A method for measuring upper lip pressures in children was developed to evaluate the effects of myofunctional therapy. Five children with oral habits such as tongue thrust or abnormal swallowing performed functional exercises for the lips and perioral muscles over a period of more than three months. The upper lip pressures were measured before and after 1.5 and 3 months of therapy by a strain gauge pressure transducer placed on the labial surface of the upper central incisors. After placement of the transducer, the children were studied in both sitting and supine positions and the lip pressures were recorded at rest and swallowing in each position.
The average values of the resting lip pressures were 1.26g/cm² (sitting) and 1.38g/cm² (supine) before therapy and were 2.41g/cm² (sitting) and 2.18g/cm²(supine) after three months of therapy. Analyses of the resting lip pressures and time-pressure integrals revealed that the resting lip pressures increased in four children after three months of therapy. All of the children performed the daily exercises satisfactorily, but one child who discontinued the exercises did not show a significant change in the resting lip pressure.
Average values of maximum lip pressures at swallowing were 3.1g/cm² (sitting)and 2.6g/cm² (supine) before therapy and were 8.6g/cm² (sitting) and 7.8g/cm² (supine) after three months of therapy. The maximum lip pressures increased markedly along with exercises. However, the waveforms of the lip pressures and the maximum pressure values differed considerably from each other in the swallowing trials.
The children who showed a tendency toward increased lip pressures prolonged the duration of the closed time of the mouth and had suitable tension in their lips. However, there seemed to be no change in their occlusion after three months of therapy.

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The aim of this study was to investigate the effect of varied F concentrations of APF solution on the F uptake of modified human surface enamel and the change of the acid resistance of the surface enamel, and also to find out the effective topical application procedure with the least fluoride concentration.
The sound enamel blocks were prepared from human premolars which were lightly processed by applying 0.05 M H₃PO₄ for 1 min., which has been used as a routine clinical procedure, called the mild etching, for the topical application of APF solution.
APF solutions of which the F concentrations varied from 0.05% to 1.2%, were applied for 4 min. to the enamel blocks and immersed into calcifying solution containing no fluoride for 30 min. The F uptake was determined by using the enamel biopsy technique and acid resistance was assessed by determining the dissolved amount of calcium when the enamel blocks were exposed to the acetic acid-sodium acetate buffer solution of pH 4.0.
The results obtained were as follows:
1. It was confirmed that after the mild etching, the surface enamel to which the APF solutions containing varied concentrations of F were applied, took up more fluoride than that without the mild etching. Obviously the mild etching did not alter the visual appearance of enamel surface leaving its original luster.
2. In the acid resistance test, APF applications with the mild etching enhanced acid resistance more than those without the mild etching. More than 0.5% F in the APF solution with the mild etching did not show any significant differences in the acid resistance of the surface enamel.

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Nine cases diagnosed as partial anodontia because of multiple agenesis of the permanent teeth without any other remarkable systemic disorders, were subjected to survey of the location of the congenital missing teeth occuring and its frequency in these cases and to estimate the effects of multiple agenesis of permanent teeth on the growth of occlusal height by analyzing their denture pattern as well as their skeletal pattern by using radiographic cephalometrics.
Congenital missing teeth occured most frequently among the upper second premolars followed by the upper second molars and lower central incisors. In each case the agenesis of the teeth occured almost symmetrically and followed the phylogenic degeneration phenomenon.
The cephalometric analyses revealed the undergrowth of the nasomaxillary area in 8 cases. The undergrowth of the occlusal height and the decreased degree of the mandibular plane angle were also pointed out in 4 cases. The remaining 5 cases showed the normal occlusal height for their ages.
From these findings it could be said that partial anodontia apparently affects the growth of the skeletal pattern, and agenesis of the upper anterior teeth and premolars causes undergrowth of the midface and agenesis of the molars reduces their occlusal height which causes anterior upward rotation of the mandible.
In addition to these findings, a case of partial anodontia with a complaint of temporomandibular arthralgia was presented. A female patient with agenesis of 24 permanent teeth including multiple molars complained of the pain in the temporomandibular joint when she was 11 years old. Improvement of her occlusal height by newly constructed dentures solved her problems, indicating the importance of keeping adequate occlusal height during the growth process of the patient with partial anodontia.

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The purpose of this study was to investigate the influence of thermal cycling on the adhesion of the resin on the primary ground enamel which was etched with different etching times.
Labial surfaces of 50 extracted and frozen bovine mandibular primary incisors were used. The etchant used in this study was 40% phospholic acid gel and the etching times were 0,10,20,30 and 60 seconds. All of the specimens were washed with an air water spray after etching. The bonding agent and composite resin used in this study were Photo Bond and Photo Clearfil A (Kuraray Co. ). After thermal cycling tests of 10,000 temperature cycles between 60°C and 4°C water baths, shear bond strengths on the ground enamel were measured. After the shear bond strength tests, all the test surfaces of the enamel and resin specimens were observed using the SEM. The results of this study were compared with the previous results which were not thermal-cycled.
The following conclusions were obtained.
1) The etching time which showed the highest bond strength was 30 seconds (78.99±10.93MPa).
2) The enamel specimens which had undergone all of the etching time tests had significantly higher bond strengths than specimens which were not etched.
3) In the etched groups, the bond strength with 30 seconds of etching time was significantly higher than those with 10,20, and 60 seconds of etching times.
4) In all the etching time groups except the 20 second group, the bond strengths of the thermal-cycled groups were lower than those of the non thermal-cycled groups. In the 20 second etching group, the bond strength of the thermalcycled group was significantly higher than that of the non thermal-cycled group.
5) On the enamel specimens after the shear bond strength tests, the frequency of the clear prism structures observed on the enamel was higher in the groups which showed higher bond strengths. However, the differences were not significant.

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Retzius' lines of human primary enamel are not clear usually, but they are clear when developmental disturbances exist. We established the times when the Retzius' growth lines were formed, and examined them with their histories.
The materials were extracted anterior deciduous teeth of handicapped children without enamel hypoplasia. We conducted observations with general microscopy and polarized light microscopy. We examined 15 cases in which Retzius'lines except the neonatal line existed. We determined the times when the Retzius'lines were made by the neonatal line and the growth pattern of human teeth by Schour. We examined histories of pregnancy and postnatal situations by questionnaires and questionings.
The results obtained were as follows.
1. In no cases did the Retzius' lines appear in prenatally. In 12 cases, they appeared postnatally. In e cases, they appeared prenatally and postnatally.
2. In 12 cases, the timing of the Retzius' lines coincided with the histories in 5cases.
3. In 3 cases, the timing of the Retzius' lines agreed with histories in 2 cases.2 cases had prenatal and postnatal histories.
4.6 cases showed many Retzius' lines (over 10 lines).

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We studied the relationship between the development of the first molar in its eruption locality during the period of deciduous dentition and changes in the eruption of the first molar in the jaw bone and examined the effect of the eruption locality size on the deciduous dentition. The material used in this study consisted of serial dental casts of the early and late stages of deciduous dentition and right and left oblique(45°)cephalograms of 26 caries-free children with clinically normal deciduous dentition (12 boys and 14 girls). Eruption locality on the serial dental casts was examined by moire topography, and the relationships between changes in eruption of the first molar, the size of the apical base and dental arch, and the interdental space volume were studied. The results obtained were as follows:
1) The use of moire topography facilitated determination of the precise volume and morphology of the eruption locality of the first molar.
2) The length of the eruption locality on the moire topograms increased by 2.11mm in the case of the maxilla and by 1.65 mm in the case of the mandible from the early stage to late stage of deciduous dentition.
3) The eruption locality volume increased by 58.86% in the case of the maxilla and by 24.13% in the case of the mandible from the early to late stages of the deciduous dentition.
4) With regard to mesial and distal positional changes in the highest portion of the eruption locality, both the maxilla and mandible tended to move distally. With respect to buccolingual positional changes, the highest portion of the eruption locality tended to move buccally in the maxilla and lingually in the mandible.
5) As far as the relationship between development of the eruption locality and changes in the eruption of the first molar are concerned, the eruption locality was completely formed in the maxilla with eruption of the first molar, and while the axial inclination of the first molar was related to the size of the eurption locality in the early stage of deciduous dentition in the mandible. There was, however, no such relationship in the late stage.
6) There was a relationship between the posterior development of the apical base and increase in eruption locality, but no clear relationship between the size of the dental arch and the interdental space.
7) It is important for occlusal guidance to take into consideration three-dimensional changes in the development of the first molar.

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The growth of the dentocraniofacial structures of 13 Japanese girls was investigated during two year and six month (2 1/2 year) periods by using 39 lateral cephalograms of the deciduous dentition. At the first visit their deciduous incisors were reversely occluded, and when their permanent lower incisors erupted, they were reversely occluded also.
Results:
1. On the axis of cordinates based on the sella turcia, all of the measurements except the orbitale changed significantly in height, but none of the measurements except the nasion and lower permanent incisor changed significantly in depth.
2. The permanent interincisor angle and the lower incisor angle to the mandibular plane changed significantly in eighteen angular measurements, but the other measurements did not change significantly.
3. In eight linear measurements, the length of the anterior cranial bone and the mandibular ramus height did not change significantly, but the other measurements increased significantly. The total mandibular length, anterior facial height, and mandibular body length showed significant increase compared to the maxilla bone length, facial depth and mandibular ramous height respectively.
4. The variance of growth change between the deciduous dentition completion period and the lower incisor eruption period was not significant in most items except in the permanent incisor. Most of the permanent upper and lower central incisors decreased once in angle before the eruption, and then it increased during eruption.
Conclusion:
In the growth of dentocraniofacial structures of Japanese girls over a period of 2 1/2 years in deciduous reversed occlusion, angular measurements did not change significantly and the facial height grew more than the depth. However the direction and amount of growth did not change in the meantime.

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We studied the establishment of a toothbrushing instruction system for developmentally retarded children.
This investigation was carried out in order to confirm the results of such a system for them. The subjects were 53 developmentally handicapped children without motor dysfunction. In total,165 toothbrushing instruction sessions were conducted for them over a period of one year (or an average of 3.1 sessions per person).
The results were as follows:
1. OHI-S values tended to decrease with each toothbrushing session.
2. After toothbrushing instruction,50.9% of the subjects improved in evaluation of the brushing score.
3. The rate of the subjects who could brush roughly all regions increased from 9.4% to 28.3% after the toothbrushing instruction.
4. Subjects under 3 in the developmental age (determined by the basic daily habits of Enjoji's Infant Analytic Developmental Test), were not able to recognize a new task. On the other hand, the subjects more than 3 years in the developmental age could recognize a new task.
5. Tasks for which they were unable to comprehend as toothbrushing instruction were valueless.
6. When the subjects were over 3 years old in the developmental age, they could acquire a new task effectively.
7. Toothbrushing instruction according to learning theory was suitable for practicing the instructions for which the subjects were capable.

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The purpose of this study was to investigate the influences of oral hygine, elapsed time after meals, elapsed time after tooth brushing with or without tooth paste on the caries activity tests scores.
The caries activity tests were performed on 100 children (male: 49, female: 51) ranging in age from 3 years to 17 years 6 months (average: 7 years 3 months). The caries activity tests used in this study were MSB broth (Mucount: Showa), Resazurin Disc test (RD test: Showa) and Cariostat (Cariostat ^TM: Sankin). The following results were obtained.
1. The influence of oral hygine on the test scores was significant only in the 48hour scores of Cariostat.
2. The influence of the elapsed time after tooth brushing on the test scores was significant only in the 48 hour scores of Cariostat.
3. Elapsed time after meals and whether brushing was done with or without tooth paste did not influence on the scores of all the caries activity tests.
4. For using the caries activity tests, plaque and saliva should not be collected soon after tooth brushing and soon after taking meals.

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In children, we often encounter cases associated with impacted teeth and the abnormal position of the unerupted permanent teeth. These abnormalities may cause malocclusion or cysts as a result. There has been little study to identify the accurate relationship regarding space between the impacted tooth and other teeth in dentition and the morphology of the involved tooth, all of which is necessary for occlusal guidance and surgical treatment. Three-dimensional assessment was therefore investigated with use of computed tomography (CT).
The material used was a dry skull of a child in which the tooth with curved root was attached on the maxilla. The silicone impression of the dental arch was then taken and the plaster model of the dental arch was made. The plastic sheet on which the 28 reference points were composed with the gutta-percha was prepared on the dental cast.
The computed tomography was then take on the dry skull and was put on the plastic sheet at 1 mm intervals. The total number of images was 26, which were printed as the same size as the actual one.
The data were compared between the image constructed from CT and the three-dimensional measurement on the actual tooth.
The results were as follows:
1. The difference of the three-dimensional length between Orale, the upper left front teeth and the impacted tooth was very small (-0.03∼+1.66mm).
2. Regarding the volume of the impacted tooth, the difference was 27mm³.
3. The reconstructed images was a satisfactory one which could be applied to the clinical use.

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The aim of this study was to detect the abnormality in eruption time of first permanent molars early on. The extent of the eruption process of first permanent molars was observed with the use of the panoramic tomograms.
The subjects were 2245 Japanese children (from 3 to 11 years old).
The criteria of classification was judged by the following procedures.
Each radiograph was traced, and the eruption stages of first permanent molars were classified into 5 grades by arbitrary lines set on the second deciduous molars. Finally the standard age of each eruption stage of first permanent molar was assessed.
The reproducibility of this procedure was statistically excellent.
This system might be very useful and easy for screening of abnormal cases with the eruption time of first permanent molar.

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After bone debility was induced in three-week-old male rats of the Wistar strain, the rats were treated by a method combined with high calcium food and a physiologic active substance and the effect on the mandibular condyle was investigated with a scanning electron microscope.
The results were as follows:
1. The cartilage layer in the calcium-deficient food group as compared with the control group showed calcospherites fused to the matrix in the cartilage lacuna. The cartilage lacuna wall however showed many sparse portions, and unclear portions in each cartilage lacuna segment increased. In the calcium-deficient food + high calcium food group, the cartilage layer became thinner and in the ECT combined treatment group, clear portions of the segments of the cartilage lacuna increased and cord-like portions increased on the cartilage lacuna wall.
2. In the trabecula in the calcium-deficient food group, bone resorption images increased and the openings unclear in contour of the bone tubules increased. In the ECT combined treatment group as compared with the calcium-deficient food + high calcium food group, the matrix in the area surrounding the bone tubule showed increase in the appearance of collagen fibrils running in a fixed direction. Many openings of bone tubules were observed on the cartilage lacuna wall.

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Study on the maxillofacial growth by means of chronological age and cephalgrams was investigated in 483 children (217 of male,266 of female) from 2.5 to 10.5years of age who visited the pedodontic clinic of Fukuoka Dental College.
In the present study, the maxillofacial growth of children was evaluated by measuring the distance and angle in cephalograms based on the chronological age which was classified in to 8-categories. The following results were obtained:
1. The maxillofacial growth of children was more developed in depth than in height.
2. In the observation of the growth in height, the growth rate increased from 4to 6 years of age. Also, those changes showed earlier in the females than in the males.
3. Compared with the change of growth, a greater growth rate was shown in height than in depth.
4. Compared with quantitative measuring results of males and females, the former showed a higher value than in the latter. This tendency was strong in the measuring results concerning height.
5. In comparison to the study that has reported about 30 years ago, it was shown that the mandibular angle expanded. Also, these results were observed as a general tendency in females.

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Interproximal caries in the primary teeth are routinely revealed with bitewing radiographs. However, overexposure of radiation is not desirable. In order to reduce radiation exposure, dental floss is used as an alternative for caries detection.
The relationship between the results of the examination with bitewing radiographs and dental floss was studied. The results of bitewing radiograph examinations were classified by three examiners into four stages: caries-free, doubtfull, enamel carious and enamel-dentin carious. The results of the dental floss examinations were classified by one examinar without seeing the radiographs into three stages of feelings of surface roughness: smooth, rough and floss cut. These two results were compared and the caries detection ability was evaluted.
1) The percentage of coincidence with the results of the two kinds of examination was 67.1%∼94.3%, depending on the carious teeth.
2) Interproximal between the 1st and 2nd deciduous molars, most of the cases that were felt to be rough or floss cut with dental floss, revealed enamel or enamel dentin caries. However half or a third of the cases that was felt to be smooth with dental floss, revealed enamel or enamel dentin caries.
3) To aid bitewing radiographs, dental floss can be used to examinate interproximal caries in the primary teeth.

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The aim of this study was to examine the diagnostic effectiveness of frontal section FCR on TMJ for adolescent patients with TMJ dysfunction syndrome. The diagnostic effectiveness of frontal section FCR was examined by comparison with a diagnosis by means of sagittal section FCR.
The following results were obtained:
1. The condyle position in fossa and the morphological abnormality of the condyle could be diagnosed by frontal section FCR while a location of the articular disk could not be diagnosed.
2. In the comparison between the diagnosis by frontal section FCR and by sagittal section FCR, the concurrence of the vertical position of the condyle in fossa was 84.2% and the concurrence of prevalence on morphological abnormality of condyle was 81.6%.
It is suggested that the diagnosis of TMJ by FCR could be sufficiently done by only sagittal section FCR.

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We had two cases of 7-year-3-month and 8-year-4-month old girls who had inflammatory follicular cysts and malposition of left lower second premolars which were associated with chronic apical periodontitis of the preceding deciduous teeth. In case 1, nine months after root canal filling with Vitapex, there was an unclearly demarcated swelling of the alveolar bone ranging from the apical region of the left lower second deciduous molar to the mucobuccal fold. X-ray examination showed radiolucent findings of root resorption at the left lower second deciduous molar involving the crown of the left lower second premolar, with the resorption of Vitapex.
In case 2, seven months after root canal filling with Vitapex, there was a swelling with the size of the tip of the thumb in the buccal alveolar bone region of the left lower second deciduous molar, which showed a similar finding to case 1 in the X-ray examination.
For treatment of the two cases, tooth extraction of the deciduous precessors and marsupialization were carried out. Space maintenance for the premolars which were abnormally positioned, led to their normal position.
These cases indicated that periodic radiographic evaluation following pulpal therapy, especially in infected root canal treatment of deciduous molars, was very important to avoid the development of inflammatory follicular cysts involving the developing permanent tooth bud.

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Application of pit and fissure resin sealant has been widely used as a caries preventive measure, particularly in pediatric dental practice. A light cured fluoride slow releasing sealant (Teethmate-F) which contains about 1wt% fluoride ions, provides not only mechanical protection of caries susceptible pits and fissures, but also enhances the acid-resistanse of the adjacent area of the surface enamel, by supplying fluoride ions slowly released from the sealant by hydrolysis. The sealant was applied to 50 permanent molars and premolars of 25 children and evaluated clinically regarding the rates of sealant retention as well as the caries prevention in these teeth after 1-year-3-month observation. The retention rates of this sealant was 78.0%, whereas the rates of the detected carious lesion was 2.0%.

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The Ellis-van Creveld syndrome is characterised by chondrodysplasia, ectodermal dysplasia, postaxial polydactyly of bilateral hands, and congenital heart disease.
The patient was a 3-year 6-month old boy. Dwarfism due to shortening of the extremities and bilateral postaxial polydactyly of the hands were found at birth, and he was diagnosed as having the Ellis-van Creveld syndrome when he was 2-month old. He was born by incest between his mother and “her father”. He had no congenital heart disease.
In this paper, we report especially with respect to his oral findings.
1) A failure in fusion was found in the middle portion of the mandibular bone.
2) Because of the direct connection of the upper lip to the gingiva and numerous buccal frenums, the mucobuccal fold was narrow in the anterior region.
3) Congenitally missing teeth and a serrated alveolar ridge were found in the maxillary and mandibular anterior regions.
4) The shapes of crown, root, and pulp chamber of all the primary teeth were malformed. The primary canines were peg shaped, while the primary molars were small and malformed. The maxillary first and second primary molars and the mandibular first primary molars had single roots, and the mandibular second primary molars showed taurodont teeth.

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Observatory study was carried out on the 16 cases diagnosed as having dentigerous cysts of the permanent teeth in children from 4 years 10 months to 14years 10 months old with a mean age of 10 years. The patients were 11 boys and 5 girls. Most of the cases were detected by gingival and mandibular bone swelling not accompared by pain or during the recall check-ups without any subjective symptoms. These cysts were observed most frequently in the lower premolars.
Pulp and/or restorative treatment was performed on all of the primary predecessors. Moreover, in most of the cases, where the history of these treatments were known, the cystic change occurred from 3 to 6 years after treatment. This result apparently indicates the importance of follow-up observation after the caries treatment.
Before the extraction of the primary teeth and the marsupialization of the cysts, examination of the dentition and occlusion was performed from the occlusal guidance view point. According to the result of the examination, the treatment plan was setup and the cases were assigned to each of three groups as follows;
I. Cases where natural eruption was expected.
II. Cases needing space maintenance.
III. Cases needing active occlusal guidance (space gaining or regaining).
In the all of the cases, except 2 cases which are still under observation and one case which was reffered to an orthodontist, the patients had no trouble with the cysts and the unerupted permanent teeth were successfully guided into the regular position with the dental arch.

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Ciclosporin (CYA), originally termed “Cyclosporin A”, is a powerful immunosuppressant used in organ transplant procedures for preventing rejection. One of the side effects of this drug is gingival hyperplasia. This study was designed to investigate the side effects of CYA on the periodontal tissue of Japanese pediatric patients following liver transplantation. The experimental group contained nine children between 2 to 14 years of age, with a mean age of 6.10 years. The control group contained eleven healthy children randomly selected with a mean age of 7.0 years.
The CYA group showed statistically significant increases in probing pocket depth, gingival index and the severity of gingival hyperplasia. There were no significant differences in plaque index and calculus index between the CYA group and the control group. The relationship between the five dental factors (probing pocket depth, gingival index, plaque index, calculus index and the severity of gingival hyperplasia) and the three CYA factors (trough level with CYCLO-Trac technique, oral dose and the days after transplantation) were estimated. There was no signifficant correlation between any of the CYA factors and any of the dental factors measured.

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