Individual Bite Research Articles

A test of the individual feeding activity and food size preference in rainbow trout using demand feeders

Feeding activity and food size preferences were investigated in three groups of rainbow trout with initial weights ranging from 200 to 1000 g. Fish were given the option of releasing food from either of two demand feeding devices that contained either 6 mm or 9 mm food pellets. Individual biting activity (to activate release of food) was continuously monitored using specially designed passive integrated transponders (PIT-tags). In each of the groups, biting activity was strongly influenced by three individuals, which accounted for 70–85% of the total. Thus, high bite activity by few individuals indicates the development of social dominance hierarchies. There was no statistically significant correlation between number of bites and growth rate, indicating that the fish that operated the demand feeders did not gain any growth advantage. Trout that dominated the actuation of the feeders were found among both medium- and large-sized fish. There was no evidence of active food size selection, and the fish that most frequently operated the feeders defended one area of the tank rather than preferring the trigger that would have delivered food of the optimal size.

Monitoring the feeding activity of individual fish with a demand feeding system

Feeding activity of individual Arctic charr (Salvelinus alpinus) was recorded automatically for 29 days using a demand feeding system. Each of three groups of 15 fish was kept in 1 m3 tanks, containing brackish water at 10° C. Individual biting activity was continuously monitored using a PIT‐tag (Passive Integrated Transponders) system with unique individual codes. The accuracies of the bite detection system were 91, 93.1 and 99.5% respectively, in the three tanks. In all tanks, most of the individuals (12–14) bit on the releasing trigger a few times during the first 3 days. Thereafter, one or two individuals per tank accounted for almost all of the biting activity. This pronounced shift in bite‐number distribution among individuals was probably due to the development of a dominance hierarchy, in which the dominant individuals monopolized the trigger. Growth rates appeared to be highest among high ranking fish. The implications of using demand feeding and PIT‐tag devices in feeding studies are discussed.

Monitoring the feeding activity of individual fish with a demand feeding system

Feeding activity of individual Arctic charr (Salvelinus alpinus) was recorded automatically for 29 days using a demand feeding system. Each of three groups of 15 fish was kept in 1 m3 tanks, containing brackish water at 10° C. Individual biting activity was continuously monitored using a PIT-tag (Passive Integrated Transponders) system with unique individual codes. The accuracies of the bite detection system were 91, 93.1 and 99.5% respectively, in the three tanks. In all tanks, most of the individuals (12–14) bit on the releasing trigger a few times during the first 3 days. Thereafter, one or two individuals per tank accounted for almost all of the biting activity. This pronounced shift in bite-number distribution among individuals was probably due to the development of a dominance hierarchy, in which the dominant individuals monopolized the trigger. Growth rates appeared to be highest among high ranking fish. The implications of using demand feeding and PIT-tag devices in feeding studies are discussed.

Swinglock removable partial denture and biting forces in partially edentulous patients. Comparison of individual biting forces with and without swinglock removable partial denture.

Several studies have shown that swinglock removable partial dentures are effective for stability of the abutment teeth and the surrounding tissues including alveolar bone. This efficacy has been thought to be due to the dynamic structure of the swinglock attachment. Individual biting force was measured to determine the physiological efficacy of teeth splints by use of the attachment. The results showed that individual biting forces with the swinglock removable partial denture were 10-25% higher than those without the denture. Furthermore, statistical analysis showed that the individual biting forces with the swinglock removable partial denture were significantly higher. The swinglock attachment can stabilize partially edentulous dentition by splinting all residual teeth. In addition, when physical forces are applied to the abutment teeth and the artificial teeth, this attachment can deliver and distribute the stress to the other abutment teeth and alveolar mucosa. The present findings suggest that the swinglock attachment augments the ability to withstand physical forces such as those occurring during biting and mastication.

Remodelling of periodontal tissues adjacent to sites treated according to the principles of guided tissue regeneration (GTR).

The aim of the present study was to assess the remodelling of alveolar bone adjacent to periodontal sites following therapy according to the principles of guided tissue regeneration (GTR) using computer-assisted densitometric image analysis (CADIA), and to compare the radiographic results to traditional clinical parameters. As required for digital subtraction analyses, periodically reproducible radiographs were obtained using a modification of the Rinn System and individual acrylic bite blocks for periodical identical radiographs. Ideally, a digital subtraction image from a site where absolutely no change in density had occurred would show a perfect cancellation of the structures. An average grey level value of 128 (the middle of the digitizer grey level range set by software) would show up at each pixel. Areas with grey levels < 128 in the subtraction image would indicate loss in density and grey levels > 128 would indicate increase in density. Within the subtraction images, areas were defined using the cursor to draw "regions of interest" (ROI) projected on the bony defect exposed to GTR covering the crestal bone as well as the region of potential "bonefill". The mean, median, the standard deviation and range of the grey levels of pixels within a particular ROI were calculated. Similarly sized ROI were drawn in bone areas not exposed to the GTR procedure serving as controls. The differences in the mean grey levels of all pixels within a particular ROI between the baseline, 3 and 12 months images were calculated for documentation of gain or loss in density. From 14 patients, standardized radiographs were available from baseline, 3 months and 12 months postsurgically, depicting one infraosseous defect before and after treatment according to the principles of GTR. The densitometric changes observed in these defects were compared to the clinically assessed changes measured at the site with the deepest baseline pocket depth. A mean clinical attachment gain of 2.36 mm after 3 and 3.22 mm after 12 months was measured. This was associated with a mean reduction in the PPD amounting to 3.36 mm and 3.79 mm, respectively. The changes in the level of the FGM were rather small considering the deep original mean PPD of 7.07 mm. Over the first months, a mean recession of 1.14 mm was observed which was followed by a coronal displacement of 0.43 mm. With respect to the remodelling of the alveolar bone adjacent to the defects assessed by means of CADIA, the most pronounced changes occurred when comparing the baseline to the 12 months radiographs.(ABSTRACT TRUNCATED AT 400 WORDS)

Automatic Recordings of Masticatory Motions of Leaf-Chewing Insects2

Vibrations caused by masticatory movements of insects chewing on leaves stretched on a support were detected by a displacement sensor and recorded on a chart. Patterns of individual biting motions of larvae of 5 species, Epilachna varivestis Mulsant, Heliothis zea (Boddie), Autographa precationis Guenée, Notolophus Icucostigma (Abbot & Smith), and Spilosoma virginica E. showed 3 distinct chewing processes. The technique is being employed to bioassay biting stimuli, and to analyze feeding rhythms.

Studies on the Individual Biting Forces of the Teeth suffering from Parodontopathia

The author undertook a series of measurements, with the use of a measuring deviceand method designed by Dr. Takamizawa, on a group of 80 male and 76 female patients, all in the age bracket of 30's, who were the out-patients for treatment of Parodontopathia at Nihon University Dental Hospital, regarding the individual biting forces of each tooth.In carrying out the measurements, the resorption degreeof their alveolar bone was used as an indication and, thus, correlations between the degrees of resorbed alveolar bone and individual biting forces were studied.Generally speaking, the individual biting forces of the each proper tooth in the concerned teeth group were reduced than that of the control group, in correspondence to the degrees of alveolar bone resorbed.As a result with the percentage of the individual biting forces of the concerned teeth group against that of the control teeth group, the author arrived at the following conclusions.1. With the concerned four groups, A. B. C. and D., the distributions of individual biting forces are as follows. That is, group A refers to patients whose resorption of the alveolar bone was within 1/4 of the total length of roots, group B refers to cases where the resorption of the alveolar bone was anywhere from within 1/4 to 1/2, group C refers to cases where the resorption of the alveolar bone was beyond 1/2 to 3/4, and lastly group D refers to cases where the resorption of the alveolar bone was more than 3/4._??_2. In terms of kg. measurements of individual biting forces of the concerned teeth in the 4 groups, the data are as follows._??_In common with these 4 groups above, there are not observed significant differences in terms of sex, upper or lower jaw(with the exceptions of second premolars in Group A, first molars in Group B, lateral incisors and second molars in Group C) and the side of jaw whether right or left.On the strength ofthe measurement data give above, it is to be concluded that they will serve as scientific indications of the degree of functional ability in mastication of the teeth, suffering from Parodontopathia.

Studies on the Masticatory Ability of the Late Persistent Second Deciduous Molars, especially those followed by no succeeding Premolars

The seventy persons (38, 32), who were between 20 and 28 years old and had late persistent second deciduous molars, were found in 28, 580 people over the age of 20 (16, 830, 11, 750), who were examined at random.On those subjects and the 143 late persistent second deciduous molars had, the author conducted clinical examinations, roentgenograms, measuring the individual biting forces and the comparison of those on one side in a person and those of the second permanent premolars on opposite.For measuring biting forces, the biting forces measuring appartus with four strain gauges attached and Multiplex monitor-recorder (RM-150 type) made by Nihon Koden co. were used, and the following results were obtained.1) The seventy subjects with those deciduous molars were found in 28, 580 people exmined. It is ratio to the total number of the people examined was 0.25 per cent.2) Those subjects were 38 men from 16, 830 examined and 32 women from 11, 750. It is ratio to the total number was 0.23 per cent in male and 0.27 pe cent in female. But there is no significant difference between in male and female.3) The subjects with two persistent molars to the total number of the subjects were about 66 per cent, those with one about 20 per cent, those with four about 10 per cent and those with three about 4 per cent, least.4) When observed the kind of the late persistent second deciduous molars, the following finding were obtained.E. 32 (22.4 per cent) E. 36 (25.2 per cent)E. 39 (27.3 per cent) E. 36 (25.2 per cent)There were no significant difference between those.5) The late persisent second deciduous molars without second permanent premolars to the total number were141/143 (98.6 per cent) and those with second permanent premolars were 2/143 (1.4 per cent).6) When the relationships between maxilla and mandibule, and right and left sides of jaws were observed based on #4 findings, the late persistent second deciduous molars were found 47.6 per cent in maxilla and 52.4 per cent in mandible. There was no significant difference between those. And there was also no significant difference in per cent of the persitent molars between right and left sides of in maxilla and in mandible.7) The subjects for either type of E/E and E/E to the total number of the subjects were 21.4 per cent (15/70 in number), 10.0 per cent (10/70 for either type of E/E and E/E E/E 8.6 per cent (6/70) for either type of E and E, 5.7 per cent (4/70) for E/E types, 4.3 per cen (3/70) for either type of E/E and E/E/E, 2.9 per cent 2/70 for E/E type and 1.3 per cent (1/70) for either type of E and E.8) The individual biting forces of the persistent molars, when observed by each group, were as follows.The mean value of the individual biting forces of each persistent molar in group [A] (male and female involved), which is vital, and without dental caries and any restorations except light attrition, and has neither resorption of dental root nor permanent premolars in roent genograms, was as follows:E: 36.7Kg, E: 35.2Kg, E: 37.7Kg, E: 37.1KgThere was no significant difference in biting forces between maxilla and mandible, and between right and left sides of jaws, among the four values above.Then mean value of the individual biting forces of each sex was as follows:E: 38.1 Kg 34.9 KgE: 36.0 Kg 34.3 KgE: 38.9 Kg 36.4 KgE: 39.1 Kg 35.3 KgThere was a tendency which the biting force in male was greater than in female, but no significant difference was found between them. And also there were no significant differences between kind of tooth, and in maxilla and mandible, and right side and left side.9) The individual biting forces of the late persistent second deciduous molars which were restorated with amalgam, gold inlay and gold crown were about 5-7 Kg less than those of #8 findings.

Study on the Individual Biting Forces of the Human Deciduous Teeth

In the present study, measurements were undertaken on a total of 5, 728 healthy deciduous teeth and those which had the first class amalgam restorations in a mixed group of boys and girls ranging in age from 36 to 72 postnatal months. For measurement purposes, use was made of the biting force measuring apparatus with the strain gauges attached in association with a multiple monitoring recorder. The measurement data were then analyzed in terms of postnatal months, sex distinctions, stability and resorption of the dental root, etc. As a result of these efforts, the following conclusions were obtained.1. Concerning individual biting forces of the deciduous teeth under study, there were not observed any significant differences between the sexes, upper and lower jaws and right and left sides of the body.2. The maximum biting force and the postnatal months in which each deciduous tobth registered the maximum value were as follows. As regards deciduous central incisors, the maximum biting forces that took place in the 48th postnatal month were respectively 6.34kg for the upper and 6.52kg for the lower jaws, and deciduous lateral incisors in the 60th postnatal month registered 7.04kg for the upper and 7.16kg for the lower jaws. Deciduous cuspids gave the maximum biting forces in the 72nd postnatal month respectively 13.70kg and 14.03kg for the upper and lowet jaws. The maximum biting forces of deciduous first molars in the 72nd postnatal month were 21.66kg for the upper and 22.02kg for the lower jaws and those of deciduous second molars in the 72nd postnatal month were 22.68kg for the upper and 23.27kg for the lower jaws.3. When the maximum biting forces of these deciduous teeth were compared with those of corresponding permanent successors (an age group of 20's males used by TAKAMIZAWA), the deciduous central incisors, lateral incisors, cuspids, first molars and second molars were respectively 0.4, 0.5, 0.5, 0.5 and 0.5 times in the case of upper jaw. On the other hand, in the case of lower jaw they were 0.3 for deciduous central incisors, 0.4 for lateral incisors, 0.5 for deciduous cuspids and first molars alike and 0.4 times for deciduous second molars.4. When chronological changes were investigated in the individual biting forces, a slight increase was observed between the 36th postnatal month to the 48th postnatal month with reference to the deciduous central incisors, and a decrease in the 60th postnatal month. As regards the deciduous lateral incisors, . on the other hand, there was observed a slighti ncrease between the 48th postnatal month and the 60th postnatal month and a decrease in the 72nd postnatal month. With reference to individual biting forces of deciduous cuspids and molars their individual biting forces increased in a period from the 48th postnatal month to the 72nd postnatal month.5. The root of deciduous central incisors had been already formed by the 36th postnatal month and the root resportation was observed occasionally. The root resorption progressed to a fair degree in the 48th postnatal month, in which the cases of good root stability and root resorption were observed more or less to the same extent. The majority had their roots resorbed by 1/2 and the cases where the root resorption was more than 1/2 were only few. However, the root resorption became much advanced in the 60th postnatal month. Here the root resorption was either by 1/2 or more than 1/2.6. As regards the deciduous lateral incisors, on the other hand, the root resorption had not yet begun in the 48th postnatal month with a few exceptions but after the 60th postnatal month it became quite apparent, in which the cases of root stability, apical resorption and 1/2 root resorption were mixedly found. In the 72nd postnatal month, the root resorption was further advanced and here all the cases were the root resorption by 1/2 or more than 1/2.

Genetic Variability in Aedes aegypti (Diptera: Culicidae). IV. Mutation Load in Some African Populations1

Individual biting females were collected from 5 different localities in Africa. Eggs were obtained and F1 progeny were sib-mated. F2 progeny were scored for visible mutations; each mutant isolation was indicative of heterozygosity in the parent generation. A total of 64 females was tested, involving 382 F1 pair matings and examination of 24,000 F2 progeny. There were 34 different kinds of mutations recovered among 142 different isolations. Two populations from the coast of Kenya gave 2.96 and 2.72 mutations per mosquito, carried in the heterozygous condition. Populations from West Africa gave 0.52 (Ghana), 0.72 (Nigeria) and 0.84 (Rep. de Congo). Each population carried a distinctive array of different kinds of mutants. The populations from East Africa were above and those from West Africa were below the value of 1.32 mutations per mosquito obtained in 3 laboratory strains by VandeHey.

Studies on the Individual Biting Force of Pulp-extirpated Teeth

In order to know how much the teeth which had undergone the pulp extirpation have recovered their masticatory function, i. e. for the evaluation of clinical effect of the treatment, it is most logical to measure directly the individual biting force of each tooth concerned. For this measuring, the author selected 825 male and female patients, from 20 to 39 in age who had the crown restored teeth (number of them: 3, 175), without any subjective disturbances after the treatment, possessing the masticatory function satisfactorily at the time of the survey. These teeth with the good clinical effects were divided into A and B groups, in which 1, 871 teeth in Group A (radiographic normal), and other 1, 304 teeth in Group B (radiographic periapicosis to be described in 6).Individual biting forces of these teeth in two groups were separately measured by the use of the biting force measuring apparatus with four strain guages attached. For controls, individual biting forces were additionally measured on each of the intact teeth same-named as those in groups A and B. Consequently, when the individual biting force (means) of each tooth of the lower and upper jaws is observed in males and females in the age groups of 20's and 30's respectively, there is no significant difference between both ages or sexs. For this reason, the age and sex distinctions were ignored in the treatment of data in the three groups. Based on the means of those measurments in the three groups, the author obtained the following conclusions.1. Respective individual biting forces of Controls, A and B groups are as follows._??_2, Individual biting forces of teeth in Group A are smaller than those in controls, and those in Group B are still much smaller.3. When individual biting forces in Groups A and B are compared with those in controls in terms of each tooth, the fact is noted that though there is a decrease from 2 to 10% in the upper anteriors in Group A, there is no significant difference between them and controls. On the other hand, as regards other teeth there is definitely a significant difference between them and controls, with a decrease being anywhere from 12 to 19%. In paticular, a marked decrease in individual biting forces is observed in the lower incisors with as much as 20 %.Also in Group B, individual biting forces are reduced by as much as 25 to 38 %, and there is observed a significant difference between them and controls. This is particularly noteworthy in the lower incisors, where the reduction is as much as 44%.4. When the reduction of individual biting forces of teeth in both Groups A and B against those of controls is observed as regards the same-named teeth on the upper and lower jaws, it is found that in Group A its rate of 21/12 is more than that of 21/12, whereas in Group B that of 54/45 is more than that of 54/45 with a significant difference in each pair. As regards other teeth in Group A and B, however, there is observed no significant difference between upper and lower same-named teeth.5. When the reduction of individual biting forces in Groups A and B as regards the samenamed teeth on the right and left sides of jaw is observed, there is no significant difference between them in the both groups.6. When individual biting forces in Group B as regards the radiographic findings of their periapical tissues are observed, individual biting forces of those teeth accompanied with the findings of the rarefaction of trabeculae are generally reduced more than that of those teeth, which give the findings of the widening at their periodontal spaces.However, there is no agreement between, in the cases with similar radiographic appearances, the degree of the spread of affected area and that of reduction in the individual biting force concerned.7. There is calculated no significant interrelation between the number of years after pulp extirpation and the individual biting force concerned.

Studies on the Co-relative and Individual Biting Forces of Normal Permanent Teeth

Studies on the Co-relative and Individual Biting Forces of Normal Permanent Teeth