External validation of ADNEX MR SCORING system: a single-centre retrospective study.

AIM: To evaluate the accuracy of the ADNEX MR SCORING system for characterising adnexal masses. MATERIALS AND METHODS: An institutional review board approved this retrospective study. The study population comprised 663 women who underwent magnetic resonance imaging (MRI) from January 2007 to December 2014 to characterise 778 adnexal masses that were indeterminate under ultrasonography (590 benign and 188 malignant). Two radiologists independently reviewed the MRI images. The masses were scored from 1 to 5 according to the ADNEX MR SCORING system. The diagnostic performance of the system was evaluated by receiver operating characteristic (ROC) analysis. Masses scored 4 or greater were considered malignant (including tumours of borderline malignancy or low malignant potential). RESULTS: The malignancy rates of masses with scores of 2, 3, 4 and 5 were 1.9% (8/419), 12.8% (19/149), 62.6% (57/91) and 87.4% (104/119) for reader 1 and 2.1% (9/424), 13.6% (20/147), 67.6% (71/105) and 86.3% (88/102) for reader 2, respectively. The areas under the ROC curves for the differentiation of benign and malignant masses were 0.929 and 0.923, respectively; the sensitivity, specificity and accuracy of diagnosis were 85.6% (161/188), 91.7% (541/590), and 90.2% (702/778) for reader 1 and 84.6% (159/188), 91.9% (542/590), and 90.1% (701/778) for reader 2, respectively. Tumours of borderline malignancy or low malignant potential had a higher rate of misclassification (46.1%) than other malignant tumours (6-7.4%). CONCLUSION: The ADNEX MR SCORING system was highly accurate in differentiating benign and malignant adnexal masses, although it may be less accurate for tumours of borderline malignancy or low malignant potential.

Evaluation of postoperative changes in vascularized iliac bone grafts used for mandibular reconstruction.

Vascularized iliac bone grafts are used for mandibular reconstruction, but the factors affecting graft maintenance are unknown. This study explored the postsurgical changes in vascularized iliac bone grafts in patients who had undergone mandibular reconstruction after segmental resection. The study involved 24 patients (16 men and eight women) with oral tumours or osteoradionecrosis. Thirteen patients required bare bone grafting (BBG) and 11 patients required reconstruction with soft tissue coverage (six with a skin paddle and five with direct closure). The bone graft maintenance rate (with regard to the height of the centre of the graft) was calculated immediately after surgery and at 3, 6, 12, 24, and 36months after surgery. The maintenance rate was significantly lower in the BBG group than in the soft tissue coverage group at 3, 6, 12, 24, and 36months, and in those who were fitted with dentures compared to those who were not at 6, 12, 24, and 36months. Local infection also influenced the maintenance rate, but not significantly so. These findings indicate that the reconstruction technique and denture use can affect the bone graft maintenance rate after mandibular reconstruction with vascularized iliac bone grafts.

Sepsis patients' renal manifestation on contrast-enhanced CT.

AIM: To evaluate renal volume and attenuation changes in patients with sepsis on contrast-enhanced computed tomography (CT) with respect to the severity of sepsis. MATERIALS AND METHODS: Forty-four patients with sepsis who underwent CT before and after the onset of sepsis were retrospectively analysed. Renal volume and CT attenuation value of the renal cortex on contrast-enhanced CT were measured for each patient and changes in renal volume and CT attenuation value from before to after the onset of sepsis were calculated. The changes were correlated with the severity of sepsis (Sepsis-related Organ Failure Assessment [SOFA] score). The time course of the renal volume and CT attenuation changes were also evaluated. RESULTS: Renal volume increased by 17.6% and CT attenuation value decreased by 19% after the onset of sepsis with statistically significant differences (p<0.001 for both renal volume and CT attenuation changes). The renal volume and CT attenuation changes had significant correlations with the SOFA score (r=0.36, p=0.018 and -0.43, p=0.005, respectively). The time course of the renal volume and CT attenuation changes seemed to be gradual compared to that of the SOFA score and to lag behind the peak of the SOFA score. CONCLUSION: In patients with sepsis, the renal volume increases and the CT attenuation value decreases in proportion to the severity of sepsis. The changes may lag behind the peak of severity of sepsis and can be observed for a relatively long time after a patient's recovery from sepsis.

Effect of articulatory rehabilitation after oral cancer surgery on higher brain activation.

The present study aimed to verify the importance of postoperative articulatory rehabilitation in patients with oral cancer and to clarify the neurological changes underlying articulatory functional recovery. A longitudinal assessment of oral function and accompanying brain activity was performed using non-invasive functional magnetic resonance imaging (fMRI). We assessed 13 patients with cancers of the tongue and oral floor before and after ablative surgery. Articulatory function was assessed preoperatively and postoperatively using a conversation intelligibility test and the Assessment of Motor Speech for Dysarthria test. Patients also performed a verbal task during fMRI scans. The assessments were then repeated after the patients had undergone 4-6 months of articulatory rehabilitation therapy. Compared to pretreatment levels, articulatory rehabilitation resulted in a significant increase in activation in the supplementary motor cortex, thalamus, and cingulate cortex. The present study offers a quantitative assessment of the effects of speech rehabilitation by investigating changes in brain activation sites.

Effect of local anesthesia on trigeminal somatosensory-evoked magnetic fields.

For objective neurophysiological evaluation of the function of the trigeminal system, magnetoencephalography- based TSEF (trigeminal somatosensory-evoked field) assessment would be valuable in providing spatial and temporal profiles of cortical responses. However, this necessitates knowledge of how TSEF varies with trigeminal nerve dysfunctions. We introduced a conduction block of the trigeminal nerve using local anesthesia (lidocaine) to temporally mimic nerve dysfunctions, and monitored TSEF changes. Following an electrical stimulation of the lower lip, a magnetic response with peak latency of approximately 20 ms was identified in all participants. Dipole for the peak was estimated on the post-central gyrus in the participant's own magnetic resonance image. After normalization to Montreal Neurological Institute (MNI) space and inter-participant data integration, the summary equivalent current dipole localization among participants remained in the post-central gyrus, suggesting validity of the use of MNI space. Partial anesthesia of the lower lip led to a loss of the waveform characteristics of TSEF for electrical stimulation to the trigeminal nerve. We verified that the 20-ms latency cortical response of TSEF components localized at the primary sensory cortex can serve as a robust neurofunctional marker of experimental trigeminal nerve dysfunction.

Comparison of brain activation via tooth stimulation.

The aim of this study was to evaluate the sensation of each tooth type at the cortical level. The tactical sensation from teeth plays an important role in controlling the masticatory system. However, the role of each tooth type has not been determined. Functional near-infrared spectroscopy (fNIRS) was used to detect changes in cerebral blood flow in the somatosensory cortex of 12 healthy volunteers. Painless vibrotactile stimuli were applied to 8 teeth (left maxillary and mandibular incisors, canines, 1(st) premolars, or 1(st) molars). The somatosensory cortex was activated during stimulation of all teeth. A comparison of cortical activation revealed significantly greater activation during stimulation of the maxillary and mandibular first molars. However, no significant differences were seen between any other teeth. These results indicate that the first molar is the most sensitive tooth type at the cortical level, and provide basic data on the relationship between input from individual tooth type and brain activation. These data could be useful for understanding the neural mechanisms of individual tooth types.

Cervical sympathectomy causes alveolar bone loss in an experimental rat model.

BACKGROUND AND OBJECTIVE: Periodontal disease, a pathological destructive inflammatory condition, is characterized by alveolar bone loss. Recent studies have suggested a correlation between the sympathetic nervous system and bone remodeling. To confirm the importance of the sympathetic nervous system in bone resorption, we investigated the effects of superior cervical ganglionectomy and oral challenge with Porphyromonas gingivalis on alveolar bone loss in rats. MATERIAL AND METHODS: Rats were divided into three groups: group A underwent a sham operation as the control group; group B underwent superior cervical ganglionectomy; and group C underwent a sham operation and oral challenge with P. gingivalis. Horizontal alveolar bone loss was evaluated by measuring the distance between the cemento-enamel junction and the alveolar bone crest. Cytokine gene expression in the gingival tissues was assessed using reverse transcription-polymerase chain reaction analyses. The furcation areas of the mandibular molars were examined histologically. RESULTS: Both superior cervical ganglionectomy and oral challenge with P. gingivalis resulted in accelerated alveolar bone loss. Gingival tissues in the superior cervical ganglionectomy group showed increased expression of the cytokines interleukin-1 alpha, tumor necrosis factor-alpha and interleukin-6. The density of neuropeptide Y-immunoreactive fibers was decreased following superior cervical ganglionectomy. Osteoclasts were observed in the superior cervical ganglionectomy and P. gingivalis-challenged groups. CONCLUSION: Both superior cervical ganglionectomy and oral challenge with P. gingivalis induced alveolar bone loss. These results provide new information on the occurrence of alveolar bone loss, in that both oral challenge with P. gingivalis and superior cervical ganglionectomy are important accelerating factors for alveolar bone loss. Thus, we suggest that the sympathetic nervous system is linked with the prevention of alveolar bone loss.

Chewing ameliorates stress-induced suppression of hippocampal long-term potentiation.

Research has established that severe stress adversely affects hippocampal memory, and chewing has been suggested to restore impaired cognitive functions in the hippocampus. To address how chewing involves stress-attenuated hippocampal memory process, we measured the long-term potentiation (LTP) of hippocampal slices of adult male rats that had experienced restraint stress, including some rats that were allowed to chew a wooden stick during the stress period and other rats that were not. The three experimental conditions were: 1) restraint stress without chewing (ST), 2) restraint stress with chewing (SC), and 3) no treatment (CT). We prepared hippocampal slices and collected trunk blood from all experimental animals. For rats in the two stressed groups, we collected tissue and blood at one of three post-stress time points: immediately after, 24 h after, or 48 h after exposure to the stressor. We found that the magnitude of LTP in both group ST and SC was significantly attenuated immediately after stress exposure. However, within 24 h after the end of the stress period, LTP had returned to the control level in group SC whereas it remained low in group ST. At the same post-stress time point, we found that facilitation of N-methyl-D-aspartate (NMDA) receptors by bath-applied glycine had less effect on the magnitude of LTP in group SC than on group ST, suggesting that most NMDA receptors had already become functionally restored in group SC by that time. Plasma concentration of adrenocorticotropic hormone was significantly elevated only in group ST immediately after exposure to the stressor, reflecting the involvement of chewing in decreasing subsequent corticosterone secretion. Thus, the present study demonstrates that chewing ameliorates the stress-induced impairment of NMDA receptor-mediated LTP, suggesting chewing as a good strategy to cope with severe stress by suppressing excessive endocrine responses.

Submandibular glands contribute to increases in plasma BDNF levels.

Brain-derived neurotrophic factor (BDNF) promotes survival and differentiation of neural cells in the central and peripheral nervous systems. BDNF has been detected in plasma, but its source has not yet been established. Expression of BDNF mRNA has been identified in the submandibular glands when male rats are exposed to acute immobilization stress. In the present study, we investigated whether plasma BDNF is influenced by the submandibular glands in this model. Acute immobilization stress for 60 min significantly increased the level of plasma BDNF. However, plasma BDNF elevation was markedly suppressed in bilaterally sialoadenectomized rats. There were no significant differences between stressed (60 min) and non-stressed rats with respect to the BDNF mRNA expression in the hippocampus, heart, lung, liver, pancreas, or spleen, as determined by real-time polymerase chain-reaction. These findings suggest that the submandibular glands may be the primary source of plasma BDNF in conditions of acute immobilization stress.

Restraint stress enhances alveolar bone loss in an experimental rat model.

BACKGROUND AND OBJECTIVE: The purpose of the present study was to examine the effects of restraint stress on periodontal breakdown resulting from Porphyromonas gingivalis-challenged periodontitis in rats. MATERIAL AND METHODS: To examine the influence of restraint stress on periodontal breakdown, rats were orally challenged with the periodontal pathogen P. gingivalis. Twenty male, specific pathogen-free (SPF) 3-wk-old, Sprague-Dawley rats were divided into four groups: group A (controls), group B (exposed to restraint stress for 12 h/d for 22 d), group C (orally challenged with P. gingivalis), and group D (exposed to restraint stress for 12 h/d for 22 d and orally challenged with P. gingivalis). After 22 d, all animals were killed. The distance from the alveolar bone crest to the cemento-enamel junction was determined, concentrations of adrenocorticotropic hormone were measured as stress markers, and atrophy of the thymus and spleen were assessed. In addition, the furcation area of the maxillary molars was examined histologically, while gingival cytokine gene expression was assessed by mRNA using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: In the restrained group, all stress markers were elevated, and the thymus and spleen were atrophied. Combined restraint stress and oral challenge with P. gingivalis resulted in significantly higher bone loss, and osteoclasts were observed. RT-PCR analysis revealed low cytokine gene expression in the restrained groups. CONCLUSION: These results suggest that the presence of restraint stress significantly enhances the progression of P. gingivalis-challenged periodontitis in rats.

Immobilization stress induces BDNF in rat submandibular glands.

Brain-derived neurotrophic factor (BDNF) promotes survival and differentiation of the cells of the central and peripheral nervous systems. BDNF has been identified in non-neural tissue, including the heart, lung, platelets, lymphocytes, and lacrimal glands. Immobilization stress modifies BDNF mRNA expression in some organs. The present study examines the effect of immobilization stress on BDNF, and its receptor TrkB, in male rat submandibular glands. Increased BDNF mRNA and protein expression were observed in duct cells as a result of immobilization stress, as demonstrated by real-time PCR, Western blot, immunohistochemistry, and analysis by microdissection. TrkB mRNA was not detected in salivary gland tissue, or oral or esophageal mucosa, by RT-PCR. Rat submandibular gland was thus identified as an organ which expresses BDNF. Furthermore, the results of this study suggest that increased salivary BDNF expression occurs following immobilization stress.

Suppression of stress-induced nNOS expression in the rat hypothalamus by biting.

Nitric oxide (.NO) modulates the activity of the endocrine system in the behavioral response to stress. The purpose of this study was to investigate the effect of restraining the body of an animal on expression of neuronal nitric oxide synthase (nNOS) in the paraventricular nucleus (PVN) of the hypothalamus, and the inhibitory effect of para-masticatory activity on restraint-induced nNOS expression. We observed an increase in nNOS mRNA expression and nNOS-positive neurons in the rat hypothalamus after 30 or 60 min of restraint. Biting on a wooden stick during bodily restraint decreased nNOS mRNA expression in the hypothalamus. In addition, the number of nNOS-positive neurons was significantly reduced in the PVN of the hypothalamus. These observations clearly suggest a possible anti-stress effect of the masticatory activity of biting, and this mechanism might be unconsciously in operation during exposure to psychological stressors.

Expression of bone sialoprotein in mineralized tissues of tooth and bone and in buccal-pouch carcinomas of Syrian golden hamsters.

The expression of bone sialoprotein (BSP) is normally restricted to mineralized connective tissues of bones and teeth where it has been associated with mineral crystal formation. However, recent studies have revealed ectopic expression of BSP in various lesions, including oral and extraoral carcinomas, in which it has been associated with the formation of microcrystalline deposits and the metastasis of cancer cells to bone. To develop a model to study the induction of BSP in carcinoma development, BSP expression in squamous-cell carcinomas induced by chemical carcinogen in the hamster cheek-pouch epithelium was investigated. Hamster BSP cDNA was first isolated and characterized, then used to prepare probes for Northern and in situ hybridization. The protein sequence of hamster BSP displayed 86% amino acid identity with a consensus mammalian BSP sequence and retained polyglutamate sequences, the RGD sequence and sites of phosphorylation, glycosylation and sulphation. The tissue-specific expression of hamster BSP mRNA and protein was confirmed by in situ hybridization and immunolocalization in developing tissues. Squamous-cell carcinomas induced in the buccal pouches of 5-week-old male Syrian golden hamsters treated with chemical carcinogen had BSP mRNA and BSP in the proliferating neoplastic epithelium. In contrast, neither BSP mRNA nor the protein could be detected in the stroma within which islands of the transformed tissue had formed. Thus, the hamster cheek pouch is a well-characterized model that can be used to study the induced expression of BSP in association with the development of squamous-cell carcinomas.

The effect of altered functional forces on the expression of bone-matrix proteins in developing mouse mandibular condyle.

Mechanical forces are known to have an effect on bone formation, maintenance and remodelling, and there is evidence that the development of the mandibular condyle in the rat is influenced by the consistency of the diet. Here a mouse model was used to investigate the relation between food, condylar development and the expression of bone sialoprotein (BSP), osteopontin (OPN), osteocalcin (OC) and type 1 collagen (COL I). Twenty-four 19-day-old male mice were randomly divided into three groups. Groups 1 and 2 were fed hard pellets and soft powdered food, respectively, for 2 weeks. Group 3 mice were fed soft food for 1 week followed by a week of hard pellets. Incisors of mice in groups 2 and 3 were trimmed twice a week to reduce occlusal forces. After killing the animals, mandibular condyles were collected for RNA extraction, in situ hybridization and immunohistochemical analyses. Histological sections showed that the condyles of mice in group 2 were underdeveloped, with a thinner layer of cartilage and fewer bone trabeculae. Northern hybridization of total RNA of the condyle from mice in this soft-food group also exhibited a significant decrease in the amounts of BSP, OPN, OC and COL I, representing 79%, 75%, 77% and 79% respectively, of that from mice fed hard food. In situ hybridization of these bone-matrix proteins demonstrated signals in bone-forming cells and BSP mRNA was also seen in the hypertrophic cartilage cells in the developing condyle. Immunohistochemical study demonstrated an obvious difference in the intensity of staining, especially for BSP. Results from group 3 were similar to those from group 1. The observed decrease in bone matrix-protein expression confirms that the consistency of the diet affects the development of the mouse mandibular condyle and that a soft diet diminishes the rate of bone formation.

Enamel epithelium expresses bone sialoprotein (BSP).

Bone sialoprotein (BSP) is a major non-collagenous extracellular matrix protein in bone and other mineralized connective tissues. BSP is synthesized and secreted by bone-, dentin- and cementum-forming cells. In this study we hypothesized that BSP may be also involved in enamel formation through its postulated role in matrix mineralization. In situ hybridization with cRNA probes for rat and hamster BSP, respectively, showed strong mRNA signals in ameloblasts actively synthesizing enamel matrix in developing incisors. However, no hybridization signals were observed at an earlier developmental stage when bell-shaped molar tooth germs were being formed. Immunohistochemical analysis of tooth tissues from transgenic mice harboring a 2.7 kb rat BSP promoter ligated to a luciferase reporter gene revealed strong staining for luciferase in the enamel epithelium of the developing tooth germ. Interestingly, BSP expression was also observed in epithelial cells of an ameloblastoma. The neoplastic epithelial nests and cords demonstrated strong mRNA signals to the human BSP probe while the connective tissue stroma showed only a background level of silver grains. Immunostaining also showed deposition of BSP by the odontogenic cells of the tumor. These results demonstrate that BSP is expressed by the enamel-forming epithelium of developing teeth, suggesting a possible role for BSP in enamel formation and its subsequent mineralization. Expression of the BSP gene in ameloblastomas is consistent with the expression of BSP by the enamel epithelium and also with the expression of BSP by neoplastic tissues, suggesting a possible role in tumorigenesis.

Inflammatory cytokine gene expression in human periodontal ligament fibroblasts stimulated with bacterial lipopolysaccharides.

The effects of Porphyromonas gingivalis lipopolysaccharide (P-LPS) and Escherichia coli lipopolysaccharide (E-LPS) on the gene expression and production of inflammatory cytokines of human periodontal ligament fibroblasts (HPLF) were examined by a Northern (RNA blot) assay and enzyme-linked immunosorbent assay, respectively. mRNAs for interleukin-6 (IL-6), IL-8, and transforming growth factor beta (TGF-beta) were detected in HPLF cells, but IL-1 alpha, IL-1 beta, tumor necrosis factor alpha, transforming growth factor alpha, and granulocyte-macrophage colony-stimulating factor were not detected by reverse transcription-PCR. The expression of TGF-beta mRNA was not influenced by either LPS. P-LPS (1 to 10 micrograms/ml) and E-LPS (100 micrograms/ml) markedly stimulated the expression of IL-6 and IL-8 mRNAs compared with the control. The synthesis of IL-6 and IL-8 was also stimulated by 10 and 100 micrograms of both LPSs per ml, but IL-8 synthesis was not stimulated with E-LPS at 1 microgram/ml. Secretion of IL-6 and IL-8 into the culture medium was detected at 6 and 3 h, respectively, after exposure to P-LPS (10 micrograms/ml). These findings suggested that P. gingivalis leads to periodontal tissue destruction and alveolar bone resorption through IL-6 and IL-8 released from HPLF cells stimulated with its LPS.

[Importance of posterior tooth-to-denture base discrepancy in the development of skeletal open-bite malocclusion].

This paper describes the relationship between the development of skeletal open-bite malocclusion and the tooth-to-denture base discrepancy. The cases which have a severe skeletal open-bite malocclusion are presented to evaluate the causing factor of the anterior open-bite. The anterior open-bite was associated with inferiorly positioned maxillary molars caused by the squeezing out effect of the tooth-to-denture base discrepancy, especially those in posterior part of dentition (posterior discrepancy), which provided a less steep maxillary occlusal plane in the denture frame. It was suggested that the posterior discrepancy induced a descending movement of the posterior teeth followed by a change of the occlusal plane and this effect of the posterior discrepancy was important factor in developing anterior open-bite malocclusion.

Computed cephalography using laser scan system.

A new imaging system with applications in dentistry has been developed which uses recent advances in both electronic and computer technology. The cephalometric radiogram is based on a newly developed laser scan system offering these characteristic features: 1. A clearer image with a wide latitude can now be obtained compared with the cephalometric radiograms taken by the conventional method. 2. Various imaging processes are available through computer enhancement which enable visualization of the sites of dense and thin bones and even the anatomical morphology of the soft tissues. Such images could be easily observed regardless of the purpose of the radiogram. 3. Data are reduced by conversion into digital signals which can be stored in the computer for long periods. 4. Exposure dose is reduced.