Sproles, R. A. (1975) reported on cervical pulp horns which extended periously close to the tooth surface on human permanent molars. However, cervical pulp horns on human primary molars remained unknown. The purpose of this investigation was to make clear whether cervical pulp horns also exist on human primary molars. Fourty extracted human primary molars were used for this experiment. The teeth were sectioned with a diamond disk with a point of 5 mm coronal to the cervical line. The specimens were washed with a supersonic washer and dried, and all soft tissue removed. Silicone rubber impression material was injected into the pulp chamber and five replica plaster models of each tooth were made. Colored wax was injected into the pulp chamber of the plaster models and the plaster models were then divided into four medio-distally. Sections were tracted and measured on a profile projector.
From the results of this experiment the following conclusions were drawn.
1) It was confirmed that cervical pulp horns were also exist on human primary molars.
2) Cervical pulp horns on human primary molars considered to be located in the cervical portion, extend buccally to the tooth surface in triangular form.
3) Fifteen cervical pulp horns were observed in 40 human primary molars (37.5%).4) The buccal extension of the cervical pulp horn is 0.32 mm on the average.

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The purpose of this study was to clarify the facial features of Down's syndrome. The faces of 30 adults with Down's syndrome, and 30 normal individuals (consisting of 15 males and 15 females in each group) were analyzed in terms of Moire topography using three-dimensional measurements. We measured the facial surface area and volume of the mid-face and lower-face, and found that a difference in facial features existed in the mid-face between those adults with Down's syndrome and normal individuals. Therefore we measured the distance between the left and right inner canthus, the distance between the left and right pupil, the distance between the left and right outer canthus, palpebral fissure size and facial width, and determined the ratio of each measurement to the facial width.
The results were as follows:
1) The value of the distance between the left and right inner canthus was nearly the same in both groups (Down's syndrome: 33.82 mm, control: 35.03 mm). The value of the distance between the left and right inner canthus/facial width ×100 was also nearly the same in both groups (Down's syndrome: 26~.97, control: 27.45).
2) The value of the distance between the left and right pupil of Down's syndrome patients was less than that of the controls (Down's syndrome: 52.70 mm, control: 59.70 mm), as was the value of the distance between the left and right pupil/facial width ×100 (Down's syndrome: 41.99; control: 46.94).
3) The value of the distance between the left and right outer canthus of Down's syndrome patients was less than that of the controls (Down's syndrome: 81.64 mm, control: 90.55 mm). The value of the distance between the left and right outer canthus/facial width ×100 of Down's syndrome patients was likewise less than that of the controls (Down's syndrome: 65.11, control: 71.21).
4) The palpebral fissure size of Down's syndrome patients was less than that of the controls (Down's syndrome: 23.70 mm, control: 27.60 mm). The value of palpebral fissure size/facial width ×100 of Down's syndrome was also less than that of the controls (Down's syndrome: 18.90, control: 21.68).
5) The value of facial width was nearly the same in both groups (Down's syndrome: 125.50 mm, control: 127.20 mm).

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The longitudinal change of the tooth axes of the upper and lower permanent central incisors in subjects with reversed occlusion was examined by means of lateral cephalograms during the period from the deciduous dentition to the early mixed dentition. The effect of MPBA on the axes was also investigated. The untreated group consisted of 20 subjects with reversed occlusion at the deciduous dentition. Three cephalograms were taken for each subject at the following stages.
Stage A. At the deciduous dentition period. Average age was 4 years and 3months.
Stage B: At the deciduous dentition period. One year and 6 months after the first examination (Stage A).
Stage C: After the ruption of the lower permanent central incisors. The average was 6 years and 9 months. For comparison with the treated group,8 subjects of the stages A to B, and 4subjects of the stages B to C were added to the untreated group. All the cephalograms showed reversed occlusion. The treated group consists of 27 reversed occlusion subjects who were treated with MPBA. MPBA was applied to 13 subjects during stages A and B, and to 14 subjects during stages B and C.
The following results were obtained. In the untreated group, the angles of the tooth axes of the upper permanent central incisors decreased during the stages A and B, and increased during the stages B and C. As to the lower permanent central incisors, there was no specific trend during stages A and B, but the angles showed distinct increase during the stages B and C. When MPBA was applied. to the subjects with reversed occlusion at the deciduous dentition period, the unerupted upper central incisors showed significant labial inclination during stages A and B, and stages B and C, and the lower central incisors showed significant lingual inclination during stages A and B when the lower incisors had not erupted yet, and during stages B and C when they were erupting.

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We encountered a case of two infants in the same family who were succeedingly infected with herpes simplex type I with manifestation of herpetic gingivostomatitis, showing gingival bleeding, gingival swelling and reddening around the teeth over a short period of time. Moreover, abscess and aphta were observed on the lips of the infants. Absorbent cotton swabs were touched on the inflammatory sites at the onset period and the cure period to investigate which was cause of these manifestation using the polymerase chain reaction technique. The specific arrangements of DNA determined from the inflammatory sites of the infants showed the same band of herpes simplex type I.
Herpes simplex type I was detected in two infants with herpetic gingivostomatitis using the polymerase chain reaction. These results also demonstrated that herpes simplex type I infected the two infants in the same family within a short period, showing intensive oral manifestation. This rapid method is useful to reveal the etiologic findings of herpetic gingivostomatitis in the period of infancy.

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The purpose of this study was to investigate the clinical effects of nitrous oxide/oxygen inhalation sedation combining the behavior modification technique for handicapped patients during dental treatment, and the relationship between the clinical effect and the developmental age of the patients. The subjects were 54mentally disabled patients, aged from 5 to 20, who could not receive routine dental treatment using the behavior modification technique, due to their the combative behavior.
The new behavior modification technique in this study encompassed three processes. Firstly, the patients received behavior modification using a face mask for inhalation sedation that had the pleasant sweet smell of vanilla essence. Secondly, the received the introduction to the dental situation using the behavior modification technique under conscious sedation (30% nitrous oxide/70% oxygen). Finally, they received the dental treatment using the behavior modification technique under conscious sedation (30% nitrous oxide/70% oxygen).
The clinical effect was evaluated during the dental treatment. The individidual developmental age was investigated using the Social Maturation Test.
The results were as follows;
1) Approximately 54% of the subjects received dental treatment behaving cooperatively as a result of this technique.
2) The cooperative patients during dental treatment had attained a higher developmental stage than that of uncooperative patients in the majority of the the items of the Social Maturation Test.
3) Approximately 72% of the patients who had attained the developmental stage of over 3 years of age with respect to developmental age, were able to receive dental treatment behaving cooperatively as a result of this technique. However, only 29% of the patients who did not attain the developmental stage of 3 years of age with respect to developmental age, were able to receive dental treatment behaving cooperatively as a result of this technique.
The results suggested when the handicapped patient attains over 3 years of age with respect to developmental age, the patient will have a high potential to change from the uncooperative to the cooperative patient during dental treatment using this technique.

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Staphylococcus aureus is one of the most important pathogens of the various infectious diseases. Recently, methicillin-resistant Staphylococcus aureus (MRSA)has been increasing and is becoming a serious clinical problem because of difficulties in it causes anti microbial chemotherapy and nosocomial infections. In this study, we endeavored to isolate MRSA from one hundred children who had no previous illness other than dental disease.
1. Ten percent of them were MRSA positive. The rate of MRSA carriers has increased about five times during the past five years.
2. All of the isolated MRSA showed resistance against all of the β-lactams. Only vancomycin was effective for all isolates.
3. There were no identical strains of isolates found based on the analysis of the biological typings. This result suggested these carrier children were not infected with MRSA in our clinic.
Our study revealed that the rate of carrier children was 10.0%, and it has increased in recent years. We will need to be more careful with nosocomial infections.

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We conducted research on the actual conditions of the home environment, the dental consciousness of the guardians and analyzed the various factors producing the difference of life style.
Questionnaires were given to 315 of the guardians, consisting of 96.8% of mothers, who children attended four preschool institutions, that is, two kindergartens and two day-nurseries, in a down townor a suburban area, respectively, in Hiroshima. The correlation between the data was analyzed statistically and the results were as follows.
1) The mean number of persons composing a family was 4.38, and the family in the suburb was significantly larger than that downtown (p<0.05). The number of cases of an only child was significantly larger in the day-nursery or in the downtown (p<0.05).
2) Only 4.2% of the guardians visited a dentist for a periodic checkup. Additionally, a guardian with a larger number of children tends to visit a dentist after feeling pain. Though the largest percent of guardians is informed about a dental floss and plaque detectors, a small number of them actually use these instruments.
3) In the oral examination for each preschool child,34.3%, of the children were indicated as having the dental caries. The indication of dental caries was found in many of the children, whose order of birth was more than the third child, or who had more than two brothers or sisters. Bad oral habits showed a tendency to decrease with increasing age. This tendency was found especially with finger sucking (p<0.05).
4) Concerning visits to the dental office for the child,73.8% of the purposes for visiting were for treatment of dental caries and a lower percentage for prevention of them was found. Sixty-one percent of the guardians desired to accompany her child to the treatment chair to be present at the dental treatment. This desire was found particularly with guardians who had a lower age, an only child or a first child.

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In humans osteoblasts derived from the cartilage bones formed by the endochondral ossification such as from the femur or tibia were well characterized, but cells from the membranous bones formed by the intramembranous ossification such as from the maxilla or mandibula have not been studied. To establish a new system of culture for normal human osteoblasts, we isolated and cultured the cells from normal human mandibular alveolar bone. Four strains of HAB cells (Human Alveolar Bone-derived cells), HAB-1, HAB-2, HAB-3 and HAB-4, were obtained from four regions of three different donors aged 13- to 21-year-old who had no metabolic diseases. Some differentiation phenotypic markers were examined and the results were as follows:
1) HAB-2, HAB-3 and HAB-4 expressed high alkaline phosphatase activity under the normal culture conditions.
2) 1α,25-dihydroxivitamine D₃ (5 nM) or dexamethasone (100 nM), the synthetic glucocorticoid, significantly increased the alkaline phosphatase activity of the HAB cells.
3) Whereas treatment with parathyroid hormone (1-34) did not increase the level of the intracellular cyclic AMP in HAB cells under the normal culture conditions, the increasing effect of the parathyroid hormone toward the intracellular cyclic AMP level was shown in HAB-2, HAB-3 and HAB-4 under the culture condition including dexamethasone (100 nM), suggesting that these cells expressed the parathyroid hormone receptors.
4) Mineralizing nodule formation was shown in HAB-2 and HAB-4 under longterm cultivation. L-ascorbic acid was required for the synthesis and maturation of the extracellular matrix in HAB celis
These results indicate that HAB-2, HAB-3 and HAB-4 have osteoblastic phenotypes while HAB-1 did not and suggest that HAB cells are useful as a model for studying bone cell biology in the growth and development of normal human maxillary and mandibular bones.

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The proximal surfaces of deciduous teeth with C2 were restored with Fuji II LC. Twenty cases were then, given polishing on the same day and another twenty cases one day after, while observation of these cases was made clinically for one year.
The results were as follows:
1. With regard to marginal adaption, the cases with polishing one day after showed some what better progress than the cases with polishing on the same day.
2. Marginal discoloration showed about the same tendency as the degree of marginal adaptation.
3. The refractory adrasiveness and color tone of the restoration showed good progress without regard to the time for polishing.
4. As to pulp reaction, the cases with polishing on the same day showed an increase in symptoms of dysphoria six months after restoration, and cases requiring pulp treatment were also found.
5. As for the occurrence of secondary caries, the cases with polishing one day after showed better progress than the cases with polishing on the same day. On the basis of the foregoing findings, restoration of the proximal surfaces of the deciduous anterior teeth with glass ionomer cement of the light-cured type for polishing produced better results when polishing was done one day after restoration than with polishing immediately after.
Further and extended investigations are necessary, for deciduous molars as well.

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When a child, lying on its back, is undergoing dental treatment with its mother standing by, how the child glances at the dentist, the dental hygienist and the mother is an interesting subject for study. In the present study, the eye movements of the little patients were measured while each of the subjects was presented with a photo panel showing the faces of the three, and the measurements were analyzed. The subjects were divided into two groups. One group consisted of those children who immediately looked at the photo of their mothers in the eye (Group A); the other group, those who did not (Group B). The results obtained by analysis of the measured eye movements were compared between the two groups. Furthermore, to find out differences in personality traits between the two groups, a multivariate analysis was performed using Hayashi's quantification theory type II. The results were examined to seek relevance to the results of the Takagi-Sakamoto juvenile personality test.
The findings were as follows:
1. The largest number of the child subjects made primary seeing was with the dentist, followed by “others”, the mother and the dental hygienist in that order.
2. The duration of eye contact was longest with the dentist, followed by the hygienist, mother and “other”. The average length of glances was 902.7ms.
3. The frequency of glances was largest toward the dentist, followed by the hygienist, the mother and “others”. The average number of times was 7.2.
4. The scanning pattern of the gaze was 51.1 % for Group A and 48.9% for Group B.
5. With the level of significance being 5%, Group A subjects fixed their eyes on the hygienist for a significantly long duration, as opposed to the Group B subjects fixing their significance, the number of glances being significantly larger in Group B than in Group A.
6. As a result of the analysis by Hayashi's quantification theory type II, the correlation ratio was worked out at 0.453 and the overall correct rate,66.7%.
7. The items with 0.200 and agove in terms of the partial correlation coefficient in the T-S personality test, which affects differentiation between the two groups, included nervous temperament, emotional stability and aggression.

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The purpose of this study was to examine the frequency of children with congenitallymissing permanent teeth (missing group) and to assess the growth anddevelopment of the missing group by referring to the dental age.
We assessed the development of the children by examining the differences betweenthe dental age and the chronological age. The dental age was determinedby the standard age of the Moorrees et al. tooth formation stage.
The materials were collected from 5,120 longitudinal orthopantomogramsand 4,850 dental x-ray photographs which were obtained from 1,623 Japanesechildren (795 male and 828 female), aged 5 to 10, at the Department of Pediatric Dentistry, Aichi-Gakuin University.
The results were as follows;
1. The frequency of the missing group was 10.9%. (male: 9.7%, female: 12.1%)
2. Approximately 86.4% of the missing group had either one or two congenitallymissing permanent teeth. (subjects missing one tooth: 53.1%, subjects missingto teeth: 33.3%)
3. The distribution of the congenitally missing permanent teeth showed that thelower second premolars were most frequently affected, followed by the lowerlateral incisors in both sexes.
4. There were no statistically significant differences between the dental age andchronological age of the missing group between sexes and ages.
5. The value of the differences between the dental age and chronological age ofthe missing group was larger than that of the non-missing group.
6. As the number of the congenitally missing permanent teeth increased, the valueof the differences between the dental age and chronological age of the missinggroup also increased.

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The purpose of the present study was to observe and investigate the coordination among tongue and jaw movement, perioral muscle activity, and sucking pressure during nutritive sucking in infants.
The subjects comprised 25 healthy infants, born normally at full-term pregnancy. The mean age was 13.0±4.5 wks after birth. A feeding bottle equipped with CCD videocamera and pressure sensor was devised to show the inside of the baby's mouth and record the sucking pressure. Muscle activity was examined by unilateral surface electromyography from the temporalis (TM), masseter (MM), orbicularis oris (OM) and suprahyoid muscles (SM). Mandible and tongue movement, muscle activity and sucking waves during the intake of the glucose solution (10%) were recorded simultaneously on video tape.
The results are as follows:
1) The tongue movements were peristaltic. When the infant began to suck, the tip of the tongue rose. The central part of the tongue then became a bell shaped bulge which moved backward toward the root of the tongue. At the final stage, the tongue receded quickly and reversed forward; i. e. the sucking cycle.
2) High correlation was recognized among tongue movement, sucking pressure and jaw movement. While the mandible pulled up until the bell shape appeared in the tongue and the nipple diameter was reduced, and sucking pressure was positive. After mouth closure the bell shape on the tongue moved backward, and the pressure was negative; the jaw also moved backward and the mouth opened.
3) The TM and MM were most active when the sucking pressure became positive and the mandible was closing. The OM and SM were active in both the positive and negative sucking phases, OM activity being most intense in the positive pressure phase, SM showing highest activity in the negative pressure phase.
4) Regarding muscle activity relating to sucking, the SM was the most active, followed by OM, MM and TM.
It was concluded that tongue movement, perioral muscle activity and sucking pressure are highly coordinated during nutritive sucking in all infants.

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Previous studies have reported that infants from diabetic mothers (IDM)manifest widened neonatal lines and enamel hypoplasia of the postnatal enamel in the primary dentition. It has been suggested that neonatal hypocalcemia may contribute to this process. However, this hypothesis has not yet been proven.
The purpose of the present study was, therefore, to investigate the effect of experimentally induced diabetes in rats on the tooth enamel structure of their offsprings and further, to study the correlation between neonatal hypoplasia and the function of the ameloblast at different developmental stages.
Six-year-old female Wistar strain rats were injected i. v. with streptozotocine to induced diabetes continuouslly. After the female rats were matured they were mated with normal male rats. Thus 1∼4 day old offspring of diabetic rat dams were used as the diabetic group and normal rat dams as the control group. Serum Ca and P analysis were performed with a spectrophotometer. From each lower incisor mid-sagittal and cross sections were prepared. Contact microradiographic analysis and electron-probe Micro-analysis were employed.⁴⁵CaCl2,³H-proline, or ³H-thymidine was injected i. p. and the distribution of silver grain on autoradiogram were then measured on the sections stained with hematoxylin and eosin.
The results were as follows:
1) in 1-day-old rats in the diabetic group significant decrease of serum Ca concentration was noticed, and it recover within 2-days, this suggesting neonatal hypocalcemia in the diabetic group.
2) Microradiographic findings showed diffused hypocalcified enamel and enamel hypoplasia of lower incisors during the maturation stage of the ameloblasts in the 8-day-old diabetic group. Eelectron-probe microanalysis revealed decreased intensities of Ca k αand P kα at the region of the enamel hypoplasia.
3) The cellpopulation renewal of the lower incisors was studied on 2-day-old rats injected with ³H-thymidine. The ameloblasts migration rate was estimated approximately 527 μm/day. Correation was assumed between the site of the enamel hypoplasia and that ol the amelo-blasts allected by hypocalcemia.
4) An inhibition of ³H-proline and ⁴⁵Ca incorporation into the ameloblasts and enamel affected by hypocalcemia was recognized in the diabetic group.
These results suggest that enamel hypoplasia found in IDM is presumably caused by the ameloblasts disfunction, namely by disturbances of the enamel protein synthesis and serection and by alteration in Ca transportation.

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Kinetic cavity preparation is a kind of cavity preparation method using a high-speed stream of carried aluminium oxide particles propelled by air pressure. We carried out cavity preparation on extracted primary and permanent teeth using the air-powder abrasive system KCP-2001J and observed the cavity through a dissecting mycroscope and SEM. The effects of cavity preparation using airentrained aluminium oxide kinetic instrumentation were compared with using high-speed rotary instrumentation.
The following conclusions were obtained.
1. The kinetic method of tooth preparation produced a smooth, clean preparation with a slightly rounded cavorsurface margin and a smooth cavity wall, without a distinct line-angle on the cavity wall to the cavity floor. No smear layer was observed.
2. Because of the above characteristics of the cavity form prepared by the airabrasive technique, advantages emerge for bonded restoration with composite resin material.
3. The nozzle of the air-abrasive instrument does not come into actual contact with the tooth, providing no tactile guidance. Skill is therefore necessary for free hand movement of the handpiece.
4. The air-powder stream cut even healthy enamel around the cavity. A preventive method is necessary for the protection of the enamel surface around the cavity.
5. No operative pressure, no vibration, very littleaudible sound, no cutting smell and high cutting speed during the air-abrasive treatment, all eliminate the tension on the part of the patient. Based on the above advantages kinetic energy instrumentation, can be considered as a suitable clinical procedure especially for Pediatric Dentistry.

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Recently, rotational panoramic apparatuses for TMJ radiography have been undergoing rapid improvement. One apparatus (AUTO III, Asahi Roentgen Co., Ltd., Kyoto, Japan) can photograph the right and left temporomandibular joints (TMJ) when opening and closing the mouth, exposing the images in each quadrant of the same film. This apparatus, however, is considered as a combination of tomography and scanography, and it is not obvious what portion of the condyle contour is taken. The images taken by such apparatuses have not been evaluated and reported on.
The purpose of this study was to evaluate the accuracy between the images and the real condyles (objects), and to examine the usefulness of TMJ images taken by rotational panoramic radiography in children. The TMJ of three human dry skulls with Hellman's dental developmental stages IIA, IIIA and IVA were used in this study. They were radiographed in the positions recommended by the manufacturer and in other positions of a different angle in order to obtain images taken at a different angle of the X-ray beam. The images of the TMJ were analyzed by visual evaluation.
The results were as follows:
1. Concerning reproducibility of the condyle contour in the IIA and IIIA stages, the method using the apparatus (AUTO III, by Asahi roentgen Co., Ltd., Kyoto, Japan) was better than the modified Schaller method.
2. In each of Hellman's dental developmental stages, the images of the contour around the top of the condyle were the most salient part of the TMJ.
3. When the dry skulls were moved upward, the images of the TMJ could be reproduced more clearly without superimposition of the bony structures.
4. Ear-rods were needed for better reproducibility of the images of the TMJ.
As a result of this evaluation, it was concluded that a TMJ mode (position)of a rotational panoramic apparatus is considered to be useful for screening the TMJ of children.

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With a view to making a comparative study of the thickness of the cortical bone at the mandibular angle in school-age children and in children at puberty, a total of 80 children,40 school-age children from 7 to 12 years old and 40 children at puberty from 13 to 18 years old, who came for examination to the outpatient ward, Department of Pediatric Dentistry, Kyushu Dental College, were used as the subjects. The cortical bone at the mandibular angle was measured on panoramic radiographs.
The results were as follows:
1. The averages were 0.90±10.23 mm for school-age children and 1.09±0.34 mm for children at puberty. The averages based on sex of the thickness of the cortical bone at the mandibular anglc were 0.88±0.20 mm for boys and 0.93±0.25 mm for girls of school-age children, and 1.07±0.41 mm for boys and 1.12±0.26 mm for girls at pubcrty. At the side, the averages were 0.87±0.21 mm for the left side and 0.93±0.22 mm for the right side of school-age children, and 1.14±0.35 mm for the left side and 1.05±0.27 mm for the right side of children at puberty.
2. No significant differences were found in the t-test based on sex, age, or side. Based on age, children at puberty showed significantly higher values than school-age children.
3. The correlation coefficient between age and thickness of cortical bone at the mandibular angle was r=0.809.

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Bloch-Sulzberger syndrome is an X-linked dominant heritable disorder with various systemic and oral problems. It is also called incontinentia pigmenti because it is easily characterized by peculiar pigmentation of the skin of infants. Intra-oral clinical findings were mainly manifested due to delay of tooth eruption, microdontia and anodontia. A three-year-old girl affected with the Bloch-Sulzberger syndrome was observed for nine years and showed the following findings.
1) Brown hyperpigmentation in the skin of the face, the upper arm and the tongue tip.
2) Alopecia with scarring on the crown of the head.
3) Weak eyesight.

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Intentional replantation was conducted for the treatment of an immature lower incisor with a posttraumatic radicular cyst after traumatic injury.
The incisor was extracted as carefully as possible so as not to impair its periodontal ligament, and the cyst was curetted and extirpated from the socket. At the same time, the root canal of the extracted tooth was irrigated and filled with a calcium hydroxide-containing material (Vitapex®). The tooth was replanted in its socket and stabilized temporarily with an arched rectangular wire and a light cured composite resin.
Nine months have passed since being discovered this treatment without clinical and radiographical abnormalities, and the root apex has been obturated by apical bridge formation.
This result shows that intentional replantation is a useful method as a treatment of an immature tooth with a periapical lesion.

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The purpose of this study was to determine whether concentration of the antibiotic in the blood, the parameter of its effectiveness, can be estimated from the concentration in the saliva.
The concentration of CLARITHROMYCIN (a new macrolide) in the blood, concentration in the saliva, were measured with the bioassay method in 11 healthy adults and were evaluated for their correlation. In addition, the clinical effectiveness of this drug in the dental and oral field was evaluated in 40 children who visited the pediatric dental clinic of Iwate Medical University.
The following results obtained:
1) As to the basic experiments, it was found that the Cmax after oral administration of CLARITHROMYCIN was 1.34 μg/ml in the blood and 1.44 μg/ml in the saliva, showing good drug transfer. Since the concentration in the blood, and in the saliva showed similar kinetic changes in the body, estimation of the concentration of CLARITHROMYCIN in the blood was considered to be possible from the concentration in saliva.
2) In 10 children for where it was used for the prevention of infection, the CLARITHROMYCIN concentration was measured in retained blood in the tooth extraction would and saliva, which was the side of action. It found that the concentration in the blood, concentration in the saliva were similar and all concentrations were more than MIC 0.39 μg/ml at any time between 40minutes and 2 hours 30 minutes after oral administration.
3) It was found that in odontogenic infection cases, the clinical efficacy of gnathitis and paradentitis case what was judged by the comparative score evaluation and the investigators, was 100.0% and that of pericoronitis was 75.5%, and in infection prevention cases, in all it was 96.0%. And the side effect occurred in only 1 case.
These results suggested that CLARITHROMYCIN was the effective and safety antibiotic in dental and oral field in children.

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As the root of the deciduous incisor is very close to its successor, trauma of the deciduous incisor easily affects the tooth formation of the permanent successor. This is a case report of arrested root formation in an upper right permanent central incisor subsequent to trauma to a deciduous predecessor.
A boy aged 5 years 9 months fell down from a bight of 2 meters and his upper deciduous central incisors were struck. The left one fell of and the right one was intruded. The intruded incisor reerupted after 2 months and spontaneously fell off 7 months after reeruption.
At the age of 7 years, the left permanent incisor erupted, but the right one did not. On the X-ray film the root of the right incisor was slightly developed on the distal side only. The right incisor erupted after surgical exposure of its crown. At the age of 8 years 9 months, he clashed against his friend and the right incisor was hit. The right one was fractured at the tooth neck and was extracted. According to the histopathological findings, there was much displastic dentin and cellular cementum inside the crown dentin and predentin, and the pulp cavity was very narrow. In the displastic dentin of the palatal side, the normal root dentin was noted. It suggested that the developping root was broken to the crown and this was caused by trauma, while the root formation of this tooth was arrested.

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We report on the clinical and radiographic findings of 26 mondibular fractures in a retrospective study of 48 pediatric trauma patients. These patients all under 12 years of age, were reffered to our university hospital during a 5-year period between 1989 and 1993. The clinical records and radiographs were reviewed for the mechanism of injury, age at the time of injury and anatomical site of the fracture.
Our results revealed no significant differences in the sex and age distribution of the cases.54.5% of the children had condylar fractures,3 cases (11.5%) had dental trauma in addition to the recognized mandibular fractures.4 cases (15.4%) earlier misdiagnosed as having no mandibular fracture prior to their refferal to our hospital, were otherwise observed to have mandibular fractures.
The implication of the results of this study is that panoramic X-ray is the best for X-ray examination.

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This paper reports on the clinical observations of inverted maxillary central incisors of 16 patients who came to our clinic. Details of the detection, causes of the impaction, the location of the impacted teeth and the age of the patients at the initial visits were recorded. The angle of the crown inclination, crown-root angulation and the stage of root formation were examined for each group of the cases of crown exposure followed by traction and the cases of extraction.
For the crown exposure and traction group, the mean age of the patients at the initial visit was 7y5m, the mean value of the crown inclination was 88.8 degrees and the mean value of the crown-root angulation was 64.0 degrees. The examination of the root formation stage at the initial visit revealed that two teeth were at Ri-R1/4, three at R1/4-R1/2, two at R1/2-R3/4, and one at R3/4-Rc.
For the extraction group, the mean age of the patients at the initial visit was 9y6m, the mean value of the crown inclination was 111.6 degrees and the mean value of the crown-root angulation was 91.6 degrees. The examination of the root formation stage at the intial visit revealed that four teeth were at R3/4-Rc and three at Rc.
These observations suggest that the treatment planning, whether for traction or extraction of the impacted and unerupted maxillary central incisors, should be made according to the crown-root angulation, the stage of root formation and the age at the intial visit in addition to the angle of the crown inclination.

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