The purpose of this study was to investigate the influence of the thermal cycling test on the adhesion of the resin on the ground primary 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 37% 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 spra y after etching. The bonding agent and composite resin used in this study (Silux group) were Scotch Bond and Silux (3M Co. ). After thermal cycling tests consisting of water baths with 10,000 temparature cycles between 60°C and 4°C, shear bond strengths on the ground enamel were measured. The results of this study were compared with the previous results of the Silux nonthermal cycled group and the PCA thermal cycled group. In the PCA groups, Photo Bond and Photo Clearfil A (Kuraray Co. ) were used.
The following conclusions were obtained.
1) The etching time which showed the highest bond strength was 60 seconds (63.61±19.64MPa).
2) The bond strength without etching was significantly lower than those with 20,30 and 60 seconds of etching time.
3) The bond strength with 10 seconds of etching time was significantly lower than those with 20,30 and 60 seconds of etching time.
4) In the 10 and 20 second etching groups of the Silux groups, the bond strengths of the thermal cycled group were significantly lower than those of the nonthermal cycled group.
5) In the 10 and 30 second etching groups of the Silux thermal cycled group and the PCA thermal cycled group, the bond strengths of the PCA group were significantly higher than those of the Silux group.

View full abstract

It is known that caries or white spots are caused by wearing removable orthodontic appliances. Fluoride (F)-releasing resin applied on the surface of these appliances can reduce the caries of teeth in contact with such appliances.
The purpose of this study was to determine the F concentrations of the saliva and enamel acquired from patients who wore orthodontic appliances using F releasing resin.
The F-releasing resin applied was Teethmate F (TF, Kuraray, Japan). Eighteen children wore orthodontic appliances using TF.
Four upper deciduous canies were extracted from 4 patients for orthodontic treatment more than 30 days after starting to wear the appliances. F concentrations in the lingual sites of those teeth were determined by the etching method.
Two ml of whole saliva were collected from 14 patients before and after wearing the appliances.
The following results were obtained.
1) The amount of F released from the appliances during the first 24 hours after immersion in distilled water was in general related to the weight of the TF used.
2) F concentrations in the saliva collected from patients who wore the appliances using more than 400 mg of TF at the 6.5th day were higher than those concentrations in saliva collected before wearing the fluoridated appliances. However, those saliva samples collected at the 34.8th day were not different from the saliva samples obtained before wearing the fluoridated appliances. In the case of patients who wore the appliances using less than 400 mg of TF, F concentrations in saliva collected at the 6.4th and 31.3rd day were not different from the concentrations in saliva before the use of fluoridated appliances.
3) The F concentration of the enamel which was in contact with TF was not different from the concentration level of the control group.

View full abstract

The purpose of this research was to investigate the influence of the severity of the impairment (we used the number of the duplication of diseases as the severity)on the dental caries incidence, the plaque control, the frequency of toothbrushing a day, the form of foods, the method to drink, the neck control, the level of motor development and so on.
The subjects were 457 they were commuting to our center (1 to 7 years of age). We divided them into 3 groups. The group S they had only one disease were 238, the group D they had double diseases were 156, and the group P they had 3 or more diseases were 63.
The results were as follows:
1) The number of the duplication of the diseases was remarkably related to the neck control and the level of motor development.
2) The form of foods and the method to drink were related to the number of the duplication of the diseases.
3) The severity of the dental caries incidence was related to the number of the duplication of the diseases.
4) The frequency of the eating between meals of the group P was decreased more than another 2 groups. On the contorary, the per cent of the person who used to drink before bedtime of the group P was increased more than another groups.

View full abstract

The use of composite resins in dental therapy has increased in recent years. In composite resin restoration, biological problems have been associated with pulpal lesions. It has been demonstrated that the pulpal lesions are the results of pulpal irritation induced by residual monomers and/or marginal leakage.
The amounts of the residual monomers (bis-GMA and tri-EDMA) remaining in three kinds of composite resins were investigated using HPLC. After polyethylene tubes (9.0mm×2.0mm inner diameter) were filled with three commercial composite resins, they were photopolymerized with four visible-likht units. The residual monomers were extracted from the cured resins with methanol and analyzed with a HPLC column, Nucleosil 5C18 (15.0cm×4.5mm inner diameter). The residual monomers remaining in the cured resins had a tendency to depend on the intensity of the visible-light sources. The ranges of the residual monomers were from 5.5 to 21.3 wt% for bis-GMA and from 0 to 26.4 wt% for tri-EDMA. The results suggest that the intensity of the visible-light source on the photopolymerization of light-cured composite resins is important.

View full abstract

The arrangement of deciduous and permanent central incisors was observed and classified using serially recorded material while subjects whose arrangement was consistent in both stages were examined with respect to tooth, dental arch and apical base morphology. The following results were obtained.
1. In the deciduous dentition, linear arrangement of the lateral incisors was most frequent in the upper jaw, while in the lower jaw a wing-like arrangement was most frequent. In the permanent dentition, the most frequent arrangement of the central incisors was the inverted wing-type in the upper jaw and the wingtype in the lower jaw, accounting for more than 50%.
2. Studies of tooth, dental arch and apical base morphology according to arrangement of the central incisors revealed differences in the rotation of the central incisors and the size of the lateral incisors in the upper jaw. The size of the maxillary lateral incisors, in particular, appeared to be closely related to winging of the central incisors.
3. Arrangement of deciduous central incisors consistent with that of the permanent central incisors amounted to 34.3% in the case of the upper jaw and 51.4%in the case of the lower jaw, demonstrating greater consistency in the lower jaw. In terms of type of arragnement, the highest rate of consistency was found in the case of type C in the upper jaw and type A in the lower jaw.
4. Subjects with consistent arrangements tended to have greater rotation of both the deciduous and permanent central incisors of the upper jaw and a shorter long-diameter of the dental arch between the deciduous canies.
5. In subjects with consistent arrangement in the upper jaw, there was a high correlation between the deciduous and permanent dentition, particulary with with respect to the width of the dental arch and apical base.

View full abstract

In an attempt to predict permanent dentition on the basis of deciduous dentition, serial dental casts (upper jaw) of deciduous and permanent dentition were obtained from subjects whose deciduous dentition with normal occlusion proceeded to permanent dentition with norma locclusion and those who developed angle I grade malocclusion after deciduous dentition with normal occlusion. Morphological features of the palates of these subjects were examined using moire topography, and the following results were obtained.
1. There were no differences in palate width between the normal occlusion group and the malocclusion group.
2. Palate length at the deciduous canies and first molars and at the permanent second premolars was shorter in the malocclusion group than in the normal occlusion group.
3. Palate height at the deciduous canies was smaller in the malocclusion group than in the normal occlusion group.
4. Palate volume anterior to the permanent canies was smaller in the malocclusion group than in the normal occlusion group.
5. The above findings indicate that the difference between subjects with normal occlusion and malocclusion of their permanent dentition is in the morphology of their palates, particularly in the anterior portion of the palate at the time of their deciduous dentition, and that those who develop malocclusion of their permanent dentition tend to have short and shallow anterior palates. These findings may provide Important information for occlusal guidance.

View full abstract

A new objective method for determining the condyle position with respect to the mandibular fossa in accordance with Blaschke's method is presented in this report. By this method it is possible to determine the position of the condyle with respect to the mandibular fossa not only before and behind but also up and down. Furthermore, by this method it is possible to express the position of condyle with respect to the fossa by XY corodinates.
The reproducibility of this new method was examined by using seventy FCR images of temporomandibular joints of thirty five patients at puberty with ternporomandibular joint dysfunction syndrome. Also high reproducibility was found in regard to the new method in accordance with Blaschek's method. The reproducibility of expression by the XY coordinates for the condyle position with respect to the fossa was found under consideration of the average of standard deviation.
The standard value for determing condyle position with respect to the mandibular fossa at the intercuspal position is presented.

View full abstract

Three-week-old male rats of the Wistar strain at the growth stage were given calcium-deficient food and bone debility was induced inthem. For debilitated mandibular condyles, calcitonin, a physiologic active substance, and an active type vitamin D³ were administered in combination at the same time. A cytological investigation was made on the ocrrelation with the mechanism of effect.
The results were as follows:
1. Osteoblasts showed an increasing tendency as compared with the calciumdeficient food group. Organelle in cells were well-developed. Inter-cellular distance were extended in places and collagen fibrils were observed markedly.
2. Among osteocytes, there were few matured types. There were many middle types between the young and matured types. Moreover, osteocytes with the peculiar morphology found in the deep portion in the calcium-deficient good group were hardly observed.
3. Osteoclasts showed a decreasing tendency as compared with the calciumdeficient food group. There were many separated from the bone surface and their ruffled borders showed applanation and active bone resorption was restrained.
4. A large number of young osteoblasts or osteoclast-like polynuclear cells formed many clusters and portions with cells not sufficiently matured were found large numbers. On the basis of the foregoing findings, it is suggested that ECT and VD3 are auxiliary in bone construction and that their combined administration with calcium is essential for recovery from bone debility.

View full abstract

We studied the relationship between interdental spaces in deciduous dentition and arrangement of permanent dentition. We used 28 subjects whose deciduous dentition had been observed annually and had become permanent dentition, classifying them according to the total volume of interdental space in their deciduous dentition into Type I (spaced type), Type II (normal type) and Type III (closed type). Changes in deciduous dentition were compared among the three types. The results obtained were as follows:
1. Type I subjects exhibited no differences in dental arch, basal arch length (A-M1), or basal arch width (d-d) in either their maxillary or mandibular deciduous dentition or permanent dentition. The total volume of space and the degree of discrepancy decreased when the teeth became permanent in Type I patients. Type II patients displayed findings similar to those in the Type I cases in both maxillary and mandibular dentition. In Type III patients, the length of the anterior basal arch was shortened in both the maxillary and mandibular permanent dentition.
2. The volume of space in the deciduous dentition of the Type I cases decreased more in the maxillary dentition. There was a decrease in the Type II cases in the mandibular dentition, and a slight increase in the Type III cases.
3. There was a significant difference in the mandibular Leeway space in all three types, but no significant difference among them in maxillary Leeway space.
4. As far as the relationship between the individual types of deciduous dentition and the arrangement of the permanent dentition is concerned, maxillary arrangement was normal in 75% of the Type I cases,64.3% of the Type II cases and 50% of the Type III cases, and mandibular arrangement was normal in 80% of the Type I cases,92% of the Type II cases, and all the Type III cases.
5. When Type I and the normal group were compared with respect to the maxilla, dental arches and basal arches were found to be similar in each case. Dental arches and bassal arches of maloculusion groups are similar in shape to Type III.
6. Total volume of space in the deciduous dentition appears to be related to the development of the maxillary into normal permanent dentition. Volume of Leeway space appears to be related to the normal permanent dentition of the mandible.

View full abstract

A new dental anxiety questionnaire was designed with the purpose of the screening of fearful children in dentistry. There ware two kinds of questionnaire, one for parents and the other for children. The questionnaires were answered by the parents. For the evaluation of the questionnaire, the following studies were carried out; first, concerning the reliability and validity of the questionnaire and secondly the relationship between the degree of dental anxiety and the dental caries experience, and thirdly the relationship between the degree of dental anxiety and the behavior during dental treatment. The following results were obtained:
1. High reliability and adequate validity were found, according to Cronbach's α coefficient and multivariate analysis.
2. It is possible that a child's anxiety was the consequence of the mother's anxiety and their own dental experience and that there was a relationship between the child's anxiety and the clinical aspect of the oral cavity.
3. Heart rate increased with the degree of dental anxiety. Skin temperature also increased, especially in the high fear group, and it was also possible to see the signs of anxiety, especially in hands and foot, in the high fear group.
The results suggested that this new questionnaire was effective for measuring the degree of dental anxiety and for screening of fearful children in dentistry.

View full abstract

Many caries activity tests have been developed with the goal of identifying and understanding individual oral conditions. The purpose of this study was to examine the validity of the caries activity test“CARIOSTAT”as a screening method for approximal caries on the primary teeth. The subjects were 58 children (mean 4.3y: range 6-8 yeard-olds) and their oral cavities were examined by the usual visual method. Also X-ray examinations were used diagnosis of approximal caries. The approximal dental plaque was sampled with commercial dental floss from visually sound approximal surfaces. The plaque sample was put into the CARIOSTAT medium and incubated at 37°C,48h. Caries activity was evaluated according to CARIOSTAT score 0-3. p. The results were as follows: (1) The patterns of caries prevalence and caries activity of the approximal surfaces on the primary teeth were similar. (2) The caries activity of carious surfaces was higher than that of carious free surfaces. (3) Higher CARIOSTAT score of the aprpoximal surfaces indicated, more caries prevalence of the approximal surfaces. (4)The maximum screening value of CARIOSTAT changed by the children's age. Conclusion: Caries activity tests CARIOSTAT indicated, high validity for the screening method of approximal caries on the primary teeth.

View full abstract

FluoroBond^TM is one kind of fluoride releasing, visible light-activated bonding system for orthodontic bracket placement. The first aim of this study was to demonstrate the fluoride uptake by the human enamel adjacent to the bracket as well as by the human enamel beneath the bracket which was placed using FluoroBond. The second aim of this study was to investigate the acid solubility, of the human enamel in contact with FluoroBond for 30 days. The third aim of this study was to examine the teeth which produced artificial caries-like lesions after the attaching of the bracket using FluoroBond for 30 days in vitro.
The following results were obtained:
1. When FluoroBond was used as a bracket bonding material, fluoride was absorbed from FluoroBond by the enamel not only under the bracket but also adjacent to the bracket.
2. The acid solubility of the enamel was reduced by contact with FluoroBond. The reduction rate of 48 hours dissolution was 42.0%.
3. FluoroBond reduced the extend of demineralization adjacent to the bracket as well as beneath the bracket.

View full abstract

This study was carried out to clarify the relation between the age of individuals with or without gingivitis and their serum antibody levels against Porphyromonas gingivalis and Fusobacterium nucleatum and to examine the correlation between serum antibody titers to those microorganisms and their infection in the periodontal region. Forty patients with gingivitis and age matched control were used as subjects. Ten patients with adult periodontitis were also used as subjects. Blood samples were obtained from those individuals. Five groups were investigated from early childhood, school age, puberty, adult, adult periodontitis group. Serum IgG and IgM antibody levels against P. gingivalis 381, F. nucleatum ATCC25586 were determined using a micro-enzyme-linked immunosorbent assay. An increased serum antibody level against P. gingivalis in the school age group with gingivitis and a marked increase in the puberty group with gingivitis were found. The mean IgG level of 6970 EU in the puberty group with gingivitis was almost the same as that of the adult group with gingivitis and was approximately 1/20 that of the adult periodontitis group. The changes of the IgM antibody with age did not follow a pattern distinct from that for IgG. The mean level of IgM antibodies in the puberty group with gingivitis was significantly higher than that in the school age group with gingivitis and the adult groups with gingivitis and periodontitis. No significant difference in serum antibody level against F. nucleatum was noted among the puberty group with gingivitis, and the adult groups with gingivitis and periodontitis. A positive correlation was found between serum IgG antibody titers to P. gingivalis and the viable cell count of the microorganisms in the puberty group, and the adult group, while no correlation was found in the other groups. In all groups except the puberty group, no correlation was found between serum IgG antibody titers to F. nucleatum and viable cell cound numbers of the microorganism in the tested periodontal regions. In all groups, no correlation between serum IgM antibody titers against P. gingivalis and F. nucleatum and viable cell count numbers of those microorganisms in the tested periodontal regions was found.

View full abstract

The purpose of this overall study was to investigate changes in muscle fiber conduction velocity (MFCV) and EMG power spectrum patterns in the masseter and biceps brachii muscles in children.
A total of 35 subjects who had no gnatho-facial dysfunction were the subjects in the study. The subjects were divided into four groups: 5 primary dentition (designated as G1),5 early mixed dentition (as G2),5 late mixed dentition (as G3)and 20 permanent dentition (as G4,10 females and 10 males). EMG activities were recorded from the m. biceps brachii with the arm bent at right angles and the masseter muscle in the intercuspal position during 50% of maximum voluntary contraction (MVC). Contraction levels of 10,25,50,100% MVC were also observed in 10 of the G4. EMGs recorded using the strip type surface electrodes array, in straight arrangement, were analyzed by fast fourie transformation. Four parameters were analyzed; MFCV, frequency of maximum peak (peak frequency), frequency range and strength of maximum peak (peak magnitude).
The results obtained in the present studies were summarized as follows;
1) There were no differences in MFCV at G4 between sexes, whereas the MFCV was significantly faster (p<0.01) in the masseter muscles (12.44±1.93m/s)than the biceps brachii (4.48±0.66m/s).
2) As the contraction level rose, the MFCV, peak magnitude and frequency range increased significantly in each muscle (p<0.01).
3) In the MFCV at G4 was significantly faster (p<0.05) than G1 in the masseter muscles, and those differences between each groups were clarified with the development.
As aforementioned, change of MFCV may be due to the differences of proportion of the muscle fiber types such as fast twitch and slow twitch fiber with development.

View full abstract

In the present study, sucking movements of human infants with special interest in the participation and coordination of various masticatory muscles were evaluated.
Two,4 and 5 month old age healthy infants, were the subjects. Muscle activities were examined by surface electromyography from the anterior belly of the temporal muscle, masseter muscle, orbicularis oris muscle, and suprahyoid muscles unilaterally. The sucking pressure (sucking waves) was recorded simultaneously using a feeding bottle specially devised at our department, and the movement of mandibular of the infants during feeding was recorded on video tape.
The following results were obtained:
1) The sucking wave could be divided into the squeezing, aspiration, and deglutition phases, and the deglutition phase appeared after 2-4 simple sucking cycles of positive and negative pressures.
2) During the squeezing phase, the action of the orbicularis oris muscle was followed by those of the masseter muscle and the temporal muscle. In the aspiration phase, the orbicularis oris muscle and suprahyoid muscles were active. During deglutition, primarily the orbicularis oris muscle and suprahyoid muscles acted with coordinated movement also of the masseter muscle.
3) The jaw shifted supra-anteriorly during the squeezing phase and infero-posteriorly during the aspiration phase.
These findings suggest that sucking movements consists of a complex series of the movements of squeezing of milk, aspiration, and deglutition, which are accomplished by coordination of the muscles around the mouth. Also, the orbicularis oris muscle and suprahyoid muscles are considered to play primary roles in sucking.

View full abstract

To study differences among mice strains, we investigated the development of caries on hydroxyapatite (HA) disks covered with saliva from inbred mice. Differences by strain were observed by measuring the effects of surcose independent mutans streptococci on the somatic adhesion reaction.
1) There were no difference among C3H/He, BALB/c and C57BL/10 mice, which had different biochemical genetic markers, in somatic adhesion to HA disks covered saliva.
2) In these caries experiments, C57BL/10 and BALB/c showed caries susceptibility, while C3H/He was caries resistant. We reconfirmed differences among strains in development of dental caries.

View full abstract

Employing a microphone especially contructed for the purpose, we recorded occulusal sound from 158 subjects. Thirty recordings were made per subject with instructions to the subjects given by tooth tapping. As a matter of course, a general dental examination as well as investigation for occlusal abnormality was given to each subject. Clear occlusal sound was collected from 130 of the subjects. The waveform changes due to the presence of malocclusion were studied with attention given to the general shape of the wave, as well as the duration and the maximum amplitude of the sound.
The results were:
1) In deciduous dention, a sliding sound was predominant in both abnormal and normal occlusion groups. The incidence of the impact sound increased from III B to IV A after which the radio of the sounds reversed.
2) The incidence of impact sound was higher in normal occlusion for whole dentition groups.
3) Among subjects with normal occlusion, there was no significant difference between the left and right side nor dentition and maximum amplitude in accordance with maturation of dentition.
4) The variation in maximum amplitude was greater than that in duration between subjects and groups.
5) There was no significant difference in maximum amplitude between the normal and abnormal groups.
6) The duration of occlusal sound was significantly greater in the abnormal group.

View full abstract

In order to study how fused and congenital missing deciduous teeth affect the dental arch forms, we conducted measurements of distances in various ways. We also conducted investigations by applying the 3rd Spline function and by highspeed Fourier analysis. As a result we were able to grasp the characteristics of dental arch forms, and we reached some interesting conclusions.
The samples used in this study were:
(1) Abnormal Dental Arch Group: Dental plaster models taken from 42infants in Hellman's dental age IIA with fused teeth and congenital missing teeth on one side of the mandible (30 of this group had fused teeth and 12 had missing teeth) and
(2) Normal Dental Arch Group: Dental plaster models taken from 56 infants with normal occlusion in contrast to Group (1).
The conclusions we reached were as follows:
1. The dental arch width of the abnormal group was significantly smaller than that of the normal group, both being measured between the canines and the primary and secondary molars. The dental arch length of the abnormal group was significantly smaller than that of the normal group, both being measured between the incisors and canines in the mandible and also between the incisors and the secondary molars, while in the maxilla, the value was significantly smaller between the incisors and canines. The dental arch height of the abnormal group was significantly smaller than that of the normal group.
2. Regarding over bite, or over jet, the value was significantly greater for the abnormal group, those with fused teeth, than for the normal group.
3. The primate space of the abnormal group was significantly larger than that of the normal group in the mandible. The value was particularly great for those with missing teeth.
4. The sum total of the interdental space in the abnormal group was significantly greater than that in the normal group in the mandible. This tendency was most apparent in those with missing teeth.
5. The section with the greatest projection on the labial and buccal sides on the average curve of the dental arch for both the normal and abnormal groups corresponds to the section between the incisors of the maxilla of the normal group, while in the case of abnormal groups the section corresponds to that 185between the secondary molars on both sides. This indicates an existence of a formative difference in the two groups.
6. When the dental arch curve of the abnormal group was placed on the average dental arch curve of the normal group, the type with two crossings had the highest frequency.
7. The results of high-speed Fourier analysis showed that up to 4 Hz constituent waves had comparatively high contribution ratios.

View full abstract

Recently, monoclonal antibodies (MAbs) have been shown to be valuable for the identification of bacterial types and to be useful for the analysis of their antigenic components, as well as providing structural information concerning their immunodeterminants. Unfortunately, it is generally observed that many MAbs either lack or have only poor antigen-precipitation properties when used as reagents in gel or solution. The introduction of enzyme immunoassay (ETA) procedures has made it possible to study primary antigen-antibody reactions rather than secondary interactions such as the precipition reaction.
The present study aimed at developing a new caries activity test using enzyme immunoassay procedures with monoclonal antibodies.
At first, the monoclonal antibody f-89 was prepared and the specificity of it against various strains of oral streptococci was measured. Secondly, S. mutans standard samples and plaque samples which were collected from 98 children aged 2 to 5 years old were analyzed using the enzyme immunoassay system with MAbf89193and counted the colony forming unit. The plaque samples were also tested using MSBB and Cariostat tests. The dmf teeth in the children were counted.
Results were as follows:
1) MAbf89 had markedly high specificity against S. mutans (serotype c, e, f)and no cross reaction against other oral streptococci.
2) In the S. mutans standard samples, there was a high positive correlation between the optical density (O. D. ) using the EIA system and the colony forming unit (CFU) using the brain heart infusion plate. The limits of detection were about 5×10⁴ CFU/ml.
3) In the plaque samples, there was a high positive correlation between the O. D. using the EIA system and the CFU using the immunostain method.
4) In the plaque samples, there was a positive correlation between the O. D. using the EIA system and the pH using Cariostat test and between the O. D. and the score using the MSBB test, respectively.
5) In the plaque samples, there were significant differences between the scores using the EIA system, Cariostat test or MSBB test and the dmf teeth, respectively.
This EIA system with monoclonal antibodies requires only one and a half hours. Based on the results above mentioned, the enzyme immunoassay system with monoclonal antibody f-89 was considered to become, after some improvement, very useful as a caries activity test.

View full abstract

The purpose of this study was to investigate the actual condition at the first visit of 1,000 patients (498 boys and 502 girls) who visited the Shinagawa Pedodontic Office from June 1987 to August 1988.
The results were as follows.
1) The distribution of the patients ages was from 0 year to 14 years and the average ages were 4 years 4 months.
2) The chief complains were caries decayed teeth (60.3%), tooth pain (14.3%), fluoride application (10.2%), malocclusion (5.0%), examination (4.1%), T. B. I. (2.0%), trauma (1.6%), Sealant (0.6%) and others (0.5%).
3) The tooth anomalies were fused teeth (3.6%), missing teeth (1.9%), hypocalcification (1.8%), supernumerary teeth (1.6%), colored teeth (1.0%), micro teeth (0.8%) and others (0.5%).
4) The oral habits were finger sucking (42.7%), bruxism (25.7%), nail biting (15.8%), lip biting (5.8%), tongue habit (4.1%), mouth breathing (3.2%)and others (2.6%).
5) The anomalies of dentition on the occlusion were over jet (23.4%), anterior cross bite (16.7%), open bite (14.4%), lower crowding (10.7%), cross bite bite of 1 or 2 teeth (7.9%), edge to edge bite (7.4%), upper and lower crowding (5.6%), over bite (5.3%), posterior cross bite (2.3%) and others (6.3%).

View full abstract

We experienced a case of solitary bone cyst in the right mandibular ramus of a boy,14 years old.
The results were as follows:
1. The case showed a multilocular radiolucent image with indistinct borders extensively in the mandibular ramus and bone screlosis around the lesion.
2. Biopsy was performed and the course was observed. Radiograms four months after the operation showed disappearance of the radiolucency of the lesion. Eighteen months after the operation, findings of apposition of new trabeculae were seen and about the same findings as those of the healthy side were seen.
3. The present case where occurrence was in the mandibular ramus and healing was by biopsy is an extremely rare case with respect to the site of occurrence, mechanism of healing, and course, as compared with cases in the past.

View full abstract

We found a supernumerary primary tooth in the maxillary left primary canine region and geminated tooth in the maxillary right primary canine region in a 3year 9-month old boy. We reported the result of his oral findings, analysis of the plaster cast, radiographic findings and a survey of the literature was done.
1. This was a rare case that had a supernumerary primary tooth in the maxillary left primary canine region and geminated tooth in the maxillary right primary canine region.
2. Two teeth in the maxillary left primary canine were judged as normal primary canine and supernumerary primary teeth based on shape, color, size, eruption form and pulp cavity form.
3. The maxillary right primary canine was very similar to the normal primary canine in shape, with a wider mesio-distal width and a fissure on the lungual surface was observed, which is usually seen in fused teeth. Also this tooth was judged as a geminated tooth based on radiographic findings.
4. A succedaneous tooth of the supernumerary primary teeth was not found and also there ware no anomalies in the succedaneous tooth of the geminated teeth.5. No obvious theory of cause was established in this case, but it might be considered that the cause of this case report was complete or incomplete separation of the tooth germ.

View full abstract

Some factors to decide the dental treatment plan for gingival hyperplasia by DPH was examined through two handicapped patients with gingival hyperplisia.
The result obtained were as follows:
1. Case 1 was a male,18 years and 8 months old. Gingivectomy was done under general anesthesia after confirmed a good capacity for plaque control at the institution by hyginist. The recurrent ginginal hyperplasia after the operation was not observed. The reasons which gingivectomy was done were the suppression of tongue function and inferior breathing function by gingival hyperplasia. These problems were improved after the operation. And maloclusion was improved by gingivectomy, a significant relationship between a degree of gingival hyperplasia and an improvement degree of malocclusion was observed.
2. Case 2 was a female,23 years old. Gingivectomy was done under general anesthesia after confirmed a good capacity for plaque control at the institution by the nurse. The recurrent gingival hyperplasia after the operation was not observed. The reasons which gingivectomy was done were poor appetite and anemic tendency by continuously slight bleeding hyperplastic gingival with inflamation. These systemic problems were improved after the operation.
3. On the above all, it was suggested that the factor for deciding gingivectomy were not only the ability of plaque control but also the systemic influence of gingival hyperplasia. The prediction of improvement degree of malocclusion by gingivectomy is possible, the improvement of malocclusion was important for a improvement of oral disfunction by gingival hyperplasia.

View full abstract

A cidophilic granuloma is a granulomatic lesion of infiltration by acidophilic cells, mainly proliferation of histocyte in the reticuloendothelial system. The symptom is termed as histiocytosis X, a subtype of one type of a disease such as the Letterer-Siwe's disease and the Hand-Shuller-Christian's disease. It is frequently found in older children. Also it is frequently seen in the jaw, and when the granuloma is caused in the jaw, such periodonto-inflammatory responses are observed. The X-ray findings revealed a malignant tumor, and the finding is difficult to distinguish from other diseases. Pathohistological findings are the only mean of confirmative diangosis. The first choice of method of treatment may be different according to the degree and area of the granuloma. Prognosis is good in general, but in some cases, the granuloma will be transfered to other subtype(s)of the Histiocytosis X, be recurrent, or spread more from the primary focus.
The present clinical case was a 3 year and 5 month old girl, who visited us for the main complaint of swelling of the right cheek. A single acidophilic granuloma was found in the right lower jaw. Systemic, dental and clinical findings were examined. The following findings were obtained.
1) The primary symptom was similar to that of a symptom of infiamation, and the X-ray picture was similar to that of a malignant tumor, but it was not confirmed. Pathohistological findings showed histotype cells, and acidophilic megalocytes were found. Thus, acidophilic granulocyte was suspected and diagnosed.
2) Fractions of the peripheral blood picture were all within the normal range.
3) 5 years of a terminating chemotherapy, recurrence has not been observed, and thus the prognosis is good. However, permanent dental pulp was included in the primary focus, so that the first molar formation was insufficient.

View full abstract

Ectodermal dysplasia may be characterized by complete abscence of teeth, abscence of sweat glands and sparseness of hair.
We experienced the case of Twins who visited the Pedodontic Clinic of Kobe Children's Hospital and were diagnosed as ectodermal dysplasia.
The dental findings were as follows:
1) The case of the elder brother was diagnosed as a hidrotic type and the case of the younger brother was considered as the same type.
2) The elder brother had at the time teeth EA|AE and l|l the permanent tooth buds. The younger brother had at the time teeth A|A and El|lE tooth buds.
3) The erupted teeth were entirely peg teeth.
4) The mandible basal bone was flat as in the aged.
5) Roentgeno-cephalometric analysis revealed the poor development of the maxilla.

View full abstract

This report concerns a case of root resorption in the bilateral maxillary first permanent molars.
Patient: 15 year old girl
Chief complaint: spontaneous pain of the bilateral maxillary first permanent molars
X-ray findings:
(1) Impaction of bilateral permanent maxillary second premolars.
(2) Root resorption of bilateral permanent maxillary first molars.
Left side:: complete root resorption
Right side: Medial buccal root was resorpted completely. Palatal root was resorpted partially. Distal buccal root was not resorpted.
Treatment
Bilateral permanent maxillary first molars were extracted and the eruption of the bilateral permanent maxillary second premolars were induced.

View full abstract

A thirteen year eight month old male who complained of clicking while opening the mouth in the bilateral temporomandibular joints and stiffness in the shoulders was examined. He had no general anamnesis except bruxism during sleep at ten years of age and stiffness in the shoulders from eleven years of age to the present.
The findings at the first visit were as follows:
1) The upper left lateral incisor was peg shaped. Because of uneruption of the lower right first and second premolars, the lower right first and second molars were inclined mesially.
2) Panoramic roentgenograph showed congenital anodontia of the upper right lateral incisor and second premolar, and the upper and lower left second premolars. The lower right second premolar was impacted horizontally.
3) Examination with the T-Scan system showed the lack of a centric stop at the bilateral premolars, the displacement in intracuspal position posteriorly, and the cuspal interference at the bilateral molars during jaw movement frontally and laterally.
4) Temporomandibular joint tomograph showed the posterior displacement of bilateral condylar heads at the intracuspal position. Magnetic resonance imaging (MRI) showed the anterior displacement of bilateral disks at mouth closing getting back to normal position at the opening.
5) Electromyograph showed unstable mastication rhythm and the lack of cooperation between each muscle.
6) In the Yatabe-Guilford personality inventory, the patient was judged C'type (Normal). In the State-Trait Anxiety Inventory, both Anxiety State and Anxiety Trait were average.
The treatment was done with a stabilization splint and temporal occlusal reconstruction for the stabilization of the occlusion, temporomandibular joints and masticatory muscles.
About three months later, the frequency of clicking in the bilateral temporomandibular joints decreased remarkably, although the stiffness in the shoulders did not improve.
In adolescence, because of the drastic physical growth and changeable emotions, the detailed examination of the occlusion, temporomandibular joints, masticatory muscles and mental state should be done for diagnosis, treatment and decision for cure of the temporomandibular joint dysfunction syndrome. In particular, magnetic resonance imaging (MRI) is very useful.

View full abstract