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Abstract Background For the surgical treatment of oral cancer, it is sometimes necessary to expand intraoral access within the oral cavity. The “swing approach” that involves lip splitting of the mandible and temporary mandibular osteotomy and the “visor approach” that does not split the lower lip and mandible are mainly used. This study analyzed postoperative outcomes such as complications, recurrence rate, and survival rate by these two approaches. The goal of this study is to evaluate the surgical outcomes of patients using these two approaches, to propose effective perioperative management for oral cancer surgery, and to compare the prognosis of oral cancer patients. Materials and methods From 2005 to 2020, 29 patients who underwent surgery at the Department of Oral and Maxillofacial Surgery of Pusan National University Dental Hospital for oral cancer lesions occurred in the mandible, floor of mouth, and tongue were selected for the study. Based on the surgical approach used, a chart review was conducted on various prognostic clinical factors such as the patients’ sex and age, primary site, TNM stage, histopathologic grade, recurrence and metastasis, postoperative survival rate, adjuvant chemo-radiation therapy, satisfaction with aesthetics/function/swallowing, length of hospital stay, tracheostomy and its duration, and neck dissection and its type. Statistical analysis was conducted using SPSS 25.0 (SPSS Inc., Chicago, IL) through Fisher’s exact t-test. Result There was no statistically significant difference between two groups in terms of clinical and pathological findings, such as survival rate, the need for adjuvant therapies, and the local recurrence rate. Although better outcomes were observed in terms of function, aesthetics, and postoperative complications in the group with visor approach, there was still no statistically significant difference between two groups. However, the duration of hospital stay was shorter in the visor approach group. Conclusion There was no statistically significant difference in clinical prognostic factors between the swing approach and the visor approach. Therefore, when choosing between the two approaches for the ablation of oral cancer, it is considered to select the surgical priority approach that can be easy access based on the size and location of the lesion. The visor approach had advantages of aesthetics and healing period.

Abstract Background The fibular free flap is considered one of the most valuable options for mandible reconstruction. A perforator flap has gained widespread acceptance in oral and maxillofacial reconstruction. Typically, the fibula flap is obtained primarily with the distal perforator due to its reliable blood supply, with less attention given to the proximal perforators during the harvesting process. Normally, the distal perforator of the fibula exhibits stability and shows limited anatomical variations. However, there have been reported cases in which the distal perforator is absent. At times, these vascular abnormalities remain undetectable through Doppler examination or preoperative angiography evaluation. Therefore, this case details the experience of encountering the rare event of vascular abnormality in oral cancer surgery. Case presentation This article reports the case of a patient who presented with a congenital absence of the distal perforator in the peroneal artery, attributed to a vascular abnormality. Additionally, we provide a review of the concept of utilizing the proximal perforator as an alternative approach in the flap harvesting process. Conclusions While the distal perforator of the peroneal artery is typically utilized for fibula free flap procedures, surgeons must remain cognizant of the potential for its absence due to aberrant anatomy. Recognizing an alternative approach in such cases can be pivotal for precise surgical planning and favorable outcomes in oral and maxillofacial reconstruction

Recent studies have explored surface treatments, such as increasing the hydrophilicity of implant fixtures, to enhance the osseointegration of implants. This prospective clinical study aimed to assess the clinical stability and efficacy of plasma treatment applied to implants with sandblast−acid etching (SLA) surfaces before placement. Twenty-eight patients requiring implant placement provided consent and were assigned randomly to either the SLA group without plasma treatment or the SLA/plasma group with plasma treatment. Recall checks were conducted one and three months after the first-stage surgery, followed by a second surgery at four months. Although no significant differences in buccal bone defects or implant stability were observed between the groups, the SLA/plasma group showed significant increases in marginal bone changes on the mesial and distal sides, as assessed using periapical radiographs. This study underscores the potential of pre-implantation plasma treatment to enhance bone regeneration around implants.

This study aims to determine whether it can distinguish odontogenic keratocyst (OKC) and simple bone cyst (SBC) based solely on preoperative panoramic radiographs through a deep learning algorithm. (1) Methods: We conducted a retrospective analysis of patient data from January 2018 to December 2022 at Pusan National University Dental Hospital. This study included 63 cases of OKC confirmed by histological examination after surgical excision and 125 cases of SBC that underwent surgical curettage. All panoramic radiographs were obtained utilizing the Proline XC system (Planmeca Co., Helsinki, Finland), which already had diagnostic data on them. The panoramic images were cut into 299 × 299 cropped sizes and divided into 80% training and 20% validation data sets for 5-fold cross-validation. Inception-ResNet-V2 system was adopted to train for OKC and SBC discrimination. (2) Results: The classification network for diagnostic performance evaluation achieved 0.829 accuracy, 0.800 precision, 0.615 recall, and a 0.695 F1 score. (4) Conclusions: The deep learning algorithm demonstrated notable accuracy in distinguishing OKC from SBC, facilitated by CAM visualization. This progress is expected to become an essential resource for clinicians, improving diagnostic and treatment outcomes.

(1) Background: The accurate diagnosis of periodontal disease typically involves complex clinical and radiologic examination. However, recent studies have demonstrated the potential of deep learning in improving diagnostic accuracy and reliability through the development of computer-aided detection and diagnosis algorithms for dental problems using various radiographic sources. This study focuses on the use of panoramic radiographs, which are preferred due to their ability to assess the entire dentition with a single radiation dose. The objective is to evaluate whether panoramic radiographs are a reliable source for the detection of periodontal bone loss using deep learning, and to assess its potential for practical use on a large dataset. (2) Methods: A total of 4083 anonymized digital panoramic radiographs were collected using a Proline XC machine (Planmeca Co., Helsinki, Finland) in accordance with the research ethics protocol. These images were used to train the Faster R-CNN object detection method for detecting periodontally compromised teeth on panoramic radiographs. (3) Results: This study demonstrated a high level of consistency and reproducibility among examiners, with overall inter- and intra-examiner correlation coefficient (ICC) values of 0.94. The Area Under the Curve (AUC) for detecting periodontally compromised and healthy teeth was 0.88 each, and the overall AUC for the entire jaw, including edentulous regions, was 0.91. (4) Conclusions: The regional grouping of teeth exhibited reliable detection performance for periodontal bone loss using a large dataset, indicating the possibility of automating the diagnosis of periodontitis using panoramic radiographs.

Abstract Background The purpose of this study was to review the clinical features of oromaxillofacial infections in patients presenting to a hospital emergency ward, to identify the key factors affecting the requirement for hospitalization, and the potential risk factors predisposing to a prolonged length of hospital stay. Methods A retrospective medical record review of the 598 patients treated for oromaxillofacial infection from 2013 to 2017 at the oral and maxillofacial surgery department, Yangsan Pusan National University Hospital, was conducted. The following information was collected from each patient: sex, age, past medical history, site of infection, etiology, admission or outpatient care, level of C-reactive protein (mg/dL), fascial spaces involved, treatment method, and duration of hospitalization. Chi-squared tests were used to identify risk factors, which were further analyzed using multivariable logistic regression. Results A total of 606 patients were eligible for inclusion in the study, of which eight were excluded due to having incomplete charts; thus, 598 patients were included: 55% were male, mean patient age was 47.1 ± 19.9 years, and 12.9% of patients were diabetic. Furthermore, 71.2% of patients had infection originating in the mandible; the most common tooth of origin was lower posterior, and 29.8% of patients were hospitalized. Risk factors for hospital admission were elderly patients with concurrent disease, elevated C-reactive protein level, and multiple-space infection in the oromaxillofacial area. The duration of hospitalization was correlated with both diabetes and age. Conclusions The requirement for hospital admission is determined by the severity of the infection; even severe infections, once treated with appropriate surgery, have no relation to the length of hospital stay. The important risk factors for increased duration of hospitalization are diabetes mellitus and older age. The understanding of risk factors associated with a prolonged hospital stay during the treatment of oromaxillofacial infection will aid in treatment planning as well as highlight the importance of adequate diabetes control in patients at risk of such infection.

This study aimed to evaluate the bone volume change at donor sites in patients who received mandibular body bone block grafts using intensity-based automatic image registration. A retrospective study was conducted with 32 patients who received mandibular bone block grafts between 2017 and 2019 at the Pusan National University Dental Hospital. Cone-beam computed tomography (CBCT) images were obtained before surgery (T0), 1 day after surgery (T1), and 4 months after surgery (T2). Scattered artefacts were removed by manual segmentation. The T0 image was used as the reference image for registration of T1 and T2 images using intensity-based registration. A total of 32 donor sites were analyzed three-dimensionally. The volume and pixel value of the bones were measured and analyzed. The mean regenerated bone volume rate on follow-up images (T2) was 34.87% ± 17.11%. However, no statistically significant differences of regenerated bone volume were noted among the four areas of the donor site (upper anterior, upper posterior, lower anterior, and lower posterior). The mean pixel value rate of the follow-up images (T2) was 78.99% ± 16.9% compared with that of T1, which was statistically significant (p < 0.05). Intensity-based registration with histogram matching showed that newly generated bone is generally qualitatively and quantitatively poorer than the original bone, thus revealing the feasibility of pixel value to evaluate bone quality in CBCT images. Considering the bone mass recovered in this study, 4 months may not be sufficient for a second harvesting, and a longer period of follow-up is required.

Abstract Background Free fibular flap is one of the most useful methods in the hard tissue reconstruction of the maxilla-mandible. Free fibular flap presents some advantages in which the reconstruction of both soft and hard tissues can be done at the same time. It also provides a safe and successful bone graft for the reconstruction, along with a low rate of complications. Despite these advantages and the rarity of a postoperative complication, particularly in oral and maxillofacial surgery procedures, a prolonged operation might exhibit some complications related with rhabdomyolysis. We experienced the rare event of rhabdomyolysis after oral cancer surgery. Case presentation In this article, we report the case of a patient who developed rhabdomyolysis after undergoing free fibular flap surgery. Conclusions Despite the advantages of the free fibular flap operation, clinicians must be aware of the risk of complications because there are multiple factors that could result in rhabdomyolysis, such as duration of operation, position of the subject, and pre-existing conditions of diabetes and hypertension. Once the diagnosis of rhabdomyolysis is confirmed, a prompt treatment plan should be made and applied as soon as possible. This will increase the chance of a full recovery for the patient who is exhibiting symptoms of rhabdomyolysis.

The dry electrodes that the automotive manufacturers use to measure electrocardiogram (ECG) signals for driver status monitoring have three technical problems: a lack of attachment flexibility, low ECG signal detection stability, and the potential to harm or irritate the driver. In addition, the complicated signal-conditioning circuits employed by automotive manufacturers to improve the SNR, increase the ECG signal detection stability, and to ensure a wider dynamic range of the electrodes increase the cost and complexity of driver ECG measuring systems. In this paper, we propose a driver ECG measuring system that resolves these three technical issues using a steering wheel covered with a conductive fabric-based dry electrode material, which is manufactured by an electroplating method. In addition, we employ a conductive fabric-shaping procedure in the development of the fabric-based dry electrode to improve the attachment flexibility and to reduce the cost and complexity of the required signal-conditioning circuit. We verify the ECG signal-measuring performance of the proposed system by comparing it with ECG signal measurement results from a clinical ECG monitoring system. In addition, despite applying a simpler signal conditional circuit than those used in conventional ECG measuring systems, we verify that the proposed system achieves higher SNR and ECG signal detection stability than conventional ECG measuring systems through various field tests in actual driving environments.

The purpose of this study was to investigate the accuracy of the airway volume measurement by a Regression Neural Network-based deep-learning model. A set of manually outlined airway data was set to build the algorithm for fully automatic segmentation of a deep learning process. Manual landmarks of the airway were determined by one examiner using a mid-sagittal plane of cone-beam computed tomography (CBCT) images of 315 patients. Clinical dataset-based training with data augmentation was conducted. Based on the annotated landmarks, the airway passage was measured and segmented. The accuracy of our model was confirmed by measuring the following between the examiner and the program: (1) a difference in volume of nasopharynx, oropharynx, and hypopharynx, and (2) the Euclidean distance. For the agreement analysis, 61 samples were extracted and compared. The correlation test showed a range of good to excellent reliability. A difference between volumes were analyzed using regression analysis. The slope of the two measurements was close to 1 and showed a linear regression correlation (r2 = 0.975, slope = 1.02, p < 0.001). These results indicate that fully automatic segmentation of the airway is possible by training via deep learning of artificial intelligence. Additionally, a high correlation between manual data and deep learning data was estimated.

This study aimed to present and evaluate alternative lesion-specific mandibulectomy methods for preserving the mandibular anatomical structures as compared with the conventional virtual surgical plan. Fifteen patients who received segmental mandibulectomy were included in this study, and the following parameters were evaluated: (1) the disease-free bone margin, (2) the volume and surface between the tailor-made resection simulation and conventional resection simulation, and (3) the preserved mandibular anatomical structures. In all 15 patients, disease-free bone margins were confirmed by histopathology. Volumes of conventional resection simulation and tail-made resection simulation were 49,468.66 ± 14,007.96 mm3 and 52,610.01 ± 13,755.33 mm3 and the surfaces were 20,927.38 ± 4471.70 mm2 and 22,356.49 ± 4185.73 mm2, respectively; these were statistically significant (both, p < 0.001). Mandibular dentition was partially preserved in six patients. Twelve of the 15 patients had changes in defect classification with preservation of the mandibular inferior border. In conclusion, alternative lesion-specific mandibulectomy was a less invasive method for effectively removing mandibular lesions while preserving the important anatomical structures of the mandible.

Schneiderian membrane perforation (SMP) is the most common complication encountered during sinus lift procedures. SMPs should be managed to prevent loss of the valuable bone graft and bone substitute materials. A fast-resorbing collagen membrane (CM) is a soft, white, pliable, and nonfriable sponge used in dental surgery. The purpose of this study was to evaluate the clinical outcomes of SMP repair using CMs when an SMP had occurred during a sinus lifting procedure. The patients were divided into three groups according to the size of the SMPs during the sinus lift procedure. (A) Group 1: there was no perforation of the Schneiderian membrane but the membrane was weakened (or thinned) and repaired using CMs. (B) Group 2: the SMP was small to medium in size (< 10 mm) and repaired using CMs and fibrin adhesive (FA). (C) Group 3: the SMP was large in size (> 10 mm) and repaired using a collagen plug. The negative control group consisted of patients who did not have any SMP (Control) and these patients were randomly selected. Orthopantomographic X-rays taken before surgery, 2–3 days following surgery, and over 6 months after surgery (follow-up) were used to evaluate the acquired bone height according to groups. Bone heights were measured from the crestal bone at the planned implant placement sites. Clinical outcomes, including implant success and complications according to repair method, were also investigated. There was no significant difference in bone heights between the groups with the exception of group 3. The overall implant survival rate was 100% for implants placed in sinuses with frank SMPs or weakened sinus membranes. The CM is applicable for small-to-moderate perforations or sinus membranes which have been weakened or thinned during sinus lift procedures.

Reverse genetic systems for RNA viruses are the platforms to introduce mutations into the RNA genomes and thus have helped understand their life cycle and harness them for human purposes to develop vaccines and delivery systems. These systems are based on the complementary DNA (cDNA) of the RNA viruses, whose transcripts derived from bacterial RNA polymerases act not only as the primary mRNA for phage protein synthesis, but also as the template for phage RNA replicases (aka. RNA-dependent RNA polymerases). Here, we present a protocol optimized for the small RNA phages of Leviviridae (i.e., leviphages) infecting Pseudomonas aeruginosa. This protocol includes three fundamental steps: (i) Creation of a promoter-fused cDNA, (ii) generation of a clone into mini-Tn7-based vector, and (iii) introduction of the clone into non-susceptible hosts. As the representative example, we describe the reverse genetic system for PP7, which infects a set of P. aeruginosa strains such as PAO1. The cDNA was fused to the T7 promoter, which was cloned in mini-Tn7-Gm. This construct was introduced into P. aeruginosa PAK and E. coli HB101. Functional assembly of PP7 phages from the culture supernatants were assessed by plaque formation on PAO1 and the phage particles were observed under transmission microscope. We found that the host cells should be cultured at 30 °C for the maximal phage production (~1012 pfu/mL). The reverse genetic systems will provide a new insight into the life cycle of the RNA phages and help develop engineered variants with new traits for phage applications regarding selective diagnosis and efficient therapy.