Endoscopic-assisted Surgical Removal of Infected Interosseous Wires 40 Years After Mandibular Surgery.

We demonstrate a highly reliable minimally invasive treatment for removal of residual wire from the mandible. The patient was a 55-year-old Japanese man who was referred to our department for a fistula in his submental area. The patient had undergone open reduction and fixation with wires for mandibular fractures (left parasymphysis, right angle fracture) more than 40 years prior and mandibular tooth extraction and drainage 6 months prior. Minimally invasive endoscopy-assisted wire removal surgery was performed under general anesthesia with good visualization in a narrow surgical field. Bone resection was minimized using an ultrasonic cutting instrument with a wide choice of tip shapes. The use of endoscopy with ultrasonic cutting tools makes it possible to effectively utilize narrow surgical fields with a small skin incision and minimal bone cutting. The advantages and disadvantages of the newer endoscopic systems in oral and maxillofacial surgical units are discussed.

Oral microorganisms and bloodstream infection in allogeneic hematopoietic stem cell transplantation.

OBJECTIVES: We aimed to compare oral and pathogenic microorganisms in bloodstream infections (BSIs) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). We also investigated the relationship between BSIs and oral mucositis to identify the ratio of BSIs caused by oral microorganisms and the pathogenic microorganisms involved. MATERIALS AND METHODS: We collected data on BSIs in 96 patients who underwent allo-HSCT in our institute between April 2009 and December 2019, including BSI pathogens isolated from blood cultures (BBSIs) and microorganisms isolated from washing the oral cavity with sterile distilled water. Oral microorganisms obtained at the onset of BSI (OBSIs) and during allo-HSCT (OSCTs) were defined as isolates collected during the week of blood culturing. Study entry was limited to samples collected up to 1 month after allo-HSCT without BSI. When the BBSI and OBSI were the same, we considered the oral microorganism to have caused the BSI. RESULTS: The incidence rate of BSIs was 27%, and the predominant microorganism was coagulase-negative Staphylococci. Normal bacterial flora were decreased to 15.8% in OBSIs and 25.5% in OSCTs. The distribution of microorganisms without normal bacterial flora showed significant difference between BBSIs and OSCTs (p < 0.05). Oral mucositis was found in 72.9%, and BSI caused by oral microorganisms occurred in 46.2% of BSIs in allo-HSCT patients. CONCLUSION: The distribution of microorganisms obtained from blood in patients with BSI during allo-HSCT was found to be similar to that of microorganisms from oral cultures. CLINICAL RELEVANCE: Oral microorganism monitoring may be able to predict BSI during allo-HSCT.

Fusuma Sliding Flap for Lip Reconstruction of Lower Lip Cancer.

Lower lip cancer is typically treated with surgical excision, and this frequently results in a large defect and severe aesthetic problems. Local flap reconstruction is suitable for restoring appearance and function, and it causes less surgical stress than a vascularized free flap. The Fusuma sliding flap is a local flap technique introduced by Kasai et al in 2008. Here, the authors report their use of this method for lip reconstruction in a 94-year-old Japanese female after the removal of a cancerous mass.

Bone metabolism of the jaw in response to bisphosphonate: a quantitative analysis of bone scintigraphy images.

We examined the changes in the bone metabolism of the jaw in response to BP treatment, and we used bone SPECT-CT to analyze the site-specific bone metabolism between the jaw and other sites of bone. We compared the changes in the bone metabolism of each part of bone in response to BP treatment by performing a quantitative analysis of bone scintigraphy images between patients treated with low-dose BP for osteoporosis (LBP group; n = 17), those treated with high-dose BP for metastatic bone tumor (HBP group; n = 11), and patients with other oral disease who required bone scintigraphy, with no history of BP treatment (control group; n = 40). The study endpoint was the mean standardized uptake value (SUV) of the uptake of Tc-99 m methylene diphosphonate (MDP) in each group. The mean SUVs of the HBP group were significantly lower at the axial bone of the cervical vertebra, thoracic vertebra, sternum, and rib compared to those of the LBP and control groups. The LBP group's mean SUV was significantly higher at the temporal bone, the anodontia part of the alveolar bone in maxilla, the vital teeth part of alveolar bone in the mandible, and the temporomandibular joint. There was no significant difference among the three groups at the mandibular angle and mandibular ramus. Our analyses revealed that the bone metabolism of the jaw and temporal bone in the BP-treated patients was enhanced, and no suppression of bone remodeling in the jaw by BP was observed.

The utility of bone scintigraphy in the assessment of mandibular metabolism during long-term bisphosphonate administration.

The duration of antiresorptive therapy is an important risk factor for medication-related osteonecrosis of the jaw. We performed a pilot study using quantitative analysis by bone scintigraphy to test the hypothesis that mandibular metabolism is affected by long-term bisphosphonate (BP) therapy. Our primary objectives were to assess changes in bone metabolism of the mandible in response to long-term BP therapy and compare the bone metabolism changes of the mandible with other bone sites. We compared the metabolic difference at the site in the mandible unaffected by disease, the humerus and the femur between 14 osteoporosis patients who were being treated with BP (BP group) and 14 patients who were not being treated with BP (control group) using a quantitative analysis and bone scintigraphy. Study endpoints were the mean and maximum bone uptake values (BUVs) quantified using bone scintigraphy images of the mandible, humerus and femur. Quantified images of the site in the mandible unaffected by disease had significantly higher mean and maximum BUVs compared to the controls (mean, 0.74 vs. 0.49, p = 0.019; max., 1.29 vs. 0.85, p = 0.009, respectively). The mean and maximum BUV of femur ROIs in the BP group were significantly lower than those in control patients (mean BUV, 0.23 vs. 0.30, p = 0.039; max. BUV, 0.43 vs. 0.53, p = 0.024, respectively). This is the first report of mandible changes in response to long-term BP treatment, using bone scintigraphy. The results using bone scintigraphy demonstrated that the bone metabolism of the intact mandible is affected by a long-term administration of BP.

Training high-performance deep learning classifier for diagnosis in oral cytology using diverse annotations.

The uncertainty of true labels in medical images hinders diagnosis owing to the variability across professionals when applying deep learning models. We used deep learning to obtain an optimal convolutional neural network (CNN) by adequately annotating data for oral exfoliative cytology considering labels from multiple oral pathologists. Six whole-slide images were processed using QuPath for segmenting them into tiles. The images were labeled by three oral pathologists, resulting in 14,535 images with the corresponding pathologists' annotations. Data from three pathologists who provided the same diagnosis were labeled as ground truth (GT) and used for testing. We investigated six models trained using the annotations of (1) pathologist A, (2) pathologist B, (3) pathologist C, (4) GT, (5) majority voting, and (6) a probabilistic model. We divided the test by cross-validation per slide dataset and examined the classification performance of the CNN with a ResNet50 baseline. Statistical evaluation was performed repeatedly and independently using every slide 10 times as test data. For the area under the curve, three cases showed the highest values (0.861, 0.955, and 0.991) for the probabilistic model. Regarding accuracy, two cases showed the highest values (0.988 and 0.967). For the models using the pathologists and GT annotations, many slides showed very low accuracy and large variations across tests. Hence, the classifier trained with probabilistic labels provided the optimal CNN for oral exfoliative cytology considering diagnoses from multiple pathologists. These results may lead to trusted medical artificial intelligence solutions that reflect diverse diagnoses of various professionals.

Risk factors for postoperative infection after bilateral sagittal split ramus osteotomy: A retrospective analysis.

BACKGROUND: This retrospective clinical study investigated risk factors for infection following bilateral sagittal split ramus osteotomy (BSSO) as orthognathic surgery, including the patients' general condition, local factors, and surgical factors. PATIENTS AND METHODS: The cases of 160 mandibular sites of 80 Japanese patients (26 males, 54 females; mean ± SD age: 25.3 ± 7.7 years, range 16-55 yrs) with a jaw deformity who underwent BSSO orthognathic surgery at our Department of Oral and Maxillofacial Surgery between Jan. 2017 and Dec. 2022 were analyzed. Potential risk factors were classified as clinical predictive variables. Descriptive and univariate statistics were computed. A multivariate analysis was performed with logistic regression. RESULTS: Fifteen mandibular sites (9.4 %) were complicated with postoperative infection. The multivariate analysis revealed significant differences in facial asymmetry (OR 24.0, p = 0.0002) and the amount of mandibular movement (OR 0.664, p = 0.011) between the sites with and without infection. CONCLUSIONS: Among clinical variables, facial asymmetry was the strongest risk factor for post-BSSO infection, followed by the amount of mandibular movement.

Risk Factors for Delayed-Onset Infection after Mandibular Wisdom Tooth Extractions.

Wisdom tooth extraction is one of the most commonly performed procedures by oral maxillofacial surgeons. Delayed-onset infection (DOI) is a rare complication of wisdom tooth extraction, and it occurs ~1-4 weeks after the extraction. In the present study, risk factors for DOI were investigated by retrospectively analyzing the cases of 1400 mandibular wisdom tooth extractions performed at Kagawa University Hospital from April 2015 to June 2022. Inclusion criteria were patients aged >15 years with a wisdom tooth extraction per our procedure. The exclusion criteria were patients with insufficient medical records, a >30-mm lesion around the wisdom tooth shown via X-ray, colonectomy, radiotherapy treatment of the mandible, the lack of panoramic images, and lesions other than a follicular cyst. The DOI incidence was 1.1% (16 cases), and univariate analyses revealed that the development of DOI was significantly associated with the Winter classification (p = 0.003), position (p = 0.003), hypertension (p = 0.011), and hemostatic agent use (p = 0.004). A multivariate logistic regression analysis demonstrated that position (OR = B for A, 7.75; p = 0.0163), hypertension (OR = 7.60, p = 0.013), and hemostatic agent use (OR = 6.87, p = 0.0022) were significantly associated with DOI development. Hypertension, hemostatic use, and position were found to be key factors for DOI; long-term observation may thus be necessary for patients with these risk factors.

Effectiveness of deep learning classifiers in histopathological diagnosis of oral squamous cell carcinoma by pathologists.

The study aims to identify histological classifiers from histopathological images of oral squamous cell carcinoma using convolutional neural network (CNN) deep learning models and shows how the results can improve diagnosis. Histopathological samples of oral squamous cell carcinoma were prepared by oral pathologists. Images were divided into tiles on a virtual slide, and labels (squamous cell carcinoma, normal, and others) were applied. VGG16 and ResNet50 with the optimizers stochastic gradient descent with momentum and spectral angle mapper (SAM) were used, with and without a learning rate scheduler. The conditions for achieving good CNN performances were identified by examining performance metrics. We used ROCAUC to statistically evaluate diagnostic performance improvement of six oral pathologists using the results from the selected CNN model for assisted diagnosis. VGG16 with SAM showed the best performance, with accuracy = 0.8622 and AUC = 0.9602. The diagnostic performances of the oral pathologists statistically significantly improved when the diagnostic results of the deep learning model were used as supplementary diagnoses (p-value = 0.031). By considering the learning results of deep learning model classifiers, the diagnostic accuracy of pathologists can be improved. This study contributes to the application of highly reliable deep learning models for oral pathological diagnosis.

The effect of zoledronic acid and denosumab on the mandible and other bones: a 18F-NaF-PET study.

OBJECTIVES: The primary purpose of this study was to determine whether both zoledronic acid (ZA) and denosumab (Dmab) equally suppress bone remodeling of the normal mandible, and the secondary purpose was to determine the influence of ZA and Dmab on other normal bones. METHODS: 18F-sodium fluoride-positron-emission-tomography (18F-NaF-PET) was used to perform quantitative analysis of the bone metabolism in various parts. The end points of the study were the mean standardized uptake value (SUV) of each member of the ZA group (n = 9), the Dmab group (n = 16), and the Control group (n = 23). RESULTS: The SUV at the thoracic vertebrae in the ZA group were significantly lower than those of the Dmab and Control group (p < 0.05) In addition, the mean SUVs of the cervical vertebrae in the ZA group were significantly lower than those in the Control group (p < 0.05). There was no significant difference among ZA, Dmab and Control group in the other sites. There was no significant difference between the Dmab and Control groups at all sites. CONCLUSIONS: The remodeling of mandible was not suppressed due to the treatment with anti-resorptive agents. Differences in the mechanisms of action between the BP and Dmab caused the specificity of the effect on the metabolism of normal bone.

Surgical navigation system for temporomandibular joint ankylosis in a child: a case report.

BACKGROUND: Computer-assisted surgical navigation systems were initially introduced for use in neurosurgery and have been applied in craniomaxillofacial surgery for 20 years. The anatomy of the oral and maxillofacial region is relatively complicated and includes critical contiguous organs. A surgical navigation system makes it possible to achieve real-time positioning during surgery and to transfer the preoperative design to the actual operation. Temporomandibular joint ankylosis limits the mouth opening, deforms the face, and causes an increase in dental caries. Although early surgical treatment is recommended, there is controversy regarding the optimal surgical technique. In addition, pediatric treatment is difficult because in children the skull is not as wide as it is in adults. There are few reports of pediatric temporomandibular joint ankylosis surgery performed with a navigation system. CASE PRESENTATION: A 7-year-old Japanese girl presented severe restriction of the opening and lateral movement of her mouth due to a temporomandibular joint bruise experienced 2 years earlier. Computed tomography and magnetic resonance imaging demonstrated left condyle deformation, disappearance of the joint cavity, and a 0.7-mm skull width. We diagnosed left temporomandibular joint ankylosis and performed a temporomandibular joint ankylosis arthroplasty using a surgical navigation system in order to avoid damage to the patient's brain. A preauricular incision was applied, and interpositional gap arthroplasty with temporal muscle was performed. After the surgery, the maximum aperture was 38 mm, and the limitation of the lateral movement was eliminated. CONCLUSIONS: A navigation system is helpful for confirming the exact target locations and ensuring safe surgery. In our patient's case, pediatric temporomandibular joint ankylosis surgery was performed using a navigation system without complications.

Symposium: Imaging modalities for drug-related osteonecrosis of the jaw (6), assessment of mandibular metabolism due to long-term administration of an anti-resorptive agent by bone scintigraphy (secondary publication).

It is not yet known why anti-resorptive agent-related osteonecrosis specifically affects the jaw. Here we assessed changes in the bone metabolism of the mandible in response to long-term bisphosphonate (BP) therapy, and we compared the bone metabolism changes of the mandible with those of other bone sites using a quantitative analysis by bone scintigraphy. The region of interest was selected by identifying without an abnormal accumulation of the mandible, humerus, second and fourth lumbar vertebrae, iliac crest, intertrochanteric femur and diaphysis. Bone scintigraphy images were quantified using a value we termed the 'bone uptake value (BUV)'. In the low-dose bisphosphonate (LBP) group (n = 21), the patients were undergoing osteoporosis treatment with low-dose BP. The high-dose BP (HBP) group consisted of 12 bone metastasis patients undergoing high-dose BP treatment. The Control group was 47 subjects with oral disease who had never been treated with an anti-resorptive agent. Our analyses demonstrated that with long-term BP administration, the bone metabolism of the iliac crest and intertrochanteric femur was suppressed but that of the mandible was enhanced. There was no significant difference in bone metabolism with either the low-dose BP or high-dose BP treatment. The effects of the long-term administration of BP were site-specific.