Deep learning-based automatic segmentation of the mandibular canal on panoramic radiographs: A multi-device study

Purpose@#The objective of this study was to propose a deep-learning model for the detection of the mandibular canal on dental panoramic radiographs. @*Materials and Methods@#A total of 2,100 panoramic radiographs (PANs) were collected from 3 different machines: RAYSCAN Alpha (n=700, PAN A), OP-100 (n=700, PAN B), and CS8100 (n=700, PAN C). Initially, an oral and maxillofacial radiologist coarsely annotated the mandibular canals. For deep learning analysis, convolutional neural networks (CNNs) utilizing U-Net architecture were employed for automated canal segmentation. Seven independent networks were trained using training sets representing all possible combinations of the 3 groups. These networks were then assessed using a hold-out test dataset. @*Results@#Among the 7 networks evaluated, the network trained with all 3 available groups achieved an average precision of 90.6%, a recall of 87.4%, and a Dice similarity coefficient (DSC) of 88.9%. The 3 networks trained using each of the 3 possible 2-group combinations also demonstrated reliable performance for mandibular canal segmentation, as follows: 1) PAN A and B exhibited a mean DSC of 87.9%, 2) PAN A and C displayed a mean DSC of 87.8%, and 3) PAN B and C demonstrated a mean DSC of 88.4%. @*Conclusion@#This multi-device study indicated that the examined CNN-based deep learning approach can achieve excellent canal segmentation performance, with a DSC exceeding 88%. Furthermore, the study highlighted the importance of considering the characteristics of panoramic radiographs when developing a robust deep-learning network, rather than depending solely on the size of the dataset.

A case report of an unusual temporomandibular joint mass: Nodular fasciitis

Nodular fasciitis (NF) is a benign myofibroblastic proliferation that grows very rapidly, mimicking a sarcoma on imaging. It is treated by local excision, and recurrence has been reported in only a few cases, even when excised incompletely. The most prevalent diagnoses of temporomandibular joint (TMJ) masses include synovial chondromatosis, pigmented villonodular synovitis, and sarcomas. Cases of NF in the TMJ are extremely rare, and only 3 cases have been reported to date. Due to its destructive features and rarity, NF has often been misdiagnosed as a more aggressive lesion, which could expose patients to unnecessary and invasive treatment approaches beyond repair. This report presents a case of NF in the TMJ, focusing on various imaging features, along with a literature review aiming to determine the hallmark features of NF in the TMJ and highlight the diagnostic challenges.

Head and neck manifestations of fibrodysplasia ossificans progressiva: Clinical and imaging findings in 2 cases

Fibrodysplasia ossificans progressiva is a rare hereditary disorder characterized by progressive heterotopic ossifica-tion in muscle and connective tissue, with few reported cases affecting the head and neck region. Although plain radiographic findings and computed tomography features have been well documented, limited reports exist onmagnetic resonance findings. This report presents 2 cases of fibrodysplasia ossificans progressiva, one with limited mouth opening due to heterotopic ossification of the lateral pterygoid muscle and the other with restricted neck movement due to heterotopic ossification of the platysma muscle. Clinical findings of restricted mouth opening or limited neck movement, along with radiological findings of associated heterotopic ossification, should prompt consideration of fibrodysplasia ossificans progressiva in the differential diagnosis. Dentists should be particularly vigilant with patients diagnosed with fibrodysplasia ossificans progressiva to avoid exposure to diagnostic biopsy andinvasive dental procedures.

Mucormycosis-related osteomyelitis of the maxilla in a post-COVID-19 patient

Mucormycosis is a rare, invasive fungal infection that progresses aggressively and requires prompt surgery and appropriate treatment. The number of cases of mucormycosis in coronavirus disease 2019 (COVID-19) patients has recently increased, and patients with uncontrolled diabetes mellitus are particularly at an elevated risk of infection. This report presents a case of mucormycosis-related osteomyelitis of the maxilla in a 37-year-old man with diabetes mellitus. The patient complained of severe and persistent pain in the right maxilla, accompanied by increased tooth mobility and headache. On contrast-enhanced computed tomographic images, gas-forming osteomyelitis of the right maxilla was observed. Destruction of the maxilla and palatine bone then proceeded aggressively. Sequestrectomy was performed on the right maxilla, and the histopathological diagnosis was mucormycosis. Further investigation after the first operation revealed the patient's history of COVID-19 infection.

Deep learning-based apical lesion segmentation from panoramic radiographs

Purpose@#Convolutional neural networks (CNNs) have rapidly emerged as one of the most promising artificial intelligence methods in the field of medical and dental research. CNNs can provide an effective diagnostic methodology allowing for the detection of early-staged diseases. Therefore, this study aimed to evaluate the performance of a deep CNN algorithm for apical lesion segmentation from panoramic radiographs. @*Materials and Methods@#A total of 1000 panoramic images showing apical lesions were separated into training (n=800, 80%), validation (n=100, 10%), and test (n=100, 10%) datasets. The performance of identifying apical lesions was evaluated by calculating the precision, recall, and F1-score. @*Results@#In the test group of 180 apical lesions, 147 lesions were segmented from panoramic radiographs with an intersection over union (IoU) threshold of 0.3. The F1-score values, as a measure of performance, were 0.828, 0.815, and 0.742, respectively, with IoU thresholds of 0.3, 0.4, and 0.5. @*Conclusion@#This study showed the potential utility of a deep learning-guided approach for the segmentation of apical lesions. The deep CNN algorithm using U-Net demonstrated considerably high performance in detecting apical lesions.

Effect of compositional variation of dental MTA cements on setting time / 대한치과재료학회지

The long setting time of dental MTA (Mineral Trioxide Aggregate) cement is a major disadvantage in clinical use. In this study, the setting time (ST) of nine commercial MTA cements was tested according to the ISO 6876:2012 standard (n = 5).Materials evaluated were ProRoot MTA (PR), Ortho MTA (Ortho), Retro MTA (Retro), Endocem MTA (Endocem), Endoseal MTA (Endoseal), One-Fil (OF), MTA Cem (MC), EZ-Seal (EZ), and Biodentine (BD). XRD and XRF analysis were performed to evaluate the effect of composition on ST. Kruskal-Wallis test as a non-parametric ANOVA followed by Duncan’s post hoc test was used for statistical analysis. The ST was PR > EZ > OF > Ortho > Retro > MC > Endoseal > BD > Endocem in decreasing order (p < 0.001). PR showed the longest (369.4 min) and Endocem showed the shortest (2.4 min) ST. Endocem (2.4 min), BD (16.0 min) and Endoseal (47.0 min) contained calcium carbonate. MC (48.8 min), Retro (43.6 min), Ortho (65.0), and OF (165.4 min), which had the next short setting time, contained dicalcium aluminate. In EZ (182.4 min), dicalcium silicate was the main crystalline phase rather than tricalcium silicate, which contributes to the early strength, and it contained calcium sulfate. Endocem, which showed the shortest setting time, showed the smallest d90 particle size of 6.12 µm. The information obtained from this study would be helpful in developing a composition for controlling the setting time of MTA cement and selecting a product with a setting time suitable for each clinical case.

Establishment of particulate matterinduced lung injury model in mouse / 한국실험동물학회지

Background@#Particulate matter (PM) is one of the principal causes of human respiratory disabilities resulting from air pollution. Animal models have been applied to discover preventive and therapeutic drugs for lung diseases caused by PM. However, the induced severity of lung injury in animal models using PM varies from study to study due to disparities in the preparation of PM, and the route and number of PM administrations. In this study, we established an in vivo model to evaluate PM-induced lung injury in mice. @*Results@#PM dispersion was prepared using SRM2975. Reactive oxygen species were increased in MLE 12 cells exposed to this PM dispersion. In vivo studies were conducted in the PM single challenge model, PM multiple challenge model, and PM challenge with ovalbumin-induced asthma using the PM dispersion. No histopathological changes were observed in lung tissues after a single injection of PM, whereas mild to moderate lung inflammation was obtained in the lungs of mice exposed to PM three times. However, fibrotic changes were barely seen, even though transmission electron microscopy (TEM) studies revealed the presence of PM particles in the alveolar macrophages and alveolar capillaries. In the OVA-PM model, peribronchial inflammation and mucous hypersecretion were more severe in the OVA+PM group than the OVA group. Serum IgE levels tended to increase in OVA+PM group than in OVA group. @*Conclusions@#In this study, we established a PM-induced lung injury model to examine the lung damage induced by PM. Based on our results, repeated exposures of PM are necessary to induce lung inflammation by PM alone. PM challenge, in the presence of underlying diseases such as asthma, can also be an appropriate model for studying the health effect of PM.

Exercise Training Attenuates Ovariectomy-Induced Alterations in Skeletal Muscle Remodeling, Apoptotic Signaling, and Atrophy Signaling in Rat Skeletal Muscle / 대한배뇨장애요실금학회지

Purpose@#The effects of aerobic exercise training on soleus muscle morphology, mitochondria-mediated apoptotic signaling, and atrophy/hypertrophy signaling in ovariectomized rat skeletal muscle were investigated. @*Methods@#Female Sprague-Dawley rats were divided into control (CON), ovariectomy (OVX), and ovariectomy plus exercise (OVX+EX) groups. After ovarian excision, exercise training was performed using a rat treadmill at 20 m/min, 50 min/day, 5 days/week for 12 weeks. Protein levels of mitochondria-mediated apoptotic signaling and atrophy/hypertrophy signaling in the skeletal muscle (soleus) were examined through western immunoblot analysis. @*Results@#The number of myocytes and myocyte cross-sectional area (CSA) were increased and the extramyocyte space was decreased in the OVX group compared to those in the CON group. However, aerobic exercise training significantly increased myocyte CSA and decreased extramyocyte space in the OVX+EX group compared to those in the OVX group. The protein levels of proapoptotic signaling and muscle atrophy signaling were significantly increased, whereas the protein levels of muscle hypertrophy signaling were significantly decreased in the OVX group compared to that in the CON group. Aerobic exercise training significantly decreased the protein levels of proapoptotic signaling and increased the protein level of antiapoptotic protein in the OVX+EX group compared to that in the OVX group. Aerobic exercise training significantly increased the protein levels of hypertrophy signaling and decreased protein levels of atrophy signaling in the OVX+EX group compared to those in the OVX group. @*Conclusions@#Treadmill exercise improved estrogen deficiency-induced impairment in skeletal muscle remodeling, mitochondria-mediated apoptotic signaling, and atrophy/hypertrophy signaling in skeletal muscle.

Effect of compositional variation of dental MTA cements on setting time / 대한치과재료학회지

The long setting time of dental MTA (Mineral Trioxide Aggregate) cement is a major disadvantage in clinical use. In this study, the setting time (ST) of nine commercial MTA cements was tested according to the ISO 6876:2012 standard (n = 5).Materials evaluated were ProRoot MTA (PR), Ortho MTA (Ortho), Retro MTA (Retro), Endocem MTA (Endocem), Endoseal MTA (Endoseal), One-Fil (OF), MTA Cem (MC), EZ-Seal (EZ), and Biodentine (BD). XRD and XRF analysis were performed to evaluate the effect of composition on ST. Kruskal-Wallis test as a non-parametric ANOVA followed by Duncan’s post hoc test was used for statistical analysis. The ST was PR > EZ > OF > Ortho > Retro > MC > Endoseal > BD > Endocem in decreasing order (p < 0.001). PR showed the longest (369.4 min) and Endocem showed the shortest (2.4 min) ST. Endocem (2.4 min), BD (16.0 min) and Endoseal (47.0 min) contained calcium carbonate. MC (48.8 min), Retro (43.6 min), Ortho (65.0), and OF (165.4 min), which had the next short setting time, contained dicalcium aluminate. In EZ (182.4 min), dicalcium silicate was the main crystalline phase rather than tricalcium silicate, which contributes to the early strength, and it contained calcium sulfate. Endocem, which showed the shortest setting time, showed the smallest d90 particle size of 6.12 µm. The information obtained from this study would be helpful in developing a composition for controlling the setting time of MTA cement and selecting a product with a setting time suitable for each clinical case.

Establishment of particulate matterinduced lung injury model in mouse / 한국실험동물학회지

Background@#Particulate matter (PM) is one of the principal causes of human respiratory disabilities resulting from air pollution. Animal models have been applied to discover preventive and therapeutic drugs for lung diseases caused by PM. However, the induced severity of lung injury in animal models using PM varies from study to study due to disparities in the preparation of PM, and the route and number of PM administrations. In this study, we established an in vivo model to evaluate PM-induced lung injury in mice. @*Results@#PM dispersion was prepared using SRM2975. Reactive oxygen species were increased in MLE 12 cells exposed to this PM dispersion. In vivo studies were conducted in the PM single challenge model, PM multiple challenge model, and PM challenge with ovalbumin-induced asthma using the PM dispersion. No histopathological changes were observed in lung tissues after a single injection of PM, whereas mild to moderate lung inflammation was obtained in the lungs of mice exposed to PM three times. However, fibrotic changes were barely seen, even though transmission electron microscopy (TEM) studies revealed the presence of PM particles in the alveolar macrophages and alveolar capillaries. In the OVA-PM model, peribronchial inflammation and mucous hypersecretion were more severe in the OVA+PM group than the OVA group. Serum IgE levels tended to increase in OVA+PM group than in OVA group. @*Conclusions@#In this study, we established a PM-induced lung injury model to examine the lung damage induced by PM. Based on our results, repeated exposures of PM are necessary to induce lung inflammation by PM alone. PM challenge, in the presence of underlying diseases such as asthma, can also be an appropriate model for studying the health effect of PM.

Nutrients and Diabetes Mellitus: Potassium / 임상당뇨병

Potassium (K) is an essential mineral that plays major roles in intracellular osmolality and acid-base balance. In addition, potassium affects endothelial and vascular smooth muscle functions and has been shown to decrease blood pressure. Recently, potassium intake and plasma potassium concentration have been reported to be related to insulin secretion and diabetes risk. Therefore, in this article, we review how potassium intake reduces blood pressure and affects insulin release. We also determine methods for safe consumption and dose of potassium.

Nutrients and Diabetes Mellitus: Potassium / 임상당뇨병

Potassium (K) is an essential mineral that plays major roles in intracellular osmolality and acid-base balance. In addition, potassium affects endothelial and vascular smooth muscle functions and has been shown to decrease blood pressure. Recently, potassium intake and plasma potassium concentration have been reported to be related to insulin secretion and diabetes risk. Therefore, in this article, we review how potassium intake reduces blood pressure and affects insulin release. We also determine methods for safe consumption and dose of potassium.

Evaluation of the clinical efficacy of a TW3-based fully automated bone age assessment system using deep neural networks

Purpose@#The aim of this study was to evaluate the clinical efficacy of a Tanner-Whitehouse 3 (TW3)-based fully automated bone age assessment system on hand-wrist radiographs of Korean children and adolescents. @*Materials and Methods@#Hand-wrist radiographs of 80 subjects (40 boys and 40 girls, 7-15 years of age) were collected. The clinical efficacy was evaluated by comparing the bone ages that were determined using the system with those from the reference standard produced by 2 oral and maxillofacial radiologists. Comparisons were conducted using the paired t-test and simple regression analysis. @*Results@#The bone ages estimated with this bone age assessment system were not significantly different from those obtained with the reference standard (p>0.05) and satisfied the equivalence criterion of 0.6 years within the 95% confidence interval ( - 0.07 to 0.22), demonstrating excellent performance of the system. Similarly, in the comparisons of gender subgroups, no significant difference in bone age between the values produced by the system and the reference standard was observed (p>0.05 for both boys and girls). The determination coefficients obtained via regression analysis were 0.962, 0.945, and 0.952 for boys, girls, and overall, respectively (p=0.000); hence, the radiologist-determined bone ages and the system-determined bone ages were strongly correlated. @*Conclusion@#This TW3-based system can be effectively used for bone age assessment based on hand-wrist radiographs of Korean children and adolescents.

Effects of Acute Exercise on Mitochondrial Function, Dynamics, and Mitophagy in Rat Cardiac and Skeletal Muscles / 대한배뇨장애요실금학회지

PURPOSE@#This study aimed to investigate the effects of single-bout exercise on mitochondrial function, dynamics (fusion, fission), and mitophagy in cardiac and skeletal muscles.@*METHODS@#Fischer 344 rats (4 months old) were randomly divided into the control (CON) or acute exercise (EX) group (n=10 each). The rats performed a single bout of treadmill exercise for 60 minutes. Mitochondrial function (e.g., O₂ respiration, H₂O₂ emission, Ca²⁺ retention capacity), mitochondrial fusion (e.g., Mfn1, Mfn2, Opa1), mitochondrial fission (e.g., Drp1, Fis1), and mitophagy (e.g., Parkin, Pink1, LC3II, Bnip3) were measured in permeabilized cardiac (e.g., left ventricle) and skeletal (e.g., soleus, white gastrocnemius) muscles.@*RESULTS@#Mitochondrial O₂ respiration and Ca²⁺ retention capacity were significantly increased in all tissues of the EX group compared with the CON group. Mitochondrial H₂O₂ emissions showed tissue-specific results; the emissions showed no significant differences in the left ventricle or soleus (type I fibers) but was significantly increased in the white gastrocnemius (type II fibers) after acute exercise. Mitochondrial fusion and fission were not altered in any tissues of the EX group. Mitophagy showed tissue-specific differences: It was not changed in the left ventricle or white gastrocnemius, whereas Parkin and LC3II were significantly elevated in the soleus muscle.@*CONCLUSIONS@#A single bout of aerobic exercise may improve mitochondrial function (e.g., O₂ respiration and Ca²⁺ retention capacity) in the heart and skeletal muscles without changes in mitochondrial dynamics or mitophagy.

Diagnostic considerations in central odontogenic fibroma of the maxilla: 2 case reports

Central odontogenic fibroma (COF) is defined as a fibroblastic odontogenic tumor characterized by varying density of the tooth epithelium. It is an extremely rare benign neoplasm that occurs in the maxilla and the mandible; only a few reports of COF are available in the literature. Diagnosis of the lesion based only on the radiological features of COF is difficult due to variation in the findings regarding this condition. This report describes 2 clinical cases of middle-aged women with COF. Clinical examination revealed palatal mucosal depression; additionally, oral examination, as well as panoramic radiographs, intraoral radiographs, and computed tomography scans, revealed severe root resorption. This report highlights the clinical and radiological imaging features of COF, with the goal of enabling straightforward differential diagnosis of the lesion by the clinician and thereby appropriate treatment of the patient.

Association of Nutritional Status with Cognitive Stage in the Elderly Korean Population: The Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's Disease

BACKGROUND AND PURPOSE: Epidemiological studies have suggested the presence of strong correlations among diet, lifestyle, and dementia onset. However, these studies have unfortunately had major limitations due to their inability to fully control the various potential confounders affecting the nutritional status. The purpose of the current study was to determine the nutritional status of participants in the Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's Disease (KBASE) and to identify clinical risk factors for being at risk of malnutrition or being malnourished. METHODS: Baseline data from 212 participants [119 cognitively unimpaired (CU), 56 with mild cognitive impairment (MCI), and 37 with dementia] included in the KBASE database were analyzed. All participants underwent a comprehensive cognitive test and MRI at baseline. The presence of malnutrition at baseline was measured by the Mini Nutritional Assessment score. We examined the cross-sectional relationships of clinical findings with nutritional status using multiple logistic regression applied to variables for which p<0.2 in the univariate analysis. Differences in cortical thickness according to the nutritional status were also investigated. RESULTS: After adjustment for demographic, nutritional, and neuropsychological factors, participants with dementia had a significantly higher odds ratio (OR) for being at risk of malnutrition or being malnourished than CU participants [OR=5.98, 95% CI=1.20–32.97] whereas participants with MCI did not (OR=0.62, 95% CI=0.20–1.83). Cortical thinning in the at-risk/malnutrition group was observed in the left temporal area. CONCLUSIONS: Dementia was found to be an independent predictor for the risk of malnutrition compared with CU participants. Our findings further suggest that cortical thinning in left temporal regions is related to the nutritional status.

Inhibition of STAT3 signaling induces apoptosis and suppresses growth of lung cancer: good and bad / 한국실험동물학회지

Signal transducer and activator of transcription 3 (STAT3) modulates a variety of genes involved in the regulation of critical functions, including cell proliferation, differentiation, apoptosis, angiogenesis, metastasis, and immunity. For many cancers, elevated levels of STAT3 signaling have been associated with a poor prognosis and the development of chemotherapy resistance. In this study, we investigated the inhibitory effects of a novel small-molecule inhibitor of STAT3, STX-0119, on the cell viability and survival of human lung cancer cells. STX-0119 inhibited activated STAT3 and the expression of STAT3-regulated oncoproteins such as c-Myc, cyclin D1, and survivin in lung cancer cells. STX-0119 also decreased the amount of STAT3 in the nuclear fraction as well as induced apoptosis of these lung cancer cell lines as evidenced by increases in apoptotic cells (Annexin V positive) and poly (ADP-ribose) polymerase (PARP) cleavage. The efficacy of STX-0119 in a mouse xenograft model was confirmed. However, a hematological side effect, which had not been previously reported, was observed. The level of white blood cells was significantly lowered when treated at the dose at which STX-0119 alone showed a significant tumor-suppressive effect. In conclusion, we suggest that STX-0119 may be a potent therapeutic agent against lung cancer. Consideration of the side effect suggests, it is necessary to study whether low-dose STX-0119 is effective for lung treatment with a combination of classic lung cancer therapeutics.

Steatocystoma multiplex: A case report of a rare entity

Steatocystoma multiplex is an uncommon benign skin disease, which typically manifests as numerous intradermal cysts that can be scattered anywhere on the body. Although usually asymptomatic, it can be significantly disfiguring. One type of steatocystoma multiplex is known to be associated with the autosomal dominant inheritance of a mutation in the gene coding for keratin 17 (KRT17). In such cases, it is often concurrent with other developmental abnormalities of the ectoderm-derived tissues, such as the nails, hair, and teeth. To the best of our knowledge, few cases have been reported of steatocystoma multiplex of the oral and maxillofacial region. This report describes a case of steatocystoma multiplex of both sides of the neck and multiple dental anomalies, with a focus on its clinical, radiological, and histopathological characteristics, as well as the possibility that the patient exhibited the familial type of this condition.

Unusual malignant neoplasms occurring around dental implants: A report of 2 cases

Osseointegrated implants are now commonplace in contemporary dentistry. However, a number of complications can occur around dental implants, including peri-implantitis, maxillary sinusitis, osteomyelitis, and neoplasms. There have been several reports of a malignant neoplasm occurring adjacent to a dental implant. In this report, we describe 2 such cases. One case was that of a 75-year-old man with no previous history of malignant disease who developed a solitary plasmacytoma around a dental implant in the left posterior mandible, and the other was that of a 43-year-old man who was diagnosed with squamous cell carcinoma adjacent to a dental implant in the right posterior mandible. Our experiences with these 2 cases suggest the possibility of a relationship between implant treatment and an inflammatory cofactor that might increase the risk of development of a malignant neoplasm.

Linear accuracy of cone-beam computed tomography and a 3-dimensional facial scanning system: An anthropomorphic phantom study

PURPOSE: This study was conducted to evaluate the accuracy of linear measurements of 3-dimensional (3D) images generated by cone-beam computed tomography (CBCT) and facial scanning systems, and to assess the effect of scanning parameters, such as CBCT exposure settings, on image quality. MATERIALS AND METHODS: CBCT and facial scanning images of an anthropomorphic phantom showing 13 soft-tissue anatomical landmarks were used in the study. The distances between the anatomical landmarks on the phantom were measured to obtain a reference for evaluating the accuracy of the 3D facial soft-tissue images. The distances between the 3D image landmarks were measured using a 3D distance measurement tool. The effect of scanning parameters on CBCT image quality was evaluated by visually comparing images acquired under different exposure conditions, but at a constant threshold. RESULTS: Comparison of the repeated direct phantom and image-based measurements revealed good reproducibility. There were no significant differences between the direct phantom and image-based measurements of the CBCT surface volume-rendered images. Five of the 15 measurements of the 3D facial scans were found to be significantly different from their corresponding direct phantom measurements (P < .05). The quality of the CBCT surface volume-rendered images acquired at a constant threshold varied across different exposure conditions. CONCLUSION: These results proved that existing 3D imaging techniques were satisfactorily accurate for clinical applications, and that optimizing the variables that affected image quality, such as the exposure parameters, was critical for image acquisition.