Wearable functional near-infrared spectroscopy for measuring dissociable activation dynamics of prefrontal cortex subregions during working memory.

The prefrontal cortex (PFC) has been extensively studied in relation to various cognitive abilities, including executive function, attention, and memory. Nevertheless, there is a gap in our scientific knowledge regarding the functionally dissociable neural dynamics across the PFC during a cognitive task and their individual differences in performance. Here, we explored this possibility using a delayed match-to-sample (DMTS) working memory (WM) task using NIRSIT, a high-density, wireless, wearable functional near-infrared spectroscopy (fNIRS) system. First, upon presentation of the sample stimulus, we observed an immediate signal increase in the ventral (orbitofrontal) region of the anterior PFC, followed by activity in the dorsolateral PFC. After the DMTS test stimulus appeared, the orbitofrontal cortex activated once again, while the rest of the PFC showed overall disengagement. Individuals with higher accuracy showed earlier and sustained activation of the PFC across the trial. Furthermore, higher network efficiency and functional connectivity in the PFC were correlated with individual WM performance. Our study sheds new light on the dynamics of PFC subregional activity during a cognitive task and its potential applicability in explaining individual differences in experimental, educational, or clinical populations. PRACTITIONER POINTS: Wearable functional near-infrared spectroscopy (fNIRS) captured dissociable temporal dynamics across prefrontal subregions during a delayed match-to-sample task. Anterior regions of the orbitofrontal cortex (OFC) activated first during the delay period, followed by the dorsolateral prefrontal cortex (PFC). PFC disengaged overall after the delay, but the OFC reactivated to the test stimulus. Earlier and sustained activation of PFC was associated with better accuracy. Functional connectivity and network efficiency also varied with task performance.

Deep Learning Model Based on You Only Look Once Algorithm for Detection and Visualization of Fracture Areas in Three-Dimensional Skeletal Images.

Utilizing "You only look once" (YOLO) v4 AI offers valuable support in fracture detection and diagnostic decision-making. The purpose of this study was to help doctors to detect and diagnose fractures more accurately and intuitively, with fewer errors. The data accepted into the backbone are diversified through CSPDarkNet-53. Feature maps are extracted using Spatial Pyramid Pooling and a Path Aggregation Network in the neck part. The head part aggregates and generates the final output. All bounding boxes by the YOLO v4 are mapped onto the 3D reconstructed bone images after being resized to match the same region as shown in the 2D CT images. The YOLO v4-based AI model was evaluated through precision-recall (PR) curves and the intersection over union (IoU). Our proposed system facilitated an intuitive display of the fractured area through a distinctive red mask overlaid on the 3D reconstructed bone images. The high average precision values (>0.60) were reported as 0.71 and 0.81 from the PR curves of the tibia and elbow, respectively. The IoU values were calculated as 0.6327 (tibia) and 0.6638 (elbow). When utilized by orthopedic surgeons in real clinical scenarios, this AI-powered 3D diagnosis support system could enable a quick and accurate trauma diagnosis.

Congenital epulis in a newborn.

Congenital epulis (CE) is an extremely rare benign tumor of the gingiva that is found on the alveolar ridge of newborns, and the main treatment option is simple excision. Postoperative prognosis is very good, and spontaneous regression may occur despite incomplete excision. This report presented a rare case of CE and its healing process after surgery under local anesthesia. The treatment plan was decided upon through consultation between a medical team and the patient's family, with surgical excision for the main lesion, which benefitted from surgery, and follow-up for a very small-sized lesion, which was thought to be appropriate for a newborn. No recurrence was found after its removal, and favorable healing was observed.

Primary xanthoma inferior to the right mandibular third molar and intraoral vertical ramus osteotomy.

Intraosseous xanthoma of the mandible is a rare benign disorder. A 17-year-old male patient presented with a suspected abscess in the right mandibular third molar, detected on a panoramic radiograph. The patient had no history of systemic or lipid-related metabolic diseases and complained of no specific symptoms or pain. A radiographic examination revealed a heterogeneous radiolucency extending from the apical to the distal aspect of the right mandibular third molar tooth germ. The lesion measured 9×16×24 mm (antero-posterior×mediolateral×supero-inferior) and showed a relatively well-defined, multilocular, foamy appearance with hyperostotic borders spreading to the inferior alveolar nerve canal. After excisional biopsy, a diagnosis of central xanthoma was made. The lesion recurred, and intraoral vertical ramus osteotomy was done near the lesion. For the treatment of xanthoma of the mandible, extensive and delicate surgical treatment under general anesthesia should be considered.

Changes in facial width according to the ostectomy level of the proximal bone segment in intraoral vertical ramus osteotomy for mandibular prognathism.

BACKGROUND: This study aimed to investigate the changes in facial width according to the ostectomy level of the proximal segment after orthognathic surgery using intraoral vertical ramus osteotomy (IVRO) in patients with mandibular prognathism. METHODS: The participants included 32 individuals who were diagnosed with class III malocclusion prior to surgery. All participants underwent orthognathic surgery using either version of IVRO. The surgery patients were categorized into two groups depending on the type of proximal bone-segment ostectomy technique used: patients whose osteotomy height was at the level of the mandibular tooth occlusal surface (the mandibular tooth surface-level group) and patients whose osteotomy height was at the level of the mandibular inferior border (the mandibular inferior border-level group). The distances between the mandibular width and soft tissue width at the height of the sigmoid notch, mandibular foramen, and alveolar bone and at the anterior-posterior location of the mandibular condyle, mandibular foramen, and coronoid process were compared between the groups. All data were compared to identify differences between preoperative and postoperative measurements. RESULTS: The postoperative change in facial soft tissue width at the intersection of the coronal plane with the coronoid process and the horizontal plane at the height of the mandibular alveolar bone in the group with osteotomy at the level of the mandibular occlusal surface differed significantly from that in the group with osteotomy at the level of the mandibular inferior border, with respective increases (mean ± SD) of 1.3 ± 3.5% and 4.7 ± 5.6%, compared to preoperative measurements (p = 0.050). CONCLUSIONS: Proximal segment ostectomy at the level of the mandibular occlusal surface must be considered with regard to postoperative facial soft tissue width in vertical ramus osteotomy. Additionally, it is necessary to study the visual effect of the width of the mandible appearing small because of the posterior position of the mandible, even when the mandibular facial width is maintained.

The incidence of postoperative hemorrhage after tooth extraction in patients with thrombocytopenia.

OBJECTIVES: The risk of bleeding after tooth extraction in thrombocytopenia patients remains unclear. Therefore, the present study aimed to assess the risk of bleeding after tooth extraction in patients with thrombocytopenia. MATERIALS AND METHODS: : The study included 220 patients who had a medical history of thrombocytopenia and underwent tooth extraction (330 teeth). The patients were divided into those who had thrombocytopenia (platelet count <150k) immediately before the tooth extraction, and those who had platelet counts that were between 150k and 250k before the extraction. Bleeding complications were recorded and compared between the patient groups. RESULTS: : Of the 220 patients, 130 underwent tooth extractions while having thrombocytopenia (platelet count <150k), and 90 had platelet counts that were between 150k and 250k before tooth extractions. Bleeding complications occurred in 11 patients (5.0%) of the 220 patients. Among those 11 patients with bleeding complications, 10 patients (7.7%) had thrombocytopenia (platelet count <150k) of the 130 patients, and 1 patient (1.1%) had a normal platelet count of the 90 patients. There was a significant difference between the patient groups regarding bleeding after extractions (P<0.001). No significant difference in the incidence of post-extraction bleeding was found between the subgroups by platelet count within the thrombocytopenia group. CONCLUSION: Thrombocytopenia (platelet count <150k) increases the risk of post-tooth extraction bleeding. Therefore, bleeding control under the proper evaluation of hemostasis and performing delicate tooth extraction procedures using hemostatic plugs is necessary during the tooth extraction of patients with thrombocytopenia.