STATEMENT OF PROBLEM: Higher stresses at the cervical bone around dental implants have been seen as a primary cause of the bone resorption at the site. PURPOSE: To determine the possibility of stress reduction by assembly of different abutment and implant in diameters. MATERIALS AND METHODS: Abutments of several different diameters assembled on the top of XiVE(R) implants were axisymmetrically modeled for a series of finite element analyses. Abutments of 3.4, 3.8, 4.5, and 5.5 mm diameters were assumed to be sit on implants of the same or bigger diameters. All the abutments with an exception of 3.4mm dia. are technically possible to be assembled on bigger implants. Main consideration was given to the stresses at the cervical cortical bone induced by loads of parallel to the implant axis. RESULTS AND CONCLUSIONS: 1. Higher stresses were observed at the cervical area of all the models of the same diameters of abutment and fixture. The peak stresses, which were shown to be a function of the fixture diameter, were from 1-1.85MPa. 2. Difference in the diameters of the abutments and the implants actually reduced the cervical bone stresses. 3. Downsizing of the abutment by one step resulted in 0.1MPa (5%) reduction of the stresses. In light of the relatively lower bone stress, however, this amount of stress reduction was decided to be biomechanically insignificant.
Axis, Cervical Vertebra ; Bone Resorption ; Dental Implants ; Finite Element Analysis

No abstract available.
Coronavirus Infections* ; Disasters* ; Middle East*

STATEMENT OF PROBLEM: High stress concentration on the crestal cortical bone has been regraded as a major etiologic factor jeopardizing long term stability of endosseous implants. PURPOSE: To investigate if the design characteristics of crestal module, i.e. internal type, external type, and submerged type, affect stress distribution on the crestal cortical bone. MATERIAL AND METHODS: A cylindrical shaped implant, 4.3 mm in diameter and 10 mm in length, with 3 different crestal modules, i.e. internal type, external type, and submerged type, were analysed. An axisymmetric scheme was used for finite elment formulation. A vertical load of 50 N and an oblique load of 50 N acting at 45degrees with the implant's long axis was applied. The peak crestal bone stress acting at the intersection of implant and crestal bone was compared. RESULTS: Under vertical load, the crestal bone stress was high in the order of internal, external, and submerged types. Under the oblique loading condition, it was in the order of internal, submerged, and external types. CONCLUSION: Crestal module design was found to affect the level of the crestal bone stresses although the actual amount was not significant.
Axis, Cervical Vertebra ; Dental Implants ; Finite Element Analysis

STATEMENT OF PROBLEM: Crestal bone loss, a common problem associated with dental implant, has been attributed to excessive bone stresses. Design of implant's transgingival (TG) part may affect the crestal bone stresses. PURPOSE: To investigate if concavely designed geometry at a dental implant's TG part reduces peri-implant bone stresses. MATERIAL AND METHODS: A total of five differently configured TG parts were compared. Base model was the ITI one piece implant (Straumann, Waldenburg, Switzerland) characterized by straight TG part. Other 4 experimental models, i.e. Model-1 to Model-4, were designed to have concave TG part. Finite element analyses were carried out using an axisymmetric assumption. A vertical load of 50 N or an oblique load of 50 N acting at 30degrees with the implant's long axis was applied. For a systematic stress comparison, a total of 19 reference points were defined on nodal points around the implant. The peak crestal bone stress acting at the intersection of implant and crestal bone was estimated using regression analysis from the stress results obtained at 5 reference points defined along the mid plane of the crestal bone. RESULTS: Base Model with straight configuration at the transgingival part created highest stresses on the crestal bone. Stress level was reduced when concavity was imposed. The greater the concavity and the closer the concavity to the crestal bone level, the less the crestal stresses. CONCLUSION: The transgingival part of dental implant affect the crestal bone stress. And that concavely designed one may be used to reduce bone stress.
Axis, Cervical Vertebra ; Dental Implants ; Finite Element Analysis ; Models, Theoretical

Background and Objectives: The purpose of this study was to investigate the effect of unvoiced segments on the cepstral analysis in patients with vocal cord paralysis (VCP).Subjects and Method A total 302 subjects (173 subjects with VCP and 129 normal voice subjects) participated in this study. The sustained vowel /a/ 2 seconds and one sentence of ‘Sanchaek’ were edited, and analyzed by Praat script. The cepstral analyses were performed using sustained vowel (SV), continuous speech (CS), and extracted continuous speech (EXT) samples. The auditory-perceptual (AP) rating was also completed by three raters. Results: First, there were significant differences in all variables except low-to high spectral ratio(L/H ratio)_EXT between two groups. Second, cepstral peak prominence (CPP), smoothed cepstral peak prominence (CPPS), and L/H ratio showed significant differences in SV, CS, and EXT samples. Third, cepstral measurements were highly correlated with the AP ratings. Finally, the level of discrimination of dysphonia estimated from CPP and CPPS gotten from SV and CS values was more than area under the curve (AUC) of 0.941. AUC of 0.880 or more was also found in EXT. Conclusion In this study, we confirmed that both CS and EXT are highly predictive of pathologic speeches. Further study will also need to be validated for a more diverse group of voice disorders.

BACKGROUND: The use of the extracts from evening primrose seeds as a health functional food has been gradually increased. Therefore, the monitoring and screening process has been considerably required for its quality control. OBJECTIVE: This study aimed to estimate the measurement uncertainty associated with determination of penta-o-galloyl β-D-glucose (PGG) in extracts from evening primrose seeds by high-performance liquid chromatography. METHODS: The sources of measurement uncertainty was expressed in accordance with mathematical/statistical theories of GUM & EURACHEM Guide. The expanded uncertainty was calculated by using the relative standard uncertainty between analytical result and sources of uncertainty in measurement (sample weight, final volume, extraction volume, standard solution, matrix and instrument etc). RESULTS: In the results of 95% confidence interval, the uncertainty in measurement was 10,253.34 ± 1,844.50 µg/kg (k = 2.0). CONCLUSION: In this study, it showed that the value of uncertainty in measurement for determination of PGG in extracts from evening primrose seeds by HPLC has about 18.0% influence on PGG contents of the analytical results. The results would be very useful for the monitoring and screening of evening primrose seeds marketed in Korea for its quality control as dietary supplement.
Chromatography, High Pressure Liquid ; Chromatography, Liquid ; Dietary Supplements ; Functional Food ; Gingiva ; Korea ; Mass Screening ; Oenothera biennis ; Prostaglandins G ; Quality Control ; Uncertainty

BACKGROUND AND OBJECTIVES: High-speed videolaryngoscopy (HSV) is the only technique that captures the true intra-cycle vibratory behavior of the vocal folds by capturing full images of the vocal folds. However, it has problems of no immediate feedback during examination, considerable waiting time for digital kymography (DKG), recording duration limited to a few seconds, and extreme demands for storage space. Herein, we demonstrate a new post-processing method that converts HSV images to two-dimensional digital kymography (2D-DKG) images, which adopts the algorithm of 2D videokymography (2D VKG). MATERIALS AND METHODS: HSV system was used to capture images of vocal folds. HSV images were post-processed in Kay image-process software (KIPS), and conventional DKG images were retrieved. Custom-made post-processing system was used to convert HSV images to 2D-DKG images. The quantitative parameters of the post-processed 2D-DKG images was validated by comparing these parameters with those of the DKG images. RESULTS: Serial HSV images for all phases of vocal fold vibratory movement are included. The images were converted by the scanning method using U-medical image-process software. Similar to conventional DKG, post-processed 2D DKG image from the HSV image can provide quantitative information on vocal fold mucosa vibration, including the various vibratory phases. Differences in amplitude symmetry index, phase symmetry index, open quotient, and close quotient between 2D-DKG and DKG were analyzed. There were no statistical differences between the quantitative parameters of vocal fold vibratory movement in 2D-DKG and DKG. CONCLUSION: The post-processing method of converting HSV images to 2D DKG images could provide clinical information and storage economy.
Kymography ; Methods ; Mucous Membrane ; Vibration ; Vocal Cords ; Voice

BACKGROUND AND OBJECTIVES: Burning mouth syndrome (BMS) refers to a collection of symptoms of patients who complain about burning sensation of their mouths without any specific causes. Although this is not a rare disease, the etiology and effective treatment are not well established. We tried to compare the efficacy and side effects of the agents that are reported to be relatively effective to BMS. SUBJECTS AND METHOD: Fifty-one patients who were diagnosed as BMS were chosen as candidates. Trazodone, Paroxetine, Clonazepam, and Gabapentin, which were known to be effective medicines for BMS in previous research were prescribed randomly. We prescribed medication for two weeks and evaluated patients for the effect and side effects at the end of the treatment. The medication was prescribed for 2 more weeks and the patients were evaluated again. RESULTS: Three of 11 (27.3%) patients were prescribed Trazodone, 8 of 12 (66.7%) Paroxetine, 8 of 14 (57.1%) Clonazepam and 12 of 14 (85.7%) Gabapentin. Q showed improvements after 4 weeks of medication. The differential effectiveness among the medications was not significant, except for the inferiority of Trazodone. Five of 11 (45.5%) patients who had been prescribed Trazodone, 2 of 12 (16.7%) who had been prescribed Paroxetine, 2 of 14 (14.3%) who had been prescribed Clonazepam, 2 of 14 (14.3%) who had been prescribed Gabapentin complained of side effects during 4 weeks of medication. CONCLUSION: We can expect high success rates of treatment for burning mouth syndrome with Paroxetine, Clonazepam and Gabapentin. A further study for long term outcomes and side effects in large groups is warranted.
Amines ; Burning Mouth Syndrome ; Burns ; Clonazepam ; Cyclohexanecarboxylic Acids ; gamma-Aminobutyric Acid ; Humans ; Mouth ; Paroxetine ; Rare Diseases ; Sensation ; Trazodone

The present study was aimed at investigating whether the calcium current in the vascular smooth muscle (VSM) cells is altered in renal hypertension. Two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension were made in Sprague-Dawley rats. Rats without clipping the renal artery or implanting DOCA were used as control for 2K1C and DOCA-salt hypertension, respectively. Four weeks after clipping, systolic blood pressure was significantly higher in 2K1C rats than in control (192+/-24 and 119+/-4 mmHg, respectively, n=16 each). DOCA-salt rats also showed a higher blood pressure (180+/-15 mmHg, n=18) compared with control (121+/-6 mmHg, n=14). VSM cells were enzymatically and mechanically isolated from basilar arteries. Single relaxed VSM cells measured 5 ~ 10 mum in width and 70 ~ 150 mum in length were obtained. VSM cells could not be differentiated in size and shape between hypertensive and normotensive rats under light microscopy. High-threshold (L-type) calciumcurrents were recorded using whole-cell patch clamp technique. The amplitude of the current recorded from VSM cells was larger in 2K1C hypertension than in control. Neither the voltage-dependence of the calcium current nor the cell capacitance was significantly affected by 2K1C hypertension. By contrast, the amplitude of the calcium current was not altered in DOCA-salt hypertension. These results suggest that high-threshold calcium current of the VSM cells is altered in 2K1C hypertension, and that calcium channel may not be involved in calcium recruitment of VSM in DOCA-salt hypertension.
Animals ; Basilar Artery ; Blood Pressure ; Calcium Channels ; Calcium* ; Desoxycorticosterone ; Desoxycorticosterone Acetate ; Hypertension ; Hypertension, Renal* ; Microscopy ; Muscle, Smooth, Vascular* ; Rats ; Rats, Sprague-Dawley ; Renal Artery

The present study was conducted to investigate the possible role of the sympathetic nervous system in two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension. 2K1C and DOCA-salt hypertension were made in Sprague-Dawley rats. Four weeks after induction of hypertension, systolic blood pressure measured in conscious state was significantly higher in 2K1C (216+/-18 mmHg) and DOCA-salt (205+/-29 mmHg) groups than that in control (128+/-4 mmHg). The third branches (<300 micrometer in outer diameter) of the mesenteric artery were isolated and cut into ring segments of 2apprx3 mm in length. Each ring segment was mounted in tissue bath and connected to a force displacement transducer for measurement of isometric tension. The arterial rings were contracted by application of norepinephrine (NE) in a dose-dependent manner. The amplitude of the NE-induced contraction of the vessels was significantly larger in hypertension than in control. The NE-induced contraction was significantly enhanced by neuropeptide Y (NPY) in hypertension. Reciprocally, NPY-elicited vasocontraction was increased by NE in hypertension. These results suggest that the sympathetic nervous system contributes to the development of 2K1C and DOCA-salt hypertension.
Animals ; Baths ; Blood Pressure ; Desoxycorticosterone ; Hypertension ; Mesenteric Arteries* ; Neuropeptide Y* ; Neuropeptides* ; Norepinephrine* ; Rats* ; Rats, Sprague-Dawley ; Sympathetic Nervous System ; Transducers