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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.

Trend and characteristics of maxillofacial fractures in 2,636 patients over 32 years were analyzed retrospectively. Patients comprised 1,764 males and 872 females with ages ranging from 0 to 99 years. Patients younger than 30 years consisted of 60% maxillofacial fractures in the early period but decreased to 40% in the late period. In contrast, patients older than 60 years gradually increased to 30%. In terms of cause, traffic accidents consisted of more than 50%, predominantly motorcycle accidents, but gradually decreased to 40%. In contrast, falls markedly increased from less than 10 to 30%. Fractures occurred in the midface in 938 patients, in the mandible in 1,490, and in both in 208. In the midface, zygoma fractures consisted of 50% throughout the period. In the mandible, condyle fractures were observed in 40%, followed by fractures of the symphysis and angle. The ratio of condylar fractures slightly increased. Open reduction and internal fixation (ORIF) were performed in 782 patients, followed by observation in 716, maxillomandibular fixation (MMF) in 605, intramaxillary splinting (IMS) in 294, transcutaneous reduction (TCR) in 126, and others in 113. MMF markedly decreased from more than 30 to less than 5% and observation increased from 20 to 40%.

The purpose of this study was to investigate stress on poly-L-lactic acid (PLLA) plates with a thickness of 1.4 mm and titanium plates with a thickness of 1.0 and 1.4 mm placed for mandibular symphyseal fractures with or without conservatively treated, unilateral condylar fractures using finite element analysis. The symphyseal fracture region was defined by the following three conditions: the defect, the callus, and the contact condition. Stress on the plates was analyzed by an applying occlusal force of 478.1 N on the first molar of the non-condylar fracture side. In the model of isolated symphyseal fracture, the maximal stresses were below the material strength in all plate types and conditions. In the models with condylar fracture, the maximal stresses on these plates were much higher than those in the models of isolated symphyseal fracture, especially for the defect condition. Although the maximal stresses on all types of plates in the contact condition were below the material strengths, some of those in the defect condition were higher than these strengths. These results suggest that a PLLA plate can theoretically withstand stress under good reductions of symphyseal fractures, even for condylar fractures; however, both the PLLA plate and titanium miniplate may be at risk of fracture under poor reduction., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Ki-67, cytokeratin 13, and/or cytokeratin 17 detection by immunohistochemistry has been reported to be useful for the diagnosis of oral precancerous lesions. However, the use of these markers remains controversial because of the lack of appropriately designed statistical studies. We assessed the hypothesis that Ki-67, cytokeratin 13, or cytokeratin 17 immunohistochemistry could facilitate the diagnosis of oral precancerous lesions and/or predict prognosis., Methods: Epithelial dysplasia was classified as low grade (none or mild dysplasia) or high grade (moderate dysplasia, severe dysplasia, or carcinoma in situ). This study included 58 low-grade and 36 high-grade dysplasia cases. We used logistic regression to assess the diagnostic values of Ki-67, cytokeratin 13, and cytokeratin 17 for high-grade dysplasia. Correlations between these markers and the prognosis of oral atypical epithelium were assessed using the Cox proportional hazards model., Results: Ki-67 overexpression and cytokeratin 13 loss were independent diagnostic markers for high-grade dysplasia (odds ratios, 1.92 and 2.53; 95% confidence intervals, 1.03-3.58, and 1.19-5.38, respectively). The area under the curve of Ki-67 was 0.73 and that of cytokeratin 13 was 0.72. However, the combination of Ki-67 and cytokeratin 13 yielded the area under the curve of 0.78. Ki-67 overexpression was significantly associated with recurrence and/or malignant transformation of oral atypical epithelium (hazard ratio, 7.25; 95% confidence interval, 1.07-48.92)., Conclusions: Ki-67 overexpression and cytokeratin 13 loss may be useful for distinguishing oral precancerous lesions from reactive atypical epithelium. Moreover, Ki-67 overexpression may be a risk factor for recurrence and/or malignant transformation of oral atypical epithelium., (© 2014 The Authors. Journal of Oral Pathology & Medicine Published by John Wiley & Sons Ltd.)

Background: [(18)F]fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) is widely used to evaluate tumor metabolic activity. The aim of this study was to evaluate the usefulness of FDG-PET in assessing the histopathological response to preoperative concurrent chemoradiotherapy (CRT) in patients with oral squamous cell carcinoma (OSCC)., Methods: Forty-five patients with resectable advanced OSCC who had received preoperative CRT followed by tumor ablative surgery between January 2004 and December 2011 were included in the study. All patients underwent FDG-PET before and after preoperative CRT. The maximum standardized uptake value (SUVmax) before (pre-SUV) and after preoperative CRT (post-SUV) and the SUVmax reduction rate (ΔSUV %) were used to evaluate the response to preoperative CRT. Correlations among SUVmax, histopathological response, and expression of cancer antigen Ki-67 and hypoxia-inducible factor-1α (HIF-1α) were analyzed., Results: Preoperative CRT significantly reduced intratumoral FDG uptake (P < 0.001). The pre-SUV and post-SUV were significantly lower in patients with a pathological complete response (pCR) than in those with a non-pCR (pre-SUV P = 0.037; post-SUV P = 0.001). ΔSUV % was higher in patients with pCR than in those with non-pCR (P = 0.029). The pre-SUV was significantly correlated with Ki-67 and HIF-1α expression in pretreatment biopsy specimens (Ki-67 P = 0.046, R = 0.292; HIF-1α P = 0.007, R = 0.385). The expression of both Ki-67 and HIF-1α was significantly lower in patients with pCR than in those with non-pCR (Ki-67 P < 0.001; HIF-1α P < 0.001)., Conclusions: Low pre-SUV and post-SUV and high ΔSUV % may predict a good histopathological response to preoperative CRT. Ki-67 and HIF-1α expression in pretreatment biopsy specimens were predictors of histopathological response to preoperative CRT.

Many kinds of bone graft materials have been developed and reported to repair various bone defects. The defects are usually created by surgical resection of pre-existing bone tissue. However, spontaneous healing of bone defects without implantation of materials could be seen, because bone tissue possesses inherent repairing property. The central portion of the lower jaw bone in many animals consists of fibrous tissue and is called the mandibular symphysis. It persists even in old animals and thus can be interpreted as a physiological bone gap or a non-healing bone defect. We implanted calcium phosphate porous ceramics alone or composites of the ceramics and bone marrow stromal cells (BMSCs) into the bone defect (mandibular symphysis) to examine whether it could be filled with new bone tissue, resulting in bone union. Eight weeks after implantation, micro-computed tomography (micro-CT) and histological and biomechanical analyses demonstrated that bone union of the mandibles occurred in all rats with composites but in none of those with ceramics alone. These results showed that the rat mandibular symphysis is a unique bone defect site for the evaluation of bone graft materials. These analyses demonstrated that ceramics alone could not contribute to bone healing in the defect; however, supplementation with BMSCs drastically changed the properties of the ceramics (turning them into osteogenic ceramics), which completely healed the defect. As BMSCs can be culture-expanded using small amounts of bone marrow, the use of the composites might have clinical significance for the reconstruction of various bone tissues, including facial bone., (Copyright © 2012 John Wiley & Sons, Ltd.)

In preoperative planning for mandibular reconstructive surgery, it is necessary to determine the osteotomy lines for fibular shaping and the proper placement of fibular segments in the mandible. Although virtual surgical planning has been utilized in preoperative decision making, current software designs require manual operation and a trial-and-error process to refine the reconstruction plan. We have developed volumetric fibular transfer simulation software that can quickly design a preoperative plan based on direct volume manipulation and quantitative comparison with the patient's original mandible. We propose three quantitative shape indicators-volume ratio, contour error, and maximum projection-for symmetrical lesions of the mandible, and have implemented a parallel computation algorithm for the semiautomatic placement of fibular segments. Using this virtual planning software, we conducted a retrospective study of the computed tomography data from nine patients. We found that combining direct volume manipulation with real-time local search of placement improved the applicability of the planning system to optimize mandibular reconstruction.

Expression of the LIM homeodomain transcription factor Lhx8 is restricted to and up-regulated in the mesenchyme of the upper face prominence before lip fusion. Msx1/2 acts in early development to control cell proliferation and differentiation. Deficiency of these genes is associated with nonsyndromic cleft lip with/without cleft palate. Since retinoid is a potential patterning influence on the developing face, we have examined whether retinoic acid (RA) signaling regulated Lhx8, Msx1 and Msx2 transcription through fibroblast growth factor (FGF) signals in the maxillary prominence. Application of exogenous RA caused severe defects of the maxilla. Citral also induced a specific loss of derivatives from the maxillary prominences by blocking RA synthesis. Real-time RT-PCR and semi-quantitative RT-PCR analysis of the maxillary mesenchyme revealed that the expressions of Lhx8, Msx1 and Msx2 were significantly down-regulated by RA as well as by citral. The downregulated Lhx8 was rescued by combined treatment with FGF-8b, which indicated a downstream of RA signaling. FGF-8b induced up-regulated Lhx8 expression whereas SU5402, a pan-FGF family antagonist, down-regulated and caused defective maxillary morphogenesis and cleft lip. Our data suggest that Lhx8 is regulated by RA signaling through FGF signals and the level window of RA and FGF-8b could control the upper jaw morphogenesis., (Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

Purpose: The purpose was to analyze the clinical course of surgically treated mandibular angle fractures from the viewpoint of routine removal of the plate because these fractures are associated with high rates of complications and plate removal., Subjects and Methods: The subjects were 40 patients with unilateral mandibular angle fracture, which was intraorally reduced and principally fixed with a single miniplate on the external oblique ridge. The third molar in relation to the fracture line was extracted in seven patients during the surgery. Clinical course was evaluated in terms of removal of the plate, preservation of the third molar and complications., Results: One patient showed a wound infection postoperatively, and two patients developed pericoronitis during the follow-up. These were managed with medication and local irrigation. One patient with a preserved third molar did not make a required visit and was lost from the follow-up. Removal of the plates was performed in 39 patients after confirmation of good fracture healing, mostly within a year. Twenty-four of 32 preserved third molars were simultaneously extracted. These procedures were generally performed under local anesthesia on an outpatient basis, and they did not cause any complications., Conclusions: Routine removal of the plate after surgical treatment for mandibular angle fractures, simultaneously with extraction of the third molar if indicated, may be beneficial to avoid complications related to the plate and the third molar later in life.

Introduction: The differences in verbal and emotional responses to a baby seal robot, PARO, of elderly people with dementia residing at an elderly nursing care facility were analyzed. There were two groups of elderly people: one was with mild/moderate dementia (M-group) that consisted with 19 elderly residents in the general ward, and the other was with severe dementia (S-group) that consisted with 11 elderly residents in the dementia ward., Method: Each elderly resident in both groups interacted with either PARO or a control (stuffed lion toy: Lion) brought by a staff at each resident's private room. Their responses were recorded on video. Behavioral analysis of the initial 6 min of the interaction was conducted using a time sampling method., Results: In both groups, subjects talked more frequently to PARO than to Lion, showed more positive changes in emotional expression with PARO than with Lion, and laughed more frequently with PARO than with Lion. Subjects in M-group even showed more negative emotional expressions with Lion than with PARO. Furthermore, subjects in S-group showed neutral expression more frequently with Lion than with PARO, suggesting more active interaction with PARO. For subjects in M-group, frequencies of touching and stroking, frequencies of talking to staff member, and frequencies of talking initiated by staff member were significantly higher with Lion than with PARO., Conclusion: The elderly people both with mild/moderate dementia and with severe dementia showed greater interest in PARO than in Lion. The results suggest that introducing PARO may increase willingness of the staff members to communicate and work with elderly people with dementia, especially those with mild/moderate dementia who express their demand of communication more than those with severe dementia.

[Purpose] This study aimed to investigate the characteristics of upper quadrant posture of young women with temporomandibular disorders. [Subjects] The participants were 19 female patients with temporomandibular disorders (patient group: mean age, 30.1 years) and 14 controls (control group: mean age, 24.6 years). [Methods] Outcome measures were the neck inclination angle (formed by a line connecting C7 and the ear tragus with a horizontal line), the angle of the shoulder (formed by a line connecting C7 and the acromial angle with a horizontal line), the cranial rotation angle (formed by a line connecting the ear tragus and the corner of the eye with a horizontal line), and the neck-length/shoulder-width ratio [the ratio of the neck length (from C7 to the tragus) to the width of the shoulder between the acromial angle]. The maximum range of mouth opening was measured using a scale. [Results] The neck inclination angle and maximum range of mouth opening were significantly smaller in the patient group than in the control group. No significant differences were observed in the other outcome measures between the two groups. [Conclusion] Temporomandibular disorders with limited mouth opening in young females are associated with the head position relative to the trunk.

Transport and Golgi organisation protein 1 (TANGO), also known as MIA3, belongs to the melanoma inhibitory activity (MIA) gene family. Although MIA acts as an oncogene, MIA2 and TANGO have a tumour-suppressive function in several malignancies; accordingly, the role and function of the MIA gene family in tumours remain controversial. Here the roles of TANGO were investigated in oral squamous cell carcinoma (OSCC). We analysed expression and function of TANGO in human OSCC cell lines. TANGO expression was also examined in 171 cases of primary OSCC by immunohistochemistry and statistically assessed the correlation between TANGO positivity and the clinicopathological parameters including vessel density. By TANGO knockdown in OSCC cells, the growth and invasion were repressed and apoptosis was induced. Activities of platelet-derived growth factor beta polypeptide (PDGFB) and Neuropilin2 were inhibited by TANGO knockdown. TANGO immunoreactivity was detected in 35.1% (60/171) cases of OSCC. TANGO expression was strongly associated with tumour progression, nodal metastasis, clinical stage and number of blood or lymph vessels in OSCC. Patients showing TANGO-expression fared significantly worse disease-free survival than cases without TANGO expression. These findings suggest that TANGO might promote angiogenesis and lymphangiogenesis by upregulation of PDGFB and Neuropilin2 in OSCC., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The development of the vertebrate face is regulated by complex interactions among several signaling pathways. Dickkopf-1 (Dkk-1), an inhibitor of the Wnt/β-catenin signaling pathway, can affect midfacial morphogenesis. The downstream target genes of the Wnt/β-catenin signaling pathway in morphogenesis of the developing upper jaw and lip remain unknown. To investigate the functional roles of Wnt/β-catenin signaling in facial development, we performed a loss-of-function experiment using local implantation of beads soaked with Dkk-1 during lip fusion at the maxillary prominence of chick embryos at stage 22(HH22). Antagonism of Wnt/β-catenin signaling by Dkk-1 induced deformities of the premaxilla and jugal bone, which are derived from the maxillary mesenchyme. Real-time and semi-quantitative RT-PCR analysis showed the significant reduction of Lhx8, Msx1 and Msx2 expression levels around the beads in the maxillary mesenchyme at 6 and 24 h after bead implantation. Time course experiments in the HH 22 embryos showed the effect of Dkk-1 on Lhx8, Msx1 and Msx2 expression was not significant after 48 h of the treatment. At HH 26 when the fusion of facial primordial started, Dkk-1 application did not exhibit any significant reduction of those genes. Our findings suggested that Dkk-1 regulates maxillary morphogenesis in chick embryos through Lhx8, Msx1 and Msx2 signals. Wnt/β-catenin signaling is responsible for intrinsic upper jaw development before the lip fusion., (Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

5-Fluorouracil (5-FU) is widely used in clinical cancer therapy. It is commonly used either alone or in combination with other drugs and/or radiation for head and neck, and other types of cancers. 5-FU induces DNA double-strand breaks (DSBs). Inhibition of the repair of 5-FU-induced DSBs may improve the therapeutic response in many tumors to this anticancer agent. The aim of the present study was to further our understanding of the pathways which are involved in the repair of 5-FU-induced DSBs. Cell survival after drug treatment was examined with colony forming assays using Chinese hamster lung fibroblast cells or Chinese hamster ovary cell lines which are deficient in DSB repair pathways involving the homologous recombination repair-related genes BRCA2 and XRCC2, and the non-homologous end joining repair-related genes DNA-PKcs and Ku80. It was found that BRCA2 was involved in such repair, and may be effectively targeted to inhibit the repair of 5-FU-induced damage. Observations showed that knockdown of BRCA2 using small interference RNA suppression increased the sensitivity to 5-FU of human oral cancer cell lines (SAS and HSC3). These findings suggest that downregulation of BRCA2 may be useful for sensitizing tumor cells during 5-FU chemotherapy.

Background: Postoperative sore throat should be recognized seriously as an avoidable complication because of high incidence and dissatisfaction with anesthesia. The aim of the study was to identify the risk factors of postoperative sore throats in patients undergoing general anesthesia., Methods: We retrospectively studied 1,733 patients (above 18 years of age) who had undergone general anesthesia from January to December 2010 and who had visited Department of Anesthesia, postoperative anesthesia clinic., Results: Age, ASA classification, position, airway device, methods of postoperative pain management and site of surgery were significantly identified as the associated factors for postoperative sore throat using univariate analysis. Under 65 year of age (odds ratio 2.3), operation of head and neck and pharynx (odds ratio 1.6), spine surgeries (odds ratio 0.33), laryngeal mask (odds ratio 0.47), and postoperative intravenous patient-controlled analgesia (IV-PCA, odds ratio 0.4) were significantly identified as the factors with multivariate studies., Conclusions: Six associated factors for postoperative sore throat were identified in this study.

Purpose: Pathologic fracture of the mandible after removal of a lesion historically has been a clinical problem. The present study aimed to evaluate mandibular strength after removal of a lesion and to illustrate the theoretical efficacy of preventive measures against pathologic fracture based on a 3-dimensional finite element (FE) analysis., Materials and Methods: A computed tomographic (CT)-based FE model of the mandible of a patient with a dentigerous cyst including a third molar was constructed. Using this model, the decrease of mandibular strength after virtual removal of the lesion was analyzed. The effect of the decrease of occlusal force and reinforcement by a miniplate was analyzed using a simple FE model of the mandible. Based on these analyses, removal of the cyst with the third molar was performed with a decrease of occlusal force and reinforcement by a miniplate. The validity of these procedures was analyzed using a CT-based FE model constructed after surgery., Results: The von Mises stress in a CT-based FE model after virtual removal of the cyst with the third molar was markedly greater than that in the original FE model. In the analysis using a simple FE model, the stress around the fenestrated area was decreased after premolar loading compared with that after molar loading. In addition, miniplate placement around the fenestrated area markedly decreased the stress. Based on these results, the cast crowns of the first and second molars were removed and the fenestrated area of the mandible was reinforced with a 1.5-mm locking miniplate in the actual surgery. The von Mises stress in the fenestrated area was decreased and primarily borne by the miniplate in the analysis of a CT-based FE model constructed after surgery., Conclusion: The present study illustrated the theoretical efficacy of plate application for the decrease of stress on the mandible after surgical removal of a cyst including a third molar based on a simulation by FE analysis., (Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. All rights reserved.)

Prospero homeobox 1 (Prox1) and forkhead box (FOX) C2 regulate angiogenesis and/or lymphangiogenesis. However, the detailed role and function of Prox1 and FOXC2 in cancer remains controversial. In the present study, we examined the expression of Prox1 and FOXC2 proteins in specimens from 163 cases with oral squamous cell carcinoma (OSCC). Furthermore, the role of Prox1 and FOXC2 in cancer cell growth and invasion was evaluated in cultured OSCC cells. Prox1 expression was significantly associated with local progression of the tumor (P = 0.0023), clinical stage (P<0.0001), lymphovessel density (LVD) (P<0.0001), nodal metastasis (P<0.0001), and worse prognosis (P<0.0001). Immunoreactivity of FOXC2 was strongly correlated with microvessel density (MVD) (P<0.0001) and poor prognosis (P = 0.0076). In vitro analysis demonstrated that Prox1 regulates cell growth, proliferation, invasion, and lymphangiogenesis by activating vascular endothelial growth factor (VEGF)-C expression. Furthermore, FOXC2 enhanced the expression level of Prox1 and promoted angiogenesis by enhancement of VEGF-A expression. Our results suggested that Prox1 and FOXC2 play key roles in OSCC progression and that further studies focusing on these proteins may yield useful insights for diagnosis and therapy of OSCC.

The expression of glucocorticoid receptors (GRs) was investigated immunohistochemically in two different lineages of oligodendrocytes, using carbonic anhydrase (CA) II and neuron glial antigen (NG) 2 as markers of mature oligodendrocytes and oligodendrocyte progenitors, respectively. We focused on the gray matter regions, including CA1, CA3 and the dentate gyrus of the hippocampus, the primary somatosensory cortex barrel field and the basolateral amygdala, and the white matter regions, including the corpus callosum, external capsule and fimbria of the hippocampus. More than 80% of CAII-immunoreactive (IR) cells and more than 95% of NG2-IR cells expressed GRs in various regions of the brain. In contrast, neither CAII-IR cells nor NG2-IR cells expressed mineralocorticoid receptors (MRs) in the same regions. The intensity of GR expression was drastically reduced in CA II-IR cells and NG2-IR cells in the same regions in adrenalectomized mice. Finally, steroid receptor co-activator (SRC)-1 and p300, both of which are cofactors for GR, were expressed in the gray and white matter regions in NG2-IR cells, but not in CAII-IR cells. These results suggest that the expression of GRs in oligodendrocytes and their progenitor cells mediates several functions in vivo, including differentiation and myelination, as a major target of glucocorticoids and their cofactors.

Purpose: To analyze the features of midfacial fractures., Methods: Data of 320 patients treated for midfacial fractures during the past 10 years were retrospectively analyzed., Results: Patients were 192 male and 128 female. Their age ranged from 1 to 96 years old with the average of 42.1. Injury most frequently occurred by traffic accidents in 168 patients, followed by falls in 78, assaults in 31 and sports in 25. Pattern of the fractures was classified into zygoma in 159 patients, alveolus in 60, multiple sites in 54, maxilla in 45 and nasal bone in 2. Facial injury severity scale ranged from 1 to 12 with the average of 1.52. Injuries to other sites of the body were found in 90 patients. Fractures of multiple sites showed higher facial injury severity scale and were associated with injuries to other sites of the body at a higher rate. Observation was most frequently chosen in 153 patients, followed by open reduction and internal fixation in 72, intramaxillary fixation in 43 and transcutaneous reduction in 26., Conclusions: Midfacial fractures showed a variety of features in terms of the site and severity and associated injuries. Understanding these features is important to manage these patients properly.

Head and neck cancer including oral squamous cell carcinoma (OSCC) is the sixth most common cancer in the world. OSCC has a high potential for local invasion and nodal metastasis, and the overall 5-year survival rate has not significantly changed during the past 30 years. Recent research has elucidated the detailed molecular mechanisms of carcinogenesis, tumor progression, and metastasis of OSCC. It is generally accepted that OSCC arises from multiple genetic alterations caused by chronic exposure to carcinogens such as alcohol, smoking, viral infections, and inflammation. The molecular mechanisms of carcinogenesis, tumor progression, and metastasis of head and neck cancer have been elucidated by recent advances in molecular biology. However, many unsolved questions remain. In this review, we describe the current molecular biological findings such as human papillomavirus infection, epithelial-mesenchymal transition, microRNA, and our novel molecular pathological findings of OSCC.

Background: Taste disorders are frequently observed in cancer patients undergoing chemotherapy and are serious adverse events which impair the quality of life (QoL) of the cancer patient. Nevertheless, taste disorder mechanisms in cancer patients undergoing chemotherapy have not yet been fully elucidated. The aim of this study was to reveal taste disorder-related peripheral mechanisms using the two-bottle preference test (TBPT) and histological examination of tongues by hematoxylin-eosin staining and immunohistochemistry with protein-gene product 9.5., Methods: In the TBPT, one bottle was filled with the 0.01 mM quinine hydrochloride (quinine), as a bitter compound, and the other was filled with water. Doses of 50 and 100 mg kg(-1) day(-1) S-1 (tegafur/gimeracil/oteracil potassium) are lethal to Wistar rats. Therefore, doses ranging from 2-20 mg kg(-1) day(-1) were administered to the rats for 3 weeks. The S-1 dose of 2 mg kg(-1) day(-1) corresponds to the clinical dose administered to cancer patients. The part of the tongue containing the circumvallate papillae was excised the following TBPT., Results: The rate of increase in terms of the average preference rate for the quinine vs. all intake (quinine plus water) was significant from the initial S-1 period to the final one, compared with that in control rats, suggesting the possibility of a worsening sensation for the bitter taste. In S-1 rats, the area of taste nerve fibers were significantly decreased and the rate of degeneration of intra-tongue ganglionic nerve cells was significantly increased. These changes were significantly correlated with the rate of increase in average preference rate of the quinine., Conclusion: Neuropathy of the gustatory nerve at the periphery may be involved in taste disorders induced by an anticancer drug.

Head and neck cancer, including oral squamous cell carcinoma (OSCC), ranks as the sixth most common malignancy worldwide. Overall 5-year survival rates of OSCC have not significantly improved during the past 3 decades and the 5-year survival rate is less than 50%. Several invasion grading systems have been employed in OSCC, however, their utility is still controversial. HuD belongs to the Hu protein family and acts as an RNA-binding protein involved in mRNA stability and translational regulation. Although HuD has a pivotal role for neuronal differentiation, the functional role of HuD in OSCCs is still unclear. In this study, we examined HuD expression in 82 OSCC cases. Expression of HuD was observed in 36.6% of OSCCs and significantly associated with histological differentiation, nodal metastasis and mode of invasion. HuD expression in high-metastatic HSC3 cells was higher than in low-metastatic HSC4 cells, and inhibition of invasion ability and activation of caspase-3 were shown by HuD siRNA-treated HSC3 cells. Furthermore, we clarified that HuD regulates expression of vascular endothelial growth factor (VEGF)-A, VEGF-D, matrix metallopeptidase (MMP)-2 and MMP-9. These results suggest that HuD is a useful diagnostic and therapeutic target in OSCCs.

A 74-year-old male patient consulted us for an elastic firm mass in the right buccal mucosa. CT examination revealed a well-circumscribed oval cystic lesion in the anterior region of the masseter muscle. On MRI, the lesion showed a low signal on T1-weighted image and a high signal on T2-weighted image. Aspiration biopsy demonstrated the presence of squamous cells in whitish liquid. Under the diagnosis of epidermoid cyst, the lesion was intraorally extirpated under general anesthesia. The lesion was cystic at the size of 30 × 25mm. Histologically, the cyst wall was lined with parakeratinized squamous epithelium corrugated on its surface, the basal layer of which consisted of cuboidal cells showing palisading of the nuclei. Immunohistochemically, the lining epithelium was positive for CK17 and negative for CK10. The basal and suprabasal cells were labeled for Ki-67 at a relatively high rate. These features are compatible with those of keratocystic odontogenic tumor.

We analyzed the data for 53 patients with histologically proven primary squamous cell carcinoma of the head and neck treated with radiotherapy between February 2006 and August 2009. All patients underwent contrast-enhanced (CE)-CT and (18)F-fluorodeoxyglucose (FDG)-PET before radiation therapy planning (RTP) to define the gross tumor volume (GTV). The PET-based GTV (PET-GTV) for RTP was defined using both CE-CT images and FDG-PET images. The CE-CT tumor volume corresponding to a FDG-PET image was regarded as the PET-GTV. The CE-CT-based GTV (CT-GTV) for RTP was defined using CE-CT images alone. Additionally, CT-GTV delineation and PET-GTV delineation were performed by four radiation oncologists independently in 19 cases. All four oncologists did both methods. Of these, PET-GTV delineation was successfully performed in all 19 cases, but CT-GTV delineation was not performed in 4 cases. In the other 15 cases, the mean CT-GTV was larger than the PET-GTV in 10 cases, and the standard deviation of the CT-GTV was larger than that of the PET-GTV in 10 cases. Sensitivity of PET-GTV for identifying the primary tumor was 96%, but that of CT-GTV was 81% (P < 0.01). In patients with oropharyngeal cancer and tongue cancer, the sensitivity of CT-GTV was 63% and 71%, respectively. When both the primary lesions and the lymph nodes were evaluated for RTP, PET-GTV differed from CT-GTV in 19 cases (36%). These results suggested that FDG-PET is effective for defining GTV in RTP for squamous cell carcinoma of the head and neck, and PET-GTV evaluated by both CE-CT and FDG-PET images is preferable to CT-GTV by CE-CT alone.

Members of the tropomyosin receptor kinase (Trk) family have a high affinity for neurotrophins and regulate neuronal survival. The role of Trks in cancer is still controversial. The expression and role of TrkB and TrkC were examined in colorectal cancer (CRC). Immunohistochemical analysis of TrkB and TrkC was performed in 133 patients with CRC. Using human CRC cell lines, expression of vascular endothelial growth factor (VEGF) and transforming growth factor β, cell growth, invasion, and apoptosis were examined by knockdown methods. Immunohistochemistry showed positive results of TrkB and TrkC (23.3% and 12.8%, respectively). TrkB expression was associated with local progression (P = .0284), clinical stage (P = .0026), nodal metastasis (P = .0068), and peritoneal metastasis (P = .0026). TrkC expression was only related to liver metastasis (P = .0001). Coexpression of TrkB or TrkC and their ligands was found in 80.6% and 82.4% of cases, respectively. In vitro analysis using human CRC cells showed that TrkB positively regulated gene expression of VEGF-A (P < .05) and VEGF-C (P < .05), whereas TrkC suppressed transforming growth factor β expression (P < .05). TrkB and TrkC induced cell growth (P < .05) and invasion (P < .05), respectively. Both TrkB and TrkC showed antiapoptotic effect (P < .05). These results suggest that TrkB and TrkC have a tumor progressive function and may be a useful diagnostic and therapeutic target in CRC., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: The purpose of the present study was to analyze the effect of clenching on the biomechanical response of human mandible and temporomandibular joint (TMJ) to traumatic force by the finite element (FE) method., Material and Methods: FE models of the mandible and the TMJ in resting and clenching positions were prepared. Distribution and magnitude of von Mises stress were analyzed by applying force as a point load in the symphyseal, canine, body and angle regions of the mandible. In addition, strain energy density (SED) at the articular disc and in posterior connective tissue of TMJ was analyzed., Results: In the resting position, von Mises stress was mainly concentrated at the condylar neck and in the retromolar region of the mandible. In the clenching position, the stress at the condylar neck decreased in all loadings. The stress in the retromolar region similary decreased in the symphyseal, canine and body loading, respectively; however, higher stress was observed in the retromolar region on the loading side in the angle loading. High SED was generated at the articular disc and in posterior connective tissues of TMJ in the resting position. The SED in these tissues decreased in all loadings in the clenching position., Conclusions: Clenching generally reduces stress at the condylar neck and in the retromolar region of the mandible, and strain energy at the articular disc and in posterior connective tissue of TMJ by traumatic forces on the mandible; however, clenching induces greater stress in the retromolar region on the loading side by traumatic force to the angle region.

Background: The role of melanoma inhibitory activity 2 (MIA2) was examined in human oral squamous cell carcinoma (OSCC)., Methods: MIA2 role was examined by immunohistochemistry of human OSCCs and knockdown studies using human 3 OSCC cell lines with MIA2 expression., Results: MIA2 expression was observed in 62 (66.7%) of 93 OSCCs and was associated with tumour expansion and nodal metastasis. Melanoma inhibitory activity 2 expression was inversely correlated with intratumoral infiltration of lymphocytes. Invasion and anti-apoptotic survival were reduced by MIA2 knockdown in HSC3 cells. MOLT-3 lymphocytes infiltrating the HSC3 cell layer was enhanced by MIA2 knockdown or MIA2 depletion with the antibody. In HSC3 cells, MIA2 knockdown decreased the expressions of vascular endothelial growth factor (VEGF), VEGF-C, and VEGF-D. The downregulation of VEGF-C and -D was caused by inhibition of p38 and extracellular signal-regulated kinase (ERK)1/2, respectively. Melanoma inhibitory activity 2 was co-precipitated with integrin α4 andα5 in HSC3 cells. Integrin α4 knockdown decreased p38 phosphorylation and increased apoptosis, whereas integrin α5 knockdown decreased c-Jun N-terminal kinase (JNK) phosphorylation and apoptosis. Inhibition of JNK decreased apoptosis in the HSC3 cells., Conclusion: These findings suggest that the roles of MIA2 might be based on the variety of the integrins and the subtypes of mitogen-activated protein kinase.

Maxillofacial fractures of pedestrians injured in a motor vehicle accident were retrospectively analyzed. The patients were 38 males and 26 females, and their age was distributed almost evenly from 1 to 91 years old (average 45.9 ± 24.8 years old). Motor vehicle collisions were with an automobile in 46 patients (71.9%), a motorcycle in 17 (26.6%), and a train in 1 (1.6%). The midface was involved in 32 patients (50.0%), the mandible in 19 (29.7%), and both the mandible and the midface in 13 (20.3%). Fractures were frequently observed in the zygoma and alveolus in the midface and in the condyle, symphysis, and body in the mandible. The facial injury severity scale (FISS) rating ranged from 1 to 9 (average 2.30 ± 1.79). Injuries to other sites of the body occurred in 29 patients (45.3%). Observation was most frequently chosen in 26 patients (40.6%), followed by open reduction and internal fixation (ORIF) in 18 (28.1%), and maxillomandibular fixation (MMF) in 8 (12.5%). The FISS rating was higher in patients treated with ORIF and MMF. Injuries to other sites of the body were observed at a higher rate in patients who collided with an automobile and were also treated by ORIF.

The function of tropomyosin receptor kinase (Trk) family including TrkA, TrkB, and TrkC in cancer remains unknown. The role of Trks in oral squamous cell carcinoma (OSCC) was examined. Knockdown of Trks provided inhibition of growth or invasion and decrease of apoptosis in OSCC cells, which expressed Trks at high levels. VEGF expression was associated with TrkA and TrkB expression; a decrease of VEGF-C and VEGF-D was observed in OSCC cells with TrkB knockdown. TrkC did not affect the expression of VEGF family. An immunohistochemical analysis of 102 OSCCs showed that TrkB expression was related to microvessel density (MVD), lymph vessel density (LVD), and poor prognosis. TrkC expression was correlated with clinical stage, lymph node metastasis, MVD, LVD, and poor prognosis. TrkA expression was associated with VEGF expression, whereas TrkB expression was associated with the expressions of VEGF, VEGF-C and VEGF-D. No significant association was found between the expression of TrkC and genes of the VEGF family. Expression of Trks was not associated with RUNX3 silencing by methylation in OSCC cells. Trks expression was inversely correlated with RUNX3 expression in the OSCC cases. These results suggested that Trks enhances progression of OSCC through angiogenesis and lymphangiogenesis.

This is a case report of anterosuperior alveolar distraction using an implant-fixed provisional prosthesis. Osteotomy and placement of a distraction device were performed in a healthy 69-year-old woman. To avoid lingual inclination during the distraction period, the device's rod was buried in the labial side of a provisional prosthesis supported by posterior implants. The mandibular bone was obliquely distracted by 0.3 mm every 2 days. Implant insertion was performed, and a good prognosis was anticipated. Inclination is thought to be caused by soft tissue on the lingual side. Many reports propose methods to avoid inclination, but these methods require established support from the teeth and cannot be adapted for an edentulous case. The method reported here is useful for distraction osteogenesis because it can be adapted for edentulous cases.

Maxillofacial fractures in Japanese children were retrospectively analyzed. The subjects were 287 patients aged 15 years and younger seeking treatment for maxillofacial fractures in the Department of Oral and Maxillofacial Surgery, Nara Medical University. The patients were 186 males and 101 females. Injuries most frequently occurred as a result of traffic accidents in 125 patients, 92 of which were bicycle-related accidents. Injuries by falling from one level to another were found in 49, primarily in younger children. One hundred seventy-nine fractures occurred in the mandible, 100 in the midface, and 8 in both. In the mandible, fractures most frequently occurred in condyle followed by symphysis. In the midface, alveolus was mostly involved. The facial injury severity scale ranged from 1 to 9 with an average of 1.83 and was higher in traffic accidents. Injury to other sites of the body was found in 33 patients, 28 of which occurred in traffic accidents. Observation was most frequently chosen in 84 patients. Intramaxillary fixation was chosen in 79, primarily for alveolar fractures and in younger children. Maxillomandibular fixation was chosen in 62 for mandibular fractures in older children. Open reduction and internal fixation was performed in 40, primarily in older children. The facial injury severity scale was higher in patients treated by open reduction and internal fixation and maxillomandibular fixation. Maxillofacial fractures in Japanese children showed characteristic features primarily depending on their age in terms of etiology, patterns, and treatment modalities.

This presentation introduces a new software design for virtual preoperative planning for free fibular transfer in mandibular reconstructive surgery. Direct volume resection and manipulation of superimposed fibular segments allow interactive editing of the surgical plan without the need for a surface modeling process. We also introduce three shape indicators: volume ratio, contour error and maximum projection for evaluating the reconstruction plan from geometrical aspects. The indicators significantly quantify the difference between 2-segment and 3-segment cases, and suggest optimization of preoperative planning while satisfying appropriate placement margins for fibular segments.

For the doctors and other medical staff treating oral cancers, it is necessary to standardize basic concepts and rules on oral cancers to progress in the treatment, research and diagnosis. Oral cancers are integrated in head and neck cancers and are applied to the general rules on head and neck cancer, but it is considered that more detailed rules based on the characteristics of oral cancers are essential. The objectives of this 'General Rules for Clinical and Pathological Studies on Oral Cancer' are to contribute to the development of the diagnosis, treatment and research of oral cancers based on the correct and useful medical information of clinical, surgical, pathological and image findings accumulated from individual patients at various institutions.

Background: MicroRNA (miRNA)-126 (miR-126) is an endothelial-specific miRNA located within intron 7 of epidermal growth factor-like domain 7 (EGFL7). However, the role of miR-126 in cancer is controversial., Methods: We examined the function of miR-126 in oral squamous cell carcinoma (OSCC) cells. Furthermore, a series of 118 cases with OSCC were evaluated for the expression levels of miR-126., Results: MicroRNA-126 (miR-126) was associated with cell growth and regulation of vascular endothelial growth factor-A activity, and demethylation treatment increased expression levels of miR-126 and EGFL7 in OSCC cells. A significant association was found between miR-126 expression and tumour progression, nodal metastasis, vessel density, or poor prognosis in OSCC cases. In the multivariate analysis, decreased miR-126 expression was strongly correlated with disease-free survival., Conclusion: The present results suggest that miR-126 might be a useful diagnostic and therapeutic target in OSCC.

Although mutations and deletions in the p53 tumor suppressor gene lead to resistance to low linear energy transfer (LET) radiation, high-LET radiation efficiently induces cell lethality and apoptosis regardless of the p53 gene status in cancer cells. Recently, it has been suggested that the induction of p53-independent apoptosis takes place through the activation of Caspase-9 which results in the cleavage of Caspase-3 and poly (ADP-ribose) polymerase (PARP). This study was designed to examine if high-LET radiation depresses serine/threonine protein kinase B (PKB, also known as Akt) and Akt-related proteins. Human gingival cancer cells (Ca9-22 cells) harboring a mutated p53 (mp53) gene were irradiated with 2 Gy of X-rays or Fe-ion beams. The cellular contents of Akt-related proteins participating in cell survival signaling were analyzed with Western Blotting 1, 2, 3 and 6h after irradiation. Cell cycle distributions after irradiation were assayed with flow cytometric analysis. Akt-related protein levels decreased when cells were irradiated with high-LET radiation. High-LET radiation increased G(2)/M phase arrests and suppressed the progression of the cell cycle much more efficiently when compared to low-LET radiation. These results suggest that high-LET radiation enhances apoptosis through the activation of Caspase-3 and Caspase-9, and suppresses cell growth by suppressing Akt-related signaling, even in mp53 bearing cancer cells., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a new disease entity characterized by limited mouth opening due to contracture of the masticatory muscles, resulting from hyperplasia of tendons and aponeuroses. In this case series, we report what methods of airway establishment were conclusively chosen after rapid induction of anesthesia. We had 24 consecutive patients with MMTAH who underwent surgical release of its contracture under general anesthesia. Rapid induction of anesthesia with propofol and rocuronium was chosen for all the cases. In 7 cases, intubation using the Macintosh laryngoscopy was attempted; however, 2 of those cases failed to be intubated on the first attempt. Finally, intubation using the McCoy laryngoscopy or fiber-optic intubation was alternatively used in these 2 cases. In 7 cases, the Trachlight was used. In the remaining 10 cases, fiber-optic intubation was used. Limited mouth opening in patients with MMTAH did not improve with muscular relaxation. "Square mandible" has been reported to be one of the clinical features in this disease; however, half of these 24 patients lacked this characteristic, which might affect a definitive diagnosis of this disease for anesthesiologists. An airway problem in patients with MMTAH should not be underestimated, which means that other intubation methods rather than direct laryngoscopy had better be considered.

This study evaluated survival in 154 patients with stages II-IV oral squamous cell carcinoma (OSCC) treated with preoperative concurrent chemoradiotherapy and assessed the future use of this treatment strategy. 14 patients exhibited advanced stage II, 73 exhibited stage III and 67 exhibited stage IV. All patients received 40Gy irradiation and concurrent cisplatin-based chemotherapy in two courses. Radical surgery was undertaken after 2-6 weeks. The clinical tumour response, histopathologic regression grade, residual tumour grade (RGrade) in the primary tumour and the level of residual pN+ were associated with prognosis. 90% of patients with complete response and 73% of patients with good partial response in the primary tumour were RGrade 0 (no residual tumour cells) or RGrade 1 (viable tumour cells remained within central superficial portion). In patients with complete response in the neck, residual pN+ was only seen in levels IB (8%) and IIA (8%); the higher the level of residual pN+, the lower the survival rate (p<0.0001). This treatment strategy was excellent for stages II-IV OSCC. It may be possible to perform minimally invasive surgery in which the extent of resection in primary tumour and neck is reduced in patients who achieve good response following preoperative chemoradiotherapy., (Copyright © 2011 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

A comparative study between 17 Japanese and 19 Indian patients with oral squamous cell carcinomas (OSCCs) revealed that the tumour prognostic indicator mean vessel density (MVD) count for angiogenesis was relatively high at 57.1 in Indian as compared to 39.3 in Japanese (P=0.001) cases, whereas the lymph-vessel density (LVD) count for lymphangiogenesis was lower (12.8 vs 48.0, P=0.002). Both male and female Indians had higher MVD counts, but LVD counts were only slightly lower in females. MVD count was relatively high among the cases below 65 years old in both the countries (P=0.4). Japanese cases with Tongue cancer had higher MVD count, but the Indian cases had lower LVD counts. Size-wise, T2 and T3 had higher counts of MVD both in Indian and Japanese cases. MVD and LVD count was higher in grades II and III both in Japanese and Indian cases. There was insignificant difference of the MVD counts among smokers, but the tobacco chewers in Indian cases had higher counts of MVD and LVD (P value by Bartlett test 0.35, 0.57 respectively). The hot-spots of tumour sites had variable rates of lymphocyte infiltration showed higher MVD counts in all the cases. Although the clinical characteristics and demographic variables usually relate to MVD and LVD counts, the tendency of higher values, especially among tobacco chewers, identified as the highest risk group for occurrence of oral cancer needs to be investigated further.

Background: The aim of this multi-center phase II study was to clarify the clinical benefit of an opioid-based pain control program for head and neck cancer patients during chemoradiotherapy., Patients and Methods: Head and neck cancer patients who were to receive definitive or postoperative chemoradiotherapy were enrolled. The opioid-based pain control program consisted of a three-step ladder, with basic regimens of: The primary endpoint of this study was compliance with radiotherapy., Results: A total of 101 patients from 10 institutions were registered between February 2008 and May 2009 and included in the analysis. The major combination chemotherapy regimen was cisplatin alone (76%). The rate of completion of radiotherapy was 99% and the rate of unplanned breaks in radiotherapy was 13% (13/101, 90% confidence interval: 9.9-16.5%). Median maximum quantity of morphine used per day was 35 mg (range 0-150 mg)., Conclusions: Use of a systematic pain control program may improve compliance with CRT., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Nicorandil-induced oral ulceration in 3 Japanese patients is reported. The patients were men aged 86, 81, and 91 years. Ulcers of 15, 10, and 12 mm in diameter, respectively, were observed at the border of all of the patients' tongues. These were painful and persistent but not indurated. Irritation by the teeth or dentures was not evident. They had been administered nicorandil at a dose of 15 mg for 22, 54, and 90 months, respectively; therefore, ulceration induced by nicorandil was suspected. In consultation with the doctor, nicorandil was withdrawn. The ulcers disappeared 5, 8, and 9 weeks, respectively, after the cessation of nicorandil. No relapse of the ulcer was noted. The findings suggest that these were the examples of nicorandil-induced oral ulceration., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Purpose: A nationwide retrospective cohort study was conducted by the Japanese Society of Oral and Maxillofacial Surgeons to assess the occurrence of bisphosphonate (BP)-related osteonecrosis of the jaws (BRONJ) during 2006 to 2008 and to elucidate the outcome and factors associated with remission of BRONJ., Materials and Methods: A written questionnaire, including the clinical characteristics, management, and outcome of patients with BRONJ, was sent to 248 institutions certified as training facilities by the Japanese Society of Oral and Maxillofacial Surgeons in 2008., Results: A total of 568 patients with BRONJ, including suspicious cases, were registered. Of these 568 patients, 263, including the maxilla in 81, the mandible in 160, and both in 22, met the working definition of BRONJ proposed by the American Association of Oral and Maxillofacial Surgeons. The patients included 219 women (83.3%) and 44 men (16.7%). Of these patients, 152 (57.8%) had received intravenous BPs, 104 (39.5%) had received oral BPs, and 7 (2.7%) had received both. The mean duration of administration until onset of BRONJ was 23.6 months for intravenous BPs and 33.2 months for oral BPs. BRONJ was stage 1 in 42 patients (16.0%), stage 2 in 187 (71.1%), stage 3 in 32 (12.2%), and unknown in 2. Of these patients, 34.2% had remission of BRONJ, 46.0% had persistent or progressive disease, and 19.7% died of malignancy or were lost to follow-up. Statistical analysis revealed that surgical treatment, including tooth extraction, sequestrectomy, and segmental mandibulectomy, contributed to the remission of BRONJ. In contrast, conservative treatment, concurrent anticancer drugs, poor oral hygiene, and the use of intravenous BPs did not., Conclusions: The relative ratio of BRONJ related to the use of oral BPs was greater in Japan than in the United States and European Union. Surgical treatment contributed to remission of BRONJ, and conservative treatment, concurrent anticancer drugs, poor oral hygiene, and intravenous BPs did not., (Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: The purpose of the present study was to analyze the trends and characteristic features of maxillofacial fractures in older patients., Patients and Methods: The data from 247 patients aged 65 years old or older, who were treated for maxillofacial fractures at the Department of Oral and Maxillofacial Surgery, Nara Medical University, from October 1981 to March 2010, were retrospectively analyzed., Results: Of the 247 patients, 127 were men and 120 were women; 50 patients had been treated in the first third of the period, 87 in the second, and 110 in the third. Injury had most frequently occurred because of falling on a level surface (n = 126), followed by a traffic accident (n = 84). Of the fractures, 140 were in the mandible, 90 in the midface, and 17 in both. In the mandible, the fracture lines were most frequently observed at the condyle, followed by the body, exclusively in edentulous patients. In the midface, the zygoma was mostly involved. The facial injury severity scale score ranged from 1 to 10 (average 1.81). Injury at other sites of the body was found in 45 patients. Observation was most frequently chosen (n = 127), primarily for those of older age, followed by open reduction and internal fixation in 46 and maxillomandibular fixation in 41 patients. The facial injury severity scale score was greatest in patients treated by open reduction and internal fixation, followed by those treated by maxillomandibular fixation., Conclusion: Maxillofacial fractures in older patients have been increasing and showed the characteristic features of etiology, patterns, and treatment modalities., (Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

A mandibular body fracture related to mouth-opening training in a dialysis patient is reported. A 61-year-old male patient had noticed pain in the right mandibular body and difficulty in mouth opening a week previously. The patient had been performing mouth-opening training for a couple of weeks. The right lower face was slightly swollen with tenderness at the right lower border of the mandible. Hypoesthesia of the right lower lip was also observed. A bone step was palpable on the alveolar ridge of the right mandible, but mobility was not marked. The mandible was atrophic in the body region with only four anterior teeth left. Panoramic X-ray examination revealed a moderately displaced fracture in the right molar region of the mandible. The patient had no severe pain or difficulty in eating using a partial denture. The patient had received dialysis for 17 years and had also been treated by warfarin and aspirin. The patient was followed up under restricted mouth opening. Osteosynthesis with bone remodeling was confirmed after 6 months by X-ray examination. No complication requiring further treatment occurred during the follow-up period. In this patient, a medically compromised condition under long-term dialysis is considered a predisposing factor, which made the atrophic mandible more susceptible to the stress related to mouth-opening training., (© 2011 John Wiley & Sons A/S.)

Objective: The association of candy weight loss rate (CWLR) with whole saliva flow rates (WSFRs) was analyzed., Study Design: The unstimulated whole saliva flow rate (UWSFR), stimulated whole saliva flow rate by the gum test (SWSFR-GT) and stimulated whole saliva flow rate by the Saxon test (SWSFR-ST) were measured in 300 healthy young adults. CWLR was measured by passively holding sugar candy between the tongue dorsum and hard palate. The degree of discomfort was evaluated by the visual analog scale., Results: CWLR was significantly correlated with UWSFR, SWSFR-GT, and SWSFR-ST with Pearson's correlation coefficients of 0.1847 (P = .0013), 0.2097 (P = .0003), and 0.2332 (P < .0001), respectively; however, these were much smaller than those of 0.6858 (P < .0001) between UWSFR and SWSFR-GT, 0.5071 (P < .0001) between UWSFR and SWSFR-ST, and 0.5424 (P < .0001) between SWSFR-GT and SWSFR-ST. The degree of discomfort was significantly lower in the measurement of CWLR than in any WSFRs (P < .0001)., Conclusions: CWLR cannot be used as an independent alternative to WSFRs, although it can be measured with less discomfort., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Purpose: The purpose of this study was to analyze impalement injuries of the oral cavity in children., Patients and Methods: Data on 144 children with impalement injuries in the oral cavity at the Department of Oral and Maxillofacial Surgery, Nara Medical University were analyzed retrospectively., Results: The patients were 93 boys and 51 girls (age range, 7 months to 10 years). One hundred thirty-two patients (91.7%) were younger than 5 years. Injuries occurred frequently by falling onto an object held in the mouth in 77 patients (53.5%). The impaled objects were a toothbrush in 30 patients (20.8%), a cylindrical toy in 27 (18.8%), and chopsticks in 19 (13.2%). The soft palate was frequently involved in 64 patients (44.4%), followed by the hard palate in 26 (18.1%). Computed tomographic examination was performed in 16 patients (11.1%). Observation with or without medication was most frequently chosen in 98 patients (68.1%). Surgical intervention was performed in 46 patients (31.9%), 41 under local anesthesia and 5 under general anesthesia. Admission was required in 12 patients (8.3%). No complications, such as deep infection or neurologic sequelae, were observed., Conclusions: Most impalement injuries in the oral cavity in children heal spontaneously or with minimal intervention. These children can be followed on an outpatient basis with instructions to their parents about possible complications, except for a few selected cases., (Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: This study investigated the biomechanical behavior of the mandible after marginal resection by tensile test in a human cadaveric mandible and finite element (FE) analysis., Materials and Methods: Human cadaveric mandibular models after marginal resection were prepared with residual heights of 5, 10, and 15 mm. The strength in each of these mandibular models was examined by tensile testing. In addition, FE models of the mandible after marginal resection were prepared with residual heights of 5, 7.5, 10, 12.5, and 15 mm. Distribution and magnitude of von Mises stress were analyzed by applying bite forces of 151 N as a point load on the incisal region and 355.2 and 478.1 N on the premolar and molar regions on the nonresected and resected sides, respectively. At the molar region of the resected side, bite forces of 368.5 N and 286.9 N (80% and 60%, respectively, of 478.1 N) were also applied., Results: On tensile testing, all cadaveric mandibular models were broken at the posterior resection corner. The tensile force was significantly larger in the model with a residual height of 15 mm compared with that of those with a 5- or 10-mm residual height. On FE analysis, von Mises stress was concentrated at the resection corner. The region of maximal von Mises stress concentration in FE models was consistent with that showing destruction on tensile testing. The relationship between the residual height and von Mises stress in the resection area was linear in models of the incisal, premolar, and molar loading on the nonresected side and quadratic in models of the premolar and molar loading on the resected side. The maximal von Mises stress in the resection area was highest during molar loading on the resected side under the present loading condition and exceeded the threshold for the development of pathologic fracture in the model with a residual height of around 10 mm or less. However, the maximal von Mises stress decreased in parallel with the reduction of bite force in the molar region of the resected side., Conclusions: The residual height and bite force are critical factors for the prevention of pathologic fracture of the mandible after marginal resection. Currently, a residual height of more than 10 mm and reduction of bite force are recommended to reduce the risk of fracture., (Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study was to analyze maxillofacial fractures sustained in bicycle accidents by demographics, cause of injury, site and severity of fractures, injuries to other sites of the body, and treatment modalities., Patients and Methods: Data on 307 patients treated for maxillofacial fractures sustained in bicycle accidents in the Department of Oral and Maxillofacial Surgery, Nara Medical University from 1981 through 2009 were analyzed retrospectively., Results: The patients were 166 males and 141 females (average age, 30.9 years). Causes of injury were a fall on a level surface in 169 patients, an automobile accident in 56, fall from 1 level to another in 28, and a motorcycle accident in 24. One hundred seventy-five fractures were observed in the mandible, 117 in the midface, and 15 in the mandible and midface. In the mandible, fracture lines were exclusively observed at the condyle. In the midface, the zygoma was most frequently involved. The Facial Injury Severity Scale ranged from 1 to 7 (average, 1.88). Injuries at other sites of the body were found in 47 patients and were frequently found in automobile and motorcycle accidents. Maxillomandibular fixation was most frequently chosen in 81 patients, followed by observation in 76 and open reduction and internal fixation in 71. The Facial Injury Severity Scale was highest in patients treated by open reduction and internal fixation, followed by those treated by maxillomandibular fixation., Conclusions: Maxillofacial fractures sustained in a bicycle accident frequently occurred by falling on a level surface and were not so serious in most cases; however, in accidents with motor vehicles, injuries to other sites of the body were observed at a higher rate., (Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

One hundred and three patients with maxillofacial fractures due to work-related accidents were analysed. Ninety-nine patients (96.1%) were male and 4 (3.9%) were female. The average age was 46.8 years (range 18-75 years). The injuries were most commonly sustained during construction (42 patients, 40.8%) followed by agriculture and forestry (31 patients, 30.1%) and manufacturing (15 patients, 14.6%). Being struck by an object was the main cause of injury (43 patients, 41.7%) followed by fall from one level to another (31 patients, 30.1%). Fifty-four patients (52.4%) had fractures in the mandible, 41 (39.8%) in the midface, and 8 (7.8%) in both the mandible and the midface. The most common sites for fractures were the condyle and symphysis in the mandible and zygoma in the midface. The facial injury severity scale ranged from 1 to 6 with an average of 1.99±1.18. There was no difference in the nature of the work being undertaken or the cause of the injury. Fractures in other sites were observed in 22 patients (21.4%). Open reduction and fixation was the most frequent treatment for mandibular fractures (25 patients, 40.3%) followed by maxillomandibular fixation (19 patients, 30.6%). Observation was most commonly used for midface fractures (18 patients, 36.7%) followed by open reduction and fixation (15 patients, 30.6%) and transcutaneous reduction (8 patients, 16.3%)., (Copyright © 2010 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)