摘要:

Abstract –Demineralized, H‐E stained longitudinal and transversal sections of unerupted permanent incisors from 1/2–3‐yr‐old calves were studied by light microscopy. The most incisal dentin in all teeth was. characterized by a regular pattern of straight axially oriented giant tubules situated in the axiomesiodistal plane with interglobular dentin between them. In younger teeth, the pulpal part of every giant tubule contained an afferent and an efferent blood vessel, forming a hairpin loop and being surrounded by basophil cells. Incisal to the blood vessel loops, cells enbedded in an eosinophil matrix were present in the giant tubule lumina, showing increasing degenerative changes incisally. In older teeth there was a mesiodistally extended eosinophil dentin band near the pulp, with few, irregularly arranged, tortuous dentinai and gianl tubules, the latter containing single blood vessels accompanied by pulpal cells. Isolated degenerating odontoblasts in lacunar cavities were seen in the transition area of the normal circumpulpal dentin and the eosinophil dentin band. A hypothesis on the initiation and subsequent development of giant tubules is

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01778.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract –A method is presented which allows the average daily rate of enamel apposition to be estimated based on measurements of the length of prisms in longitudinal ground sections, and on available data for the time of formation of the tooth crown. The method was applied on 21 sections of human maxillary premolars. The reproducibility of the method was satisfactory, the error of measurement being in the order of 3.8%. After corrections having been made for the deviation of prisms from a radial direction, the average daily rate of enamel apposition along the prisms for any maxillary premolar was estimated to be within a range of from 2.0 to 6.1 μm, while a more probable rate would be 2.7–4.6 μm. These results are in agreement with experimental data, and are also compatible with the observed cross‐striation prism periodicity. The present study supports the theory that there exists a relationship between the prism periodicity and a 24‐h rhythm in enamel apposition in hu

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01779.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract –The purpose of the present study was to assess whether the degree of severity of enamel changes in a population exhibiting rather severe dental fluorosis may be related to posteruptive tooth age and to describe the clinical manifestations of the enamel destructions. All permanent teeth in 102 children aged 10–15 yr who were born and reared in a 2 ppm fluoride area of Kenya were examined for dental fluorosis using the TF‐Index. Clinically, at time of eruption all teeth appeared chalky white, but already prior to coming into occlusion discrete pits had formed. A variety of more extensive damages to the surface enamel was found in teeth already in occlusion. In particular, the maxillary incisors exhibited extensive artificial attrition for cosmetic reasons, which make these teeth unreliable for accurate scoring of severity in the present population. An analysis of the proportion of teeth exhibiting TF1‐scores 4+, 5+ and 6+ showed that children aged 13–15 yr had a significantly greater proportion of teeth with TFI‐scores>6 compared to children aged 10–12 yr (Wilcoxou,P<0.0001). This finding is unlikely to be a result of different fluoride exposures in the two age groups and indicates that even several years after eruption there is a trend towards an increasing severity of enamel surface destructions in children exhibiting pronounced degrees of subsurface enamel hypomineralization at tim

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01780.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract –The influence of a low force appliance on the maxilla in correction of unilateral cross‐bite was studied clinically and radiographically in 29 preschool children following a standardized treatment schedule. Four weeks' expansion was followed by a 4‐wk retention and a 12‐wk postretention period. Inter‐ and intraobserver evaluations of the reliability of the measurements on radiographs were performed. In all children but one the cross‐bites were corrected after 4 wk of expansion. The mean maxillary expansion was 3.3 mm in the second molar and 1.3 mm in the canine region, but decreased to 1.5 mm and 1.0 mm, respectively, at the end of the postretention period without relapse of the corrected malocclusion. No significant remaining orthopedic effects could be registered on radiographs by this low force appliance used. The modified quad helix appliance was found to be suitable for correction of unilateral crossbite in the primary dentition and was well tolerated by t

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01781.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract –A retrospective longitudinal study was performed on 20 patients with oral leukoplakia, 10 of which developed an oral squarnous cell carcinoma, to assess whether any alterations in the local immunologic reactivity could be found of value in predicting the subsequent behavior of the lesions. During the major period of follow‐up, the relative frequency of in situ IgA‐producing plasma cells was significantly higher in biopsies from patients subsequently developing cancer than in patients showing no cancer development. Preceding the malignant transformation by 12 to 15 months, however, a remarkable shift from IgA to IgG plasma cell predominance was noticed in the biopsies of the cancer series, not detectable in the non‐cancer group. HPV group specific capsid antigens were found in seven cases of the cancer series and in six of the non‐cancer group. The possible diagnostic implications of these results are

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01782.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract –The present study was undertaken in a community, where the tap water has been optimally fluoridated since 1959 (1.0–1.2 ppm). The material consisted of 92 children and adolescents including 30 sibling‐couples. The mean age of the participants was 11.8 ± 2.45 (SD) yr. 56 children had consumed fluoridated water all their life, the others only a part of the developmental period of their permanent dentition. Enamel biopsies were taken from 212 permanent teeth and 33 primary teeth by etching the tooth surface for 6 or 30 s. The etch depth was calculated from the mean of dissolved enamel calcium and phosporus. The fluoride concentration in the outermost enamel was almost similar in the teeth of the lifelong residents and the rest of the children. Towards the deeper layers the amount of fluoride decreases depending on its availablity during the development of the enamel. There was no striking similarity neither in the fluoride concentration nor in the amount of dissolved enamel between the siblings when compared with the other children. The posteruptive incorporation of fluoride takes place only on the outermost surface of the enamel. The results suggest that in subsurface layers the fluoride exposure during tooth formation is the dominating determinant of enamel fluoride concent

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01783.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract –Thirty‐four patients provided with removable partial dentures (RPDs) were reexamined after 3 yr. Caries that had developed during the period were analyzed with regard to the following potential caries risk factors: Lactobacilli, Streptococcus mutans, flow rate and buffer pH of paraffin stimulated saliva, oral hygiene and daily sucrose intake. Of 436 initially intact surfaces 31 (7.1%) had decayed and/or were restored during the 3‐yr period. Caries recurred in 26 (6.2%) out of 422 initially restored surfaces during the same period. The development of new or recurrent caries had no correlation to whether or not the surfaces affected were in contact with the RPDs. No single caries risk factor seemed to be sufficiently closely correlated to the number of caries lesions developed to be used alone in the selection of patients at risk. When the sum of assumed negative factors was used a correlation was found for the group as a whole between the number of negative factors and the development of caries. However predicting the development of caries in any individual case seems to be more compli

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01784.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract –Gingival biopsies from five patients with cyclosporin A (CsA) induced enlargement of the gingiva contained prominent mononuclear infiltrates beneath the epithelial basement membrane. These infiltrates and surrounding tissues were studied using monoclonal antibodies directed against lymphocytes and their subgroups (OKT 3, OKT 4, OKT 8, Leu 3 and Leu 4), monocytes (OKM 1) and the framework structure of HLA‐DR antigens (OKI al). As revealed by the reactivity of these antibodies the vast majority of the mononuclear cells in two individuals consisted of monocytes and in the others of T‐Iymphocytes. Virtually no B‐lymphocytes were observed. The ratio between T‐cells bearing T 4 and T 8 antigens, in separate biopsies, varied between 6 and 0.3. Control biopsies were obtained from the gingiva of seven healthy individuals without gingivitis. These biopsies contained relatively few mononuclear cells all of which had T‐lymphocyt

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01785.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract –In 52 patients with oral lichen planus topographically related to amalgam restorations, the fillings were replaced by other materials in 18, 16 of whom experienced complete remission of the lessions within 1–12 months. These results are discussed in relation to the results of epicutaneous patch tests for possible allergy to a number of mercury compounds. The term “oral lichenoid reaction”, is suggested to describe these

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01786.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract –The alterations during healing in laser and scalpel incised palate and tongue mucosa were studied in 37 Spraque‐Dawley rats by taking specimens for light and electron microscopic inspection immediately and 4, 7, H and 21 days after the treatments. The laser incision differed from the conventional incision: it was horizontally broader, more superficial, not bleeding and contained some charred and necrotic tissue particles; there were more inflammatory cells during healing, and the healing was slightly retarded. The damaged area around the laser incision was very narrow. In EM, the lasered areas showed total cell disruption with no morphologic details seen at the treated site. Adjacent to those sites, charred‐appearing particles were seen scattered and embedded also in the connective tissue. The most resistant cell organelles against lasercaused disruption were desmosomes and nuclear membranes. After 21 days' observation the ultrastructural study still revealed cell damage even though the reepithelialization as such seemed to be com

ISSN:0909-8836    

DOI:10.1111/j.1600-0722.1986.tb01787.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY