Aichi Gakuin Daigaku Shigakkai shi最新文献

{"title":"[A carbohydrate histochemical study of the growth of rat parotid glandular cells].","authors":"J Shimano","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Objective: </strong>The submandibular gland is used in most studies of the development and differentiation of the salivary glands. There are only a few reports on the genesis and growth of the parotid gland: reports by Emi (1939), Uehashi (1960), Harold (1961), Redman and Sreebny (1971), Eguchi (1975), Takeuchi (1978) and Redman et al. (1980) who used rats and those by Akiyoshi (1929) and Iwata (1958) who used humans. Since there are no reports on the carbohydrates in parotid glandular cells, we carried out histochemical studies of changes in the carbohydrates of the secretory granules in parotid glandular cells in young rats.</p><p><strong>Materials and methods: </strong>Wistar rats were mated, and 5 male offspring were killed with chloroform daily between the time of birth (day 0) and day 13 and weekly between the 2nd and 8th weeks after birth. Their parotid glands were immediately resected, fixed in buffered formalin, embedded in paraffin and cut into 6 mu sections for the following histochemical reactions (Tables 1 and 2): PAS reaction (Lillie's technique), PAS-dimedone reaction reaction and salivary digestion test for the determination of glycogen; acetylation-PAS reaction, acetylation-saponification-PAS reaction and sulfation-toluidine blue reaction (TB; pH 2.5) for the determination of neutral mucopolysaccharides; Sugiyama's neutral red technique and Alcian blue staining (AB; pH 2.5) for the determination of weekly acidic mucopolysaccharides; Sugiyama's neutral red technique and Alcian blue staining (pH 1.0 and 0.5) for the determination of strongly acidic mucopolysaccharides; high iron diamine (HID) test, periodic acid-treated HID test, HID-AB (pH 2.5) test, low iron diamine (LTD) test and periodic acid-treated LID test for the determination of compound carbohydrates; and PA-Con A-HRP-AB test (pH 2.5) and PA-red-Con A-HRP-AB test (pH 2.5) as paradox lectin tests.</p><p><strong>Results: </strong>Histological findings: The terminal of the parotid gland of the young rats showed two types of granule-containing cells. One of the two types was mucoid cells with large irregular massive granules strongly positive for PAS present above the nucleus (L cells), and the other, serous cells with fine granules moderately to weakly positive for PAS (S cells). L cells were present between days 1 and 11 after birth, being most abundant between days 4 and 7. In S cells, the morphology of granules began to be obvious on day 1 and to be similar to that of cells in adult rats at week 4 after birth. 1. Glycogen: i) PAS reaction: L cells showed moderately positive reaction between days 1 and 3 after birth and strongly positive reaction between days 4 and 11. S cells showed weakly positive reaction between days 1 and 3 after birth and moderately positive reaction between day 4 and week 8. ii) PAS-dimedone reaction: No glycogen was detected in the L or S cells of any animal. iii) Salivary digestion test: No glycogen was detected in the L or S cells of a","PeriodicalId":75458,"journal":{"name":"Aichi Gakuin Daigaku Shigakkai shi","volume":"28 2","pages":"547-71"},"PeriodicalIF":0.0,"publicationDate":"1990-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12889511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Process of the tooth brushing habit formation in children. 1. Period of the start and present circumstances classified by age].","authors":"Y Suzuki","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The purpose of this study was to investigate the process by which the tooth brushing habit was formed in children. The study is based on questionnaires about the habit of tooth brushing from mothers of kindergarten pupils aged from one to six years living in Nagoya and the suburbs. The results of this study were summarised as follows: 1. Period of the start: 1) The number of children who started tooth brushing before the age of one year and six months was 75.7%, and before the age of two, 88.3%. 2) The item of \"Eruption of the teeth\" showed the highest ratio (49.2%) regarding the motive for the start of tooth brushing. 3) The children who started tooth brushing with the motive which construction about caries prevention with mothers as the main tended to start the earliest. 4) The ratio of persons who actually brush the children's teeth were as follows, \"mother brushes (51.6%)\", \"mother after her child (37.1%)\" and \"child brushes (6.8%)\". 5) The number of children who started using a tooth-brush before the age of two years was 78.8%, and before the age of two years and six months, 92.5%. 2. Present circumstances classified by age: 1) The number of children whose teeth are brushed by themselves or their mothers more than once a day before they were six years old was 61.8%. 2) In all ages, the group of once or twice a day showed a high ratio for frequency of tooth brushing. 3) \"mother brushes (47.4%)\" for one year olds, and \"mother helps her child's brushing (85.7-53.6%)\" for two to five year olds, and \"child brushes (64.8%)\" for six years olds were the highest ratios regarding the persons who actually brush the children's teeth. 4) Co-operative attitude of the children towards their mother's help is bad for one year olds, but good above two years old. 5) Attitude of the children towards tooth brushing is negative under three years old, and positive above four years old. 6) There is little hope that children can brush well by themselves under two years old. 7) children who have experienced guidance in tooth brushing from their mothers before they were three years old numbered 84.7%, and from a dentist or dental hygienist before they were six years old numbered 49.8%.</p>","PeriodicalId":75458,"journal":{"name":"Aichi Gakuin Daigaku Shigakkai shi","volume":"28 2","pages":"639-61"},"PeriodicalIF":0.0,"publicationDate":"1990-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Study on the porcelain veneer restoration. 3. Effect of various treatments of porcelain surface on the bonding strength at porcelain-resin interface].","authors":"M Kondo,&nbsp;M Ikeda,&nbsp;N Takeuchi,&nbsp;K Kanamori,&nbsp;K Kamiya,&nbsp;A Gomi,&nbsp;T Asai,&nbsp;A Senda","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In a previous report, observations were made on the apporopriate concentrations of hydrofluoric acid and durations of application in treating porcelain surfaces to improve the bonding strength at the porcelain-resin interface. Particular concentrations and durations were found, such as 4%, 6 min. for Supper Porcelain AAA, 8%, 6 min. for VMK 68, and 6%, 3 min. for Cosmotech Porcelain, and it was clearly shown that hydrofluoric acid treatment was the most effective treatment for porcelain-resin micro-mechanical bonding. However, because of its strong corrosive action, the use of hydrofluoric acid is very dangerous, and it must be handled with extreme care even in the laboratory. Accordingly, there is a need to find a safer and more effective way of treating porcelain surfaces, particularly in the field of interoral repairs to fractured porcelain restoratives by means of porcelain-resin micro-mechanical bonding. In the present study, 2% acidulated phosphate fluoride (APF), which corrodes the surface of porcelain restoratives, PorceLock (PL), which is a 2.5% buffered hydrofluoric acid made by DenMat Co. and a 6% hydrofluoric acid (HF) preparations were applied to the surface of porcelain specimens and the resulting effects on treated porcelain surfaces were examined by means of SEM observations and shear bonding strength tests. The following results were obtained: 1. In comparison with control specimens which were not treated with any acids or fluoride, a much higher bonding strength at the porcelain-resin interface was obtained in the specimens treated with 2% APF, PL and 6% HF. 2. Regarding to SEM observations, both of the specimens treated 6% HF or PL showed extremely micro-porous surfaces.2+ surfaces of the</p>","PeriodicalId":75458,"journal":{"name":"Aichi Gakuin Daigaku Shigakkai shi","volume":"28 2","pages":"631-8"},"PeriodicalIF":0.0,"publicationDate":"1990-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effect on the development of permanent successors due to the extraction and non-extraction of infected deciduous teeth].","authors":"H Ishiguro","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The purpose of this study was to clarify the effects on the eruption and root formation of the permanent successors of deciduous teeth affected by periapical periodontitis. Materials used were forty-one healthy infant dogs about two months old. Standardized X-ray films were taken every two weeks. The period of study ran from the age of ten weeks to twenty eight weeks until the roots of the permanent successors were completed. A total of 328 mandibular teeth were used and classified as P2 and P3 with their preceding deciduous teeth being Dp2 and Dp3. The following four groups were used in this experiment. 1) Extraction group with infected deciduous teeth: The infected deciduous teeth were extracted after being left for four weeks following pulpectomy. 2) Extraction group with healthy deciduous teeth: Healthy deciduous teeth were extracted from fourteen-week olds. 3) Left-alone group with infected deciduous teeth: After pulpectomy the infected deciduous teeth were left until they were shed naturally. 4) Healthy group (control): Untreated teeth were observed which represented the opposites of all the teeth examined in the previous three groups. A study was made of the changes in location, eruption and root formation of the permanent successors of deciduous teeth in affected with periapical periodontitis and the condition of eruption and root formation of the permanent successors. The result were as follows. 1. Appearance rate of periapical periodontitis: 1) DP2: Two weeks after pulpectomy, periapical periodontitis was observed in eleven out of twenty-one teeth (52.4%), and after four weeks in seventeen out of twenty-one teeth (81.0%). 2) Dp3: Two weeks after pulpectomy, periapical periodontitis was observed in eighteen out of twenty-one teeth (85.7%), and after four weeks in all of the experimental teeth. The appearance rate of periapical periodontitis in Dp3 was higher than in Dp2. 2. Eruption of permanent successors: 1) Extraction group with infected deciduous teeth: (1) The eruption of permanent successors was accelerated more than the other experimental groups. This tendency was stronger in P3 than in P2. (2) There were changes in location in the upper and lower directions of P2 before extraction of Dp2, in the lower direction for P3 before extraction of Dp3, and in the upper direction for P2 and P3 after extraction of Dp2 and Dp3. 2) Extraction group with healthy deciduous teeth: (1) Eruption of P2 appeared to be almost the same as the control group, but the eruption of P3 was delayed slightly at the eruption from the alveolar bone.(ABSTRACT TRUNCATED AT 400 WORDS)</p>","PeriodicalId":75458,"journal":{"name":"Aichi Gakuin Daigaku Shigakkai shi","volume":"28 1 Pt 1","pages":"93-121"},"PeriodicalIF":0.0,"publicationDate":"1990-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[A study on the reference planes and lines for dental practice].","authors":"T Kato","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In prosthetic dentistry, determination of the occlusal plane has a great influence on functional articulation and esthetic aspects. However, we have no means to decide the occlusal plane, because we have too many points for deciding the occlusal plane in the data. The data which we usually use were decided in the past and much of this does not conform to the present changed Japanese physical standards. The author has studied ways to decide the occlusal plane. One of them is based on the points which were decided in the past, the other is based on new points which were decided by the author. The results were as follows. 1. When the posterior points of Camper's plane are at the lower part of the tragions, it is parallel to the occlusal plane within the sagittal plane. 2. There is no difference between Camper's planes whether the frontal points are at the lower part of the alare or the subnasal point. 3. There are few differences between the Frankfort planes whatever 3 points are chosen from both orbital points and both tragions in the sagittal plane. 4. There are few individual differences between the Frankfort planes based on points at the right tragion and the left tragion in the frontal plane. 5. The angle of Dürer's plane towards the occlusal plane tends to be similar to the angle of the Frankfort plane towards the occlusal plane in the sagittal and frontal planes. 6. The HIP plane shows a slight tendency to acclivity towards the occlusal plane in the sagittal plane, but parallel is the occlusal plane closely in the frontal plane. 7. The inclinations toward the occlusal plane in the sagittal plane of the three lines of the nasion to the left alare, the nasion to the right alare, and the nasion to the subnasal point, are similar. 8. The lines from the center of the upper first incisal edge to the left subaurale point, and from the center of the upper first incisal edge to the right subaurale point, are parallel to the occlusal plane in the sagittal plane. 9. The three lines from the left orbital point to the right orbital point, the left alare to the right arale, and the left subaurale point to the right subaurare point parallel the occlusal plane closely in the frontal plane. 10. The line from the nasion to the subnasal point makes a right angle with the occlusal plane in the frontal plane.(ABSTRACT TRUNCATED AT 400 WORDS)</p>","PeriodicalId":75458,"journal":{"name":"Aichi Gakuin Daigaku Shigakkai shi","volume":"28 1 Pt 1","pages":"1-19"},"PeriodicalIF":0.0,"publicationDate":"1990-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Structure of medical X-ray films].","authors":"T Okano,&nbsp;A Kikuchi","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Characteristic comparisons were made on various medical and dental X-ray films such as Agfa-Gevart, Dupont, Hanshin, Kodak, Konica, Nix, Sun Dental film. 1) Silver grains coated on the film base of regular and dental films showed a round (polyhedron) or potato-like shape. Grains of orthochromatic films were hexagonal or triangular in shape, although those of Konica orthochromatic films were small and round. 2) Size of silver grains ranged from 1.09 microns in the Fuji HRS film to 2.09 microns in the Konica film. 3) Thickness of the film base was the same (170 microns) in all types of film. 4) Thickness of the emulsion layer was 7 microns for non-screen type film, whereas that in the screen type was 4 microns to 8 microns. 5) Size of the silver grain of Kodak Ekta speed was large, and the thickness of the emulsion of this film was thin when compared to others. 6) In screen type films, the silver grains were only sparsely coated. In the non-screen type, however, a large number of silver grains were coated compactly on the film base. 7) Kodak TMG (T-mat) showed flattened silver grains which were piled up on the film layer.</p>","PeriodicalId":75458,"journal":{"name":"Aichi Gakuin Daigaku Shigakkai shi","volume":"28 1 Pt 1","pages":"195-202"},"PeriodicalIF":0.0,"publicationDate":"1990-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effect of dihydrotachysterol on the periodontal tissues in rats].","authors":"T Hirukawa","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The purpose of the present study was to investigate the histological changes of the periodontal tissues in rats produced by oral administration of dihydrotachysterol (DHT). Forty-five rats, 6 weeks old, were divided equally into 9 groups (Groups A-I). Groups A, D and G, control groups, received an administration of corn oil (0.5 ml) once a day for 1, 2 and 4 weeks, respectively. Groups B, E and H received an administration of DHT (25 micrograms) once a day for 1, 2 and 4 weeks, respectively. Groups C, F and I had an administration of DHT (50 micrograms) once a day for 1, 2 and 4 weeks, respectively. The animals of all groups were killed 24 hours after the last administration. The periodontal tissues of the maxillary first molar of all animals were examined histologically and histometrically. Histological and histometrical findings: 1. In Groups A, D and G, control groups, the periodontal ligament, alveolar bone and cementum appeared normal during the entire experimental period. 2. In Group B, the peridontal tissues were almost similar to those of the control group. 3. In Groups C and E, osteoid tissue was observed in the alveolar bone surface. The thickness of the periodontal ligament decreased and the bone marrow spaces were slightly enlarged. The volmetric density of the alveolar bone decreased compared with that of the control groups. 4. In Groups F, H and I, the thickness of the periodontal ligament decreased significantly. In the periodontal ligament, destruction of collagen fibers was observed, and fibroblasts, collagen fibers and oxytalan fibers decreased in number. Dental ankylosis was also found. An abnormal darkly-stained layes (using the PAS staining method) was observed in the cementum surface. The alveolar bone marrow spaces were enlarged and replaced by fibrous tissue. In the histometrical findings, the thickness of the periodontal ligament and the volumetric density of the alveolar bone had decreased, and the volume of the cementum had increased significantly. The result of the present study suggested that oral administration of dihydrotachysterol to the rats induced the changes of the periodontal tissues similar to those seen in aging humans.</p>","PeriodicalId":75458,"journal":{"name":"Aichi Gakuin Daigaku Shigakkai shi","volume":"28 1 Pt 2","pages":"367-87"},"PeriodicalIF":0.0,"publicationDate":"1990-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13288958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effect of prostaglandin E1 on the rat mandibular condyle in organ culture].","authors":"Y Suzumura","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The purpose of the present study was to investigate histologically and ultrastructurally the effect of prostaglandin E1 (PGE1) on the development and growth of the rat mandibular condyle in organ culture. The mandibular condyles of rats were divided into 5 groups (Groups 1-5) for light microscopy and 5 groups (Groups I-V) for electron microscopy. In Groups 1 and I, the mandibular condyles were removed from rats 1, 2, 4, 6 and 8 days after birth. In Groups 2 and II, 3 and III, 4 and IV, and 5 and V, the mandibular condyles were removed from rats immediately after birth and were cultured for 1, 2, 4, 6, and 8 days in the four media, namely BGJb, BGJb with 1% ethanol, BGJb with 0.5 micrograms of PGE1/ml, BGJb with 5 micrograms of PGE1/ml, respectively. The mandibular condyles of 5 groups (Groups 1-5) were examined histologically at 1 to 8 days, and the mandibular condyles of the other 5 groups (Groups I-V) were examined ultrastructurally at 4 and 6 days. 1. Light Microscopic Observation. i) Group 1 (in vivo) The zones of articular surface, proliferation, differentiation and hypertrophy of the mandibular condyle showed normal development. ii) Group 2 (BGJb) and Group 3 (BGJb+1% AL) The zones of proliferation and differentiation displayed a slight decrease in cell number compared with those of Group 1. iii) Group 4 (BGJb+0.5 micrograms PGE1) and Group 5 (BGJb+5 micrograms PGE1) The zone of proliferation showed a moderate decrease in cell number and in thickness compared with those of Groups 2 and 3. The zone of differentiation exhibited a marked decrease in cell number and in thickness, so that the level of the zone of hypertrophy moved upwards and close to the zone of proliferation. 2. Electron Microscopic Observation i) Group I (in vivo) The cells of the zones of articular surface, proliferation, differentiation and hypertrophy showed normal development in their cell organella such as mitochondria, rough surfaced endoplasmic reticulum and Golgi apparatus. ii) Group II (BGJb) and Group III (BGJb+1% AL) The cells of the zones of proliferation, differentiation and hypertrophy exhibited poor development in their cell organella compared with those of Group I. iii) Group IV (BGJb+0.5 micrograms PGE1) and Group V (BGJb+5 micrograms PGE1). The cells of the zone of proliferation exhibited poor development in their cell organella compared with those of Groups II and III. Furthermore, the zone of proliferation contained the fragments of cells in its intercellar areas.(ABSTRACT TRUNCATED AT 400 WORDS)</p>","PeriodicalId":75458,"journal":{"name":"Aichi Gakuin Daigaku Shigakkai shi","volume":"28 1 Pt 2","pages":"389-433"},"PeriodicalIF":0.0,"publicationDate":"1990-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13288959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Some characteristics of orthodontic treatment in high mandibular cases].","authors":"M Baba","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Maxillary protrusion cases with a high mandibular plane angle have some clinical difficulties. In such cases, each cephalometric plane spreads out with large angles and masticatory muscles are weak. Due to these morphological and functional abnormalities, anchorage loss as well as elongation of anchor teeth is easily caused and retrusion of the mandible is hard to be improved. Maxillary protrusion cases with a high mandibular plane angle were reestimated through a consideration of how natural anchorage is established by occlusal force. The first case showed a high mandibular plane and occlusal plane angles. Cervical head gear and class II elastics were used for a short period of time, which caused elongations of 6/6 and the opening of the mandibular plane angle by 3 degrees. The lateral profile, however, did not worsen since the mandibular ramus had a fair growth. The second case showed no opening of the mandibular plane angle as the result of an unusual extraction of 4/6. There was, however, no skeletal improvement because of an adult case. The third case showed the opening of the mandibular plane angle from the effect of the cervial head gear besides a weak muscular force, although the initial record revealed no high angles in cephalometric data. It may be suggested that cephalometric data are not enough to estimate function of orthodontic cases.</p>","PeriodicalId":75458,"journal":{"name":"Aichi Gakuin Daigaku Shigakkai shi","volume":"28 1 Pt 2","pages":"499-507"},"PeriodicalIF":0.0,"publicationDate":"1990-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Root resorption of mandibular second molars by impacted third molars. A case report with some reviews].","authors":"S Sakai,&nbsp;K Miyajima,&nbsp;T Yamakawa","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>A case is presented here in which mandibular third molars resorbed second molars bilaterally 4 years 9 months after orthodontic treatment was finished. The initial problem was open bite, which was treated by non-extraction followed by a period for observing the third molars. During that period, the mandibular third molars moved mesially to resorb the roots of the second molars. The injured second molars were, therefore, extracted and the third molars were uprighted. During adolescence, third molars are erupting. When the posterior space is not enough for the third molars, they often erupt buccally or lingually, or impact distally toward the second molars and cause root resorption. It is suggested that the third molars should be observed carefully till they erupt or are extracted.</p>","PeriodicalId":75458,"journal":{"name":"Aichi Gakuin Daigaku Shigakkai shi","volume":"28 1 Pt 1","pages":"259-66"},"PeriodicalIF":0.0,"publicationDate":"1990-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}