Yasumasa Kakei

Clinical evaluation of application of polyglycolic acid sheet and fibrin glue spray for partial glossectomy.

PURPOSE The aim of this study was to evaluate the usefulness of covering open wounds with a polyglycolic acid (PGA) sheet and a fibrin glue spray after partial glossectomy. MATERIALS AND METHODS We clinically evaluated postoperative pain and scar contracture in 44 patients who underwent partial glossectomy followed by covering with a PGA sheet and a fibrin glue spray (PGA sheet group), as compared with 29 patients who were closed primarily (primary closure group). RESULTS Duration of nonsteroidal anti-inflammatory drugs was almost the same between the PGA sheet group and the primary closure group. The degree of scar contracture was mild in many cases in both groups. In the case in which the excision area was wide and depth was shallow, there was a tendency for the scar contracture to be less in the PGA sheet group. CONCLUSIONS Our findings showed that the use of a PGA sheet and fibrin glue spray for open wounds resulting from partial glossectomy was useful in terms of rapid relief from postoperative pain and prevention of scar contracture.

Risk factors associated with inferior alveolar nerve injury after extraction of the mandibular third molar—a comparative study of preoperative images by panoramic radiography and computed tomography

In this study we investigated the relationships among the risk factors for inferior alveolar nerve injury (IANI), and the difference between preoperative imaging findings on panoramic radiographs and computed tomography (CT), by univariate and multivariate analyses. We determined the following to be significant variables by multivariate analysis: panoramic radiographic signs, such as the loss of the white line of the inferior alveolar canal or the diversion of the canal; excessive haemorrhage during extraction; and a close relationship of the roots to the IAN (type 1 cases) on CT examination. CT findings of type 1 were associated with a significantly higher risk (odds ratio 43.77) of IANI. In addition, many panoramic findings were not consistent with CT findings (275 of 440 teeth; 62.5%). These results suggest that CT findings may be able to predict the development of IANI more accurately than panoramic findings. Panoramic radiography alone did not provide sufficiently reliable images required for predicting IANI. Therefore, when the panoramic image is suggestive of a close relationship between the impacted tooth and the IAN, CT should be recommended as a means of conducting further investigations.

Risk factors associated with postoperative delirium after surgery for oral cancer

OBJECTIVE The purpose of this study was to retrospectively investigate the multivariate relationships among the various risk factors for postoperative delirium in patients undergoing oral cancer surgery. MATERIAL AND METHODS The medical records of all patients with oral cancer who underwent curative head and neck surgery between April 2011 and March 2013 at our institution were retrospectively reviewed. There was a total of 188 patients, including 110 males and 78 females. RESULTS We found that older age, extensive surgical procedure, longer operation, excessive hemorrhage, blood transfusion, longer postoperative management in the intensive care unit, longer postoperative hospital stay, lower albumin level in the preoperative blood test, and lower total protein, albumi, n and hemoglobin levels and a higher C-reactive protein (CRP) level in the postoperative blood tests were significant variables in the univariate analysis (p < 0.05). We also determined that an older age (odds ratio [OR] = 6.83), intraoperative lower hemoglobin levels (OR = 6.82), and excessive hemorrhage (OR = 3.62) during surgery were significant variables in the multivariate analysis. CONCLUSION Clinicians should pay special attention to preventing delirium during the postoperative management of older patients with these risk factors. Furthermore, increasing the hemoglobin levels during surgery may be able to prevent postoperative delirium.

Alteration of Cell–Cell Junctions in Cultured Human Lymphatic Endothelial Cells with Inflammatory Cytokine Stimulation

BACKGROUND To maintain normal function, the lymphatic endothelium is regulated by cell-cell junctions. There have been few studies of lymphatic endothelial cell junctions using standard cell biological methods. This study had two purposes: to characterize cell junctions in cultured lymphatic endothelial cells and to investigate the effects of the inflammatory cytokine TNF-α on altered cell-cell junctions. METHODS AND RESULTS Cultured human dermal lymphatic endothelial cells (HDLEC) were immunostained with the tight junction marker, ZO-1, and adherens junction markers, VE-cadherin and PECAM-1. In TNF-α-treated HDLEC, we evaluated changes in endothelial cell junctions by immunostaining and through the use of transendothelial electrical resistance (TER). Immunofluorescence staining of HDLEC revealed heterogeneity among the endothelial cell junctions, which could be classified into continuous and discontinuous junctions. In these cell junctions, ZO-1 and VE-cadherin were co-localized. Double immunofluorescence staining revealed the broad distribution of VE-cadherin at the cell periphery, where VE-cadherin and PECAM-1 were co-localized. TNF-α treatment decreased TER, caused a predominance in the appearance of discontinuous junctions with a reduction in the broad distribution of VE-cadherin at the cell periphery in HDLEC. CONCLUSIONS The results indicate a heterogeneous distribution of cell junctions in HDLEC involving continuous and discontinuous junctions. Our data also suggest that TNF-α alters the normal distribution of cell junctions and affects the endothelial barrier of cultured lymphatic endothelial cells. The broad distribution of VE-cadherin at the cell periphery may reflect the lymphatic permeability.

Incidence of Venous Thromboembolism After Oral Oncologic Surgery With Simultaneous Reconstruction

PURPOSE Patients with oral cancer who undergo resection with simultaneous reconstruction are presumed to be at high risk for developing venous thromboembolism (VTE) according to current criteria. The primary purpose of this retrospective study was to report the incidence of VTE after oral cancer surgery requiring primary reconstruction and to identify the potential risk factors for VTE in this population. MATERIALS AND METHODS This retrospective study evaluated 133 consecutive patients who had undergone oral cancer resection with simultaneous reconstruction from April 2007 through December 2014. Bilateral lower-extremity venous duplex ultrasonography (VDUS) was routinely performed 2 days after surgery. Pulmonary embolism was confirmed with computed tomography. The Caprini risk score (CRS) was obtained for each patient. Patients with and without VTE were compared using the χ2 test and Student t test with some variables. Univariate predictors associated with VTE were entered into a multivariate logistic regression analysis. A P value less than .05 was regarded as indicating statistical significance. RESULTS The incidence of VTE after oral oncologic surgery with simultaneous reconstruction was 26.3% (35 of 133 patients): deep vein thrombosis (DVT) and pulmonary embolism occurred in 2.3% (3 of 133) and DVT alone was found in 24.0% (32 of 133). Multivariate logistic regression analysis showed that only a high CRS was statistically relevant to VTE occurrence. CONCLUSIONS Because a high incidence of VTE was found after major oral and maxillofacial surgery, lower-extremity VDUS should be undertaken in patients who undergo oral cancer surgery with simultaneous reconstruction, especially those with a high CRS.

Sequential evaluation for bone union of transferred fibula flaps in reconstructed mandibles: panoramic X-ray versus computed tomography

The purpose of this study was to sequentially evaluate bone union of fibular grafts in mandibular reconstruction. Patients who underwent routine follow-up computed tomography (CT) and panoramic X-ray imaging during a period of ≥2 years were enrolled. On panoramic X-ray images, bone union was scored as 0 (absent callus formation) or 1 (complete callus formation). On CT images, a scale of 0 to 2 was used (0, absent callus formation; 1, complete callus formation only on the labial side; 2, complete callus formation on both the labial and lingual side). A total of 56 bone junctions were evaluated in 20 patients. Five of 56 junctions (9%) in four of 20 patients (20%) showed radiological non-union (panoramic X-ray score=0, CT score=0 or 1) at 2 years after surgery. All bone junctions with radiological non-union were located at the mandibular angle. No categorical values, including diabetes mellitus and radiation therapy, were significantly associated with radiological non-union. In conclusion, assessing at least two sides (i.e. labial and lingual sides) on CT images is adequate to evaluate bone union in transferred fibula flaps. Careful fixation at the mandibular angle may improve the rate of bone union.

Four-dimensional computed tomography evaluation of jaw movement following mandibular reconstruction: A pilot study

PURPOSE The purpose of this study was to analyze jaw movement during mastication in patients who underwent mandibular reconstruction following segmental mandibulectomy, including mouth opening and mastication time, based on four-dimensional computed tomography (4D CT) images. MATERIAL AND METHODS This study included six surgical patients, who underwent segmental mandibulectomy and simultaneous reconstruction with a free fibula osteocutaneous flap, and four controls. 4D CT was performed during mastication of a cookie to evaluate the movement of the jaw during natural function. The maximum mouth opening, mastication time, and movement of the mandibular angle during mastication were evaluated from the 4D CT images. RESULTS 4D CT images enabled visualization of jaw movement during mastication. When compared with the controls, the maximum mouth opening during mastication and excursion of the mandibular angle, especially on the diseased side, tended to decrease in surgical patients; however, this did not occur with mastication time. The numerical differences between the diseased and nondiseased side in surgical patients tended to be higher than the crosswise differences in controls. CONCLUSION 4D CT images revealed differences in jaw function between patients who underwent mandibular reconstruction and controls. 4D CT could be used to evaluate postoperative outcomes following mandibular reconstruction.

Expression of Ror2 associated with fibrosis of the submandibular gland

The submandibular gland (SMG) is one of the major salivary glands that play important roles for variety of physiological functions, such as digestion of foods, prevention of infection, and lubrication of the mouth. Dysfunction of the SMG, often associated with a salivary inflammation, adversely influences a persons quality of life. However, the mechanism underlying inflammation-driven dysfunction of the SMG is largely unknown. Here, we used a mouse model in which the main excretory duct of the SMG is ligated unilaterally to induce inflammation of the gland and examined the expression of Wnt5a, Ror1 and Ror2 genes, encoding Wnt5a ligand and its cognate receptors, which have been implicated in tissue damage or inflammatory responses in variety of tissues. We show that expression levels of Ror1, Ror2, and Wnt5a are increased in the ligated SMG undergoing interstitial fibrosis, which is accompanied by robust expression of fibrosis-associated genes, such as TGF-β1, TNF-α, IL-1β, and MMP-2. Increased immunostaining signal of Ror2 was detected in the fibrotic tissues with abundant accumulation of fibroblasts and collagen fibers in the ligated SMG, suggesting that Ror2-mediated signaling might be activated in response to tissue damage and associated with progression of fibrosis in the SMG.Key words: submandibular gland, Ror2, Wnt5a, fibrosis, inflammation.

p16 overexpression in malignant and premalignant lesions of the oral and esophageal mucosa following allogeneic hematopoietic stem cell transplantation

ObjectivesSecondary malignancy in the oral mucosa is recognized as one of the most serious complications in patients who received allogenic hematopoietic stem cell transplantation (HSCT). However, potential risk factors associated with carcinogenesis after HSCT that have been reported remain elusive. We experienced a rare case of secondary malignancies of the oral and esophageal mucosa and analyzed the expression of tumor suppressor gene product p16.Case reportA 35-year-old male had malignant lesions of the oral and esophageal mucosa two years after HSCT. Partial maxillectomy and endoscopic submucosal dissection were performed. Immunohistochemical analyses revealed that the tumor cells of malignant and premalignant lesions of the oral cavity and esophagus but not keratosis were positive for p16.ConclusionsPathological examinations with p16 immunohistochemistry may contribute to an early diagnosis of secondary malignancy after HSCT.

Multi-center retrospective study of the prognosis and treatment outcomes of Japanese oral squamous cell carcinoma patients with single lymph node metastasis and extra nodal extension

Oral squamous cell carcinoma (OSCC) containing single lymph node metastasis (pN1) with extra nodal extension (ENE) is a rare clinical situation. Therefore, it is unclear whether pN1 with ENE is at high risk of recurrence among the OSCC population, or whether postoperative radiotherapy (RT)/concomitant chemoradiotherapy (CCRT) is effective in these cases.