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Array comparative genomic hybridization (aCGH) provides a genome-wide technique for identifying chromosomal aberrations in human diseases, including cancer. Chromosomal aberrations in cancers are defined as regions that contain an increased or decreased DNA copy number, relative to normal samples. The identification of genomic regions associated with systematic aberrations provides insights into initiation and progression of cancer, and improves diagnosis, prognosis, and therapy strategies. The McNemar test can be used to detect differentially expressed genes after discretization of gene expressions in a microarray experiment for the matched dataset. In this study, we propose a method to detect significantly altered DNA regions, shifted McNemar test, which is based on the standard McNemar test and takes into account changes in copy number variations and the region size throughout the whole genome. In addition, this novel method can be used to detect genomic regions associated with the progress of oral squamous cell carcinoma (OSCC). The performance of the proposed method was evaluated based on the homogeneity within the selected regions and the classification accuracies of the selected regions. This method might be useful for identifying new candidate genes that neighbor known genes based on the whole-genomic variation because it detects significant chromosomal regions, not independent probes. [ABSTRACT FROM AUTHOR]

Lymph node metastasis is an important prognostic factor in oral squamous cell carcinoma. However, the lack of significant biomarkers for lymph node metastasis can cause patients to be inappropriately treated and produce a poor prognosis. Therefore, there is a need to identify gene sets that are associated with lymph node metastasis. In this study, we used three expression datasets obtained from a public database and selected candidate gene sets that were related with lymph node metastasis from two datasets and a combined dataset. We evaluated the selected gene set using OOB error rates in a validation dataset. The gene set detected from the combined dataset classified the lymph node status more accurately in the validation dataset and clear expression patterns classifying the lymph node status based on chromosomal location were observed. The combined dataset holds promise for use as a more accurate candidate gene set for the diagnosis of lymph node metastasis and the selected gene set could be used for biological validation in further studies. [ABSTRACT FROM AUTHOR]

In this report, a tumor exhibited EWSR1::RORß gene fusion, to our knowledge, is the first such reported case. The Ewing sarcoma breakpoint region 1 gene (EWSR1) is known to be associated with several soft tissue tumors although its specific role remains unclear. Its fusion with a member of the ETS family, including FLI1 and ERG, results in Ewing sarcoma, and its fusion with other genes unrelated to the ETS family, including NFATC2 and PATZ1, results in round cell sarcoma with EWSR1-non-ETS fusions, previously referred to as Ewing-like sarcoma. RORß encodes retinoic acid-related orphan receptor ß, a nuclear receptor (NR), and is involved in circadian rhythm modulation and cancer regulation. The specific role of RORß in tumorigenesis remains unclear; however, this case report suggests that it may form part of a new tumorigenic entity., Competing Interests: Declaration of interests None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objectives: To compare the efficacy of patient-specific 3-dimensional (3D)-printed plates (PSP) and pre-bent universal reconstruction plates (PBP) in preserving the 3D position of the mandibular condyle and total operation time during mandibular reconstruction with a fibula-free flap., Materials and Methods: This retrospective study included 18 patients who underwent mandibular reconstruction using fibular free flaps. Both groups utilized virtual surgical planning (VSP) and 3D-printed surgical guides. Nine patients received PSP, and 9 received PBP. Postoperative and computed tomography (CT) scans were analyzed to assess 3D deviations of the mandibular condyles and operation times., Results: PSP demonstrated superior accuracy in medial-lateral condylar displacement (2.5 ± 1.42 versus 4.92 ± 2.42 mm, P = 0.02) and better angular accuracy in the coronal (1.46 ± 1.16 deg versus 5.45 ± 2.75 deg, P = 0.001) and transverse planes (3.55 ± 2.82 deg versus 8.99 ± 5.56 deg, P = 0.023). There was no significant difference in total operation time between PSP and PBP groups (487.7 ± 90.1 versus 547.3 ± 110.1 min, P = 0.226), despite all PSP patients having additional immediate implant placement and prosthesis delivery., Conclusions: PSP offers better condylar accuracy and allows immediate implant placement without increasing surgical time compared with PBP., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of Mutaz B. Habal, MD.)

Introduction: This study aimed to analyze the factors affecting the occurrence of peri-implant medication-related osteonecrosis of the jaw (PI-MRONJ) in patients using anti-resorptive drugs (ARDs) on different implant position, inclinations, and types of prosthesis., Methods: The data of 75 patients with bone necrosis that progressed around the implant between 2018 and 2022 were retrospectively examined to identify the factors influencing PI-MRONJ. Data, including patient demographics (age, sex, smoking status, concomitant disease, time of ARD therapy, dose of ARDs, and parafunctional habits) and implant-specific information (type of prosthesis, angle of insertion), were extracted from medical and dental records., Results: Tilted implants with an angle ≥ 5.1° relative to the occlusal plane of the prosthesis had a stronger association with PI-MRONJ in comparison to non-tilted implants (inclination was < 5°). Additionally, the boundary of the area of osteonecrosis around the fixture was larger for the splinted implant-supported crowns than for the single implant supported crowns)., Conclusion: In patients taking anti-resorptive medications the inclination of the implant was associated with the occurrence of PI-MRONJ. Further studies are required to confirm the clinical findings., (© 2024 The Author(s). Clinical Implant Dentistry and Related Research published by Wiley Periodicals LLC.)

The aim of this study was to characterize the clinicopathological features and prognostic factors of T1/2 size (<4 cm) gingival squamous cell carcinoma (SCC) and to verify the impact of bone invasion. This was a single-centre, retrospective cohort study involving 206 patients with gingival SCC (maxilla or mandible), treated between 2000 and 2020. The patients were divided into three subgroups based on tumour size and bone invasion. The 5-year overall survival (OS) and disease-free survival (DFS) were 80.6% and 67.6%, respectively. Histological differentiation, advanced T stage, positive resection margin, bone invasion, and postoperative adjuvant therapy were associated with a poor prognosis (P < 0.05). Multivariate Cox analysis indicated that only histological differentiation (hazard ratio (HR) 2.68, P = 0.007) and bone invasion (HR 2.08, P = 0.036) were significantly associated with DFS. Bone invasion was observed in 145 (70.4%) patients, of whom 43 (20.9%) had a T1/2 size tumour. The subgroup with bone invasion and T1/2 size showed significantly worse OS and DFS when compared to the subgroup without bone invasion and similar or worse survival when compared to the subgroup with bone invasion and T3/T4 size. Histological differentiation and bone invasion were poor prognostic factors for gingival SCC, even in cases with small-sized tumours. For suspected bone invasion in small-sized tumours, an adequate bone margin is necessary and postoperative adjunctive therapy needs to be considered., (Copyright © 2024 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Objectives: This study aimed to compare the risk of osteoradionecrosis and implant survival in oral cancer patients undergoing immediate dental implants during jaw reconstruction, termed "Jaw in a Day" (JIAD), with those receiving no implants or delayed implants (non-JIAD)., Patients & Methods: Clinicopathologic data were collected from prospectively enrolled JIAD patients (n = 10, 29 implants) and retrospectively from non-JIAD patients (n = 117, 86 implants). Survival analyses were performed to assess implant survival and osteoradionecrosis-free survival., Results: Osteoradionecrosis occurred in 0 % of JIAD cases compared to 19.3 % in non-JIAD cases without implants and 71.4 % in non-JIAD cases with delayed implants (p = 0.008). Osteoradionecrosis-free survival was significantly better in the JIAD group than the non-JIAD group (p = 0.0059). Implants in the JIAD group all survived regardless of radiation therapy (29/29, 100 %) and 95.1 % (58/61) of implants survived in delayed implants in non-irradiated fibula without radiotherapy. Meanwhile, only 11 of 25 implants placed in irradiated fibula flaps survived, even when the implants were placed after a median time interval of 624 days after radiotherapy, and none of them were earlier than 360 days. The survival analysis revealed a significant difference (p < 0.0001)., Conclusion: JIAD appears to offer superior outcomes in terms of implant survival and osteoradionecrosis prevention compared to delayed implant placement. Placing implants in irradiated fibula, even after years, significantly poses high risk of implant failure and osteoradionecrosis. JIAD represents a promising approach for optimal rehabilitation, particularly in oral cancer patients requiring postoperative radiotherapy. Proper positioning and orientation of implants and flaps are crucial for implant survival., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The widespread acceptance of robotic surgery is extending to oral procedures. The demand for minimally invasive techniques is driving research into the cosmetic and oncologic benefits of robotic neck surgery. This study used propensity score matching to analyze the clinical course and postoperative outcomes of robot-assisted neck dissections for oncologic efficacy and surgical safety. Between May 2020 and April 2024, 200 OSCC patients underwent surgery and 42 were excluded. The cohort included 158 patients, 128 of whom underwent unilateral neck dissection and 30 of whom underwent bilateral neck dissection. Robotic-assisted neck dissection (RAND) was performed in 36 patients while conventional transcervical neck dissection (CTND) was performed in 122 patients. Data analysis included several factors, including lymph node retrieval and perioperative outcomes, with 1:1 propensity score matching to ensure fairness. Each of the 39 neck specimens with 36 patients was selected. The CTND group was 8 years older overall than the RAND group, but otherwise similar in terms of primary site and clinical stage. The RAND group had a 55-min longer operative time and 140 cc more hemovac drainage than the CTND group, but the hospital stay and intensive care unit duration were the same, and the number of lymph nodes retrieved was the same. Survival rates also showed no difference across all stages. This shows that RAND is in no way inferior to CTND in terms of perioperative or oncologic outcomes, and demonstrates the safety of robot-assisted surgery, even in patients who require flaps or in patients with advanced stages., (© 2024. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Background/aim: Cancer-associated fibroblasts (CAFs) have recently been suggested as critical cellular components of bone invasion in oral squamous cell carcinoma (OSCC). However, the underlying molecular mechanisms and subtypes related to their bone-invasive function are unclear. This study investigated the implications of thymidine phosphorylase (TP)-positive CAFs (TP + CAFs) in OSCC bone invasion., Materials and Methods: TP expression was determined in 116 patients with OSCC using immunohistochemistry. The influence of TP expression on the biological behavior of CAFs was investigated in vitro. The possible impact of TP + CAFs on bone invasion in OSCC was further evaluated using patient-derived xenograft (PDX) mouse models., Results: In bone-invasive OSCC tissues, TP + CAFs were mainly distributed on the surface of resorbed bone tissue rather than on the tumor side. High levels of TP + CAFs were significantly associated with higher T-stage, bone invasion, and worse overall survival and recurrence-free survival in our study cohort. Recombinant human TP promoted the proliferative and invasive abilities of CAFs and increased matrix metalloproteinase-9 mRNA expression in vitro, related to bone resorption. In the PDX mouse models, TP + CAFs were found in early bone resorption on the surface of resorbed bony tissues. Bone resorption occurred more frequently in the PDX models with TP + CAFs than in those without., Conclusion: TP + CAFs were significantly associated with bone invasion and the prognosis of OSCC. This study provides insights into cellular and molecular targets for the early diagnosis and treatment of bone-invasive OSCC., (Copyright © 2024 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Positioning clothing parts ( S s) such as sleeves and collars has been in the realm of manual task that had to be done meticulously in order to prevent unnecessary tanglements during the simulation. This paper proposes an optimization-based method to computerize the above S-positioning task. For that, we embed each S to an abstracting cylinder C such that S-positioning can be done by adjusting only 3  ∼ 4 DOFs (e.g., translating/rotating C or adjusting its radius) instead of per-vertex-full-DOFs. Then, we formulate an objective function E by scoring undesirableness of S' s position (e.g., S penetrating the body, S making cloth-to-cloth intersection). In organizing E into the loop of the Newton's method, the main challenge was to calculate the symbolic gradient and hessian, for which this paper makes several novel contributions. The resultant S-positioning method works quite successfully; S* s (the output of the S-positioning method ) are tanglement-free thus running the simulator to that configuration produces acceptable draping quickly; Experiments show that, in obtaining acceptable draping, the proposed method produces about ×9.7 speed up compared to when not using it.

Although some surgeons prefer anterolateral thigh and latissimus dorsi flap for soft tissue reconstruction in the head and neck area because it minimizes donor site complications, the radial forearm flap remains the workhorse for soft tissue reconstruction due to its reliability. To reduce donor site morbidity, the authors developed a novel technique for radial forearm flap harvesting using a robotic device. 42 radial forearm free flap reconstruction cases were studied, consisting of 31 conventional and 11 robot-assisted cases. 1:1 propensity score matching was done according to age, sex, previous and postoperative radiation therapy history and method used for vein anastomosis. There was no significant difference in flap outcome, which was 100% vitality in the robot-assisted group and 90.9% vitality in the conventional group. The robot-assisted group showed significantly longer mean harvesting time than did the conventional group, being 107.2 min and 67.0 min, respectively. Robot-assisted radial forearm flap harvesting can reduce donor site complications by minimizing incision. When more surgical experience is gained under appropriate case selection, we expect our robot-assisted method will yield a harvesting time similar to that of the conventional method and thus become more reliable and feasible., (© 2023. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Background: The number, location, and pattern of perforators in anterolateral thigh(ALT) flap vary and predicting them preoperatively will aid in reconstructing complex head and neck defects. This article suggests guidelines for utilizing CTA imagery to predict perforators of ALT-free flaps., Methods: We retrospectively analyzed 53 Korean patients who underwent reconstruction with ALT flap in our department from March 2021 to July 2022. The location, course, origin, and pedicle lengths predicted in CTA and confirmed in the operation field were recorded and compared., Results: Among the 85 intraoperatively-found perforators, 79 were also identified in CTA. Six perforators unidentified in CTA were newly found intraoperatively. The positive predictive value of CTA for the perforator was 100%, with a sensitivity of 79/85 = 92.9%. Of the 79 perforators depicted by the CTA for the flap, CTA and intraoperative findings for the course were consistent in 52 cases, a 9.6 mm median discrepancy being noted between the actual location and CTA., Conclusions: The overall pattern or location of perforation was not significantly different between the two, although some differences were observed. It is suggested that the addition of Doppler imaging, in conjunction with CTA, can aid in perforator detection and help minimize such discrepancies.

Background: Predominant traditional approaches for most patients who have advanced-stage oral cancer with transcervical incision lines left irreversible scars. To address this, surgeons have continuously refined minimally invasive surgery (MIS) techniques, including robot-assisted neck surgeries. This article introduces and discusses the feasibility, versatility, and availability of free-flap reconstruction via the retroauricular approach (RA), considered difficult to date., Methods: This study retrospectively analyzed 90 consecutive patients who had free-flap reconstruction performed by a single surgeon (D.K.) in the Department of Oral and Maxillofacial Surgery, Yonsei University, from March 2021 to April 2022. The type of defects and flaps, hospitalization days, total operation time, and type of vessels and anastomoses were compared statistically., Results: The type of vessels used did not differ between the RA and the transcervical approach (TA) groups, nor in duration of hospital stays. Likewise, the total reconstruction time did not differ significantly between the TA group (240 min) and the RA group (245 min) (p = 0.756). However, the total operation time was about 1 h less in the TA group, a statistically significant difference (TA group [593 ± 152 min] vs. RA group [655 ± 117 min]; p = 0.044). All flaps were successful in the RA group, whereas one flap in the TA group led to a total loss (TA group [98.3%] vs. RA group [100.0%]; p = 1.000)., Conclusions: Even for patients with advanced oral cancer who require massive tumor ablation, it is feasible to obtain an aesthetic and functional surgical outcome by performing free-flap reconstruction via the retroauricular approach., (© 2022. Society of Surgical Oncology.)

Background: We investigated dental implant outcomes in patients who had previously received radiotherapy (RT) for head and neck malignancies., Methods: We reviewed 90 dental implants in 27 patients who received RT for head and neck cancer and received dental implants afterwards. The cumulative implant survival rate (CISR) was calculated. In addition, the implant quality was assessed using "Health Scale for Dental Implants.", Results: The CISR at 3 years was 79.6%. The mean radiation dose at the implant site (D mean ) was identified as an independent prognostic factor for implant survival. No implant failed if D mean was less than 38 Gy. Regarding implant quality, dental implants in grafted bone and D mean were independent risk factors., Conclusions: D mean was identified as an independent prognostic factor for implant survival and quality. Dental implants can be safely considered when D mean is lower than 38 Gy., (© 2022 The Authors. Head & Neck published by Wiley Periodicals LLC.)

Objectives: The concept of adequate surgical margins remains controversial in oral squamous cell carcinoma (OSCC) surgery. This study aimed to identify surgical margin-related indicators that might impact recurrence and survival of OSCC patients., Materials and Methods: Histopathological examination was performed using hematoxylin-eosin-stained surgical margin tissue sections in 235 OSCC patients. Axin2 and Snail expression at the surgical margin was detected by immunohistochemistry. The impact of the Axin2-Snail cascade on tumorigenesis of the immortalized human oral keratinocyte (IHOK) line was investigated in vivo ., Results: The width and dysplasia of surgical margins were not significantly associated with the outcome of OSCC patients. In a multivariate analysis using variable clinicopathologic factors and with Axin2 and Snail expression as cofactors, higher age (hazard ratio [HR]:1.050; P =0.047), Axin2 (HR:6.883; P =0.014), and Snail abundance (HR:5.663; P =0.009) had independent impacts on worsened overall survival. Similarly, lesion site in retromolar trigone (HR:4.077; P =0.010), upper (HR:4.332; P =0.005) and lower gingiva (HR:3.545; P =0.012), presence of extranodal extension (HR:9.967; P <0.001), perineural invasion (HR:3.627; P =0.024), and Snail abundance (HR:3.587; P <0.001) had independent impacts on worsened recurrence-free survival. Furthermore, Axin2 knockdown induced decreased Snail expression and attenuated tumorigenesis in the IHOK line., Conclusion: Histopathological examination of surgical margins may not be reliable to predict OSCC patient outcome. Molecular analysis may provide a more accurate risk assessment of surgical margins in OSCC. In particular, Axin2 and Snail are potential predictive biomarkers for the risk assessment of surgical margins in OSCC., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Pei, Han, Kim, Kim, Nam, Kim, Cho, Kim, Cha and Zhang.)

This article proposes a new discrete collision handling method (DCH method) that can be used for resolving tanglements in clothing simulation, based on the existing continuous collision handling methods (CCH methods). The proposed method performs intersection analysis of the clothing mesh at every time step, and stores the result in the form of coloring the vertices, edges, and triangles. Referring to the coloring, the method resolves the tanglements in the out-to-in manner by applying the proposed operations, the triangle shrinkage and vertex pull, to the triangles and vertices around the intersection path. We take note of the CCH methods that use some small tolerance value to defend the round-off errors for the purpose of preventing false negatives. This work gives a second thought to that tolerance value, and proposes a new DCH method which uses the tolerance value for the resolution purpose. Under certain conditions, the method turns out to guarantee resolution of the tanglements in a finite number of time steps.

Quantifying the spin-orbit torque (SOT) efficiency with changing the layer thickness is crucial for understanding the physical background of SOT. This study investigates the Nb-thickness-dependent SOT efficiency of two types of layered heterostructures: Ta/Nb/CoFeB and Pt/Nb/CoFeB. We find that the Nb thickness dependence of the SOT efficiency in the two samples is quite different. In the Pt/Nb series, the SOT sign changes according to the thickness variation because Pt and Nb have different spin-orbit coupling signs. We observe the resulting reversal in switching polarity through current-induced SOT switching experiments. However, due to the same spin-orbit coupling signs of Ta and Nb, no such polarity reversal was observed in Ta/Nb series. Further, we extract the spin diffusion length of Nb in each heterostructure. These results provide a systematic understanding of the material- and thickness-dependent SOT characteristics., (© 2021. The Author(s).)

Purposes: Although clinical and radiological examinations can be used to diagnose oral cancer, and surgical pathology remains the gold standard, these conventional methods have limitations. We evaluated the feasibility of longitudinal next-generation sequencing-based liquid biopsy for oral squamous cell carcinoma surveillance., Materials and Methods: Eleven patients were enrolled, and plasma and saliva were collected before, and 1, 3, and 6 months after surgery. Tumor-specific mutations were selected using paired, whole-exome analyses of tumor tissues and whole blood. Genes frequently mutated in head and neck cancer were identified using the Cancer Genome Atlas (TCGA) and Catalogue of Somatic Mutations in Cancer (COSMIC) databases to design targeted deep sequencing panels., Results: In five of the six patients with recurrent cancer, circulating tumor DNA (ctDNA) was detected earlier with liquid biopsy than with conventional monitoring techniques. Moreover, patients without recurrence exhibited decreased ctDNA allele frequency post-treatment., Conclusions: Longitudinal liquid biopsy of plasma and saliva may be feasible for detecting somatic mutations associated with oral squamous cell carcinomas. It might be attributable to determine early tumor recurrence through genetic analysis of ctDNA., Competing Interests: HSK, JYP, and JAP, who are employees of Theragen Bio, solely contribute their scientific expertise and knowledge to conduct next-generation sequencing and bioinformatics analysis for this study. They do not have any competing interests. Also, I would like to declare that Theragen Bio did not provide any funding for this study and does not alter my adherence to PLOS ONE policies on sharing data and materials.

The aim of the present study was to examine the conditions, characteristics, and risk factors of level IIb lymph node metastases in oral squamous cell carcinoma and to formulate surgical criteria for level IIb lymph node dissection. We analyzed clinical and pathological records for 541 oral squamous carcinoma patients in relation to level IIb metastasis. Univariate and multivariate analyses were performed to detect risk factors for level IIb lymph node metastasis; a predictive model was built based on multivariate analysis and tested in a validation group. Univariate and multivariate analyses using the training group indicated that level IIa metastasis and Lymphovascular permeation (LVP) were two independent risk factors for level IIb lymph node metastasis. This model was built and tested in a validation group, the area under the curve being 0.697 (P < .0.001). The model's sensitivity was 66.7% and specificity was 77.4%. Nomogram incorporating validated variables was developed for level IIb metastasis prediction. Expected survival probabilites were analysed to specify significance of model's variable on patients' overall survival and recurrence. Level IIb dissection should be performed in patients with level IIa metastasis and LVP. However, thorough consideration of the oncologic safety of omitting level IIb dissection is compulsory., (© 2021. The Author(s).)

Purpose: The aim of this study was to conduct epidemiologic investigations on the pattern of the lesion and differences between treatment modalities in terms of recurrence by reviewing follow-up records to form a basis for planning patient follow-up visits., Materials and Methods: In this retrospective, single-center cohort study, 266 patients diagnosed with odontogenic keratocyst between 1993 and 2013 were included. Medical records and radiographic images were analyzed for age distribution, occurrence site and size, treatment modalities, and recurrence., Results: The average age at first diagnosis was 33.1 years, and the male to female ratio was 1.33:1.00. The highest rate of incidence was in the third decade followed by the fourth, second, and fifth decades. The incidence in the maxilla was 34%, and 66% in the mandible. Mandibular ramus was most commonly involved. Lesions between 3 and 6 crowns were the most common, and the rate of recurrence increased with size. Enucleation after decompression had higher rate of recurrence (35.8%) than enucleation (27.1%), but there was no statistical significance., Conclusion: The recurrence of odontogenic kerotocyst (OKC) was significantly associated with large size, multilocular form, and surgical procedure. A 10-year follow-up period is recommended to determine any recurrence of OKC.

The manipulation of magnetization with interfacial modification using various spin-orbit coupling phenomena has been recently revisited due to its scientific and technological potential for next-generation memory devices. Herein, we experimentally and theoretically demonstrate the interfacial Dzyaloshinskii-Moriya interaction characteristics penetrating through a MgO dielectric layer inserted between the Pt and CoFeSiB. The inserted MgO layer seems to function as a chiral exchange interaction mediator of the interfacial Dzyaloshinskii-Moriya interaction from the heavy metal atoms to ferromagnet ones. The potential physical mechanism of the anti-symmetric exchange is based on the tunneling-like behavior of conduction electrons through the semi-conductor-like ultrathin MgO. Such behavior can be correlated with the oscillations of the indirect exchange coupling of the Ruderman-Kittel-Kasuya-Yosida type. From the theoretical demonstration, we could provide approximate estimation and show qualitative trends peculiar to the system under investigation.

Objectives: We aimed to collect and report data from all patients who have been diagnosed with mucosal malignant melanoma to obtain the epidemiology and principles of current treatments., Materials and Methods: Between January 2008 and December 2018, 20 patients underwent surgery or follow-up observations at Yonsei University Dental Hospital. The patients' clinical information was reviewed retrospectively., Results: Seventeen of 20 patients had undergone definitive surgery, while only 6 patients received adjuvant radiotherapy or systemic therapy. Eight of 20 patients, including those that had recurrent lesions, were provided immunotherapy. The 3-year survival for all stages was 50%, with a local recurrence rate of 75% and a metastasis rate of 65%., Conclusion: The overall survival of patients receiving surgical treatment was longer than that of patients who did not undergo surgical resection. Eight of 20 patients received immunotherapy as the first-line regimen at our clinic, and those patients exhibited longer overall survival compared to patients in reported keynote studies.

Background/purpose: Surgery followed by postoperative radiotherapy (RT) has been considered the standard treatment for oral cavity squamous cell carcinoma (OCSCC) of advanced stages or with adverse prognostic factors. In this study, we compared the outcomes in patients with OCSCC who received postoperative concurrent chemoradiotherapy (CCRT) or postoperative RT alone using modern RT techniques., Methods: A total of 275 patients with OCSCC treated between 2002 and 2018 were retrospectively analyzed. Adverse prognostic factor was defined as extranodal extension (ENE), microscopically involved surgical margin, involvement of ≥2 lymph nodes, perineural disease, and/or lymphovascular invasion (LVI). In total, 148 patients (54%) received CCRT and 127 patients (46%) received RT alone. More patients in the CCRT group had N3 disease and stage IVB disease (46.6% vs. 10.2%, p <0.001), ENE (56.1% vs. 15.7%, p <0.001), LVI (28.4% vs. 13.4%, p =0.033)., Results: With a median follow-up of 40 (range, 5-203) months, there were no significant differences in the 5-year overall survival (OS) and PFS between treatment groups. In the subgroup analysis according to high risk, the concurrent use of chemotherapy showed significantly improved OS in patients with ENE (HR 0.39, p =0.003)., Conclusion: Our retrospective study showed that postoperative CCRT group had comparable survival outcomes to those in the RT alone group for advanced OCSCC in the era of modern RT techniques and indicated that concurrent chemotherapy should be administered to patients with ENE. Prospective randomized studies for confirmation are needed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Kim, Cha, Choi, Kim, Kim, Kim, Keum and Lee.)

Indocyanine green near-infrared fluorescence (ICG-NIRF) imaging has recently come into use as a novel method in peri-operative microvascular flap assessment. However, a majority of the many commercial devices launched for clinical use lack mobility, portability, and cost-efficiency and are thus unsuitable for intra-oral applications. This study introduces a cost-effective, customized, handheld NIRF device following principles of ICG-NIRF imaging. Moreover, the novel characteristics of our prototype, considered in conjunction with a literature review highlighting the significance of fluorescence devices in microvascular surgery, point to a new generation of devices for use in microvascular flap surgery.

The purpose of this study was to investigate the effect of administering intermittent parathyroid hormone (iPTH) before tooth extraction versus after tooth extraction on the risk of developing MRONJ in experimental animal model. Twenty-five ovariectomized rats received 6 weeks of bisphosphonate therapy. They were classified into 3 groups, based on the timing of the medication, as Control, Pre-PTH and Post-PTH groups. For Control group, normal saline was administered before and after tooth extraction. iPTH was administered during 4 weeks before tooth extraction for Pre-PTH group and after tooth extraction for Post-PTH group. The animals were euthanized 8 weeks after tooth extraction. Macroscopic, histological, micro-computed tomography (micro-CT), and histomorphometric examinations were conducted. The incidences of impaired healing were 11.11% both in Pre-PTH and Post-PTH groups, which was lower than the Control group (42.86%). Bone healing in the extraction socket, based on micro-CT and histomorphometry evaluations, was best in Post-PTH and worst in Control group. The Pre-PTH group showed moderate healing pattern. Despite of limitations in this study, the authors identified Pre-PTH group seems to have positive effect on extraction socket healing. With regard to timing, administering iPTH after tooth extraction was superior to applying it before tooth extraction.

Magnetic skyrmions are stable spin textures with quasi-particle behavior and attract significant interest in fundamental and applied physics. The metastability of magnetic skyrmions at zero magnetic field is particularly important to enable, for instance, a skyrmion racetrack memory. Here, the results of the nucleation of stable skyrmions and formation of ordered skyrmion lattices by magnetic force microscopy in (Pt/CoFeSiB/W) n multilayers, exploiting the additive effect of the interfacial Dzyaloshinskii-Moriya interaction, are presented. The appropriate conditions under which skyrmion lattices are confined with a dense two-dimensional liquid phase are identified. A crucial parameter to control the skyrmion lattice characteristics and the number of scans resulting in the complete formation of a skyrmion lattice is the distance between two adjacent scanning lines of a magnetic force microscopy probe. The creation of skyrmion patterns with complex geometry is demonstrated, and the physical mechanism of direct magnetic writing of skyrmions is comprehended by micromagnetic simulations. This study shows a potential of a direct-write (maskless) skyrmion (topological) nanolithography with sub-100 nm resolution, where each skyrmion acts as a pixel in the final topological image.

It has been recognized that systemic inflammatory markers (SIMs) are associated with patient survival in various types of cancer. This study aimed to determine the optimal cut-off values, and to evaluate the prognostic performance of SIMs for oral squamous cell carcinoma (OSCC) within the framework of the American Joint Committee of Cancer (AJCC) cancer staging manual, 8th edition. Records were collected for a total 291 patients who had had a peripheral blood test within 1 week prior to surgery and had undergone the surgical resection of OSCC in a single institution between 2005 and 2018. The cut-off values of SIMs were obtained, and the survival analyses for overall survival (OS) and disease-free survival (DFS) were performed. Multivariate analyses incorporating other clinicopathologic factors were performed to verify the independent risk factors for survival. The cut-off values of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were 2.23, 135.14 for OS and 2.16, 131.07 for DFS, respectively, demonstrating a significant association for OS and DFS in OSCC. AJCC pathologic regional lymph node category (pN) (P < 0.001), perineural invasion (PNI) (P < 0.001) and NLR (P < 0.001) were independent predictors for OS. Meanwhile, for DFS, AJCC pN (P = 0.018) and NLR (P = 0.015) were shown to be independent predictors. Before the curative surgery, NLR and PLR could be auxiliary parameters for OS and DFS in OSCC. And based on the 8th edition of AJCC staging system, elevated NLR will be a potential indicator of the worse OS or DFS along with pN or PNI in OSCC.

Patients with odontogenic cysts and tumors may have to undergo serious surgery unless the lesion is properly detected at the early stage. The purpose of this study is to evaluate the diagnostic performance of the real-time object detecting deep convolutional neural network You Only Look Once (YOLO) v2-a deep learning algorithm that can both detect and classify an object at the same time-on panoramic radiographs. In this study, 1602 lesions on panoramic radiographs taken from 2010 to 2019 at Yonsei University Dental Hospital were selected as a database. Images were classified and labeled into four categories: dentigerous cysts, odontogenic keratocyst, ameloblastoma, and no cyst. Comparative analysis among three groups (YOLO, oral and maxillofacial surgeons, and general practitioners) was done in terms of precision, recall, accuracy, and F1 score. While YOLO ranked highest among the three groups (precision = 0.707, recall = 0.680), the performance differences between the machine and clinicians were statistically insignificant. The results of this study indicate the usefulness of auto-detecting convolutional networks in certain pathology detection and thus morbidity prevention in the field of oral and maxillofacial surgery.

Prognosis prediction of squamous cell carcinoma (SCC) with mandibular invasion is controversial, and a more sophisticated staging system to aid prognosis could be developed with imaging characteristics of bone invasion. Imaging-feature analysis provides practical, stratified results for survival prognosis in oral SCC (OSCC) of the mandible, and imaging advances enable more detailed tumor visualization. We retrospectively evaluated significant bone-invasion features associated with poor outcomes in mandibular OSCC to assess the predictive value of staging criteria that combined imaging features and histologic grade (combined imaging-histology (IH) grade) in 65 patients (39 men, 26 women) with mandibular SCC diagnosed from 2006 to 2016. Clinicopathologic features, including T-stage and histologic grade, and prognosis were retrieved. Tumors were classified into three types by extent of mandibular invasion on pretreatment imaging studies. Moreover, we assessed the involvement of the mandibular canal. We examined the correlation of factors associated with locoregional recurrence and overall mortality. The Harrell Concordance Index (C-index) determined prognostic performance of predictors. Nineteen (29%) patients showed locoregional recurrence and 13 (20%) died. For locoregional recurrence and mortality rates, imaging-detected mandibular canal (MC) involvement is a stronger prognostic factor for recurrence (C-index = 0.61 > 0.58) and survival (C-index = 0.58 > 0.63) than histopathologically confirmed perineural invasion, as was the IH grade, especially IH Grade 3, which was significantly associated with worse locoregional recurrence (p < 0.02). Imaging-based staging showed higher prognostic performance than T-staging (C-index = 0.57 (recurrence), 0.60 (death)), when combined with histologic grading (C-index = 0.69 for both) or used alone (C-index = 0.63 (locoregional recurrence), 0.69 (death)). Overall survival was significantly stratified by Imaging type and IH grade. Therefore, analysis of imaging features provided more specific, practical results for survival prognosis in mandibular OSCC. Imaging advances can potentially provide detailed gross views of tumor masses to facilitate development of prognostic criteria for OSCC., Competing Interests: The authors declare no conflict of interest.

The Cox proportional hazards model commonly used to evaluate prognostic variables in survival of cancer patients may be too simplistic to properly predict a cancer patient's outcome since it assumes that the outcome is a linear combination of covariates. In this retrospective study including 255 patients suitable for analysis who underwent surgical treatment in our department from 2000 to 2017, we applied a deep learning-based survival prediction method in oral squamous cell carcinoma (SCC) patients and validated its performance. Survival prediction using DeepSurv, a deep learning based-survival prediction algorithm, was compared with random survival forest (RSF) and the Cox proportional hazard model (CPH). DeepSurv showed the best performance among the three models, the c-index of the training and testing sets reaching 0.810 and 0.781, respectively, followed by RSF (0.770/0.764), and CPH (0.756/0.694). The performance of DeepSurv steadily improved with added features. Thus, deep learning-based survival prediction may improve prediction accuracy and guide clinicians both in choosing treatment options for better survival and in avoiding unnecessary treatments.

Objectives: Ameloblastomas are the most common odontogenic epithelial tumors with high recurrence rate. The aim of this study was to identify apoptosis-related genes with recurrence of ameloblastomas and to evaluate its feasibility as a prognostic marker and as a target molecule preventing from recurrence., Materials and Methods: Public microarray data were analyzed. To evaluate their expression in ameloblastoma patients, immunohistochemical staining was performed in 89 human ameloblastoma tissues. Quantitative PCR was performed by use of ameloblastoma cell line (AM-1). Fluorescence activated cell sorting analysis and western blotting were conducted following transfection with siRNA. Further, AM-1 cells were implanted in the renal subcapsular layer of immunodeficient mice., Results: Microarray data analysis revealed that osteoprotegerin (OPG) and B-cell lymphoma 2 (Bcl-2) were the two most upregulated genes in ameloblastoma. Only Bcl-2 expression was significantly (p = 0.020) associated with recurrence in conservative treatment group (n = 17) among 89 patients. Silencing of Bcl-2 increased apoptosis in AM-1 cells in vitro and inhibited tumor nodule formation of AM-1 cells in vivo., Conclusion: These results suggest that Bcl-2 expression is a useful biomarker to predict recurrence of ameloblastomas, and as a therapeutic target molecule to prevent recurrence of ameloblastoma., (© 2019 The Authors Oral Diseases Published by John Wiley & Sons Ltd.)

We recently achieved favorable results in 3 pediatric patients with mandibular osteosarcomas that were treated at our hospital, including with immediate reconstructive surgery performed after tumor resection. Based on a literature review and practical investigation, we discuss the considerations for mandibular reconstruction after malignant lesions are removed from the mandible in children. Mandibular reconstruction for pediatric patients requires an understanding of the changes in bone and soft-tissue architecture due to growth and development at both the donor and recipient sites. Immediate mandibular reconstruction with a free flap can be considered a reasonable option even for young children who require extensive mandibular surgery. However, the variables affecting decisions about treatment planning vary between the different conditions in individual patients, and moreover, these cases are not common in the pediatric population. Therefore, long-term follow-up treatment and further investigations are required for the optimized diagnosis, treatment, and prognosis of pediatric mandibular malignancies.

Introduction: The aim of this study was to build and validate five types of machine learning models that can predict the occurrence of BRONJ associated with dental extraction in patients taking bisphosphonates for the management of osteoporosis., Patients & Methods: A retrospective review of the medical records was conducted to obtain cases and controls for the study. Total 125 patients consisting of 41 cases and 84 controls were selected for the study. Five machine learning prediction algorithms including multivariable logistic regression model, decision tree, support vector machine, artificial neural network, and random forest were implemented. The outputs of these models were compared with each other and also with conventional methods, such as serum CTX level. Area under the receiver operating characteristic (ROC) curve (AUC) was used to compare the results., Results: The performance of machine learning models was significantly superior to conventional statistical methods and single predictors. The random forest model yielded the best performance (AUC = 0.973), followed by artificial neural network (AUC = 0.915), support vector machine (AUC = 0.882), logistic regression (AUC = 0.844), decision tree (AUC = 0.821), drug holiday alone (AUC = 0.810), and CTX level alone (AUC = 0.630)., Conclusions: Machine learning methods showed superior performance in predicting BRONJ associated with dental extraction compared to conventional statistical methods using drug holiday and serum CTX level. Machine learning can thus be applied in a wide range of clinical studies., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: To evaluate the ability of xenogenic bone and absorbable collagen sponge to function as an rhBMP-2 carrier and the osteoinductivity of bisphosphonate by comparison with recombinant human bone morphogenetic protein-2 (rhBMP-2)., Materials and Methods: Thirty-two Sprague-Dawley male rats were divided into four groups. Segmental ostectomy of both fibulae was performed, and the defect area was then treated with Rapiderm Pad (absorbable collagen sponge; COL&#95;BMP) or CollaOss (xenogenic bone; XENO&#95;BMP) with application of rhBMP-2. Alternatively, both fibulae were grafted with xenogenic bone with different bisphosphonate concentrations (XENO&#95;Low BP, XENO&#95;High BP). After 4 or 8 weeks, animals were sacrificed, and radiographic, histological, histomorphometric, and immunohistochemical analyses were performed., Results: Recombinant human bone morphogenetic protein-2 promoted bone formation, regardless of the carrier, and exhibited continuity between the graft material and defect area. Moreover, the results showed that higher concentrations of bisphosphonate were associated with greater bone formation than lower concentrations of bisphosphonate., Conclusion: Absorbable collagen sponges with rhBMP-2 were advantageous in that there was no remaining graft material and that the bone was remodeled to resemble the existing fibula. The local application of bisphosphonate promoted new bone formation, particularly when used at high concentrations. High-concentration bisphosphonate induced new bone formation comparable to rhBMP-2 with lesser remaining bone material., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. All rights reserved.)

Unlike the levels of anatomical exploration, there is no consensus on the extent of lymph node dissection, or lymph node count (LNC), during selective neck dissection (SND). The aim of this study was to validate the prognostic impact of LNC on survival and to determine an optimal LNC cut-off value for SND. A retrospective investigation identified 78 patients with a diagnosis of oral squamous cell carcinoma (OSCC) who underwent SND (levels I-III or levels I-IV). LNC and clinicopathological variables were analyzed for any association with survival in Cox proportional hazards models. Based on the receiver operating characteristic curve, a cut-off value of 19 lymph nodes was found to predict overall survival (OS) (area under the curve 0.732, sensitivity 67.8%, specificity 75.0%; P=0.026) and disease-specific survival (DSS) (area under the curve 0.762, sensitivity 68.1%, specificity 77.8%; P=0.011). On Cox regression, LNC (≥19 vs. <19) was the only independent predictor of OS (hazard ratio 5.29, 95% confidence interval 1.39-20.05; P=0.014) and DSS (hazard ratio 6.76, 95% confidence interval 1.40-32.77; P=0.018). Similar results were obtained in the pathologically lymph node-negative subgroup (n=66). Based on the study findings, SND should include 19 or more lymph nodes for a survival benefit., (Copyright © 2018 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Although osteoradionecrosis (ORN) is a serious complication of craniofacial radiotherapy, the current management methods remain suboptimal. Teriparatide (TPTD), a recombinant human parathyroid hormone (1-34), has shown beneficial effects on osseous regeneration in medication-related osteonecrosis of the jaw or periodontitis. However, TPTD therapy in irradiated bones has not been indicated yet because of the theoretical risk of osteosarcoma seen in rat models. Hence, we first report here two patients with tongue cancer with late-emerging ORN who were successfully treated with TPTD for 4-6 months with serum calcium and vitamin D supplementation. In contrast to the usual progress of ORN, the bone defect regenerated well and bone turnover markers including serum C-terminal telopeptide of type 1 collagen and osteocalcin were restored with TPTD therapy. Our experience might suggest that TPTD therapy with careful monitoring can provide an effective treatment option for patients with ORN in select refractory cases, with the benefits outweighing the potential risks.

Background: For this study, the aim was to identify combined biomarkers associated with bisphosphonate-related osteonecrosis of the jaw (BRONJ)., Materials and Methods: Microarray data for GSE7116 were downloaded from the Gene Expression Omnibus database, which contains 26 samples, including without ONJ, and 5 healthy volunteers. The combined biomarkers were identified using principal component analysis, and the pathway enrichment analyses were performed using the DAVID online tool., Results: Two hundred differently expressed genes between groups were detected according to the significances. From functional annotation, Y-box binding protein 1 and heterogeneous nuclear ribonucleoprotein C were found to be included in the most significant 10 pathways. Ten combined gene sets were identified that were effective in classifying multiple myeloma (MM) with ONJ and MM without ONJ., Conclusion: Identifying combined gene expression profiles is expected to contribute to more personalized management of BRONJ and to improve existing therapies, and it will be helpful in finding new therapies by identifying more predictive biomarkers., (© 2017 Wiley Periodicals, Inc.)

In this study, we investigated the consensus gene modules in head and neck cancer (HNC) and cervical cancer (CC). We used a publicly available gene expression dataset, GSE6791, which included 42 HNC, 14 normal head and neck, 20 CC and 8 normal cervical tissue samples. To exclude bias because of different human papilloma virus (HPV) types, we analyzed HPV16-positive samples only. We identified 3824 genes common to HNC and CC samples. Among these, 977 genes showed high connectivity and were used to construct consensus modules. We demonstrated eight consensus gene modules for HNC and CC using the dissimilarity measure and average linkage hierarchical clustering methods. These consensus modules included genes with significant biological functions, including ATP binding and extracellular exosome. Eigengen network analysis revealed the consensus modules were highly preserved with high connectivity. These findings demonstrate that HPV16-positive head and neck and cervical cancers share highly preserved consensus gene modules with common potentially therapeutic targets., Competing Interests: CONFLICTS OF INTEREST All authors declare that there are no conflicts of interest.

Objectives: Odontogenic keratocyst (OKC), also known as keratocystic odontogenic tumor (KCOT), has clinical significance due to its high incidence as well as high recurrence rate after surgical enucleation. Current clinical management for OCK is entirely dependent on surgical approach. While various genetic alterations, such as PTCH1 mutation and loss of heterozygosity in tumor suppressor genes, have been reported, the molecular background of OKC is not well-understood. Although recent identification of BRAF V600E mutation and subsequent activation of mitogen-activated protein kinase (MAPK) pathway in ameloblastoma and odontogenic tumors provide additional options with targeted therapeutics, the molecular background of OKC is not well understood., Materials and Methods: In this study, we examined BRAF V600E mutation from paraffin embedded OKC samples by tumor cell enriched microdissection and TA cloning of amplified DNA. We further examined the relationship between BRAF V600E mutation and clinical parameters., Results: We found frequent BRAF V600E mutation in OKC (24 of 38 samples, 63.2%). However, BRAF V600E mutational status is not related with clinical indexes such as size, location, and recurrence. In orthokeratinized odontogenic cyst, there is one case of BRAF 600E mutation from 11 samples (9.1%)., Conclusion: These results indicate that BRAF V600E mutation occurs in OKCs at a high rate and plays an important role in the pathogenesis of OKCs., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objectives: Oral leukoplakia (OL) has a well-documented potential risk of malignant transformation into oral squamous cell carcinoma (OSCC), although biomarker(s) predicting malignant potential are limited in capability. The aim of this cross-sectional and retrospective cohort study was to investigate the predictive role of canonical Wnt genes Axin2 and Snail (SNAI1) expression in the malignant transformation of OL lesions., Materials and Methods: The expression of epithelial-mesenchymal transition (EMT) genes Snail and Axin2, which are regulated by the canonical Wnt pathway, were determined using immunohistochemical staining in an OL cohort consisting of 154 samples of patients with long-term follow-up and then evaluated as risk factors for malignant transformation of OL., Results: Increased Axin2 and Snail abundance were found in 107 (69.5%) and 58 (37.7%) of OL patients, respectively. In a multivariate analysis using gender, age, lesion site, Axin2, and Snail as cofactors, both Axin2 and Snail were independent risk factors for malignant transformation with a hazard ratio of 7.47 (95% confidence interval, 2.23-25.02; P=0.001) and 4.41 (95% confidence interval, 1.78-10.93; P=0.001), respectively. A nomogram for predicting 5-, 10-, and 15-year cancer-free survival probability was developed in patients with OL by including gender, age, lesion site, Axin2, and Snail expression with ac-index of 0.760., Conclusion: The increased abundance of Snail and Axin2 is highly correlated to malignant transformation of OL, making them novel biomarker(s) predicting oral cancer development., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objectives: In order to assess clinical behavior, response to treatment, and factors influencing prognosis of Korean patients with osteosarcoma of the jaws (OSJ)., Materials and Methods: A retrospective study of clinical, and pathological records of 26 patients with OSJ treated at the Department of Oral and Maxillofacial Surgery in Yonsei University Dental Hospital from 1990 to March 2017., Results: Of 26 patients, there were 9 men (34.6%) and 17 women (65.4%). Twenty-one of 26 patients had osteosarcoma of the mandible, and 5 of 26 patients had osteosarcoma of the maxilla. The histopathology of OSJ is highly variable, ranging from chondroblastic type (6 out of 26), osteoblastic type (10 out of 26), fibroblastic type (2 out of 26), to the rare variants like mixed type, small cell osteosarcoma types and more. All patients underwent gross total excision and only a few patients underwent neoadjuvant chemotherapy. Postoperative chemotherapy was given to most of the patients as adjuvant treatment or in combination with radiotherapy. The overall survival rate was 73.1% with an overall 2-year survival rate of 83.3%. The overall 5-,10-,15-year survival rates in this study were 73.5%, 73.5%, 49%, respectively. Using Kaplan-Meier analysis with log rank tests, the size of tumor (T-stage), and resection margins were found to affect the survival rate significantly. The chemotherapy was not significantly associated with improved survival rate., Conclusion: Surgical resection with a clear margin is the most important factor in disease survival. The role of chemotherapy and radiotherapy in OSJ remains controversial, and deserves further studies., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported.

Objectives: To define the risk of occult cervical metastasis of maxillary squamous cell carcinoma (SCC) and the therapeutic value of elective neck dissection (END) in survival of clinically negative neck node (cN0) patients., Materials and Methods: Sixty-seven patients with maxillary SCC and cN0 neck were analyzed retrospectively, including 35 patients with maxillary gingiva and 32 patients with maxillary sinus., Results: Of 67 patients, 10 patients (14.9%) had occult cervical metastasis. The incidence of occult cervical metastasis of maxillary gingival SCC was higher than that of maxillary sinus SCC (17.1% and 12.5%, respectively). The 5-year overall survival rate was 51.9% for the END group and 74.0% for the non-END group. The success rate of treatment for regional recurrence was high at 71.4%, whereas that for local or locoregional recurrence was low (33.3% and 0%, respectively)., Conclusion: The incidence of occult cervical metastasis of maxillary SCC was not high enough to recommend END. For survival of cN0 patients, local control of the primary tumor is more important than modality of neck management. Observation of cN0 neck is recommended when early detection of regional recurrence is possible irrespective of the site or T stage. The key enabler of early detection is patient education with periodic follow-up., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported.

Tissue defect reconstruction using radial forearm free flap (RFFF) is a common surgical technique whose success or failure is mainly dependent on venous drainage. RFFF has two major venous outflow systems, superficial and deep vein. Drainage methods include combining both systems or using one alone. This review aims to recapitulate the vascular anatomy and network of RFFF as well as shed light on deep vein as a reliable venous drainage system. We also discuss basic evidence for and advantages of single microanastomosis with coalesced vein to overcome technical difficulties associated with the deep vein system.

Purpose: We aimed to identify a combined prognostic factor for predicting better performance in risk stratification., Materials and Methods: We reviewed the clinical and pathological variables of 316 patients with oral squamous cell carcinoma (OSCC) who underwent surgery. To identify a combined predictor, principal component analysis (PCA) was performed., Results: Univariate analysis showed that the independent prognostic variables for overall survival (OS) were pathologic T stage (T1 vs T4, HR = 1.99, 95% CI: = 1.083-3.675, P = 0.026) and pathologic N stage (N0 vs N2, HR=1.90, 95% CI: = 1.17-3.08, P = 0.008). In the multivariate analysis, only pathologic T stage was significant (P = 0.006 and P = 0.007); however, the multivariate model was not significant (P = 0.191). The multivariate model became significant by including lymph node ratio (LNR) instead of pathologic N stage (P = 0.0025 in numeric LNR, P = 0.0007 in categorized LNR). Also, the performance of prediction model was improved by a combined prognostic factor (P = 0.0002)., Conclusions: The newly identified combined prognostic factor included resection margin, differentiation, and LNR, and they were insignificant factors independently except for LNR. This combined prognostic factor showed a good performance although it did not include molecular markers; therefore, it may be used conveniently for risk stratification of patients with OSCC by combining only clinical information., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: Chemotherapy targets all rapidly growing cells, not only cancer cells, and thus is often associated with unpleasant side effects. Therefore, examination of the chemosensitivity based on genotypes is needed in order to reduce the side effects., Materials and Methods: Various computational approaches have been proposed for predicting chemosensitivity based on gene expression profiles. A linear regression model can be used to predict the response of cancer cells to chemotherapeutic drugs, based on genomic features of the cells, and appropriate sample size for this method depends on the number of predictors. We used principal component analysis and identified a combined gene expression profile to reduce the number of predictors., Results: The coefficients of determinanation (R 2 ) of prediction models with combined gene expression and several independent gene expressions were similar. Corresponding F values, which represent model significances were improved by use of a combined gene expression profile, indicating that the use of a combined gene expression profile is helpful in predicting drug sensitivity. Even better, a prediction model can be used even with small samples because of the reduced number of predictors., Conclusion: Combined gene expression analysis is expected to contribute to more personalized management of breast cancer cases by enabling more effective targeting of existing therapies. This procedure for identifying a cell-type-specific gene expression profile can be extended to other chemotherapeutic treatments and many other heterogeneous cancer types., Competing Interests: relevant to this article was not reported.

Objectives: To evaluate the results of elective neck dissection versus those of observation in the treatment of early stage oral squamous cell carcinoma and to identify factors related to recurrence and survival., Materials and Methods: This was a retrospective study of 52 patients who underwent elective neck dissection and 27 who did not receive neck dissection., Results: In survival analyses, elective neck dissection showed a benefit in overall recurrence ( P =0.027), especially in stage I patients ( P =0.024). With regard to survival, the benefit was statistically insignificant ( P =0.990). In multivariable analysis, overall recurrence was independently related to poor histologic grade (odds ratio [OR]=9.65, P =0.006), and cancer-specific death was independently related to advanced age (OR=6.3, P =0.022), higher clinical T stage (OR=15.2, P =0.01), and poorly differentiated histologic grade (OR=6.6, P =0.025)., Conclusion: Though there was lower recurrence in the elective neck dissection group, there were no statistically significant results on survival. The characteristics of the tumor itself, such as clinical T stage and poor histologic grade, may be more important in cancer-specific survival., Competing Interests: No potential conflict of interest relevant to this article was reported.

Objectives: The aim of this study was to investigate the potential role of microcrack accumulation in the pathogenesis of bisphosphonate-related osteonecrosis of the jaw (ONJ) through an animal model., Materials and Methods: Twenty-four ovariectomized rats were randomly divided into a bisphosphonate group (n = 19) and control group (n = 5) and weekly injected with zoledronic acid and normal saline, respectively. After 6 weeks, surgical intervention was performed, and the injections were continued for eight additional weeks. Then, the animals were sacrificed, and ONJ lesions were inspected for the presence of microcracks using scanning electron microscopy. Measurements included bone dimension, number of cracks, crack length, and normalized indices; crack density (Cr.Dn) and crack surface density (Cr.S.Dn) were used for group comparison., Results: Both number of cracks and crack length in the bisphosphonate group were greater than those in the control group (P < 0.05). Of the 19 rats injected with bisphosphonates, 13 rats (68.4 %) were classified into the ONJ group. Cr.Dn and Cr.S.Dn were significantly greater in the ONJ group than in the non-ONJ group, indicating accumulation of unrepaired microcracks (P < 0.05). Seventy-two percent of microcracks in the ONJ group conformed to the defined length that was considered significant according to a previous literature (30-80 μm); whereas 12 % of microcracks in the non-ONJ group were considered significant (P < 0.05)., Conclusion: Accumulation of unrepaired microcracks was significantly associated with the development of bisphosphonate-related ONJ. Further research is required to determine the role of microcracks in the pathogenesis of bisphosphonate-related ONJ., Clinical Relevance: Long-term bisphosphonates use may deteriorate the biomechanical and physiological bone integrity, contributing to the pathogenesis of bisphosphonate-related ONJ.