Host beta-globin gene fragments in crevicular fluid as a biomarker in periodontal health and disease.

BACKGROUND AND OBJECTIVE: Leukocytes and epithelium are the first line of defense in preventing bacterial invasion into periodontium. Some of these cells die in gingival crevicular fluid, whereupon their DNA is spilled out. The present study was designed to investigate the profile of host beta-globin gene fragments in the gingival crevicular fluid of various periodontal conditions. MATERIAL AND METHODS: Gingival crevicular fluid from 40 teeth with chronic periodontitis, 30 with gingivitis and 22 that were clinically healthy were centrifuged (3,000 g, 10 min). The supernatant (cell-free gingival crevicular fluid) was centrifuged again (13,000 g, 10 min), resulting in the pellet and the supernatant as debris and debris-free fractions, respectively. Specific primers for amplifying 110 bp, 536 bp and 2 kb amplicons of human beta-globin gene were used to investigate host DNA by quantitative and qualitative polymerase chain reaction. RESULTS: The periodontitis group showed the largest amount of host beta-globin gene fragments, while the healthy group had the lowest. In the debris and debris-free fractions, the 536 bp and 2 kb amplicons were more often detected in the periodontitis group than in the other groups. Interestingly, the presence of 2 kb amplicon in the debris fraction could be used to discriminate periodontitis from gingivitis and healthy groups because we found it in 85% of periodontitis samples but only in 13% of gingivitis samples, and it was absent in the healthy group. CONCLUSION: This study shows the different DNA profiles of cell-free gingival crevicular fluid in periodontal health and disease. It suggests that the quantity and quality of host DNA are dependent on the disease conditions. Therefore, the beta-globin gene fragments in cell-free gingival crevicular fluid may be a potential biomarker of periodontal disease progression.

Inter- and intra-rater reliability in fibroptic endoscopic evaluation of swallowing.

Fibroptic endoscopic evaluation of swallowing (FEES) is a useful way for dentists to evaluate oropharyngeal dysfunction. However, no study has paid attention to inter- and intra-rater reliability of FEES evaluation about oropharyngeal dysfunction. The purpose of this study is to verify whether dentist who trained and experienced for evaluation of dysphagia could diagnose oropharyngeal function with FEES. Nine dentists independently evaluated FEES images of 10 cases four times each. At first, evaluators performed the first evaluation without consulting the evaluative criteria. Subsequently, evaluators independently re-evaluated at 1-week intervals for three consecutive weeks, consulting the evaluative criteria. And then, inter- and intra-rater reliability was calculated. Cohen's Kappa was used to assess reliability. The results found that overall inter-rater reliability was 0·35±0·04 (first evaluation), 0·45±0·05 (s), 0·44±0·05 (third) and 0·46±0·04 (fourth). Most of inter-rater reliability related to aspiration was moderate to high, but lower for categories that evaluated timing of swallowing and mastication. In contrast, intra-rater reliability was moderate to high for overall categories, at 0·53±0·04 (first vs. second evaluation), 0·55±0·04 (first vs. third), 0·53±0·04 (first vs. fourth), 0·55±0·03 (second vs. third), 0·60±0·03 (second vs. fourth) and 0·78±0·03 (third vs. fourth). FEES is reliable for experienced dentists to diagnose oropharyngeal function. Moreover, repeated evaluation with the aids of evaluative criteria is useful to improve the reliability of FEES.

Perfusion imaging of meningioma by using continuous arterial spin-labeling: comparison with dynamic susceptibility-weighted contrast-enhanced MR images and histopathologic features.

PURPOSE: The goal of the present study was to determine the utility of continuous arterial spin labeling (CASL) for characterization of meningioma by MR perfusion imaging and to compare these results with those obtained from the T2 dynamic susceptibility contrast (T2DSC) method and from histopathologic examination. METHODS: Twenty-one cases of meningiomas were examined at 1.5T. CASL perfusion imaging was implemented on the basis of multisection single-shot echo-planar imaging with velocity-driven adiabatic spin-inversion preparation. T2DSC perfusion imaging was also performed by using a double-echo spoiled gradient echo sequence in a section containing the tumor. By focusing on the regions of interest, maps of % signal intensity change and cerebral blood flow (CBF) were determined from CASL and cerebral blood volume (CBV). CBF and mean transit time (MTT) were obtained from T2DSC. The microvessel area (MVA) was determined from specimens immunostained with anti-CD31 in 14 cases by measuring the total amount of staining in each histologic section. Linear regression analysis was performed for rCBF values from both perfusion methods and for % signal intensity change and MVA. RESULTS: There was a significant correlation between CBF values determined from both perfusion methods (r(2) = 0.73; P < .001); however, the slope from T2DSC to CASL was less than unity, likely because of the different vascular weighting used for each method. There was also a significant correlation between CASL-% signal intensity change and MVA determined by histopathology (r(2) = 0.91; P < .00001). Perfusion values were the greatest for angiomatous meningioma and lowest for fibrous meningioma when using either perfusion method. CONCLUSIONS: CASL and T2DSC perfusion methods are comparable in the characterization of meningiomas. Further, CASL is of use in assessing tumor microcirculation.

Electron microscopic visualization of cathepsin D using mercury-labeled pepstatin as an enzyme inhibitor.

Pepstatin, a specific inhibitor of pepsin, cathepsin D (E), renin, etc., was used in a new method to demonstrate the sites of enzymes. Pepstatin (Pst) was covalently attached to glutathione (GSH), using a dicyclohexylcarbodiimide, and CH3Hg+ was then put in the residue of SH for electron microscopic observation. Pst-GS-HgCH3 thus obtained was nonisotopical, had a very low molecular weight (about 1,200 daltons), and still almost completely retained its inhibitory activity. Sections of rat liver (less than 1 mm3 thick), prefixed by glutaraldehyde, were incubated in the prepared reaction medium. Cathepsin D, located in the lysosomes, was demonstrated by this compound, but when the sections were preincubated with pepstatin, this was not the case. These results demonstrate that mercury-labeled pepstatin is a useful reagent for the histochemical staining of acid proteases for electron microscope.

Coregistration of FDG PET and MRI of the head and neck using normal distribution of FDG.

UNLABELLED: For better localization of head and neck structures by PET with 2-(18)F-2-deoxy-D-glucose (FDG), direct incorporation of anatomical information from MRI by the coregistration of FDG PET and MRI without external markers is proposed. METHODS: Seventeen patients with neoplasms and 16 normal subjects who had both FDG PET and MRI were studied. First, the three-dimensional normal distribution of FDG was evaluated, and then the structures of the head and neck regions with normal distribution patterns of FDG were used as internal markers for the coregistration of PET and MRI. The effectiveness of the coregistration was evaluated using focal neoplasms that were identified by both PET and MRI as fiducial internal markers. RESULTS: The normal structures selected as internal landmarks for coregistration were the tonsils, salivary glands, mucosal layers of the oral cavity and pharynx, spinal cord, inferior portion of the frontal lobe, cerebellum and nasal turbinates. These structures were more easily observed in sagittal or coronal sections than in transaxial sections. All primary neoplasms were delineated by PET, whereas 4 were missed by MRI. Thirteen primary tumors and 7 cervical lymph node metastases coregistered well, with a center-of-mass distance of <2 mm, whereas 10 lymph node metastases were slightly misregistered, with a center-of-mass distance of 7.8+/-6.5 mm (mean+/-s.d.), probably due to differences in neck positions. CONCLUSION: Normal distribution of FDG uptake in the head and neck regions delineated by multidirectional sections is important for effective coregistration of FDG PET with MRI.

Fluorine-18-fluorodeoxyglucose PET versus thallium-201 scintigraphy evaluation of thyroid tumors.

UNLABELLED: To determine whether PET could help differentiate malignant from benign thyroid tumors, 18F-fluorodeoxyglucose (FDG) accumulation and 201Tl scintigraphy were examined relative to histological diagnosis. METHODS: Nodular thyroid lesions in 11 patients were evaluated before surgical resection. Static PET scanning with 370 MBq FDG was done for 20 min (from 40 to 60 min postinjection) in all patients, and standardized uptake values (SUVs) in these lesions were calculated. In addition, eight patients were evaluated with dynamic PET scan up to 60 min postinjection, and the lesions were further evaluated using graphical analysis. Thallium-201 delayed images were visually evaluated in 10 patients. RESULTS: Four of 11 nodules were well-differentiated papillary carcinoma, another five were benign follicular adenomas, one was a multinodular goiter and another a case of chronic thyroiditis that was proved not to contain a nodule. Time-activity curves of FDG uptake showed different patterns in malignant and benign tumors. In the malignant tumors, FDG uptake increased with time after the tracer injection. By contrast, FDG uptake in benign tumors gradually decreased. With use of a cutoff value of 5.0 mg/ml for SUV and 10 microl x min(-1) x ml(-1) for Kc (K complex value determined using the linear fitting of the time-activity curve of FDG accumulation), all of the four malignant nodules and the six benign nodules were separated correctly. Chronic thyroiditis had high SUV in the malignant range. Of the four patients with thyroid carcinoma, the delayed 201Tl images revealed a slightly higher or equal uptake to background activity. In a patient with chronic thyroiditis, the delayed 201Tl images revealed diffuse accumulation higher than background activity. CONCLUSION: FDG-PET is superior to 201Tl in differentiating malignant from benign tumors. Both SUVs and Kc values were useful indexes for this discrimination. Although careful evaluation is needed for chronic inflammatory lesions, this technique appears to be useful in evaluating thyroid nodules.

Increase in the susceptibility of hemoglobin to trypsin on treatment with glutathione or cysteine.

1. Native human hemoglobin A was digested with proteases after treatment with reduced or oxidized glutathione, cysteine, or cystine. 2. The treatment of hemoglobin with a 40-fold molar excess of reduced glutathione or cysteine at 37 degrees C for 4 enhanced its susceptibility to trypsin 4 or 6 times, respectively. However, oxidized glutathione and cystine had little or no effect on its susceptibility to the protease. 3. The enhanced susceptibility was not due to conformational change in hemoglobin, such as dissociation to dimers or monomers, or to unfolding of alpha-helical structure, but was due to dissociation of heme from the globin moiety, judging from measurements of the absorption spectrum and circular dichroism spectrum, and gel-filtration analysis.

Limited proteolysis of p-chloromercuribenzoate-dissociated hemoglobin by trypsin.

p-Chloromercuribenzoate-treated hemoglobin was digested by trypsin. The hydrolysate was subjected to gel-filtration on Bio-Gel P-4 and Sephadex G-50 columns, ion-exchange chromatography on CM-Sephadex and DE 52 columns, and paper electrophoresis. Peptides obtained by this procedure were analyzed for amino acid compositions and amino-terminal amino acid sequences. The results showed that p-chloromercuribenzoate-treated hemoglobin was hydrolyzed to a limited extent by trypsin at the bonds involving the carboxyl group of a lysine or arginine residue in planes A--E in the parent hemoglobin, which represent the external region of the parent tetramer. It is concluded therefore that the slight modification of hemoglobin enhances the susceptibility of the protein to proteases and that the hydrolysis of the modified protein is limited.

Contribution of baroreceptor reflexes to blood pressure and sympathetic responses to cholecystokinin and vasoactive intestinal peptide in anesthetized dogs.

The effects of synthetic vasoactive intestinal peptide (VIP) and cholecystokinin (CCK) on systemic blood pressure and renal nerve activity were studied before and after cervical vagotomy, and sino-aortic denervation with vagotomy in anesthetized dogs. Intravenous injection of VIP (5 micrograms/kg) in animals with an intact neuraxis produced a significant decrease in systemic blood pressure and a significant increase in renal nerve activity. These responses to VIP did not change after vagotomy and after complete denervation, VIP did not cause any change in renal nerve activity, even during hypotension. The level of hypotension after complete denervation was greater than that under other conditions. These results indicate that the cardiovascular effects of VIP are reduced by activation of the systemic baroreceptors. Intravenous injection of CCK (10 micrograms/kg) in animals with an intact neuraxis produced significant decreases in blood pressure and renal nerve activity. These responses to CCK were abolished in animals with cervical vagotomy only. However, following complete denervation of the carotid sinus and total section of the vagal nerves, CCK caused a significant increase in blood pressure and renal sympathetic nerve activity. These results indicate that the sympathetic depressor effect of CCK may be mediated by activation of the vagal afferents, and that the sympathetic pressor effect may be due to a direct action of CCK on the central nervous system. Thus, each gastrointestinal peptide may regulate the cardiovascular system through a different mechanism.

Blood volume of gliomas determined by double-echo dynamic perfusion-weighted MR imaging: a preliminary study.

BACKGROUND AND PURPOSE: After bolus injection, gadopentetate dimeglumine causes a T2* rate change in permeable tissue that is contaminated by the T1 shortening effect due to the leakage of contrast agent. Therefore, tumor vascularity as reported in previous single-echo perfusion-weighted MR imaging studies has been underestimated. Our aim was to quantitatively and qualitatively evaluate the degree of blood volume of glioblastoma multiformes (GBMs) underestimated by this T1 shortening effect. METHODS: We used double-echo dynamic MR imaging after a bolus injection of gadopentetate dimeglumine (double-echo perfusion-weighted MR imaging) to simultaneously determine tumor blood volume without (V(T1U)) and with (V(T1C)) T1 shortening correction. MR imaging was performed in five consecutive patients with GBMs. The ratios of V(T1U) and V(T1C) were calculated and compared by means of quantitative analysis. The degree of tumor blood volume as determined by V(T1U) and V(T1C) maps were qualitatively compared using a three-point scale. RESULTS: All GBMs showed contrast enhancement on postcontrast T1-weighted images. In all subjects, the values of V(T1U) were significantly lower than those of V(T1C) (mean +/- SD, 2.05 +/- 1.01 vs. 3.62 +/- 1.40, respectively [P <.05]), indicating that tumor blood volume obtained by double-echo perfusion-weighted MR imaging was significantly higher than that by single-echo imaging. In the qualitative analysis, tumor blood volume on the V(T1U) map was less conspicuous than that on the V(T1C) map. CONCLUSION: Careful attention should be paid to the underestimation of tumor blood volume resulting from T1 shortening effects when using single-echo perfusion-weighted MR imaging. Double-echo imaging may be more suitable for the analysis of blood volume in GBMs.

The role of macrophages in demyelination in experimental allergic neuritis.

The role of macrophages and serum factors in demyelination in experimental allergic neuritis (EAN) was examined by a simple in vitro method. Cultivated rabbit peritoneal macrophages, preincubated with serum obtained from rabbit EAN produced by sensitization with bovine spinal nerve roots, could agglutinate and phagocytize purified bovine or rabbit peripheral nerve myelin. Sera from normal animals or from controls given adjuvant alone could not. Adhesion and phagocytosis were inhibited if EAN sera were absorbed with peripheral nerve myelin. Rabbit red blood cells were not phagocytized by macrophages exposed to EAN serum. Concomitant to these observations, three lysosomal acid hydrolases: acid proteinase, acid phosphatase and beta-glucuronidase, were assayed with respect to their topographical and chronological distribution. In the group examined at clinical onset, increases in the specific activities were 1.5-3.0-fold in the spinal roots and 1.0-1.5-fold in the sciatic nerves compared with control. The degree of increase in total activities per whole root or sciatic nerve was much higher for specific activities. The topographical distribution of the increase closely corresponded to the histological distribution of EAN lesions. These observations suggested that the increased lysosomal activity originated from lysosomal-rich infiltrating cells. These observations strongly indicated the significant role of macrophages activated by EAN serum in the demyelination of EAN.

Quantification of pulmonary perfusion with MR imaging: recent advances.

Recent advances in magnetic resonance pulmonary perfusion imaging are reviewed, focusing on magnetic resonance perfusion imaging using gadolinium contrasts agents or spin labeling of blood using naturally flowing spins as the source of intravascular signal. These recent developments in magnetic resonance imaging have made it possible to analyze data quantitatively which holds significant potential for clinical imaging of lung perfusion and opens windows to functional MR imaging of the lung. We believe that fast magnetic resonance functional imaging will play an important role in the assessment of pulmonary function and the pulmonary disease process.

Structural basis for pulmonary functional imaging.

An understanding of fine normal lung morphology is important for effective pulmonary functional imaging. The lung specimens must be inflated. These include (a) unfixed, inflated lung specimen, (b) formaldehyde fixed lung specimen, (c) fixed, inflated dry lung specimen, and (d) histology specimen. Photography, magnified view, radiograph, computed tomography, and histology of these specimens are demonstrated. From a standpoint of diagnostic imaging, the main normal lung structures consist of airways (bronchi and bronchioles), alveoli, pulmonary vessels, secondary pulmonary lobules, and subpleural pulmonary lymphatic channels. This review summarizes fine radiologic normal lung morphology as an aid to effective pulmonary functional imaging.

Multiple single sections Turbo FLASH MR arterial portography in the detection of hepatic neoplasms.

OBJECTIVE: To determine the sensitivity of multiple single sections Turbo FLASH MR arterial portography (MRAP) in the detection of hepatic neoplasms. METHODS AND PATIENTS: Twelve patients with hepatic mass underwent MRAP prior to hepatic resection. Findings of MRAP were compared with surgical specimen and intra-operative ultrasonography (US). RESULTS: A total of 19 separate malignant neoplastic nodules were identified in the resected specimens or intra-operative ultrasonography. The sensitivity was 89.5% (17/19) for MRAP. MRAP depicted all neoplasms more than 1.0 cm in diameter. Two lesions not depicted on MRAP had a diameter of 5 and 9 mm, respectively. One lesion identified by MRAP was confirmed to false positive lesion by intra-operative US. CONCLUSION: Multiple single sections Turbo FLASH MRAP may be a valuable adjunct for pre-operative detection of malignant hepatic neoplasms.

Degradation of arginine and other amino acids by butyrate-producing asaccharolytic anaerobic Gram-positive rods in periodontal pockets.

The use of 20 amino acids by butyrate-producing asaccharolytic anaerobic Gram-positive rods (AAGPRs) in periodontal pockets, i.e. Eubacterium minutum, Filifactor alocis, E. infirmum, E. sulci and E. saphenum, was studied. E. minutum used only arginine and lysine, and produced substantial amounts of butyrate and ammonia as the main metabolic products from arginine, and acetate, butyrate and ammonia from lysine. Fi. alocis used arginine alone and produced butyrate and ammonia. E. infirmum, E. sulci and E. saphenum used lysine alone and produced acetate, butyrate and ammonia. The growth of these bacterial species was supported and enhanced by arginine and/or lysine enriched to culture media, but not by the other amino acids. Arginine deiminase, ornithine carbamoyltransferase and carbamate kinase activity were detected in the cell-free extract of E. minutum, suggesting that arginine was metabolised to citrulline initially, and subsequently to ornithine and carbamoyl phosphate. Ornithine and carbamoyl phosphate were further converted to butyrate, and carbon dioxide and ammonia, respectively. Enzymatic activity of arginine deiminase and ornithine carbamoyltransferase was not detected in Fi. alocis, indicating that Fi. alocis converted arginine to ornithine directly, not via citrulline, and further to butyrate.

Reflex responses on blood pressure and renal nerve activity to local intra-arterial injection of capsaicin in anesthetized dogs.

The present study was performed to examine effects of intra-arterial and intravenous injection of capsaicin on efferent renal sympathetic nerve activity (RNA) in pentobarbital anesthetized dogs. In animals with intact baroreceptors, intra-arterial injection of capsaicin (4 +/- 1 microgram) produced significant increases in mean blood pressure (MBP) and heart rate (HR) by +43 +/- 8 mmHg and +33 +/- 15 beats/min at 20 s after the injection, respectively. There followed a recovery toward the control so that 60 s after the intra-arterial injection changes in MBP and HR were +8 +/- 5 mmHg and +18 +/- 8 beats/min, respectively. RNA showed a biphasic response, comprising of an initial increase (+52 +/- 28% of the control at 20 s) followed by a decrease by -30 +/- 8% of the control 60 s after the injection. Following bilateral cervical vagotomy the initial increase in RNA did not differ significantly from the value of RNA in animals with intact baroreceptors. However, the later decrease in RNA reversed above the control so that 60 s after the injection change in RNA was +5 +/- 10% of the control. Complete baroreceptor denervation showed a similar response on RNA in the vagotomized animals (+49 +/- 9 and +14 +/- 10% of the control at 20 and 60 s after the injection, respectively). In contrast, intravenous injection of capsaicin (6 +/- 1 microgram/kg) resulted in significant decreases in MBP (-19 +/- 11 mmHg) and HR (-9 +/- 4 beats/min). RNA at 20 s after the injection showed a unidirectional decrease by -16 +/- 7% of the control in animals with intact baroreceptors. These responses reversed above the control after cervical vagotomy. Thus, these data indicate that activation of C-fiber afferents in skeletal muscles by intra-arterial injection of capsaicin results in renal sympathoexcitation, and that the later sympathoinhibition is mediated by combined activation of systemic baroreceptors.

Effect of hypertonic saline infusion on renal vascular resistance in anesthetized dogs.

Changes in renal vascular resistance (RVR) and their mechanisms were investigated following infusion of 7.5% hypertonic saline (4 ml/kg) in anesthetized dogs. In all animals the left kidney was perfused at a constant perfusion flow (59 +/- 6 ml/min) with heparinized blood using a pulsatile roller pump. Renal perfusion pressure (RPP), systemic blood pressure (SBP), central venous pressure (CVP), and heart rate (HR) were measured simultaneously. Electrical stimulation of renal sympathetic nerves was also performed to evaluate the neurally mediated change in renal vasculature before and after infusion of hypertonic saline. In animals with intact vagi, intravenous administration of hypertonic saline resulted in significant increases in both mean blood pressure (MBP) and CVP, and caused significant decreases in HR and RVR. These effects were not affected by bilateral cervical vagotomy. In both intact and vagotomized animals, changes in RVR in response to renal nerve stimulation were attenuated after infusion of hypertonic saline. These results suggest that reduction in RVR after intravenous infusion of hypertonic saline is not a reflex effect mediated by vagal afferents. Instead, vascular response of the renal artery to hypertonic saline may result from a suppression of neurotransmission from renal sympathetic nerve endings to renal vascular smooth muscle.

Vitamin K2 (menatetrenone) induces iNOS in bovine vascular smooth muscle cells: no relationship between nitric oxide production and gamma-carboxylation.

It has been recently reported that vitamin K2 (menaquinone-4: menatetrenone, VK2) has an anti-atherogenic effect as well as the ability to produce clotting factors and improve osteoporosis. However, the mechanism by which VK2 acts on atherosclerosis is still unclear. In this paper, we investigated the effects of vitamin K and its side chain on NO production as an anti-atherogenic substance in a cultured vascular system. Treatment of bovine vascular smooth muscle cells (SMC) with VK2 (30 microM) caused a time-dependent (24-72 h) increase in the nitrite (NO2) level in the conditioned medium, but not in bovine vascular endothelial cells. Classical NOS inhibitor (L-nitro arginine) and iNOS-specific inhibitors completely blocked the increased nitrite level induced by VK2 treatment, but D-nitro arginine could not it. Immunostaining and Western blotting analysis showed that VK2 induced iNOS protein in the SMC. VK2 has a naphtoquinone nucleus, which is identical in menadione (VK3), and an unsaturated side chain, which is called geranylgeraniol (GGO). To determine whether the structure of VK2 was related to an increasing nitrite level, we investigated the nitrite level in conditioned medium treated with VK3 or GGO. Neither VK3 nor GGO treatment of SMC increased the nitrite level. In addition, warfarin, an inhibitor of VK2-dependent gamma-carboxylation, did not affect the increased nitrite level induced by VK2 in SMC. In conclusion, VK2 caused NO production through iNOS induction in bovine SMC, that was not related to the structure of VK2, naphtoquinone nucleus or its side chain, independently of gamma-carboxylation.

Distribution of abnormal Q waves on body surface in relation to left ventricular wall motion abnormalities in myocardial infarction.

This study was undertaken to determine the possible one-to-one relationship between each site of asynergy of the left ventricle and the body surface area to which ensuing abnormal electrical phenomena are reflected. In 140 post-myocardial infarction (MI) patients, distribution of abnormal Q waves on the body surface was correlated with the abnormal segments of LV wall motion identified by left ventriculography (LVG). Unipolar lead electrocardiograms (ECGs) were recorded from 87 lead points over the precordium and the back with Wilson's central terminal as the reference point. Data acquisition and mapping was accomplished through a mapping system HPM 5100 microcomputer. In all cases, coronary arteriography (CAG) and LVG were performed at least 2 months after the acute episode of MI. The LVG findings were evaluated separately in seven wall segments in accordance with the American Heart Association (AHA) reporting system. Sensitivity, specificity, diagnostic accuracy, positive predictive value, and negative predictive value of the abnormal Q wave in each lead point were obtained in cases with abnormal wall motion in segments 2, 3, and 6, respectively, and in infero-posterior segments 4 or 5. Statistical analysis was performed by comparing two groups of patients with or without asynergy of each wall segment concerned. Results of the study revealed some abnormal Q areas of high diagnostic accuracy that correlated highly with the site of abnormal contractility.

The influence of craniofacial form on bite force and EMG activity of masticatory muscles. VIII-1. Bite force of complete denture wearers.

Today, Japan as a society is aging. The average life expectancy of Japanese people is approximately 80 years. One result of this is that preservation of masticatory functions in elderly people has become increasingly important from the viewpoint of quality of life. In the future, the use of dentures in facilitating masticatory functions as a substitute for teeth that are lost during the aging process will assume greater significance. Accordingly, appropriate evaluation and judgment of complete dentures for edentate jaws is crucial. This study was designed to elucidate the effects of the craniofacial form in complete denture wearers on the mode of activity of gnathic functions. First, subjects wearing complete dentures in both the upper and lower jaws were instructed to carry out vertical clenching, and bite force direction was determined. These data were then related to the subject's craniofacial morphology. These results suggest that the bite force direction in complete denture wearers is not affected by gender differences, but is closely associated with lateral craniofacial morphology, and that appropriate setting of occlusal plane and the occluded vertical dimension is extremely important in the preparation of complete dentures.