isolates recovered in Japan from odontogenic infections in 2013.

We report on the findings of the first antimicrobial susceptibility surveillance study in Japan of isolates recovered from odontogenic infections. Of the 38 facilities where patients representing the 4 groups of odontogenic infections were seen, 102 samples were collected from cases of periodontitis (group 1), 6 samples from pericoronitis (group 2), 84 samples from jaw inflammation (group 3) and 54 samples from phlegmon of the jaw bone area (group 4) for a total of 246 samples. The positivity rates of bacterial growth on culture were 85.3%, 100%, 84% and 88.9%, respectively, for groups 1, 2, 3 and 4. Streptococcus spp. isolation rates according to odontogenic infection group were 22% (group 1), 17.7% (group 3) and 20.7% (group 4). Anaerobic isolation rates were 66.9% (group 1), 71.8% (group 3) and 68.2% (group 4). Drug susceptibility tests were performed on 726 strains excluding 121 strains that were undergrown. The breakdown of the strains subjected to testing was 186 Streptococcus spp., 179 anaerobic gram-positive cocci, 246 Prevotella spp., 27 Porphyromonas spp., and 88 Fusobacterium spp. The isolates were tested against 30 antimicrobial agents. Sensitivities to penicillins and cephems were good except for Prevotella spp. The low sensitivities of Prevotella spp is due to ß-lactamase production. Prevotella strains resistant to macrolides, quinolones, and clindamycin were found. No strains resistant to carbapenems or penems were found among all strains tested. No anaerobic bacterial strain was resistant to metronidazole. Antimicrobial susceptibility testing performed on the S. anginosus group and anaerobic bacteria, which are the major pathogens associated with odontogenic infections, showed low MIC90 values to the penicillins which are the first-line antimicrobial agents for odontogenic infections; however, for Prevotella spp., penicillins combined with ß-lactamase inhibitor showed low MIC90 values.

Which symptoms negatively affect the oral health-related quality of life in patients with osteonecrosis of the jaw?

OBJECTIVES: One of the treatment goals for osteonecrotic lesions of the jaw, such as medication-related osteonecrosis of the jaw (MRONJ) or osteoradionecrosis (ORN), is restoration of quality of life (QOL). This study aimed to identify symptoms that negatively affect QOL in patients with unhealed MRONJ or ORN. STUDY DESIGN: This cross-sectional study included patients who were previously diagnosed with MRONJ or ORN and who underwent treatment at the Kobe University Hospital between June 2015 and February 2016. Patient QOL was measured by using the Oral Health Impact Profile (OHIP-14). The predictor variable was disease status (stage and healing). The outcome variable was OHIP-14. One-way analysis of variance and Tukey's test were performed. RESULTS: The study included 74 patients (37 men and 37 women; mean age 70 years). Although there was no significant difference between the OHIP-14 scores of unhealed MRONJ and ORN (stages 1-3) and those of healed ones, the "worsened sense of taste" resulted in significant differences among stages in patients with unhealed MRONJ (P = .027) and the "painful mouth aching" in patients with unhealed ORN (P = .041). CONCLUSIONS: Worsened sense of taste and pain negatively affected QOL in patients with unhealed MRONJ and ORN.

Effect of low-intensity pulsed ultrasound after intraoral vertical ramus osteotomy.

OBJECTIVE: The present study investigated the effect of low-intensity pulsed ultrasound (LIPUS) on long-term osseous healing of the cleavage space between bone fragments after intraoral vertical ramus osteotomy (IVRO). STUDY DESIGN: Patients undergoing IVRO were randomly assigned to the LIPUS group (n = 12) or the control group (n = 9) after surgery. LIPUS treatments were applied daily to the cleavage space between bone fragments for 3 weeks. We observed 3-dimensional quantitative color mapping of the whole mandible created by computed tomography (CT) data at 1 month, 6 months, and 1 year postoperatively. On the basis of CT values, the color grades were classified as D1 to D5 by using the Misch criteria. We then calculated mean CT values and rated each color grade in different selection ranges. RESULTS: The mean CT values of the LIPUS group were significantly higher than those of the control group at 1 month, 6 months and 1 year postoperatively (P < .01). The color grades of the cleavage between bone fragments increased from D5 to D1 over time. CONCLUSIONS: Our results indicated that LIPUS promoted osseous healing after IVRO, thus improving bone density and offering clinical benefits.

Effect of size difference between hemiglossectomy and reconstruction flap on oral functions: A retrospective cohort study.

BACKGROUND AND OBJECTIVE: Forearm free flaps are used after hemiglossectomy. However, no investigation has been performed on whether oral functions are better preserved when sizes of the resection and reconstruction flap are exact matches, or whether the size of the resection should be changed. We aimed to retrospectively examine whether size differences between the resection and reconstruction flap affect speech and swallowing functions postoperatively, and to determine whether there are more favorable flap size ratios. METHODS: This is a retrospective cohort study of patients undergoing hemiglossectomy using a forearm free flap between 2006 and 2016 at Kobe University Hospital, Japan. The effect of size difference between the resection and reconstruction flap on maintained oral function was assessed. Speech and swallowing functions were assessed, and their correlation with the ratio of the flap size to that of the resected area was determined. With these data, distribution maps of the relationship between the functional level and reconstructed dimension ratio were prepared. The more suitable reconstructed dimension ratio was examined and evaluated. The Fisher exact test, Kruskal-Wallis test, and Scheffe test were used in statistical analyses. RESULTS: Eighty-eight patients underwent hemiglossectomy using a forearm free flap during a 10-year period. Of these cases, 66 patients were included in this study, while 22 were excluded. The ratio of the area of the reconstruction flap to that of the resection site was 0.59-2.79 (median: 1.61). Sixty patients had flaps greater than the resection area, whereas 6 had smaller flaps. Significant differences were found in speech intelligibility and swallowing function when the reconstructed dimension ratio was categorized as follows: ≤1.3, 1.3-1.8, and ≥1.8. CONCLUSION: Our findings suggest that postoperative deterioration of oral functions after hemiglossectomy could be reduced if reconstruction is performed using a forearm free flap with a surface area 1.3 to 1.8 times greater than that of the resection area.

Long-Term Effects on Volume Change in Musculocutaneous Flaps after Head and Neck Reconstruction.

OBJECTIVE: Musculocutaneous flap reconstruction surgery is one of the standard procedures following head and neck cancer resection. However, no previous studies have classified flaps in terms of muscle and fat or examined them after long-term follow-up. The purpose of this study was to estimate the fat and muscle volume changes in musculocutaneous flaps during long-term follow-up. METHODS: We conducted a retrospective analysis of 35 patients after musculocutaneous flap reconstruction. The total, fat, and muscle volumes of the musculocutaneous flaps were measured using 3-dimensional images. Changes in flap volumes over time (1 month, 1 year [POY1], and 5 years [POY5] postoperatively) were assessed. Flap persistence was calculated using flap volumes at 1 month after reconstruction for reference. RESULTS: Flap persistence at POY5 was 42.0% in total, 64.1% in fat, and 25.4% in muscle. Muscle persistence was significantly decreased (p < 0.0001). In a multiple regression analysis, decreased body mass index (BMI) of ≥ 5% influenced fat persistence less than muscle persistence at POY1; however, there was no significant difference at POY5. Postoperative radiation therapy was associated with a significant decrease in total flap persistence at POY1 (p = 0.046) and POY5 (p = 0.0097). Muscle persistence significantly decreased at POY5 (p = 0.0108). Age significantly influenced muscle volume at POY1 (p = 0.0072). CONCLUSION: Reconstruction flaps are well-preserved with high fat-to-muscle ratios. Recommendations for weight maintenance are necessary for patients less than 2 years after surgery due to the influence of BMI on fat persistence. Radiation therapy is necessary for some patients based on their disease state. Intensity-modulated radiation therapy can be offered to reduce scattering irradiation to normal tissues.

Ionizing Radiation Enhances Paracellular Permeability Through Alteration of Intercellular Junctions in Cultured Human Lymphatic Endothelial Cells.

BACKGROUND: A problematic complication after radiation therapy is lymphedema. Development of lymphedema is associated with an increase in lymphatic paracellular permeability. The current study investigated the effects of radiation on intercellular junctions and paracellular permeability in cultured human dermal lymphatic endothelial cells (HDLECs). METHODS AND RESULTS: Double immunofluorescence staining with vascular endothelial (VE)-cadherin and actin immediately after X-ray irradiation (5 or 20 Gy) was performed. Morphological changes induced by irradiation were assessed. Cell viability and paracellular permeability after irradiation were also evaluated. Broad junctions in which VE-cadherin was accumulated at cell-cell contacts and almost colocalized with actin were significantly decreased in a dose-dependent manner in confluent and sparse irradiated HDLECs. Irradiation shortened the width of VE-cadherin-positive areas at the cell-cell contacts. Actin filaments did not colocalize with VE-cadherin after 20 Gy irradiation. Although cell viability was not affected by irradiation, paracellular permeability significantly increased in a dose-dependent manner. CONCLUSIONS: A dose of 5 or 20 Gy irradiation in HDLECs does not affect cell viability, but changes VE-cadherin mediated intercellular junctions and actin structure, resulting in an increase of paracellular permeability. Further investigations on the regulatory proteins involved in radiation-induced changes, which were observed in the current study, may contribute to development of lymphedema therapy.

Differences between osteoradionecrosis and medication-related osteonecrosis of the jaw.

PURPOSE: The appearance of osteoradionecrosis (ORN) and medication-related osteonecrosis of the jaw (MRONJ) is similar, but clinically important differences between ORN and MRONJ exist. The aim of this study was to compare the clinical data between ORN and MRONJ and to reveal the critical differences between these diseases. METHODS: We retrospectively reviewed the epidemiological data, clinical findings, and treatment in 27 ORN and 61 MRONJ patients. Radiographic signs before the initiation of treatment were also assessed. RESULTS: The median age (P = 0.0474) and the ratio of female to male patients (P < 0.0001) were significantly higher in MRONJ patients. There were significantly more MRONJ patients who reported a history of pain when compared with ORN patients (P = 0.0263). As an aetiological factor, tooth extraction was significantly more relevant to MRONJ than ORN (P = 0.0352). When assessing the radiographic signs on computed tomographic images, periosteal reaction was found only in MRONJ patients (P = 0.0158). Minimal debridement was performed significantly more frequently for MRONJ (P = 0.0093), and by contrast, surgical resection was performed more frequently for ORN (P = 0.0002). CONCLUSIONS: Understanding the clinical and underlying pathological differences between ORN and MRONJ probably contributes to the selection of appropriate treatment for each patient.

Heterogeneity of Necrotic Changes between Cortical and Cancellous Bone in Mandibular Osteoradionecrosis: A Histopathological Analysis of Resection Margin after Segmental Mandibulectomy.

BACKGROUND: This study aimed to analyze differences in necrotic changes between cortical and cancellous bone in resection margins after segmental mandibulectomy for advanced mandibular osteoradionecrosis. METHODS: Anteroposterior bone specimens from eleven patients who underwent segmental mandibulectomy with simultaneous free fibula flap reconstruction for advanced osteoradionecrosis were analyzed histopathologically for the presence of necrotic bone based on the presence of blood vessels within Haversian canals. RESULTS: Ten of eleven (91%) cortices near the inferior border of the mandible at the anterior margins were necrotic. All cancellous bones at the anterior margins were viable. Seven of eleven (64%) cortices near the inferior border of the mandible at the posterior margins were necrotic. Three of eleven (27%) cancellous bones at the posterior margins were necrotic. CONCLUSION: Necrotic changes are more prevalent in cortices than in cancellous bones in mandibular osteoradionecrosis, probably due to a decrease of periosteal blood supply caused by radiotherapy.

Literature Review of Criteria for Defining Recipient-Site Infection after Oral Oncologic Surgery with Simultaneous Reconstruction.

BACKGROUND: The lack of uniformity of criteria for defining recipient-site infection after oral oncologic surgery with simultaneous reconstruction is problematic despite numerous studies on this issue. This study aimed to investigate the difference in the criteria for defining recipient-site infection after oral oncologic surgery with reconstruction. METHODS: A Medline search was performed via PUBMED using the following combinations of key terms that were tagged in the title, abstract, or both: "surgical site infection-head neck," "surgical site infection-oral cancer," "antibiotic prophylaxis-head neck," and "surgical site infection-oral carcinoma." Search results were filtered between 2005 and 2017. Articles in which there was no mention of the criteria for definition of surgical-site infection were excluded. RESULTS: The number of articles that met the inclusion criteria was 24. The lack of uniformity in the criteria for defining recipient-site infection in each article appeared to be attributable mainly to differences in whether an orocutaneous fistula and superficial incisional infection were regarded as recipient-site infection. CONCLUSION: Reconsideration of the categorization of orocutaneous fistula as infection, regardless of the etiology, and differentiation of superficial and deep incisional infections are necessary for correct assessment of recipient-site infection in oral oncologic surgery.

Intensity and duration of neutropenia relates to the development of oral mucositis but not odontogenic infection during chemotherapy for hematological malignancy.

BACKGROUND: D-index which combines the intensity and duration of neutropenia is reported as a tool for evaluating the dynamics of neutropenia. This study aimed to analyze the relationship between D-index and oral complications (i.e., oral mucositis [OM] and odontogenic infection [OI]) during chemotherapies for hematological malignancies. METHODS: A total of 421 chemotherapeutic courses in 104 patients were analyzed. Chemotherapeutic courses in patients who finished all of the prophylactic dental treatments were defined as "treatment Finish". Chemotherapeutic courses in patients who did not finish prophylactic dental treatments were defined as "treatment not-Finish". OM was evaluated according to the Common Terminology Criteria for Adverse Events, version 4.0. D-index was compared between chemotherapeutic courses with versus without oral complications. RESULTS: D-index was significantly higher in chemotherapeutic courses with grade 1 or 2 OM (p < 0.001) than courses without OM. In contrast, higher D-index did not relate to the development of OI (p = 0.18). The occurrence of OI (p < 0.001) but not OM (p = 0.56) during chemotherapy was significantly higher in chemotherapeutic courses without the completion of dental intervention. CONCLUSIONS: Higher D-index relates to the development of OM. In contrast, OI occurs due to untreated odontogenic foci, and its occurrence does not relate to higher D-index.

Meaning and Limitation of Cortical Bone Width Measurement with DentaScan in Medication-Related Osteonecrosis of the Jaws.

Mandibular cortical bone measurement with x-ray imaging is known to be a potentially useful tool in the detection of dimensional changes caused by bisphosphonate. The primary purpose of this study was to assess the meaning and limitation of cortical bone measurement with computed tomography (CT) in patients with medication-related osteonecrosis of the jaw (MRONJ). The investigators obtained DentaScan images of the mandible from 15 patients with MRONJ, 15 patients with a history of antiresorptive agent administration without symptoms of MRONJ (non-MRONJ), and 15 control subjects. The cortical bone width measured on DentaScan images was compared between the three groups (ANOVA and Tukey's test). Interobserver reliability between two observers was also assessed. The values of interclass correlation coefficient were 0.48 in the MRONJ group, 0.29 in the Non-MRONJ group, and 0.34 in control group. The cortical bone widths calculated both by observer 1 and observer 2 were thicker in patients with MRONJ than in the non-MRONJ group and controls. There were significant differences in cortical bone width among the MRONJ, non-MRONJ, and control groups in observer 1 (P < 0.001) and observer 2 (P < 0.001), specifically comparing the MRONJ group with the non-MRONJ group and the control group. Cortical bone width measurement is useful for the distinction between medication-related osteonecrosis of the jaw and normal bone, in spite of the low interobserver reliability.

Brain Abscess Potentially Resulting from Odontogenic Focus: Report of Three Cases and a Literature Review.

INTRODUCTION: Odontogenic foci can rarely cause intracranial infection. Hematogenous spread is considered to be the most important pathophysiological mechanism of intracranial infection of odontogenic origin. To investigate the oral origin of intracranial infections, oral surgeons should understand the underlying mechanisms by which oral bacteria spread to the central nervous system. However, there have been very few reports of intracranial infection resulting from odontogenic infection. CASE REPORTS: The authors report the cases of a 64-year-old man, a 68-year-old man, and a 64-year-old woman whose brain abscesses perhaps have arisen from odontogenic foci, because other sources of intracranial infection such as endocarditis and maxillary sinusitis were not found. Bacteriological examination of brain abscess specimens identified Staphylococcus aureus in case 1, Streptococcus constellatus, Fusobacterium nucleatum, and Parvimonas micra in case 2, and Lactobacillus catenaformis, Porphyromonas gingivalis, and F. nucleatum in case 3. All suspected causal teeth had no obvious signs of acute inflammation in all three cases. CONCLUSIONS: Oral surgeons should understand these characteristics of odontogenic brain abscess, in which the potentially causal odontogenic foci often lack acute symptoms. If other origins of infection are not found, it would be better to eliminate the potentially causal odontogenic foci for improvement of oral hygiene, however, the decision making criteria to eliminate suspected causal teeth is needed to be elucidated.

A Case Series of Fibro-Osseous Lesions of the Jaws.

The aim of this case series was to reveal the difficulties in diagnosing fibro-osseous lesions with radiological and histopathological examinations and quantify the potential risk of infection to fibro-osseous legions. To analyze the concordance between radiological and histopathological diagnoses, this retrospective case series included patients who were clinically diagnosed with fibro-osseous lesions via radiological findings and excluded the patients who did not undergo histopathological examinations. This study also included the patients in whom histopathological results confirmed fibro-osseous legions when preoperative radiological diagnosis did not include fibro-osseous legions. Eleven patients (three men, eight women; median age 24.5 years, range 15-57 years) were enrolled. Although radiological diagnoses of fibrous dysplasia (FD) corresponded with histopathological diagnoses in seven patients, mismatches between radiological findings and histopathological results were found in three patients. In one patient, suspected diagnosis with radiological examinations was malignant lymphoma or FD. In two patients, the histopathological differentiation between FD and ossifying fibroma (OF) was difficult. One patient had lesion recurrence which was suspected to be OF with surgical findings and postoperative course after the initial surgery. In three patients, infections of FD were found. Preoperative diagnosis of OF with radiographic feature of unilocular radiolucency is difficult. In cases in which histopathological differentiation between FD and OF is difficult, operative findings should be used because OF is often found to be well-encapsulated and easily enucleated. Bone in FD showing mixed radiolucent-radiopaque may be vulnerable to infection.

Secondary Bilateral Orbital Involvement from Primary Non-Hodgkin Lymphoma of the Cheek.

We describe a patient with oculomotor nerve palsy due to secondary orbital infiltration from the primary malignant lymphoma of the cheek. The patient was a 78-year-old female who had non-Hodgkin lymphoma (diffuse large B cell lymphoma [DLBCL]) of the cheek. The patient received chemotherapy and local radiation therapy. The combined treatment brought about complete remission. About 6 months after the last treatment the patient began to have left blepharoptosis and impaired vision. Findings from ophthalmological and neurosurgical examinations suggested no intraorbital or intracranial lesions. Repeated MRI and CT scans also showed no such lesions. One month later, the patient suddenly had a left oculomotor disturbance, diplopia and exophthalmus, followed by right oculomotor nerve palsy. An MRI revealed bilateral intraorbital tumors. Recurrence at the orbital tissue of malignant lymphoma originated from the left cheek appeared to cause the ophthalmological symptoms. Salvage chemotherapy was performed and her ocular symptoms were recovered. However, the patient died approximately 10 months after recurrent orbital tumor onset.