To conduct research on the actual condition of the internal derangement in children is quite important for finding methods for prevention and treatment. Internal derangement is highly involved in young children with signs and symptoms of temporomandibular disorders(TMD). It has also been reported that anterior disc displacement is revealed in adults without the signs and symptoms of TMD. Few reports using MR imaging concerning aspects of anterior disc displacement in children without and with the signs and symptoms of TMD have been found.
I studied and compared MR images among children with and without signs and symptoms of TMD. The following results were obtained.
1. In children without signs and symptoms of TMD, anterior disc displacement was found in 16.7%(5/30), of which 20%(1/5) was without reduction.
2. In children with signs and symptoms of TMD, anterior disc displacement was found in 80.3%(53/66), of which 73.6%(39/53) was without reduction.
3. The degrees of disc displacement of 80.0%(4/5) and 20.0%(1/5) among children without TMD signs and symptoms was slight and moderate, respectively, while those of 62.3%(33/53) and 3.8%(2/53) among children with signs and symptoms of TMD, were moderate and severe, respectively.
4. A temporomandibular joint deformed disk was found in 10.0%(3/30) of children without signs and symptoms of TMD and was found in 59.1%(39/66) of children with signs and symptoms of TMD.
5. No joint effusion was found in children without signs and symptoms of TMD, while on the other hand effusion was found in 45.5%(30/66) of children with signs and symptoms of TMD.
In children with signs and symptoms of TMD, the findings of internal derangement did not show a light condition. On the other hand anterior disc displacement was obaerved in 16.7% of the children, disc deformed was 10.0% in spite of chiidren not having signs and symptoms of TMD. From above the facts, it was shown that pedodontists should be a concern and we should be solicitous concerning temporomandibular joints in children.

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The purpose of this study was to observe the changes in the internal and external behavior of child patients under no sedation and under sedation with nitrous oxide/oxygen in halation in order to lessen the stress of local anesthesia.
Sixty children (37 boys and 23 girls) who were well behaved and were from 3 years and 2 months to 11 years of age were examined.
The R-R interval (RR), and BE as the physical expression (BE) and the visual analogue scale (VAS) were used as the indexes for changes in internal and external behavior, respectively.
The effects of the stress of local anesthesia were investigated among children of difference ages and who were also administered local anesthesia several times with and without nitrous inhalation sedation, and which were called the local anesthesia with sedation group and local anesthesia group, respectively.
The results are summarized as follows:
1. There relief of pain was seen with local anesthesia in the sedation group with the children being very calm and lenitive, more than the local anesthesia group based on RR, BE and VAS.
2. The hypertonic of internal behavior (RR) at the time of injection was clearly seen in the group with the injection of local anesthesia. Otherwise in the group with local anesthesia with sedation, changes in RR were not found, and those of BE decreased with age.
3. No changes in RR, BE and VAS were found in the group with local anesthesia and the group with local anesthesia with sedation based on applied the same individuals several times.
4. Pain (VAS) was strongly complained of the 5-7 years old group at the time of the initial injection in the group with local anesthesia, while a change in RR, BE and VAS was not found in the group with local anesthesia with sedation based on administering to the same individuals several times. These results suggest that nitrous oxide/oxygen inhalation sedation is tends to inflict pain at the time of injection more than local anesthesia only.

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We investigated a radiographic follow up examination and an oral examination in both 132 primary teeth and 40 immature permanent teeth which had been treated by means of pulp capping with antibacterial drugs during the period from April 1997 to June 1998 at the Pediatric Dentistry Clinic of the School of Dentistry at Matsudo, Nihon University.
The results obtained were as follows:
1. At the time of final follow up examination for each treated tooth, there was a number of teeth judged as being successful were 164 (95.3%) and 8 (4.7%) as being unsuccessful. Results we observed especially many teeth judged as being unsuccessful during the period from 18 to 28 months after treatment.
2. For the age of the subjects with unsuccessful results, children aged 3-5 years represented 77 % for the primary tooth treatment.
3. As regards with the successful cases, the ratio of the indirect pulp capping was much higher than that of the direct pulp capping.
These findings suggested that α-Tricalcium Phosphate Liner mixed antibacterial drugs was useful in the pulp capping treatment of both primary teeth and immature permanent teeth.

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The purpose of this study was to research the problems of prenatal ultrasonic diagnosis and aid families which have a cleft lip fetus. The term of the study was about 7 years starting in 1991. There were 207 subjects and those with cleft lip amounted to 152. And we counseled or advised 11 families before birth.
We obtained the following results.
1. Of 152 fetuses with cleft lip,38 were detected using ultrasonic diagnosis.27 families (71.1%) out of the 38 were informed before birth that their child had cleft lip.
2. After detecting the cleft lip, obstetricians selected one out of three informing about the cleft lip. The first was not to inform before birth, and the second to inform only before birth. The third was to inform and then contact the support team. For 21 families (77.8% of 27) the second case was selected.
3. We counseled 8 families at a personal interview before birth.
4. In the third case, within 1 week we gave counsel after informing the parents of the cleft lip of their child.
5. In the 11 cases we aided, each family had their own problem to be solved. We believe that the purpose of ultrasonic diagnosis must be to aid with respect to the birth. For this purpose we must counsel with love and sympathy as soon as possible after information of the cleft lip.

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The purpose of this study was to investigate the influence of the carious dentin conditions on the values measured with a DIAGNOden^TM(K aVo Co. ), and to validate the effectivenesso f DIAGNOdent in judging the accurate removal of infected dentin.
Forty-three lesions from 41 carious primary teeth of 17 patients aged from 3 years and 3 months old to 11 years and 6 months old (average: 7 years and 4 months old) and 73 lesions from 70 carious permanent teeth of 41 patients aged from 7 years and 6 months old to 23 years and 11 months old (average: 13 years and 10 months old) were examined. Caries were detected by the visual, palpable and radiographice xaminationsa, nd diagnoseda s C₀: incipiente namel caries, C₁: enamel caries and C₂: dentinal caries. Identical portions of all of the lesions were measured 5 times with a DIAGNOdent attached with a small type-A detector, and the average values were obtained. Adding to the visual, p alpabler, adiographica nd DIADNOdente xaminationsf, or the restoredt eeth, the infected area was directly validated, and a final diagnosis was made. Data was statistically analyzed using ANOVA with subsequent Fisher's PSLD or correlation coefficient at p<0.05.
The following results were obtained.
1. As the results of the correlationsb etweent he DIAGNOdentv alues and color, h ardness and dry/wet conditions of the carious dentin in which the final diagnosis was C₂, for primary teeth, there was a significant correlation between the value and dry/wet condition of carious dentin, and the higher the dryness of the decayed dentin, the higher the values were, and for permanent teeth, there were significant correlations between the value and color, and value and hardness of the dentin, and the darker and harder of the decayed dentin, the higher the values were. No significant correlation was obtained between the values after the removal of infected dentin and the conditions of carious dentin.
2. The mean values of the dentin before and after the removal of infected dentin in the finally diagnosed C₂ lesions were 28.3 and 6.3 for the primary teeth, and 22.5 and 6.4 for the permanent teeth. No significant difference was obtained between the values of the primary teeth and permanent teeth.
3. DIAGNOdenwt as useful in judging the accurater emoval of infectedd entin.

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This study was carried out to evaluate the adhesive effects of sealants on the enamel surface. Premolars to be extracted for orthodontic purposes were obtained with informed consent of the donors. The buccal surface of each premolar was flattened by grinding with silicon carbide emery paper(#600). Resin sealants and glass-ionomer cement sealant were built up on the flattened buccal enamel surfaces after the surfaces had being etched according to manufacturer's instructions. After 24 hours of storage in water at 37°C, the teeth were vertically sectioned through the sealant ahd enamel using a low-speed diamond saw to produce 1×1×8 mm beam specimens. Adhesive strengths between the sealants and enamels were determined using a micro-tensile tester.
The results showed that resin sealants had significantly higher adhesive strengths than did glassionomer cement sealant(one-way ANOVA, p<0.05). Teethmate F-1 was 35.4±13.4 MPa, Clear seal F was 25.4±9.6 MPa, Fluorosealant was 36.7±11.7 MPa, and FujiIIILC was 14.8±9.2 MPa. SEM observation of fractured surfaces revealed that most of the fractures were cohesive failures within resins and glass-ionomer cement materials. Adhesive failure at the interface was not found in any of the specimens. The results demonstrated that adhesive strengths between sealants and enamels were higher than the strengths of sealant materials, indicating that the adhesive strengths of currently used sealants to enamel surfaces are sufficient.

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To clarify the relation between crowding dentition and masticatory function, arch length discrepancy (ALD), t he numbero f interocclusalc ontacts (ICP), and the EMG from four masticatorym uscles were recorded successively in each subject at different Hellman's dental age from II C to NA. The subjects were divided into four groups concerning their dentition at IVA: 1) normal males,2) crowding males,3) normal females and 4) crowding females. The results obtained were: a) At II C, ALD for crowding males and females was not different from each normal group; b) At II C, there was no significant difference between ICP for crowding males and normal males, and for crowding females and normal females, similarly. c) The frequency of free mastication in burst activity at II C and III A for crowding females was significantly larger than that for normal females, and the duration at II C for crowding females was significantly larger than that for normal females, while the difference decreased with increasing age to stage NA. Since functional differences in the EMG were observed at II C without obvious morphological differences, arch length discrepancy may be produced not only by acquired factors after II C, but also by functional factors before II C. Therefore, analysis of EMG recordings in detail at the deciduous stage may help predict a future occurrence of crowding dentition.

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Previous studies have demonstrated that different forms of human periodontal disease are associated with specific microorganisms in subgingival plaques. It is well known that adult periodontal disease is associated with the presence of Porhyromonas gingivalis (P. gingivalis) and Prevotella intermedia (P. intennedia) and that early onset periodontitis is also caused by Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans). A relationship between periodontopathic bacteria and subgingival plaques has been established for adult periodontal diseases.
However, the role of supragingival plaques is unclear in oral-microbial ecology and in the initation of gingivitis and/or periodontal disease in children.
In the present study, P. gingivalis and A. actinomycetemcomitans in supragingival plaques in children aged 2.7-16 years were detected using immunoslot blot assay with specific monoclonal antibodies for each bacteria.
Plaques with P. gingivalis-positive reactivity increased with increasing age, whereas the those with A. actinomycetemcomitans-positive reactivity were enhanced in the subject age of 8-12 years and thereafter declined. The data indicated that the supragingival plaques in children are capable of harboring periodontopathic bacteria such as P. gingivalis and A. actinomycetemcomitans.

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The purpose of this paper was to elucidate the peripheral control of jaw muscles during jaw movements in children with malocclusion such as anterior cross bite or deep bite. The subjects comprised 7adults with normal anterior interrelation but without any dysfunction of the mandibular movement. Two types of removable bite-blocks, with normal anterior bite and anterior cross bite (anterior overjet -1 mm), were fabricated to perform an anterior tapping and a molar tapping. Electromyograms were recorded from the middle part of the masseter muscle and the posterior part of the temporal muscle.
The masseter muscle activities during tapping movement on wearing the bite-block with anterior cross bite were not much different from those on wearing the normal bite-block. In the temporal muscle activities, however, the response pattern of the periodontal jaw reflex, in which the inhibitory reflex response was induced by anterior tapping but the excitatory reflex was occurred by molar tapping, was more prominently recognized when the bite-block with cross bite was worn than the normal bite-block. The magnitude of the temporal muscle activities was markedly reduced during tapping of the bite-block with cross bite.
The present results were considered to be related to the excess extension of the temporal muscle on wearing the tapping block with cross bite, and it was therefore concluded that the afferent input from the muscle spindle differed from the response pattern of the periodontal jaw reflex.

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The aim of this study was to clarify the distribution of mineral ion (Ca, P, F) concentrations, Ca/P and mode of binding F, i. e. the physiological significance of F in dental plaque from different areas of the dentition.4-day plaque samples were collected from 8 different sites of 15 male subjects living in Hokkaido (average age 25.2 yr. ); upper-anterior-buccal (UAB) and lingual (UAL), upperposteriorbuccal (UPB) and lingual (UPL), lower-anterior-buccal (LAB) and lingual (LAL), lowerposteriorbuccal (LPB) and lingual (LPL). Plaque samples were weighed, freeze-dried, and subjected to acid extraction, using a mixed-acid digestion procedure that was described by Margolis and Moreno (1992). The acid extracts were analyzed for Ca using atomic absorption, P using colorimetry and F using F ion electrode.
Statistical differences were seen in Ca, P, Ca/P (p<0.0001) and F (p<0.05) tested using two-way ANOVA. Plaque associated with the LAL, which is less prone to caries, had significantly highest levels of Ca, P and Ca/P based on Scheffe's test.
On the otherhand, the relationships among Ca, P, F and Ca/P were analyzed statistically. There were very strong associations between Ca and P, especially seen in LAL (r=0.988 p<0.0001) and LPL (r=0.997: p<0.0001), where are much prone to saliva. Positive correlations were found between Ca/P and F. Partial correlation analysis, however, showed that the F did not correlate with P if the Ca factor was fixed. These results suggested that some F in dental plaque could be bound to mineral, depending on Ca concentrations rather than P.

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The Wits appraisal by which the occlusal plane of the mandibular protrusion in the deciduous dentition and the early stage of the mixture dentition were assumed to be planes of reference were examined, adopting the infants with mandibular protrusion and normal occlusion in Hellman's dental age II A and III A as a testees, using the roentgenographic cephalogram. The items examined were effective for the diagnosis of the harmonization of the position before and behind the maxilla and mandible alveolar base part with the effectiveness based on the plane of occlusion in a morphology analysis of the mandibular protrusion of the deciduous dentition and the early stage of the mixture dentition, and the relation to other morphological analysis items. And the following conclusions were obtained,
1. When comparing, it was found that the AO-BO values of the group with mandibular protrusion and normal occlusion, the group with mandibular protrusion stage II A and stage III A intentionally showed high values compared with a normal group.
2. Concerning the Wits appraisal and other craniofacial form appraisal, the relationship of Wits appraisal and ANB showed a significant, positive correlation in both stage II A and stage Ill A group with mandibular protrusion and group with normal occlusion. A significant correlation was not found between the Wits appraisal and SN to occlusal plane angle, and between the Wits appraisal and cant of occlusal plane.

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This study examined changes in angulation and anterior-posterior position of the first molar in crowding dentition. The subjects were divided into four groups depending on their dentition scores at Hellman's dental stage IV A: 1) normal males (n=5),2) males with crowding (n=5),3) normal females (n=5) and 4) females with crowding (n=5). Tooth position was determined by lateral cephalometric X rays taken longitudinally from III A to IV A, and the following results were obtained;
(1) ANS-PNS and Me-Go for both males and females with crowding were smaller than that for normal males and females at all of the dental stages.
(2) The forward displacement of the upper first molar from III A to NA for both males and females with crowding was significantly greater than that for normal males and females.
(3)∠U 6-Pal. Pl. at III A for both males and females with crowding was smaller than that for normal males and females. The increase in ∠U 6-Pal. Pl, from III A to IV A for both males and females with crowding was larger than that for normal males and females.
(4) The forward displacement of the lower first molar from III A to IV A for both males and females with crowding was not significantly different from that for normal males and females. One characteristic of developmental change of the first molar in crowding dentition is that the upper first molar erupts with distal tipping, and subsequently migrates mesially with mesial rotation.

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The purpose of the present study was to examine the effect of fluoride and xylitol on remineralization at the early stage of the enamel caries.
In this study we employed remineralization process using in vitro artificial caries models.
The results were obtained as follows:
1. Gloups treated with NaF and Xylitol significantly increased remineralization compare with none treated group (control).
2. There was no significant difference in remineralization between the control and the xylitol alone groups.
3. Histological examination showed the board and stick structures in remineralized enamels.
4. Subsurface remineralized products and attached products mostly consist of hydroxyapatite.

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Purpose: A three-dimensional finite-element model of the mandible, including the temporomandibular joint (TMJ), was constructed in order to examine the influences of changes in the functional situation and anatomical morphology on TMJ loading. The purpose of this study was to investigate the influences of changes in the occlusal-supporting area and horizontal condylar angle on TMJ loading. Methods: Based on a juvenile human dry skull specimen, a numerical model of the mandible; including the TMJ, was developed. In this model, the ramus of mandible is excluded and the condyle and the body of mandible are connected with rigid elements. Contact elements allowed for slip and separation effects between the contact surface of the articular disk and the articular surfaces of the condyle and eminence. The magnitude and direction of the condylar displacement and the stress distributions on the articular disk during clenching were analyzed with respect to changes in the occlusal-supporting area and the horizontal condylar angle.
Results:
1. Under clenching conditions, stress distributions on the articular disk were demonstrated along the condyle, and stress was induced in the anterolateral areas of the articular disk.
2. Scenarios for the loss of posterior teeth and unilateral occlusion demonstrated increases in TMJ loading.
3. The increased horizontal condylar angle resulted in increased stress on the articular disk and a change in localization from the central area to anterolateral area. Conclusions: It was seen that changes in the occlusal-supporting area and horizontal condylar angle influence TMJ loading.

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The aim of the present study was to clarify the relationship between the Dental Fear Survey (DFS)score in adulthood and the history of dental treatment in early childhood and to examine the factors that cause dental fear in adulthood. The subjects comprised 69 patients (16.7 years of mean age) of the pediatric dental clinic in Niigata University. We checked the dental experiences of all of the subjects based on their charts and analyzed the relationship between the dental history and the DFS score. The results were as follows.
1. Mean DFS scores of the present study came to 29.64 in the males and 37.54 in the females. They were statistically lower than the scores of the average Japanese population (44.09 in male and 46.24in female) (p< 0.01).
2. The patients with negative impressions concerning dental treatment (26 percent) had a higher level of dental fear than those of the others. Based on the results of factor analysis, no relationship was found between the impression and the dental experiences although a significant relationship between the impression concerning dental treatment and the DFS score was shown.
3. In the present study,45 patients out of all of the subjects had experienced physical immobilization before 5 years of age. Of these patients,20 had the experienced physical immobilization at 5 years (group (+)) and 25 had not experienced this at 5 years (group (-)). The mean DFS scores of group (+) and group (-) were 39.35 and 30.80 points respectively and there was a significant difference (p<0.05).
4. The distribution pattern of the mean scores of 20 items in the DFS questionnaire indicated that the patients of group (+) showed a higher level of fear in the items of proximate dental treatment than those of actual dental treatment. On the other hand, the tendency was not clear in the scores of group (-). We recognized, however, little difference in their dental experiences before 5 years of age between both groups. The findings suggest that patients who need physical immobilization at 5 years of age during dental treatment were inadaptable to dental treatment due to their character as regards quantity of dental fear. We should therefore take special care of them in dealing with their behavior.

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The purpose of this study was to investigate the affect of b-FGF and TGF-βon the infant human alveolar process of the maxilla-derived osteoblastic cells(HAB). The result were as follows.
1. While b-FGF(2.5 ng/ml) and TGF-β (0.5 ng/ml) stimulated the cell proliferation of HAB, the ALP activity was inhibited.
2. While TGF-β(1.0 ng/ml) inhibited the cell proliferation of HAB, the ALP activity was stimulated.
3. TGF-β(0.5 ng/ml)+b-FGF(2.5 ng/ml) further stimulated the call proliferation of HAB, the ALP activity was further inhibited.
4. While b-FGF(2.5 ng/ml) stimulated the expression of osteocalcin mRNA in HAB, it did not markedly effect expression of ALP activity and Type I collagen in HAB.
5. While TGF-β(1.0 ng/ml) inhibited the expression of osteocalcin mRNA in HAB, it did not markedly effect expression of ALP activity and Type I collagen in HAB.
The results indicated that b-FGF and TGF-βregulate cell growth and differentiation in the infant human alveolar process of the maxilla-derived osteoblastic cells(HAB).

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In an attempt to evaluate the prognosis of traumatized primary teeth, a longitudinal clinical and radiographical follow-up study was made for forty eight children with a total of 90 traumatized primary incisors until their permanent successors erupted. The material included children aged 0 to 6 at the first visits, and 7 children (11 teeth) had their first visit more than 8 days after the trauma.15 teeth were lost at the time of the traumatic injuries, and 14 teeth were extracted at the first visit.
In 61 preserved traumatized primary incisors, for 50 teeth the first visit was within 7 days of trauma, and included 45 teeth with periodontal injuries and 5 teeth with the hard tissue fractured.
The treatments for periodontal injuries were fixation with or without reposition, or observation only. Consequences to these primary teeth comprised: color changes (29%), pulp canal obliteration (29%), pathological changes of pulp (pulpitis or pulp necrosis) (22%), eccessive tooth mobility (9%), and malformation on their permanent successors (60%) 75% of the eccessive tooth mobility was observed within one month after the first visit,75% of the pathological changes of pulp within six months, and about half of the pulp canal obliteration within one year.
Twelve teeth showed discoloration during the follow-up period, and 9 of these teeth -(75%) developed pulp canal obliteration.Two of these teeth (17%) developed pulpitis or pulp necrosis.
Pulp canal obliteration occured more frequently in the teeth of the younger age of chirdren and during the early stage of root development at the time of injury. The presence of heavy luxation seemed to increase the risk of pathological changes in the pulp, and these changes were observed more often in the teeth with complete root formation compared to the teeth with developing roots.
In 5 preserved teeth with hard tissue injuries, teeth with crown fracture normally survived after restorative therapy. It was however hard to preserve teeth with root fracture.

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The glass-ionomer cements have many advantages such as release of fluoride for caries resistance, biocompatibility, esthetics, and sufficient teeth adhesion. The purpose of this study was to determine if short fibers of CaO-P2O5-SiO2-Al2O3 (CPSA) short glass fiber (diameter,9.7±2.1μm; aspect ratio,5.0±0.9)could be effective as a reinforcing agent for glass-ionomer cement. A commercially available glass-ionomer cement (HY-BOND GLASIONOMER CX; Shofu Inc., Kyoto, Japan)was used in this study. The powder for the cement was prepared by mixing the powder of the glassionomer cement and CPSA short glass fibers. The contents of CPSA short fibers in the mixed powder were 0,20 and 50 wt%. The powder was mixed with a commercial liquid at a powder/liquid ratio of 1.46, according to the manufacturer's instructions. After mixing, the cement pastes were placed in a glass split mold. The specimens were kept in an incubator at a temperature of 37°C and relative humidity of approximately 100%. After 24 hours of storage, micro-tensile strength and flexural strength of the set cements were evaluated. The strengths of glass-ionomer cements containing 50 wt% short fibers were approximately two times larger than those non-containing short fibers. The scanning electron micrograph observation showed that the set cements dispersed with glass fibers were strengthened by bonding between the cement matrix and the short fibers. The CPSA glass short fibers played an important role as a reinforcing agent for strengthening the glass-ionomer cement due to the shape of the short fibers and the chemical reactivity between the mixing liquid (or cement matrix) and short fibers. The glass ionomer cement strengthened by glass short fiber is promising as a new dental material.

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The aim of this study was to develop a method of continuous intra-oral pH monitoring of the tooth surfaces at different regions and to evaluate the influence of saliva on the pH at different regions of the mouth. Ion-sensitive field-effect transistor (ISFET) pH electrodes were used to record the pH changes. The electrodes were fixed using adhesive resin on the buccal surface of an upper first molar (UPB), the lingual surface of a lower incisor (LALi) and on the labial sarface of an upper incisor (UAB). After the flow rates and pH were monitored in 'resting condition', the tip of tongue was stimulated by the filter paper disc soaked in 5% citric acid. Parotid saliva was collected from a single salivary gland with Lushley cannulae and the pH of the UPB at the other site was monitored simultaneously. To determine the influence of saliva on the pH at different regions of the mouth, the pH was monitored continuously at the UPB, LALi and UAB before and after the stimulation. The flow rates were increased after 6.6 seconds of the stimulation, and still showed maximum pH at 13 seconds. The maximum pH at the UPB region was recorded after 153 seconds later than the maximum flow fates. The mean highest pH of the UPB and LALi regions were 6.32±0.38 and 7.17±0.12, respectively, while the pH at the UAB region did not show any change after the stimulation. In conclusion our results suggest that the pH at different regions in the mouth was strongly effected by the saliva.

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The purpose of this study was to investigate usefulness of the mailing method of the Cariostat test. The subjects were 50 adults. Two dental plaque samples were taken from one subject at a time, and the operation was repeated four times per week. Some plaque samples were put into the Cariostat medium and incubated at 37°C for seventy-two hours. The Cariostat value and the pH value were evaluated for each twenty-four hours. Other plaque samples were mailed under four conditions (the group of the mailing method with only one swab at normal temperature, the group of the mailing method with the swab put into the Cariostat medium at normal temperature, the group of the mailing method with only one swab at low temperature, and the group of the mailing method with swab put into the Cariostat medium at low temperature), and then was operated as well as that regular method. The results were as follows;
1. The average pH value for the group of the mailing method with only one swab at normal temperature was highest of the four groups.
2. The correlation coefficient between the pH values for the group of mailing method with only one swab at low temperature and the group of the regular method was most statistically significant.

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The purpose of this study was to investigate usefulness of the mailing method of the Cariostat test.
The subjects were 64 children taken the Cariostat test on four seasons. One dental plaque sample were put into the Cariostat medium and incubated at 37°Cfor seventy-two hows. The Cariostat value and the pH value were evaluated after forty-eight and seventy-two hours. Two plaque samples were taken from same subjects at a time. Each plaque sample was mailed under two conditions (the group of the mailing method with only one swab at normal temperature, the group of the mailing method with only one swab at low temperature), and then operated as well as that regular method. The result showed no effect caused by a difference of temperature during the mailing period by using the mailing method with only swab at low temperature and cultivating for seventy-two hours,

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The laser flowmeter is a device for observing histo-blood flow bloodlessly as well as continuously. This device was well known for measuring gingival and pulpal blood flow in the dental field. The laser Doppler flowmeter was widely used for this device. Therefore, in this study two methods were applied at the same time in order to compare the effectiveness of the laser flowmeter; the first method was the laser Doppler flowmeter (back-scattered laser type) and the transmitted laser flowmeter which was developed for reducing noise; the other was the simple sphygmograph and the former electrocardiograph. The following results were obtained;
1. The corresponding blood waveform was observed in the pulpal blood flow, the pulse, and the construction. The sphygmograph was useful for substitution of the electrocardiograph.
2. The transmitted laser flowmeter had less influence on noise than the laser Doppler flowmeter.
3. The laser flowmeter was practicable to measure abnormal pulp objectively.

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This study was performed to evaluate the application of the transmitted laser flow meter for the assessment of pulpal blood flow in children. The new probe, which was the slide caliper type not recluiring the custom-made shell, was devised for this application.
We used two different types of probe (slide caliper type and shell type) for measurement of pulpal blood flow in vital and non-vital teeth of 3 adult subjects, and the flowmetry data were compared. Then, using slide caliper type probe, we measured the pulpal blood flow of children. The subjects were 46 children aged 3-16. Thirty-five primary incisors and fifty-three permanent incisors were measured.
The results were as follows;
1. The correct assessment of pulpal vitality was obtained by using the slide caliper type probe as well as the shell type probe. Furthermore, the slide caliper type enabled us to measure the pulpal blood flow easily.
2. As for the child subject, the values of the pulpal blood flow of the primary teeth were larger than those of the permanent teeth.
3. Primary teeth with completed root showed larger values of pulpal blood flow than those with resorpted root.
4. Permanent teeth in children showed larger pulpal blood flow than those in adults.

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