School-Based oral health measures should be taken based on evaluation of risk factors of oral diseases. Hypothesizing for the analysis of the risk factors of dental caries or periodontal disease requires description of the changes in oral health conditions. Therefore we attempted a descriptive epidemiological study and observed the annual changes in conditions of teeth, gingiva, tooth deposits and orthodontic appliances in primary school children of girls school from 1994 to 2001 on the basis of the data on regular check-ups.
As a result, almost constant decreases were observed in annual rates of children with caries experience in their present teeth as well as in the annual rates of children with decayed teeth. There were few changes over the observation period in the rates of children with gingivitis and in the rates of children with plaque accumulation. The rates of children with dental calculus rose after 1998 and the accumulation were highly restricted to the lingual surface of lower anterior teeth. The annual rates of children who were wearing a fixed or removable orthodontic appliance or space maintainer after 1998 were lower than before 1997. Other factors besides plaque accumulation are considered to be connected to the decline in dental caries. As recent annual rates of school children with dental caries or gingivitis are becoming lower than ever, new comprehensive analyses are thought to be required with regard to the relationship between epidemiological factors and dental diseases.

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The objectives of this study were to study the remineralization effects on initial caries enamel lesions of xylitol chewing gum containing Gloiopeltis furcata extract (of which funoran is a main component)and calcium hydrogenphosphate (CaHPO₄⋅2H₂O) and of xylitol chewing gum containing phosphoryl-oligosaccharide calcium and to make comparative evaluations of the two.
Initial caries-like enamel lesions were prepared artificially by demineralizing human enamel blocks with a 0.01 M acetate buffer (pH 4.0) for 2 days at 50°C. In vitro investigation was performed by immersing these enamel blocks for 2 weeks at 37°C in a remineralizing solution (1.0 mM CaCl₂,0.6 mM KH₂PO₄ and 100 mM NaCl; pH 7.3 with KOH) containing extracts from each chewing gum. These enamel specimens were dehydrated and embedded in polyester resin, then prepared as enamel sections 100μm in thickness. Contact microradiographs (CMR) obtained from the ground sections were observed under an optical microscope. Remineralization degrees were calculated with a computer image analyzer. Remineralization rate(%) was calculated by assigning a value of 0% to initial caries-like enamel and a value of 100% to intact enamel. Student's t-test was used to analyze the degree of remineralization of each chewing gum.
The results were as follows:
Xylitol chewing gum containing Gloiopeltis furcata extract and calcium hydrogenphosphate dramatically enhanced remineralization throughout all layers in initial caries-like enamel lesions, whereas xylitol chewing gum containing phosphoryl-oligosaccharide calcium produced little remineralized. The remineralization rate of xylitol chewing gum containing Gloiopeltis furcata extract and calcium hydrogenphosphate was 45.5%; that of xylitol chewing gum containing phosphoryl-oligosaccharide calcium was 23.7%. The remineralization rate of xylitol chewing gum containing Gloiopeltis furcata extract and calcium hydrogenphosphate was approximately 1.9 times that of xylitol chewing gum containing phosphoryl-oligosaccharide calcium (p< 0.01).
These findings clearly show that xylitol chewing gum containing Gloiopeltis furcata extract and calcium hydrogenphosphate remineralizes initial caries-like enamel lesions more effectively than xylitol chewing gum containing phosphoryl-oligosaccharide calcium.

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The aim of this study was to clarify the recognition of the parents concerning the malocclusion of their own children in Hellman's 2A stage dentition. We investigated the denture/occlusion in children and the recognition of their parents concerning the malocclusion of their own children. Questionnaires on their denture/occlusion were given to their parents. The following results were obtained.
1. The percentage of children were diagnosed with malocclusion was 64.5%.
2. The ratio of parents worrying about the malocclusion of the child amounted to 32.3%, and the most frequent type of malocclusion causing parents to worry was extreme maxillary overjet and anterior open bite. Anterior malocclusion was comparatively easy for parents to recognize.
3. The parents were concerned about the expenses and the time the treatment would take.
4. The rate of concordance of a dentist and a guardian concerning malocclusion was low.

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Dental treatment under general anesthesia was performed on both disabled and young children, unable to obtain the compliance of dental treatment at the pediatric dental clinic of Tsurumi University Dental Hospital. The purpose of this survey was to investigate the recent actual status of dental treatment under general anesthesia at our clinic during the period from April,1997 to March,2002. These results were compared with the past two reports of our clinic.
The results are as follows:
1. Dental treatment under general anesthesia was performed on 85 patients (59 males and 26 females)during this period. The total number of cases was 96. The ages of the patients ranged from 7 months to 30 years, with an average age of 12 years 9 months. In comparison with past reports, the total number of cases decreased while the average age rose.
2. The majority of the reasons for general anesthesia was disability and the greater part of the disabilities involved mental retardation. This tended to be similar to past reports.
3. The total number of treated teeth was 1,031 (11.6 per case). Restoration was rendered most frequently among the primary teeth as well as the permanent teeth. Among the restorations, composite resin restoration was the most frequent procedure. In comparison with past reports, the frequency of restoration and the sealant application increased, whereas extraction and pulp treatment decreased.
4. The average treatment time and anesthetic time was 2 hours 13 minutes (from 21 minutes to 4hours 40 minutes) and 3 hours 9 minutes (from 50 minutes to 5 hours 28 minutes), respectively. In comparison with past reports, both of these times were longer.

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The purpose of this study was to examine the effects of lower infraocclusal first deciduous molars on the dental occlusal relationship. The occlusal relationship, length of the dental arch, width of the dental arch, and the occlusal curvature of lower dentition were discussed in accordance with Hellman's dental age using 29 study casts.
The results of this study were as follows:
I. Concerning the anterior occlusal relationship, the anterior crossbite was found to occur with high frequently.
2. Concerning the occlusal relationship of the first molars in materials of dental age III A and dental age III B, Angle's class III was the most common.3. For the dentition with lower infraocclusal first deciduous molars on both sides, the width of the dental arch between the second deciduous molars was small, and the length of the dental arch was large in both maxilla and mandible.4. The occlusal curvature of the dentition with lower infraocclusal first deciduous molars on both sides was larger than the standard value of the lower occlusal curvature of the normal occlusion.5. The occlusal curvature of the dentition when one side has no lower infraocclusal first deciduous molar was close to the standard value. On the other hand, the side with the infraocclusal first deciduous molar was larger than the standard value and dissymmetrical with respect to the side with the infraocclusal first deciduous molar.6. The subjects of dental age III A showed a larger curve than those of dental age II C, showing a tendency of toward infraocclusal first deciduous molars.

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The purpose of this research was to evaluate the effect of the salivary flow rate on fluoride retention in the mouth and to measure the site specificity of oral fluoride clearance when six healthy adults were awake and when they had been sleeping.
In the first experiment, the subjects rinsed their mouth with a 450 ppm fluoride solution at 2 pm and 0:00 am immediately prior to sleeping. The unstimulated salivary flow rate and salivary fluoride concentration were measured 15, 30, 60, 120 and 150 minutes after rinsing, while the same measurements were made at 6:30 am after the subjects had awakened. In the second experiment, ten mg of Naf and 5 ml of distilled water were mixed with 0.15 g of agarose which was heated until the agarose dissolved. Aliquots were pipetted into holders and these were bonded onto mouthguards produced from the plaster casts of each subject. The bonding sites were on the labial of maxillary incisors (UAB), the buccal of right and left maxillary molars (UPB-L-R) and the lingual of lower incisors (LAL). When the subjects were awake, the upper and lower mouthguards were fixed in the mouth and exposed to saliva for 10, 20, 60 and 100 minutes. The agarose was taken out of the holder and put into 2 ml of distilled water for 90 minutes and the fluoride concentration was measured by a fluoride ion meter. To examine the retention of fluoride in the mouth during sleep, the mouthguards were placed before going to bed (0:00 am) and removed at 6 30 am and the fluoride concentration measured as above.
At 30 minutes in the first experiment, the fluoride concentration in the saliva of each examinee had decreased to 1 ppm or less. There were significant negative correlations at 15, 30 and 60 minutes after moth-rinsing between the fluoride concentration and the salivary flow rate. The mean fluoride concentration in the saliva at 6:30 am corresponded with the concentration at 30 minute after the mouthrinsing at 2 pm.
In the second experiment, The half-times (the time for the initial F concentration to decreased by half) were lowest in LAL and highest in UAB. When the subjects had slept, the half-times in UAB were also highest.
The retention of fluoride in the mouth is affected by salivary flow rate and in order to keep a high fluoride level in the saliva for a long time, one possibility is to use a fluoride rinse before going to bed. The site-specificity of fluoride clearance from various sites in the mouth advantageous for UAB.

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Diseases caused by hospital infection including infections from hepatitis B and C viruses and MRSA have become social issues in recent years. In this study, we periodically evaluated contamination of areas around the waiting room of pediatric dentistry, in the entrance to the medical treatment room.
1. About two-fold more colonies grew on the general medium in the evening, and the relation was not found by the number of patients, and the number of colonies.
2. Many colonies grew on the general medium in the play area, and the highest colony count was obtained in the air-ventilating region of the air conditioner.
3. Similarly, more colonies grew on the medium for MRSA in the evening than in the morning, and the highest number of false-positive colonies was obtained in the air-ventilating region of the air conditioner.
4. Colonies judged false positive were subjected to identification using slide latex agglutination, and all of the colonies were negative.

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The purpose of this investigation was to determine measurement reproducibility among observers of the new method for evaluating the vertical position of the condyle head in the glenoid fossa. One 3DX Multi Image Micro CT (3 DX) image of dissected temporomandibular joints (TMJ) was meas ured by ten dentists. The dissection head was placed so that the Frankfort horizontal plane remained parallel to the floor during the taking of the 3 DX. The slice images which corresponded to the apex of the condyle heads were used for the measurements. The vertical distances between the aspect of the condyle head and the surface of the glenoid fossa were measured. The measurement results were determined by one way ANOVA for examining reproducibility. Of the measured values, there was no significant difference among the observers (p<0.05). The results from the present study suggested that the new measurement method has high reproducibility for evaluating the vertical position of the condyle head in the elenoid fossa.

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In clinical pediatric dentistry, there are not few occasions in which we encounter the cases with an anomaly in the number of teeth. The abnormality in the number of teeth directly affects the development of the dentition and occlusion. We experienced a very rare case of a patient with four supernumerary teeth in the maxillary anterior region.
The patient was 7 year 3 month old boy when he was first examined. His chief complaint was an anomaly in the shape of the upper anterior teeth. Intraoral and radiographic examination revealed the presence of one erupted supernumerary tooth and three impacted supernumerary teeth in the maxillary anterior region. The tooth germs of the maxillary central incisors were located infraversion due to the presence of the supernumerary teeth. All the four supernumerary teeth were extracted under local anesthesia at the 7 years and 4 months of age. Two of the supernumerary teeth extracted were monocuspid types with the apex closed, and the other two teeth were rootless incisor types.
Fenestration was rendered at the age of 8 years and 3 months, because the upper central incisors still had not erupted after extraction of the supernumerary teeth. After the upper central incisors erupted, the maxillary anterior teeth were aligned using a lingual arch with helical springs. The occlusal management with a multi-brackets appliance was then rendered because of a case of discrepancy, and this led to normal permanent occlusion.

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Local anesthetics are frequently used in dental practice. An allergic reactions to these drugs, however, are very rare and it has been reported that they have a high safety factor. We encountered a suspicion of 2 different amide types of local anesthetics allergy. A 4 year 5 month old male patient was referred to our hospital. He had atopic dermatitis and bronchial asthma. His dental history showed thatt he first ime was afterh e was treatedu nder locala nesthetic(Ora® Ct), fivheo urs afteri njection, when he had edema of the eyes. The second time, he had a prurigo of the chest, with a different type of locala nesthetic(Citanest-Octapresin® Ct) injection Whene 15 minutes afterH. e was examined with a prick test for these anesthetic drugs a negative reaction was found. The intaradermal skin test, however, showed a positive reaction when he was still near the pediatric hospital.
We suspected for two different amide type of anesthetic allergies. Firstly, We examined the drug using the lymphocyte stimulation test(DLST)with Xylocaine®Ct and Xylocaine®for phleboclysis, these showed a negative reaction,
Secondly, we examined using an intaradermal skin test which showed a negative reaction with Xylocaine®for phleboclysis.
It does not affect the concentration of serum Ig E, histamine, and the number of eosinophilic leukocytes. These inspects, however, at a higher level compared with the healthy controls.
Thirdly, we examined using the challenge test under general anesthesia. No allergic response was shown with a dose of 1 ml Xylocaine® for phleboclysis.
There was no increase in the concentration of the serum Ig E, histamine, and the number of eosinophilic leukocytes.
In this case, we have some doubts concerning the external allergic response to the preservative agent in the anesthetic solution.

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The mucocele is commonly found in the oral cavity but is rare in the maxillary sinus. Three cases of a maxillary sinus mucocele happened to be found based upon orthopantomography for examination of caries treatment or occlusal guidance for a period of about one year. We report on three cases of a mucocele in the left maxillary sinus. None of the cases had problems such as nose diseases, trauma, allergy, relative oral symptoms and so on. No abnormal findings related to general growth were observed. One case of maxillary sinus mucocele cleared up after about eight months after discovery.
Generally, a mucocele arising in the maxillary sinus shows no symptom, and is often found by radiography. In the maxillary sinus the mucocele shows no symptom, and treatment may be unnecessary. Although, when there are some specific symptoms that are attributed to any other cause or positive clinical findings such as bone expansion, we need to remove the cyst. The above results, therefore, suggest the importance of diagnosis based on orthopantomography from time to time and the necessity of a long-term follow up.

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A 13-year-old female came to our clinic with a wound in the right infraorbital area and swelling in the right submandibular area that had been present for 1 week. An intraoral examination revealed a normal salivary flow, while the swelling had an inflammatory appearance and was tender under palpation, which suggested the presence of purulence. As it seemed to be originating from a lymph node, a provisional diagnosis of acute purulent lymphadenitis was made.
Surgical drainage and antibiotic therapy (Flomoxef Sodium, Flumarin®, Shionogi, Japan) was performed, however,2 days later the lymph node remained swollen. At this occasion, the patient reported that some days earlier, her brother had visited another hospital due to a swelling on his left arm. Thus, cat scratch disease (CSD), a very common type of zoonosis, was suspected.
After further confirmation of the circumstances, the antibiotic therapy was changed to minocycline (Minomycin®, Wyeth Lederie Japan, Japan) and a PCR assay of the pus obtained from the swelling showed the presence of Bartonella henselae, the etiologic agent of CSD.
In the present case, implementation of a PCR examination allowed a prompt diagnosis of CSD, and eliminated the need for more extensive diagnostic and therapeutic procedures.

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At the pediatric dentistry department of the dental college hospital, we train patients with abnormal myofunction, making individual myofunctional therapy programs. The case of an 8 year-old girl with open bite causing long-term thumb sucking and tongue thrust habit and abnormal speech, chewing and swallowing, confirmed the good effects obtained by using myofunctional therapy. The following results were obtained:
1. This case shows that myofunctional therapy resulted in an improvement of normal myofunction and open bite.
2. It is necessary that we assess the results of myofunctional examination on a continual basis and check the results of myofunctional therapy. Key words: Myofunctional therapy, Oral habit, Oral dysfunction,8 year-old girl

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The present patient was 7 years and 10 months of age at the first visit to our Dental Hospital, and his chief complaints were a missing maxillary right central incisor and mandibular incisor crowding. He was referred to our hospital by a local dentist.
Before the occlusal treatment, he was treated primarily to prevent caries. At the start of the occlusal treatment, he was 15 years and 3 months of age and had a rightward shift of the midline in the maxillary dentition due to the missing maxillary right central incisor, mandibular crowding, unilateral Angle II malocclusion accompanied by labial inclination of the maxillary and mandibular incisors, and skeletal class I with a low angle frame.
After extracting the maxillary left first premolar and the bilateral mandibular first premolars, the occlusal treatment was performed using SPEED appliances, a type of preadjusted edgewise appliance.
The unusual arrangement of the anterior dentition in this patient (_??__??__??_) was treated as follows:
1) the maxillary right lateral incisor was bodily moved to the central incisor area with the parallel root relationship, and the crown was then modified morphologically,
2) the maxillary right canine was moved to the lateral incisor area with lingual root torque, and the crown was modified morphologically,
3) the maxillary right first premolar was moved to the canine area with buccal root torque. After the location and inclination of these teeth were adjusted exactly, gingivectomy was performed on the lateral incisor which was moved to the maxillary right central incisor area.
After three years and one month of the occlusal treatment, the appropriate overjet, overbite and class I molar relationship were obtained. The patient had a group function occlusion, and his occlusion has been stable for one year after treatment.

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