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K Soma

Publications and source records attributed to K Soma.

At least 19 recordsLinked to original sources
PubMed1992

[High accuracy measuring device for dental cast--using device with flat laser beam].

A new system has been developed for measuring the surface morphology of the occlusal material. The main characteristic of the system is utilizing a flat laser beam to produce high accuracy measuring and to enable measuring 200 points at the same time on a line of 30 mm in length. It takes 8 to 10 minutes to digitize the whole morphology of a dental cast. The system has a central processing unit that assembles a series of digitized points into a data file of the dental morphology. It is also able to recognize the graphical image of the numerically reconstructed morphology on the CRT. Application of this measuring system enables the approach to the qualitative and quantitative evaluation of the spatial relationship between the opposing teeth at near the occlusal contact.

Dental Casting Technique↗
PubMed1992

[A dental anthropological study of Chinese in Taiwan (3). Dental trait].

Models of the upper and lower dental arches of 125 Chinese children in Taiwan with acceptable normal permanent dentition were surveyed in order to understand the developmental grades of dental traits from the viewpoint of dental anthropology. Developmental grades of dental traits were classified, calculated, statistically analysed by x2 test and results were summarized. Upper anterior teeth showed high frequency of shovel form; upper lateral incisors showed less tendency of regression. Interstitial cusp, lingual cusp, paracusp, central prominence and occlusal groove of lower premolars developed prominently. Upper molars showed low frequency of Carabelli cusps. Hypocone of upper second molars showed strong tendency of regression, but metacone had low regression tendency and a strong degree of compression. Compared to Japanese, Central American and South American Indians and Caucasians, the development of dental traits of Chinese in Taiwan was more similar to that of Japanese than to others. The characteristics of dental trait of Chinese in Taiwan and Japanese also showed greater similarity to Central and South American Indians than to Caucasians.

Anthropology, Physical↗
PubMed1991

[Genetic and environmental characteristics in dento-craniofacial morphology--using materials from survey on Latin American Indians].

Most previous researches of hereditary characteristics of the craniofacial skeleton have used the twin-study method. In this study, dental anthropological materials were used to clarify genetic and environmental characteristics of the dento-craniofacial morphology. The sample consisted of four groups including Mexican Indians (N = 71), Peruvian Indians (N = 41) and their ancient ancestors: skulls of Mexican Indians (N = 33) and Peruvian Indians (N = 34). These groups shared the common origin of the Mongoloid race. Morphological similarity and difference among these groups were examined by principal component analysis and Student t-test using the dento-craniofacial data based on roentgenographic cephalograms and dental casts. The morphological similarity means the genetic characteristics which maintained during time differences between ancient and present times and throughout regional differences between Mexico and Peru. The morphological difference means the environmental characteristics which produced during the time differences and throughout the regional differences. Results were as follows: (1) The genetic morphological characteristics were found predominantly in the anterior cranial base, the dental arch form and to a certain extent in the basal portion of the mandible and the vertical dimension of the naso-maxillary complex. (2) The environmental characteristics were found predominantly in the muscular portion of the mandible, the alveolar portions of the maxilla and the mandible, the length of the dental arch and to a certain extent in the antero-posterior dimension of the maxilla.

Adult↗
PubMed1991

[Dental anthropological study of Mongoloid in China].

The purpose of this study was to evaluate the craniofacial and occlusal characteristics of the inhabitants in China. The material consisted of cephalograms, pantomograms, dental casts and anthropological measurements taken from 517 inhabitants: 416 Han Chinese in Beijing, Shanghai, Guangzhou and Changchun and 101 Mongolians in Hohhot. The data were compared among the above five regions and also with the Japanese data. The findings were summarized as follows: I. Craniofacial characteristics; a) The Han Chinese and the Mongolians showed brachycephaly. b) The inhabitants in Guangzhou showed a tendency of bimaxillary protrusion with a smaller facial height, and the inhabitants in Changchun showed a larger gonial angle with a larger facial height than those of the other regions. c) The Mongolians had a larger value of the saddle angle and of the bi-gonial breadth. d) Compared with the Japanese, their craniofacial complex was characterized by a larger facial angle, smaller mandibular plane angle and a smaller gonial angle. II. Occlusal characteristics; a) The inhabitants in China had a similar tendency in the dental arch form and in the dental trait frequency. b) The inhabitants in Beijing had a larger mesiodistal crown-diameter of the anterior teeth than those in the other regions. c) Compared with the Japanese, their teeth were characterized by a smaller mesiodistal crown-diameter (especially on the upper first molar), higher frequency of shovel-shape and lower frequency of Carabelli's tuberculum.

Adolescent↗
PubMed1991

[A dental anthropological study of Chinese in Taiwan. I). Craniofacial morphology].

The cephalometric films were collected from 30 boys and 30 girls of 12 years of age, and from 36 males and 34 females of 18 years of age; all of whom were Chinese in Taiwan, all possessed acceptable occlusion to survey the craniofacial morphology and characteristics associated with dental anthropology. Data were analysed by the computer program at the Department of Orthodontics of Japan Tokyo Medical and Dental University. Data were compared with Japanese, North American Caucasians, Central and South American Indians from papers. It was concluded that: 1) Chinese in Taiwan were similar to Japanese, Central and South American Indians, in that; all possessed a shorter frontal cranial base and depth of face, and were completely different from North American Caucasians. The direction of growth showed counter-clockwise rotation in the four Mongoloid races; however, Caucasians showed straight--down growth. The four Mongoloid races had more frontal position of A,B point and more labial inclination of anterior tooth axis than Caucasians. 2) Chinese in Taiwan were similar to Japanese, but were different from Central and South American Indians, in having a flatter infraorbital outline, longer facial height, flattened mandibular plane angle and a more frontal position of chin. 3) Chinese in Taiwan were characteristically different from Japanese by having a smaller interincisal angle, lower frontal facial height, mandibular angle and mandibular plane angle. In summary, the results indicated that Chinese in Taiwan are characterized by having a wide but short face pattern, a retroposition of the mandible ramus, a more upright mandible angle and a prominent labial inclination of anterior tooth axis.

Adolescent↗
PubMed1991

[A dental anthropological study of Chinese in Taiwan (2). Teeth size, dental arch dimensions and forms].

Both upper and lower dental study models were collected from 30 boys (12 years old) and 30 girls (12 years old) with acceptable normal occlusion to understand the characteristics of the crown size, dental arch width and length such as (1) mesiodistal diameters of crown size from central incisor to first molar, (2) the width and length of dental arch and basal arch and (3) the morphology of dental arch form. After statistical analysis, data were compared with Japanese, Central and South American Indians and North American Caucasians from papers. The results were: (1) There was no statistical difference in teeth size between males and females, except the upper first molar of males was larger than that of females, lower central incisor of males was smaller than that of females. (2) The dimensions of dental arch of males were larger than that of females in general, especially such items as width and length of basal arch. (3) The crown size of Chinese male was in generally smaller than that of four other races, especially the upper canine, lower central incisor and first molar. The crown size of Chinese females showed that although the lower first molar was smaller than that of Central and South American Indians, but the upper first premolar, lower canine and central incisor were larger than that of Japanese. Upper lateral incisor was larger than that of South American Indians. Compared to that of North American Caucasians, Chinese females had a smaller upper central incisor and a larger upper first premolar. (4) The dimensions of dental arch in Chinese were very similar to Japanese, South and Central American Indians, but wider and shorter than Central and South American Indians. (5) The superimposition of dental arch form showed that the four races of Mongoloids had similar ovoid dental arch forms.

Asian People↗
PubMed1991

Three-dimensional digitization: method for evaluating morphological differences between teeth.

A new comparative method has been developed for evaluating morphological differences between a pair of teeth. This method consists of five steps: 1) digitization of the surface morphology of the teeth, 2) standardization to enable comparison of the teeth on a common axis, 3) reversal of data on one tooth to enable comparison with the opposite tooth, 4) qualitative evaluation by computer graphic superimposition and 5) quantitative evaluation by the set operation. To illustrate its effectiveness, this method was applied to a pair of extracted premolars. Application to the dental crown on a clinical plaster cast was also discussed.

Bicuspid↗
PubMed1989

[Study on distribution form of mesiodistal crown diameter in large sample: Part II].

The purpose of this research was to examine the distribution of the tooth size in a large sample. The objective teeth were the left upper and lower fourteen teeth except the third molar. The tooth size of 1,000 dental casts from the Japanese female orthodontic patients was measured. On each of them, a histogram and a set of statistics (mean, standard deviation, coefficient of variation, skewness, kurtosis, Geary value) are given in order to examine the distribution. The findings are as follows: 1) Each tooth may be classified into the following four types of distribution except the congenitally missing data. TYPE I: A normal distribution was observed in the upper and lower central incisors, the lower lateral incisor, the lower canine, the upper and lower first premolars, the upper second premolar, the upper and lower first molars and the lower second molar. TYPE II: A positively skewed distribution was observed in the lower second premolar. TYPE III: A negatively skewed and leptokurtic distribution was observed in the upper canine and the upper second molar. TYPE IV: An extremely negatively skewed and leptokurtic distribution was observed in upper lateral incisor. 2) With the four teeth which were classified into TYPE II, TYPE III and TYPE IV, the distribution of the lower second premolar was concluded to be of normal distribution by logarithmic transformation. The distribution of the upper canine and the upper second molar was judged to be of lognormal distribution and the upper lateral incisor also was judged to be of three parameter lognormal distribution and four parameter lognormal distribution. 3) The distribution of thirteen teeth except the upper lateral incisor was judged to be of normal distribution, by considering the congenitally missing data and the outlier in statistical data of the tooth.

Asian People↗
PubMed1989

[Dental anthropological study of the Central American Indians].

The purpose of this study was to evaluate the dento-craniofacial morphology and the occlusal characteristics in the Central American Indians from the dental-anthropological point of view. The sample consisted of cephalograms, pantomograms, dental casts, photos and records (anthropometric measurements and oral examinations) which were taken from 210 modern Central American Indians and 212 ancient Central American Indians. The results were summarized as follows: 1. Craniofacial morphology: The modern Central American Indians showed; (1) smaller facial height and shorter depth of the cranial base and jaws than those of the Caucasians. (2) posterior position of peri-orbital structures, and smaller values of anterior facial height in comparison with the Japanese, which were similar to the Peruvian Indians. (3) shorter depth of the jaws and prominence of the chin than the ancient Central American Indians. 2. Dental arch form and tooth size: The modern Central American Indians had; (1) wider dental arches than the Caucasians, while sharing similar values with the Peruvian Indians and the Japanese. (2) smaller incisors, larger premolars and molars in the mesio-distal crown diameter compared with the Caucasians. (3) smaller teeth in the mesio-distal crown diameter than the ancient Central American Indians. 3. Occlusal conditions: The modern Central American Indians showed a good mesio-distal relationship between the upper and lower first molars in 70 percent.

Adolescent↗
PubMed1989

[Measurement of small quantities of alpha 2-macroglobulin in bronchoalveolar lavage fluid by enzyme-labelled immunoassay, and its clinical implication in pulmonary disease].

We established an enzyme labelled immunoassay for the determination of alpha 2 macroglobulin (alpha 2M). The assay range was from 2 to 140 ng/ml and the within-assay coefficient of variation (CV) were 5.2% at 31.2 ng/ml and 6.4% at 62.5 ng/ml. Between-day CV ranged from 6.9% to 15.4%. Using this method, alpha 2 M was determined in the bronchoalveolar lavage fluid (BALF) from patients with interstitial lung diseases. Those diseases were active and inactive sarcoidosis, hypersensitivity pneumonitis and idiopathic pulmonary fibrosis (IPF, including collagen disease). We divided the IPF patients into two groups, 'acute type' and 'chronic type', judging from the prognosis. alpha 2 M/Albumin ratio in BALF in the active sarcoidosis and acute type IPF groups is significantly higher than that in the inactive sarcoidosis and chronic type IPF. These findings suggest that alpha 2 M in BALF can be a sensitive marker of the interstitial lung disease.

Bronchoalveolar Lavage Fluid↗
PubMed1988

Mouth occlusion pressure as a useful indicator for weaning from mechanical ventilation.

We studied the usefulness of the neuromuscular inspiratory drive (P0.1) and P0.1 normalized by ventilation (sP0.1) as indicators for weaning from mechanical ventilation. The patients were classified into two groups on the basis of outcome: a successful group who could have weaning and an unsuccessful group who could not be free from mechanical ventilation. The unsuccessful group showed significantly greater P0.1 (6.35 +/- 2.95 cmH2O) than successful group (2.81 +/- 1.21 cmH2O). The patients who failed in weaning also showed an increase in sP0.1 which would mean an increase in respiratory impedance. These results suggest that P0.1 and sP0.1 might be useful to follow the time course during weaning from mechanical ventilation.

Adult↗
PubMed1988

Ethyl eicosapentaenoate restored the immunosuppression in mice fed fat-free diet.

The effects of eicosapentaenoic acid (EPA) on the humoral immune response in fat free diet-fed (FF) mice were studied. The lowered anti-SRBC PFC activity of ICR male FF mice was restored in a dose-dependent manner when EPA was administered orally at doses of 60-360 mg/kg/day for 20 days. In in vitro experiments, EPA similarly enhanced anti-SRBC PFC activity but did not affect the response against lipopolysaccharide. Furthermore, EPA did not cause any substantial effect on T suppressor cell activity induced by Concanavalin A in vitro. On the other hand, T helper cell activity induced by keyhole limpet hemocyanin was augmented. From these results, it is suggestive that EPA caused immunopotentiation to FF mice at least partially by an enhancement of T helper cell activities.

Animals↗
PubMed1988

[Stress distribution in mandible induced by occlusal force in different horizontal mandibular positions].

The objective of this study was to investigate the stress distribution in the mandible induced by occlusal forces in a various different horizontal mandibular positions identified as neutroclusion, distoclusion, mesioclusion, and laterally shifted occlusion. A three dimensional Finite Element Method (3D-FEM) was applied to an artificial model of a simulated mandible constructed as a homogeneous, isotropic and elastic body. This model was divided into 480 elements with 785 nodes. The right and left heads of the mandibular condyles and the occlusal surfaces of the posterior teeth of the model were restrained. These restraints acted against the loading of the masticatory forces which consisted of a pair of masseter, temporal, and also the lateral and medial pterygoid muscles. The stress distributions analyzed by 3D-FEM were graphically demonstrated on a three dimensional display system. The data obtained were summarized as follows: I. Neutroclusion (1) Tensile stress appeared along the anterior border of the ramus, and compressive stress appeared along the angular portion of the ramus. (2) Compressive and tensile stress appeared on the external and the internal surfaces of the anterior portion of the mandibular body. II. Distoclusion and mesioclusion (1) As the position of the mandible was moved distally, the absolute values of the stress tended to increase on the same areas which is the external and the internal surfaces of the anterior portion of the mandibular body. (2) Compressive stress which appeared on the occlusal surfaces of the posterior teeth was very great in distoclusion. At the same time, the stress that appeared on the heads of the mandibular condyle was also great in mesioclusion. III. Right laterally shifted occlusion (1) Tensile stress appeared along the left sides of both of the left and right rami, and compressive stress appeared along the right side of both of the left and right rami. (2) A great amount of stress appeared on the left occlusal surfaces of the posterior teeth and on the left portion of the mandibular body. From these results, it was determined probably that the mandibular morphogenesis was influenced by a series of stress factors which were induced by the forces of the masticatory muscles.

Bite Force↗