Surgical Orthodontic Treatment for Skeletal Maxillary Protrusion in Sturge-Weber Syndrome: A Case Report and Review of the Literature.

Sturge-Weber syndrome (SWS) is characterized by hemangiomas, glaucoma, and central nervous system disorders. Here, we report the case of a 15-year-old boy with SWS and upper-lip hypertrophy who underwent surgical orthodontic treatment for correction of a large overjet and deep overbite. In addition to the a large overjet and deep overbite, interdental spacing was observed in both the arches. The mandible was retrognathic and deviated to the right side. No maxillary occlusal canting or temporomandibular joint symptoms were observed. The patient was diagnosed with skeletal maxillary protrusion with spaced dentition and mandibular deviation to the right due to SWS. After presurgical orthodontic treatment using a multibracket appliance, we performed a sagittal split ramus osteotomy (SSRO) alone due to the presence of a hemangioma around the maxilla. No abnormal bleeding or cerebral hemorrhage due to increased blood pressure was observed during the SSRO. Postoperatively, the maxillary and mandibular arches were well-aligned, the deep overbite and excessive overjet improved, and bilateral angle class I molar and canine relationships were established. Furthermore, mandibular deviation improved, and the midlines of both arches approximately coincided with the facial midline. In conclusion, orthognathic surgery is feasible in patients with SWS after carefully evaluating the sites and sizes of the hemangiomas.

Anesthetic management of a patient with Sturge-Weber syndrome in sagittal split ramus osteotomy surgery.

Sturge-Weber syndrome (SWS) is a neurocutaneous syndrome characterized by angiomas. This report presents airway management using submental intubation in sagittal split ramus osteotomy under general anesthesia and aimed to explore better anesthetic management for avoiding the rupture of angiomas in a patient with SWS.

Chemical inhibition of LSD1 leads to epithelial to mesenchymal transition in vitro of an oral squamous cell carcinoma OM-1 cell line via release from LSD1-dependent suppression of ZEB1.

The epigenetic regulation for gene expression determines cell plasticity. Oral squamous cell carcinoma (SCC) exhibits bidirectional cell plasticity, i.e. epithelial differentiation and epithelial to mesenchymal transition (EMT). The epigenetic regulator LSD1 is a histone H3-specific demethylase to which chemical inhibitors for its activity had been developed as an anti-cancer therapeutics. The bidirectional plasticity of the oral SCC cell line OM-1 had been characterized, but it remained unclear how chemical LSD1 inhibitors affect cell plasticity. Here we reported an adverse effect against cancer therapeutics, which was EMT induction in vitro by the chemical LSD1 inhibitor. The LSD1 inhibitor caused EMT-TF ZEB1 in OM-1 to undergo EMT. Furthermore, an additional EMT-TF Snail-dependent partial EMT phenotype in OM-1 progressed to complete EMT in conjunction with LSD1 inhibitor-dependent ZEB1 induction. The promotor activity of ZEB1 was up-regulated under LSD1 inhibition. The regulatory chromatin regions of ZEB1 accumulated histone H3 methylation under the chemical inhibition of LSD1. The LSD1 inhibitor also upregulates epithelial gene expression in vitro; however, the bidirectional effect of LSD1 inhibitor should be considered in cancer therapeutics.

Effects of CEACAM1 in oral keratinocytes on HO-1 expression induced by Candida ß-glucan particles.

OBJECTIVE: Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a member of the carcinoembryonic antigen family. Although its expression has been found in chronic oral inflammatory epithelium, this study aimed to know whether CEACAM1 in oral keratinocytes participates in host immune response against Candida albicans . METHODOLOGY: We investigated CEACAM1 expression in oral keratinocytes induced by C. albicans as well as by Candida cell wall component ß-glucan particles (ß-GPs). Furthermore, the effects of CEACAM1 on ß-GPs-induced heme oxygenase-1 (HO-1) expression and its related signals were examined. RESULTS: Fluorescence staining showed CEACAM1 expression in oral keratinocytes (RT7) cells, whereas quantitative reverse transcription (RT)-PCR indicated that both live and heat-killed C. albicans increased CEACAM1 mRNA expression in RT7 cells. Examinations using quantitative RT-PCR and western blotting indicated that CEACAM1 expression was also increased by ß-GPs derived from C. albicans . Specific siRNA for CEACAM1 decreased HO-1 expression induced by ß-GPs from C. albicans as well as the budding yeast microorganism Saccharomyces cerevisiae . Moreover, knockdown of CEACAM1 decreased ß-GPs-induced ROS activity in the early phase and translocation of Nrf2 into the nucleus. CONCLUSION: CEACAM1 in oral keratinocytes may have a critical role in regulation of HO-1 for host immune defense during Candida infection.

Sunitinib promotes apoptosis via p38 MAPK activation and STAT3 downregulation in oral keratinocytes.

OBJECTIVE: Sunitinib, a targeted cancer drug, inhibits tyrosine kinases receptors and is widely used as first-line treatment for metastatic renal cell carcinoma. Patients undergoing chemotherapy with sunitinib frequently have oral mucosal complications, such as oral stomatitis, though cytotoxic effects of the drug on oral keratinocytes remain unknown. METHODS: The effects of sunitinib on immortalized oral keratinocytes, RT7 cells, in regard to cell injury and apoptosis, as well as apoptosis-mediated signaling pathways were investigated. RESULTS: Sunitinib treatment caused a significant increase in lactate dehydrogenase (LDH) in RT7 cells and primary oral keratinocytes. Additionally, the drug induced apoptosis-related events, such as DNA fragmentation, decreased anti-apoptotic Bcl-2 protein expression, and induction of cleaved PARP and caspase 3/9 in RT7 cells. Furthermore, phosphorylation of p38 MAPK, but not of ERK or JNK, was increased. On the contrary, constitutive phosphorylated STAT3 was decreased by sunitinib treatment, which was recovered by exposure to SB203580, a p38 MAPK inhibitor. Finally, SB203580 was found to reduce sunitinib-induced cell injury and apoptosis. CONCLUSION: The present results indicate that sunitinib promotes cell injury and apoptosis in oral keratinocytes via p38 activation and STAT3 downregulation. Sunitinib-mediated oral complications may be associated with cytotoxic effects of the drug on oral keratinocytes.

Inhibition of angiogenesis and tumor progression of MK-0429, an integrin αvß3 antagonist, on oral squamous cell carcinoma.

PURPOSE: Integrin αvß3 is an essential molecule for tumor angiogenesis. This study aimed to investigate the anti-tumor effect of MK-0429, an integrin αvß3 antagonist, on oral squamous cell carcinoma (OSCC) through its inhibitory effect on angiogenesis. METHODS: In this study, we investigated the effect of MK-0429 on cellular function and angiogenesis in vitro with the use of an immortalized human umbilical vein endothelial cell, HUEhT-1, which is immortalized by the electroporatic transfection of hTERT. The effect of MK-0429 on the integrin αvß3 signaling pathway was examined by FAK, MEK1/2 and ERK 1/2 phosphorylation. The anti-angiogenic effect of MK-0429 was evaluated by in vitro tube formation assay. The anti-tumor effect on OSCC was assessed by administrating MK-0429 to mouse oral cancer xenografts. RESULTS: MK-0429 inhibited cell proliferation, migration, and adhesion of HUEhT-1 in a dose-dependent manner. FAK, MEK and ERK phosphorylation were significantly blocked by MK-0429 treatment. Tube formation was suppressed by MK-0429 in dose-dependent manner. Tumor progression was significantly suppressed by MK-0429 administration in mouse oral cancer xenografts. Histological study revealed that MK-0429 decreased tumor vascularization. CONCLUSION: These results indicated integrin αvß3 as a therapeutic target for OSCC and suggested that MK-0429 might be clinically applicable as an anti-tumor agent with potent anti-angiogenic activity.

Effects of CEACAM1 in oral keratinocytes on HO-1 expression induced by Candida β-glucan particles

Abstract Objective Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a member of the carcinoembryonic antigen family. Although its expression has been found in chronic oral inflammatory epithelium, this study aimed to know whether CEACAM1 in oral keratinocytes participates in host immune response against Candida albicans . Methodology We investigated CEACAM1 expression in oral keratinocytes induced by C. albicans as well as by Candida cell wall component β-glucan particles (β-GPs). Furthermore, the effects of CEACAM1 on β-GPs-induced heme oxygenase-1 (HO-1) expression and its related signals were examined. Results Fluorescence staining showed CEACAM1 expression in oral keratinocytes (RT7) cells, whereas quantitative reverse transcription (RT)-PCR indicated that both live and heat-killed C. albicans increased CEACAM1 mRNA expression in RT7 cells. Examinations using quantitative RT-PCR and western blotting indicated that CEACAM1 expression was also increased by β-GPs derived from C. albicans . Specific siRNA for CEACAM1 decreased HO-1 expression induced by β-GPs from C. albicans as well as the budding yeast microorganism Saccharomyces cerevisiae . Moreover, knockdown of CEACAM1 decreased β-GPs-induced ROS activity in the early phase and translocation of Nrf2 into the nucleus. Conclusion CEACAM1 in oral keratinocytes may have a critical role in regulation of HO-1 for host immune defense during Candida infection.

Indian hedgehog in craniofacial neural crest cells links to skeletal malocclusion by regulating associated cartilage formation and gene expression.

The frontal craniofacial skeleton derived from neural crest cells is vital for facial structure and masticatory functions. The exact role of Indian hedgehog (Ihh) in facial and masticatory development has not been fully explored. In this study, we generated craniofacial neural crest cells-specific Ihh deletion mice (Wnt1-Cre;Ihhfl/fl ;Tomatofl/+ ) and found the gradual dwarfism without perinatal lethality. Morphological and histological analyses revealed unambiguous craniofacial phenotypes in mutants, where we observed skeletal malocclusion accompanied by markedly hypoplastic nasomaxillary complex and reversed incisor occlusion. Both the replacement of nasal concha cartilage by turbinate bones and the endochondral ossification of nasal septum ethmoid bone were substantially delayed. We also observed hypoplastic mandibles in mutants where the mandibular ramus was unexpectedly the most affected. Both the condylar process and mandibular angle cartilages were distorted. However, dental examination showed no significant changes in teeth and dentition. Finally, a comprehensive RNA sequence analysis utilizing condylar cartilage identified Ihh-associated gene network including several cell cycle genes and 16 genes related to the extracellular matrix, sulfate transporters, transcription factors, receptors, a ciliogenesis factor, and an adhesion molecule. Our data provide direct in vivo evidence that Ihh plays crucial roles in midface and masticatory system formation, likely by activating key genes.

A novel PTCH1 mutation in basal cell nevus syndrome with rare craniofacial features.

Basal cell nevus syndrome (BCNS) is a rare, multisystem, autosomal dominant disorder that is characterized by various phenotypes, including multiple basal cell carcinomas of the skin, odontogenic keratocysts of the jaws, and occasionally cleft lip and/or palate. In this report, we describe a 6-year-old Japanese girl with a novel heterozygous nonsense mutation in PTCH1 who exhibited rare craniofacial phenotypes, such as oligodontia and a short-tooth root.

Tumor budding and adjacent tissue at the invasive front correlate with delayed neck metastasis in clinical early-stage tongue squamous cell carcinoma.

BACKGROUND AND OBJECTIVES: Some patients with early-stage oral cancer have a poor prognosis owing to the delayed neck metastasis (DNM). Tumor budding is reportedly a promising prognostic marker in many cancers. Moreover, the tissue surrounding a tumor is also considered to play a prognostic role. In this study, we evaluated whether tumor budding and adjacent tissue at the invasive front can be potential novel predictors of DNM in early tongue cancer. METHODS: In total, 337 patients with early-stage tongue squamous cell carcinoma were retrospectively reviewed. The patient characteristics and histopathological factors were evaluated for association with DNM. DNM rates were calculated; items which were significant in the univariate analysis were used as explanatory variables, and independent factors for DNM were identified by the multivariate analysis. RESULTS: The univariate analysis identified T classification, depth of invasion, tumor budding, vascular invasion, and adjacent tissue at the invasive front as significant predictors of DNM; the multivariate analysis using these factors revealed all the above variables except vascular invasion, which are independent predictors of DNM. CONCLUSION: In addition to conventional predictors, high grade tumor budding and adjacent tissue at the invasive front can serve as useful predictors of DNM in early tongue cancer.

A Multicenter Retrospective Study of Elective Neck Dissection for T1-2N0M0 Tongue Squamous Cell Carcinoma: Analysis Using Propensity Score-Matching.

BACKGROUND: This multicenter retrospective study aimed to determine whether elective neck dissection (END) can be performed for T1-2N0M0 tongue cancer. METHODS: Patients with T1-2N0M0 tongue squamous cell carcinoma who received treatment between January 2000 and December 2012 were enrolled at 14 multicenter study sites. The 5-year overall survival (OS) and 5-year disease-specific survival (DSS) were compared between the propensity score-matched END and observation (OBS) groups. RESULTS: The results showed that the OS rates among the 1234 enrolled patients were 85.5% in the END group and 90.2% in the OBS group (P = 0.182). The DSS rates were 87.0% in the END group and 94.3% in the OBS group (P = 0.003). Among the matched patients, the OS rates were 87.1% in the END group and 76.2% in the OBS group (P = 0.0051), and the respective DSS rates were 89.2% and 82.2% (P = 0.0335). CONCLUSION: This study showed that END is beneficial for T1-2N0M0 tongue cancer. However, END should be performed for patients with a tumor depth of 4-5 mm or more, which is the depth associated with a high rate of lymph node metastasis. The use of END should be carefully considered for both elderly and young patients.

Performance status scale for head and neck scores for oral cancer survivors: predictors and factors for improving quality of life.

OBJECTIVES: This study aimed to determine the factors associated with long-term quality of life of oral cancer survivors. MATERIALS AND METHODS: A total of 508 survivors were assessed using the performance status scale for head and neck (PSS-HN), which comprises Eating in Public (E-Public), Normalcy of Diet (N-Diet), and Understandability of Speech (U-Speech). Stepwise multiple linear regression analysis was performed. RESULTS: The median time between the end of treatment and participating in the survey was 38 months (range, 6-250). Overall, 57-60% of survivors achieved full performance (100 score) of each PSS-HN score, whereas 15% had moderate or severe impairment (≤ 50 score) in E-Public and N-Diet, and 4% had impairment in U-Speech. These three scores deteriorated with increasing T-stage. Age, soft tissue reconstruction, trismus, and missing occlusal contacts on the contralateral side were significantly associated with E-Public and N-Diet. Neck dissection, hard tissue reconstruction, and missing occlusal contacts bilaterally were associated with U-Speech score. CONCLUSION: Older age, T4 tumor, and soft tissue reconstruction were predictors of low E-Public and N-Diet performance scores. Increasing mouth opening and maintaining optimal occlusal contacts on the contralateral side may be effective ways to improve N-Diet and E-Public performance. Maintaining optimal occlusal contacts bilaterally may be effective for improving speech performance. CLINICAL RELEVANCE: Oral health care to increase optimal occlusal contacts and rehabilitation of trismus may be promising factors to improve the functional performance of oral cancer survivors.

Efficacy of Maxillary Anterior Segmental Distraction Osteogenesis in Patients With Cleft Lip and Palate.

OBJECTIVES: To evaluate the effects of maxillary anterior segmental distraction osteogenesis (MASDO) in patients with cleft lip and palate (CLP) and to identify risk factors for increased relapse. DESIGN: A retrospective study. PATIENTS: Thirty-one Japanese patients with CLP who underwent MASDO were eligible for study inclusion. MAIN OUTCOME MEASURES: We evaluated lateral cephalograms obtained before (T1), at 3 months (T2), and at 1 year (T3) after MASDO, and measured changes from T1 to T2 (δT1T2), from T2 to T3 (δT2T3), and from T1 to T3 (δT1T3). We also evaluated the risk factors associated with an increased relapse. RESULTS: Overall (δT1T3), MASDO improved retrusion of the maxilla. We measured a significant advancement (6.1 mm) of the anterior maxillary segment in δT1T2 (A-McNamara classification) and increases in the overjet and the SNA, ANB, and nasolabial angles. However, skeletal relapse was evident in δT2T3, and the median percentage of relapse was 10%. To explore the risk factors, we subdivided patients with a δT1T2 of >5 mm into 2 groups based on the percentage of relapse (>15% vs ≤15%). There were significant differences between these groups in the vertical positions of the anterior nasal spine and point A, and the angle formed by the SN and palatal planes (SNPP), suggestive of intraoperative counterclockwise rotation of the maxilla. CONCLUSIONS: MASDO is effective for correcting midfacial deficiencies, but counterclockwise rotation of the maxilla during surgery may cause relapse.

Significant prognostic factors affecting treatment outcomes of salivary gland carcinoma: a multicenter retrospective analysis.

The purpose of this study was to investigate the prognostic factor in salivary gland carcinoma patients. Clinical and pathological data of 211 consecutive patients who treated with curative intent were analyzed. The overall survival (OS) rate, local control rate, and distant metastasis rate were calculated. To examine a prognostic factor in salivary gland carcinoma patients, a multivariate analysis was performed. The 5-year-OS rate was 84.0%, and 10-year was 69.2%. The 5-year-local control rate was 84.6%, and 10-year was 70.1%. The 5-year-distant metastasis rate was 16.9%, and 10-year was 21.1%. In a multivariate analysis, the OS rate was affected by pN(+), high-grade malignancy, and primary tumor size. The local control was affected by the primary tumor size, high-grade malignancy, and the status of the surgical margin. The primary tumor size and pN(+) were associated with the distant metastasis. The results of this study suggested that pN(+), malignancy grade, primary tumor size, and the margin status might affect the prognosis of salivary gland carcinoma patients. Postoperative radiotherapy and adjuvant chemotherapy were suggested the possibility of contribution to the good prognosis of salivary gland carcinoma patients.

Clinical investigation of 38 cases of oral mucosal melanoma: A multicentre retrospective analysis in Japan.

BACKGROUND/OBJECTIVES: The aim of the present study was to investigate treatment modalities and outcomes in oral mucosal melanoma. METHODS: The clinical and pathological data of 38 consecutive patients with oral mucosal melanoma were retrospectively analyzed. Patients' characteristics were analyzed and overall survival (OS) rates were calculated. RESULTS: Sixteen patients had stage III (42%), 19 IVA (50%), and three had stage IVC (8%) disease. Among the therapeutic approaches used, 31 patients (82%) received radical therapy (surgery +/- chemotherapy). The 5-year OS rate was 40%. Five-year OS rates according to the clinical stage were 71% for stage III, 24% for stage IVA, and 0% for stage IVC. Five-year OS rates according to therapeutic approaches were 52% in the radical therapy group and 0% in the palliative therapy and best supportive care groups. CONCLUSIONS: The results of this multicentre retrospective analysis of patients with oral mucosal melanoma suggest that radical therapy based on surgical treatments with complete surgical excision with clear margins leads to a better prognosis.

Prognostic and staging implications of mandibular canal invasion in lower gingival squamous cell carcinoma.

A multi-institutional study was undertaken to determine whether mandibular canal (MC) invasion and mandibular medullary bone invasion are independent factors in lower gingival squamous cell carcinoma (SCC). A total of 345 patients with lower gingival SCC were retrospectively reviewed. Mandibular bone invasion was categorized into three types; no bone invasion; invasion through cortical bone (medullary); and MC invasion. The overall survival rate and factors affecting local, regional, and distant failures were assessed by Cox proportional hazards regression analysis and Kaplan-Meier estimates. Bone invasion was present in 201 (58%) patients, of whom 107 (31%) had medullary invasion and 94 (27%) had MC invasion. Using the International Union Against Cancer (UICC) staging system and American Joint Committee on Cancer (AJCC) system, 171 (50%) patients were classified as T4a. When the bone invasion criteria were excluded from the UICC/AJCC system definition, 152 T4a tumors were downstaged and reclassified to T1 in 12 (3%), to T2 in 98 (28%), and to T3 in 42 (12%). In Cox multivariate analysis, MC invasion was an independent predictor of overall survival but medullary bone invasion was not. Medullary bone invasion was an independent variable for distant control. The current T staging system has restricted prognostic utility. The authors recommend a modified T staging system, whereby tumors with MC invasion instead of medullary bone invasion are classified as T4a, and tumors are first classified as T1 to T3 based on size and then upstaged by one T classification in the presence of medullary invasion.

TGF-ß in jaw tumor fluids induces RANKL expression in stromal fibroblasts.

Odontogenic tumors and cysts, arising in the jawbones, grow by resorption and destruction of the jawbones. However, mechanisms underlying bone resorption by odontogenic tumors/cysts remain unclear. Odontogenic tumors/cysts comprise odontogenic epithelial cells and stromal fibroblasts, which originate from the developing tooth germ. It has been demonstrated that odontogenic epithelial cells of the developing tooth germ induce osteoclastogenesis to prevent the tooth germ from invading the developing bone to maintain its structure in developing bones. Thus, we hypothesized that odontogenic epithelial cells of odontogenic tumors/cysts induce osteoclast formation, which plays potential roles in tumor/cyst outgrowth into the jawbone. The purpose of this study was to examine osteoclastogenesis by cytokines, focusing on transforming growth factor-ß (TGF-ß), produced by odontogenic epithelial cells. We observed two pathways for receptor activator of NF-κB ligand (RANKL) induction by keratocystic odontogenic tumor fluid: the cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) pathway through interleukin-1α (IL-1α) signaling and non-COX-2/PGE2 pathway through TGF-ß receptor signaling. TGF-ß1 and IL-1α produced by odontogenic tumors/cysts induced osteoclastogenesis directly in the osteoclast precursor cells and indirectly via increased RANKL induction in the stroma.

Asymmetric Anterior Distraction for Transversely Distorted Maxilla and Midfacial Anteroposterior Deficiency in a Patient With Cleft Lip/Palate: Two-Stage Surgical Approach.

The present report describes a male patient with a unilateral cleft lip and palate who presented with midfacial anteroposterior and transverse deficiency. Correction involved a two-stage surgical-orthodontic approach: asymmetric anterior distraction of the segmented maxilla followed by two-jaw surgery (LeFort I and bilateral sagittal splitting ramus osteotomies). The present case demonstrates that the asymmetric elongation of the maxilla with anterior distraction is an effective way to correct a transversely distorted alveolar form and midfacial anteroposterior deficiency. Furthermore, successful tooth movement was demonstrated in the new bone created by distraction.

Preventable Sternocleidomastoid Muscular Atrophy after Neck Dissection.

BACKGROUND: Modified radical neck dissection (mRND) [preserving the sternocleidomastoid muscle (SCM) and the spinal accessory nerve] and supraomohyoid neck dissection have become common surgical procedures for treating head and neck cancer. Postoperative severe asymmetry of the neck and severe atrophy of the SCM, however, have been demonstrated. METHODS: Using computed tomographic images, cross-sectional areas of the SCMs were measured in 99 patients with carcinoma of the oral cavity who underwent unilateral mRND or supraomohyoid neck dissection. An asymmetry index was used. RESULTS: Innervation to the SCM was preserved in 91 patients. The spinal accessory nerve and the innervation were sacrificed in 3 patients; the innervation was repaired in 5 patients. Sacrifice of innervation to the SCM resulted in extremely severe asymmetry. Repair of the innervation prevented severe asymmetry in 40%. Preservation of the innervation prevented severe asymmetry in 75% at the middle portion of the neck and in 56% at the lower portion after mRND. CONCLUSION: Preserving innervation to the SCM and gentle handling of the nerve during neck dissection could prevent severe asymmetry after neck dissection.

Multicenter Retrospective Study of Adjuvant Therapy for Patients with Pathologically Lymph Node-Positive Oral Squamous Cell Carcinoma: Analysis of Covariance Using Propensity Score.

BACKGROUND: The presence of pathologically positive lymph nodes (pN+) is a well-known prognostic factor in oral squamous cell carcinoma (OSCC). The aims of this retrospective multicenter study were to assess the prognosis of OSCC patients with pN+ disease; to compare the prognosis of patients with pN+ disease who underwent surgery plus radiotherapy (RT) or concurrent chemoradiotherapy (CCRT) with that of patients who underwent surgery only; and to account for biases associated with treatment selection of adjuvant RT or CCRT. METHODS: The records of 313 OSCC patients with pN+ disease were retrospectively reviewed. The main outcome measures were 5-year disease-specific survival (DSS) and overall survival (OS) rates. To reduce selection biases associated with retrospective data, the treatment groups were evaluated by Cox proportional hazard analysis with propensity score as a covariate. RESULTS: The 5-year OS and DSS survival rates for the entire patient cohort were 51.8 and 59.2 %, respectively. T3-4 stage, closed (<5 mm) margin distance, ≥4 involved nodes, and extracapsular spread were significant poor prognostic factors for OS and DSS. In the propensity score analysis, postoperative RT/CCRT significantly improved OS and DSS compared to surgery only. However, OS and DSS were not significantly different between patients who received postoperative RT and CCRT. CONCLUSION: The addition of cytotoxic chemotherapy to RT does not provide additional survival benefit in OSCC patients with pN+ disease. Alternative strategies, such as molecular targeted therapies, are needed to further improve the survival of high-risk OSCC patients with pN+ disease.