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Biomedical subjects

M Akasaka

Publications and source records attributed to M Akasaka.

At least 37 records · Page 2Linked to original sources
PubMed1990

[Application of the Ricketts analysis to children in the primary dentition. Fourth Report: development of lateral cephalogram analysis system and consideration of facial pattern].

A lateral cephalogram analysis system has been developed allowing an extended application of the Ricketts analysis to primary dentition. Using this system, we first examined the growth of facial patterns from the BA-NA ratio profilograms. As samples, we used records of children with normal occlusions stored at Nihon University School of Dentistry Department of Pedodontics. We then used the Fuzzy theory to change Vert's formula and obtained facial types. Lastly, we obtained compositional ratios of facial types within each age group. The results were as follows: 1) Facial patterns tended to show three divisions according to three age groups; from 3 to 5-year olds, from 6 to 7-year olds and from 8 to 10-year olds. 2) The Vert's values of the BA-NA ratio profilograms in each age group based on the data of 9-year olds tended to decrease as age increased. The change was mostly restricted to the range of Mesiofacial type. 3) As for the compositional ratio of facial types in each age group, a nearly normal distribution was observed mainly with the Mesiofacial type. 4) From the lateral cephalogram analysis system which has been developed and the profilograms of the average values for each age group which have been obtained by this system, we obtained the standard values for future evaluation of facial patterns of children with malocclusions.

Age Factors↗
PubMed1990

[The management of drooling in patients with cerebral palsy--submandibular duct relocation].

Drooling is a significant problem demonstrated by individuals of all ages with a variety of etiologies such as neurological disorders, cerebral palsy, mental retardation and others. Persistent drooling not only creates troublesome hygienic problems for patients, teachers, nurses, and playmates because of the constant soiling of clothes, toys, and work materials, but also causes an odor from their clothing and bibs. The older patient with normal cognition is disturbed by the drooling and may become depressed and reclusive. Successful management of drooling alleviates these problems, improves appearance and self-esteem and significantly reduces the time involved in the care of the sufferers. The author, who had studied at the University of Toronto for 2 years, acquired the technique of submandibular duct relocation under the guidance of Dr. Crysdale. We carried out the surgical procedure of submandibular duct relocation for drooling on six patients who had cerebral palsy. The surgical procedure resulted in a dramatic decrease in drooling and odor levels. All of them improved in appearance, and the time involved in the care of the suffers was significantly reduced. The complication of ranula, however, appeared in two cases, which suggested a much higher frequency than that in the report of Crysdale. It seems that a detailed explanation to parents and teachers about the advantages and disadvantages of submandibular duct relocation is important.

Cerebral Palsy↗
PubMed1989

Distribution of movement-related cortical potential upon jaw-biting in humans.

We examined the cerebral location of the readiness potential (hereinafter referred to as "RP") upon activation of the masseter muscle by voluntary and unilateral jaw-biting movement. Four normal adults served as subjects. Five scalp electrodes were placed according to the international 10-20 method at CZ, C3, C4, T3 and T4. In addition, in one of the subjects, RPs were recorded by 12 scalp electrodes in order to study changes occurring in the distribution of RPs with time. The maximum amplitude of the RP was located at T4 in the temporal area, which was involved in the biting movement as a negative slow potential occurring 1.4-0.8 s before the beginning of the discharge to the masseter muscle. The maximum amplitude of the RP on the contralateral side was located at T3. This meant that the amplitude of the RP tended to be higher on the same side as the biting movement than on the contralateral side in all subjects. From scalp topography, the maximum amplitude of the RP was shown to be confined to T4, and was especially marked immediately before the beginning of discharge to the masseter muscle. From these results it is thought that in the case of voluntary biting movement, the RP reflects activities of the pyramidal cells in the masticatory area of the cortex, and that strong descending impulses from both sides then reach the masseter muscles.

Action Potentials↗
PubMed1989

[Survey on nutrition of infants in the Tokyo metropolitan area. 1. Carious dentitions, anomalies of occlusion and ways of eating].

In September, 1987, a survey on the nutrition of infants was conducted with 1,235 children from 3 to 6 years of age selected from six nurseries and six kindergartens in the metropolis of Tokyo. We compared the survey results with other similar survey reports with respect to three areas; 1, caries attack on primary teeth, 2, anomalies of dentition and occlusion and 3, how foods are eaten, to observe the difference by age and also between children in nurseries and in kindergartens. The following are the results of this comparative investigation. 1) The ratio of caries attacks on the 4-year-old in this survey was 69.6%, which was lower than the 83.4% of the nationwide survey of 1987 conducted by the Ministry of Health and Welfare, while the average value of the df index per person was 4.7, which was lower than the 6.1 of 1981. 2) The caries incidence rate was higher with children in kindergarten than those in nurseries and many kindergarten children had had more than one caries attack. 3) The frequency rate of anomalies of dentition and occlusion in the entire survey sample was 12.9% for deep overbite, 11.4% for open bite and 10.7% for edge-to-edge bite. 4) In the survey of how foods were eaten, the question, "Does your child like to eat things that are hard to bite on?" was asked, and 10.4% of the group answered "My child prefers eating soft food," which was quite high. To the question, "Does your child often eat things that are difficult to eat?", 17.1% of the entire group answered, "My child refuses to." This tendency was greater among the children in kindergaretens.

Child, Preschool↗
PubMed1989

[Study on the feeding function and feeding behavior of children. 1. Biting pressure and masticatory efficiency for 3, 4 and 5 years old children].

The purpose of this study was to investigate the biting pressure and masticatory efficiency of 3, 4 and 5 year old children. Some of them had trouble regarding their feeding behavior, either saying that they were not able to bite hard food or that they didn't want to bite hard food. A new method using A.T.P. (Adenosine Triphosphate) granules introduced with rubber finger protectors was used for measurement of the masticatory efficiency. 69 healthy 3, 4 and 5 year old children who had normal occlusion and were caries free were the subject. The results obtained were as follows. 1) The mean of the biting pressure for the 2nd primary molars for 69 children was 21.7 Kg. As for the data of the biting pressure for each age group, it was shown to increase with age (3 to 5 year old). 2) The mean of the masticatory efficiency for 69 children was 0.201 abs. As for the data of the masticatory efficiency for each age, it were shown to increase with age (3 to 5 year old). 3) The coefficient of the correlation of the biting pressure and the masticatory efficiency for 69 children was 0.410 which was considered statistically significant. (P less than 0.05) The coefficient of the correlation of the biting pressure and the masticatory efficiency for 3 year old children was 0.461, the coefficient of the correlation for the same items for 4 year old children was 0.395 and the coefficient of the correlation for 5 year old children was 0.353. All of these were considered statistically significant. (P less than 0.05)

Bite Force↗
PubMed1989

[A classification of foods by the amount of masticatory action involved].

With a view to classifying foods on the basis of the amount of masticatory action required, an attempt was made to correlate the properties of different foods as shown by mechanical measurements with the amount of masticatory action involved as determined by means of an electromyogram. We obtained the following results: 1) We found an extremely high correlation (r = 0.924) between the amount of masticatory action involved and the mechanical properties of our samples when these were expressed as values given by the formula: log (firmness x cohesiveness x strainess x 10) We refer to this parameter as toughness. 2) We were then able to estimate the amount of activity necessary in actual mastication of various foods from out toughness values and other values obtained through texturometer readings, a procedure which we carried out for 144 types of foods. 3) We were thus able to classify foods into ten levels according to masticatory action. We further feel justified to add masticatory action to our list of classification criteria as set out in an earlier report by the present author and others entitled "A classification of foods by physical properties."

Food↗