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1.
J Periodontal Res ; 44(1): 62-72, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18973541

ABSTRACT

BACKGROUND AND OBJECTIVE: Collagen type I elevation in cyclosporin A-induced gingival overgrowth supports evidence that gingival fibroblasts play a decisive role in the manifestation of the phenotype. To analyze the role of gingival fibroblasts under more in vivo-like conditions, we evaluated the effect of cyclosporin A on collagen type I gene and protein expression in gingival overgrowth-derived gingival fibroblasts established as cocultures with gingival keratinocytes as well as in matched gingival fibroblast monolayers. MATERIAL AND METHODS: Monolayers and cocultures of primary gingival fibroblasts were treated with cyclosporin A for 6 and 72 h. The expression of collagen type I mRNA was analyzed by quantitative real time polymerase chain reaction, while expression and secretion of collagen type I protein was analyzed by indirect immunofluorescence and western blotting. RESULTS: Compared with controls, significant elevation of collagen type I mRNA was restricted to cocultures after 6 and 72 h of treatment with cyclosporin A. In keratinocytes, collagen type I remained undetectable. In monolayers and cocultures, indirect immunofluorescence showed a slightly higher level of collagen type I protein in gingival fibroblasts in response to stimulation with cyclosporin A. Semiquantitative detection of collagen type I by western blotting demonstrated a nonsignificant increase for cell extracts in monolayers and cocultures. For secreted collagen type I, western blot analysis of the supernatants revealed elevated protein levels in cultures stimulated with cyclosporin A. Compared with the corresponding monolayers, the stimulatory effect of cyclosporin A on protein secretion was significant only in coculture. CONCLUSION: Our results indicate that collagen type I is a target of cyclosporin A and that gingival fibroblasts are decisive for the manifestation of the gingival overgrowth-phenotype. Furthermore, the results suggest that cocultures of gingival overgrowth-derived gingival fibroblasts and gingival keratinocytes permit analysis of cyclosporin A-induced effects under more in vivo-like conditions.


Subject(s)
Collagen Type I/analysis , Cyclosporine/adverse effects , Fibroblasts/pathology , Gingiva/pathology , Gingival Overgrowth/chemically induced , Keratinocytes/pathology , Adult , Blotting, Western , Cell Line, Transformed , Cells, Cultured , Coculture Techniques , Collagen Type I/drug effects , Collagen Type I/genetics , Connective Tissue Cells/drug effects , Connective Tissue Cells/pathology , Female , Fibroblasts/drug effects , Fluorescent Antibody Technique, Indirect , Gingiva/drug effects , Gingival Overgrowth/pathology , Humans , Keratinocytes/drug effects , Male , Middle Aged , Phenotype , Polymerase Chain Reaction , RNA, Messenger/analysis , Time Factors
2.
Gesundheitswesen ; 70(3): 164-9, 2008 Mar.
Article in German | MEDLINE | ID: mdl-18415924

ABSTRACT

OBJECTIVE: Having established the importance of compliance as a significant factor of a successful orthodontic treatment, the aim of the present study was to evaluate intrapersonal and interpersonal factors which could help predict patient compliance. METHODS: The attributional style of 58 patients was assessed by a standardised questionnaire. An individual questionnaire was designed to determine attitudes concerning orthodontic treatment, the doctor-patient relationship, the wearing behaviour and control behaviour. The questionnaire was answered by the patient and by the orthodontist. The compliance was evaluated by the orthodontist on the basis of commonly used indicators for compliance: wearing time, oral hygiene and reliability of keeping the appointments. RESULTS: The results showed a significant correlation between the compliance and the attributional style of the patients in positive situations, but not between the compliance and the wearing behaviour estimated by the patient. The interpersonal comparison revealed a lack of knowledge on the part of the orthodontist about the patients' daily activities and their ability to correctly wear their appliances. CONCLUSION: The questionnaire answers show compliance to be a subjective construct of the orthodontist demonstrating mostly social-emotional matters. There is no consistency with compliance and the patients' statement concerning their wearing behaviour but with a positive attitude on the part of the patients demonstrating independent responsibility.


Subject(s)
Attitude to Health , Internal-External Control , Orthodontics, Corrective/psychology , Orthodontics, Corrective/statistics & numerical data , Patient Compliance/psychology , Patient Compliance/statistics & numerical data , Physician-Patient Relations , Adolescent , Child , Female , Germany/epidemiology , Humans , Male , Psychology/statistics & numerical data , Surveys and Questionnaires
3.
HNO ; 55(11): 851-7, 2007 Nov.
Article in German | MEDLINE | ID: mdl-17684712

ABSTRACT

BACKGROUND: Velopharyngeal dysfunction (VPD) is generally known to be difficult to influence. Dysfunctional velopharyngeal motor patterns during speech were analyzed with the aim of optimizing the therapeutic strategies. METHODS: Velopharyngeal dysfunctions were videotaped and contextually analyzed during 89 speech sequences in 25 patients. Distinctive features of the motor patterns formed the basis of categorization by three therapists experienced in nasopharyngoscopy. There was a high inter-rater reliability of 94%. RESULTS: A total of four different function profiles were found: 1. VPD with retracted articulatory placement (compensatory articulation) (38%), 2. VPD with motor coordination problems characterized by mistiming of VP movements and voice onset/offset (15%), 3. VPD with verbal dyspraxia characterized by a silent positioning of VP closure before phonation started and a malregulation of muscle tonus (10%) and 4. phoneme-specific VPD (37%). CONCLUSION: Specific knowledge regarding the characteristics of dysfunctional speech motor patterns enables specifically tailored therapy.


Subject(s)
Apraxias/complications , Apraxias/diagnosis , Cleft Palate/complications , Cleft Palate/diagnosis , Velopharyngeal Insufficiency/diagnosis , Velopharyngeal Insufficiency/etiology , Adolescent , Adult , Apraxias/classification , Child , Cleft Palate/classification , Female , Humans , Male , Speech Production Measurement , Velopharyngeal Insufficiency/classification
4.
Cell Tissue Res ; 319(3): 467-78, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15668800

ABSTRACT

Although the function and effects of many growth factors and extracellular matrix (ECM) molecules have been described for several periodontal tissues in vivo and in vitro, the molecular interactions involved in the communication between cells of the periodontal ligament and the alveolar bone are poorly understood. To contribute to the identification of such interactions, we have generated co-cultures (CCs) of periodontal ligament fibroblasts (PDLs) and alveolar bone cells (ABCs) and compared mRNA expression for various growth factors, ECM molecules, and matrix metalloproteinase13 (MMP13) after 1 and 2 weeks with matched mono-cultures (MCs) by reverse transcription/polymerase chain reaction. Compared with CCs of 1 week, PDLs and ABCs after 2 weeks revealed relatively high levels of all analyzed mRNAs, viz., for EGF, HGF, VEGF, TGFbeta1, collagen-I (COL1), osteonectin (ON), fibronectin (FN1), and MMP13. At week 2, when compared with MCs, CCs showed an elevation of all tested mRNAs in PDLs and ABCs, except for TGFbeta1 and FN1, which only increased in PDLs. After 1 week, when CCs were compared with MCs, mRNAs for HGF and TGFbeta1 were less abundant in PDLs and ABCs, whereas the other genes exhibited lower expression levels in only one of the cell types. Analysis of our data indicated that the expression of mRNAs for growth factors and for COL1, ON, FN1, and MMP13 was modulated in the distinct cell types with respect to culture time and culture type. The differences in the mRNA expression patterns between CCs and MCs suggest that the respective genes are involved in the molecular interactions of PDLs and ABCs.


Subject(s)
Collagenases/genetics , Extracellular Matrix Proteins/genetics , Fibroblasts/cytology , Growth Substances/genetics , Periodontal Ligament/cytology , RNA, Messenger/biosynthesis , Tooth Socket/cytology , Adolescent , Cell Line, Transformed , Cells, Cultured , Child , Coculture Techniques , Collagenases/metabolism , DNA Primers/chemistry , Extracellular Matrix Proteins/metabolism , Female , Fibroblasts/metabolism , Fibroblasts/ultrastructure , Gene Expression , Growth Substances/metabolism , Humans , Keratinocytes/cytology , Keratinocytes/metabolism , Male , Matrix Metalloproteinase 13 , Microscopy, Electron, Scanning , Periodontal Ligament/metabolism , Periodontal Ligament/ultrastructure , Reverse Transcriptase Polymerase Chain Reaction , Tooth Socket/metabolism
5.
Cell Tissue Res ; 312(2): 189-96, 2003 May.
Article in English | MEDLINE | ID: mdl-12690441

ABSTRACT

Cells of the periodontal ligament and the alveolar bone lie in close vicinity in the periodontium. The goal of this study was to create an in vitro model to facilitate the study of the morphogenesis and proliferation of these two cell types under more in-vivo-like conditions. This was accomplished by the generation of organotypic co-cultures of primary human periodontal ligament fibroblasts (PDL) and alveolar bone cells (BC) and matched mono-cultures after 1, 2 and 3 weeks. Indirect immunofluorescence (IIF) for vimentin indicated that PDL cells exhibited sustained stratification only in the presence of BC cells, suggesting an important role for BCs in maintaining the stratification of PDL cells. In mono-cultures, only BC cells showed progressing stratification. They also displayed the most pronounced contraction of the cell culture matrix. Moreover, Ki-67 antigen detection by IIF revealed that these features coincided with cell proliferation localized on the matrix surface at the onset of cell stratification. These findings suggest that, in addition to proliferation, a further prerequisite for stratification may be cell migration. Furthermore, the maintained cell stratification, proliferation, and compartmentalization noted for PDL cells in organotypic co-cultures and BCs in mono-cultures can only be observed in a three-dimensional culture system. Thus, our system represents a novel experimental tool to further elucidate the underlying mechanisms of the growth and differentiation of PDL and bone tissue.


Subject(s)
Bone and Bones/cytology , Gingiva/growth & development , Ligaments/growth & development , Cell Division , Child , Coculture Techniques , Collagen Type I/metabolism , Culture Media , Female , Fibroblasts , Fluorescent Antibody Technique, Indirect , Gingiva/cytology , Humans , Ki-67 Antigen/biosynthesis , Kinetics , Ligaments/cytology , Male , Vimentin/metabolism
6.
Eur J Orthod ; 23(2): 145-51, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11398552

ABSTRACT

The aim of the present study was to investigate putative relationships between different malocclusions such as Class III and Class II division 1, and congenital tooth anomalies. Two-hundred Class III and 215 Class II division 1 patients were examined for the presence of any of the following congenital tooth anomalies: maxillary incisor hypodontia, maxillary canine impaction, transpositions, supernumerary teeth, and tooth agenesis. Their occurrence rates were then calculated as a percentage of the total sample and were compared for statistical differences. The results revealed no statistical difference (P > 0.05) in the occurrence rates of upper lateral incisor agenesis, peg-shaped laterals, impacted canines, or supernumerary teeth between the Class III and the Class II division 1 malocclusions. When the occurrence rate of all congenital tooth anomalies was compared between the two malocclusions, Class III subjects showed significantly higher rates (P < 0.05). Comparison with published surveys on general populations showed similar occurrence rates. It can be concluded that subjects with Class III and Class II division 1 malocclusions show patterns of congenital tooth anomalies similar to those observed in the general population. Congenital tooth anomalies may represent another criterion for the study of malocclusion, with respect to their origin and development.


Subject(s)
Malocclusion/complications , Malocclusion/genetics , Tooth Abnormalities/complications , Tooth Abnormalities/genetics , Adolescent , Adult , Anodontia/complications , Anodontia/genetics , Chi-Square Distribution , Child , Cuspid/abnormalities , Female , Humans , Incisor/abnormalities , Male , Malocclusion, Angle Class II/complications , Malocclusion, Angle Class II/genetics , Malocclusion, Angle Class III/complications , Malocclusion, Angle Class III/genetics , Middle Aged , Tooth Eruption, Ectopic/complications , Tooth Eruption, Ectopic/genetics , Tooth, Impacted/complications , Tooth, Impacted/genetics , Tooth, Supernumerary/complications , Tooth, Supernumerary/genetics
7.
Am J Med Genet ; 99(4): 280-5, 2001 Apr 01.
Article in English | MEDLINE | ID: mdl-11251993

ABSTRACT

The generic term median facial dysplasia (MFD) describes a subgroup of patients with cleft lip and palate exhibiting characteristic craniofacial defects: (1) short prolabium, (2) absence of frenulum labii, (3) hypoplasia of premaxilla, (4) absent upper central and lateral incisors of the cleft side, and (5) deficient septal cartilage and nasal spine. Gross brain malformations are usually absent in MFD. The same craniofacial malformations are also described in patients with holoprosencephaly sequence (HPE-S). We report on two male patients with bilateral cleft lip and palate showing the facial findings of MFD or HPE-S. Additional congenital malformations were anal atresia in one patient and severe cardiac defect in the other. In both, HPE was excluded by brain imaging, although uncommon brain anomalies were detected consisting of multiple white-matter lesions in the one patient and unusual enlargement and tortuosity of intracerebral blood vessels in both patients. In addition to facial anomalies, the patients also had psychiatric problems typically seen in velo-cardio-facial syndrome (VCFS). Fluorescence in situ hybridization (FISH) analysis confirmed a 22q11.2 microdeletion in both.


Subject(s)
Craniofacial Abnormalities/diagnosis , Craniofacial Abnormalities/genetics , Abnormalities, Multiple , Adolescent , Adult , Brain/abnormalities , Brain/pathology , Chromosome Deletion , Chromosomes, Human, Pair 22 , Cleft Lip/genetics , Cleft Palate/genetics , Craniofacial Abnormalities/classification , Diagnosis, Differential , Genetic Variation , Holoprosencephaly/diagnosis , Humans , In Situ Hybridization, Fluorescence , Infant , Magnetic Resonance Imaging , Male
8.
J Dent Res ; 80(11): 1984-9, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11759007

ABSTRACT

Mechanical stress has been shown in vitro to modulate integrin-beta1-mediated activation of p125FAK/FAK. To test the hypothesis whether this also applies to periodontal ligament fibroblasts (PDLs), we subjected human PDLs to mechanical stretch and analyzed stress-induced changes of p125FAK activation by quantitative immunoprecipitation of p125FAK and changes in the topography of molecules localizing in focal adhesions by indirect immunofluorescence. Generally, all components of focal contacts under study-including detection of phosphotyrosine, i.e., integrin-beta1, p125FAK, and paxillin-revealed a relative co-localization during stretch application. Under stretch, we observed a re-distribution of all components from the cell periphery to the cytoplasm following the main axes. Tyrosine phosphorylation of p125FAK was monitored up to 72 hours under stretch. While the amount of p125FAK remained essentially constant, the activation of p125FAK was clearly modulated. Tyrosine phosphorylation of p125FAK increased from 15 minutes up to 1 hour and declined after stretching periods of 24, 48, and 72 hours. The analysis of our data indicated a stretch-induced redistribution of focal adhesion components and a modulation of p125FAK activation, suggesting alterations in focal adhesions and their associated signal cascade.


Subject(s)
Focal Adhesions/metabolism , Periodontal Ligament/cytology , Periodontal Ligament/metabolism , Cells, Cultured , Cytoskeletal Proteins/metabolism , Dental Stress Analysis , Enzyme Activation , Fibroblasts/enzymology , Fibroblasts/physiology , Fluorescent Antibody Technique, Indirect , Focal Adhesion Kinase 1 , Focal Adhesion Protein-Tyrosine Kinases , Humans , Immunoblotting , Integrin beta1/metabolism , Paxillin , Phosphoproteins/metabolism , Phosphorylation , Phosphotyrosine/metabolism , Protein-Tyrosine Kinases/metabolism , Signal Transduction , Stress, Mechanical
9.
Cell Tissue Res ; 301(2): 323-7, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10955727

ABSTRACT

A decrease in gap junction-mediated cell-to-cell communication has previously been observed in monolayer cultures of human keratinocytes (HaCaT cells) expressing the human papillomavirus type 16 E5 (HPV16 E5) gene and attributed to the reduced phosphorylation of connexin 43, the most abundant connexin in HaCaT cells. In line with this observation, we have now analyzed the effect of HPV16 E5 on connexin 43 expression in raft cultures produced by transfected HaCaT cells. These keratinocytes transcribe HPV16 E5 under the control of a dexamethasone-inducible promoter. Our results show that treatment with dexamethasone leads to an almost complete disappearance of connexin 43 in rafts expressing the E5 gene but not in control rafts. In our study we discuss the possible effects of this downregulation on cell-cell communication and cellular malignant transformation.


Subject(s)
Cell Culture Techniques , Connexin 43/metabolism , Keratinocytes/metabolism , Keratinocytes/virology , Oncogene Proteins, Viral/genetics , Cell Line , Cells, Cultured , Connexin 43/immunology , Dexamethasone/pharmacology , Fluorescent Antibody Technique, Indirect , Humans , In Situ Hybridization , Keratinocytes/drug effects , Oncogene Proteins, Viral/physiology , RNA, Messenger/analysis , Transfection
10.
Eur J Cell Biol ; 79(6): 407-12, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10928456

ABSTRACT

It has been shown that the E5 protein of the human papillomavirus type 16 modulates epidermal growth factor receptor downregulation in monolayer cultures of human keratinocytes and mouse fibroblasts. We have now analysed the effect of this protein on the expression, the distribution and the activation of EGF receptors in raft cultures derived from an E5-transfected human keratinocyte cell line. The epithelia generated in these cultures were stratified and exhibited suprabasal expression of cytokeratins 1 and 10, which are known markers of early epidermal differentiation. In situ hybridization with an antisense riboprobe to the human papilloma virus type 16 E5 protein revealed a homogeneous gene expression within the entire epithelium of E5-transfected but not empty vector-transfected control cultures. Treatment of serum-starved rafts with EGF for 48 hours led to a strong decrease of suprabasal EGF receptors in control cultures, but not in rafts of E5-expressing cells. Under these conditions, no activated receptors were observed in control cultures, but activated receptors were still present in E5-raft cultures. Our results indicate that human papilloma virus type 16 E5-mediated modulation of EGF receptor expression occurs in a time- and structure-dependent manner in epithelial equivalents of human keratinocytes.


Subject(s)
ErbB Receptors/metabolism , Keratinocytes/metabolism , Oncogene Proteins, Viral/metabolism , Cell Differentiation , Cell Line , Culture Media, Serum-Free , Down-Regulation , Fluorescent Antibody Technique, Indirect , Humans , In Situ Hybridization , Keratins/metabolism , Ligands , Membrane Microdomains/metabolism , Phosphorylation , Time Factors , Transcription, Genetic , Transfection
11.
Biomaterials ; 21(15): 1549-59, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10885727

ABSTRACT

This article explores whether organotypic cultures of immortalized gingival keratinocytes constitute a suitable model for assessing the epithelial cell compatibility of two groups of dental resins, each of them representing one group used in orthodontics and temporo-mandibular disorders (TMD) therapy under conditions more closely resembling the actual tissue situation. The resins were tested with the agar diffusion assay (ADA) in conventional monolayer and organotypic cultures. Compared to the control exhibiting a neutral red destaining index of 3, the index of 4 obtained after exposure of monolayers to one soft permanent resin (Durabase) indicated the presence of a non-lytic but physiologically active substance. In contrast, the adaptation of the ADA to organotypic cultures revealed no apparent lesions at the epithelial surface by performing scanning electron microscopy, while histoarchitecture indicated the development of stratified surface epithelia. This was substantiated by undamaged cells in the uppermost cell layers and by the preservation of cell-to-cell contacts. Furthermore, indirect immunofluorescence for Ki-67 and the cytokeratins ck 14 and ck4 revealed that cell proliferation and epithelial structure were maintained, while differentiation was enhanced, possibly increasing epithelial resistance. The results obtained from the organotypic cultures suggest that (i) cell-affecting effects of materials visible in monolayer cultures may not be seen in epithelia resembling that in vivo and that (ii) enhanced differentiation may be associated with increased stability of the epithelial cells. Thus, organotypic cultures of gingival cells constitute a tissue model allowing short-term tissue compatibility studies of dental materials and rendering a potential candidate also for long-term studies.


Subject(s)
Acrylic Resins , Gingiva/cytology , Keratinocytes/cytology , Occlusal Splints , Orthodontic Appliances , Repressor Proteins , Animals , Biocompatible Materials , Cell Transformation, Viral , Humans , L Cells , Mice , Oncogene Proteins, Viral/genetics , Organ Culture Techniques/methods , Papillomaviridae/genetics , Papillomavirus E7 Proteins
12.
J Orofac Orthop ; 61(1): 2-19, 2000.
Article in English, German | MEDLINE | ID: mdl-10682407

ABSTRACT

Whilst a patient is undergoing orthodontic treatment, dental appliances based on non-precious metals or titanium remain in the oral cavity for up to several years. Throughout this period the appliance is in either direct or indirect contact with the oral mucosa. To investigate the possibility of cell damage occurring as a result of appliance corrosion, monolayer cultures of immortalized human gingival keratinocytes were assessed for acute cyto- and genotoxicity using the hexosaminidase assay and the Comet assay respectively. The materials tested included 1. a nickel-free wire, 2. a UK-1 bond, 3. nickel-free as well as nickel-containing brackets with and without color signature and 4. a titanium expansion screw. Each of the test materials was corroded in a solution consisting of equal amounts of lactic acid and sodium chloride (0.1 M) for 1, 3, 7 and 14 days. The cell cultures were then exposed to eluates exhibiting the highest ion concentrations. None of the eluates was found to exhibit acute cytotoxicity, regardless of the type of test system used. Qualitative assessment using neutral red dye for live cells and either trypan blue or propidium iodide to disclose dead cells failed to reveal any significant increase in cell damage when exposed cells were compared to control cultures. Unrestricted cell vitality was confirmed by quantifying viable cells through measurement of hexosaminidase enzyme activity. Furthermore, assessment of genotoxicity revealed no apparent DNA damage to immortalized gingival keratinocytes following exposure to the test eluates. Because the materials tested in this study were corroded using the exacting methods normally applied to precious metals or gold-containing alloys, the lack of either acute cyto- or genotoxic effects following exposure to the test eluates indicates that the materials tested exert no adverse effects on cells similar to those of the target tissue exposed to the materials in situ.


Subject(s)
Dental Materials/toxicity , Gingiva/drug effects , Keratinocytes/drug effects , Orthodontic Appliances/adverse effects , Cell Culture Techniques/methods , Cell Line , Cell Survival/drug effects , Comet Assay/methods , Corrosion , Dental Materials/chemistry , Gingiva/cytology , Humans , Mutagenicity Tests/methods , Mutagenicity Tests/statistics & numerical data , Orthodontic Appliances/statistics & numerical data , Statistics, Nonparametric , Time Factors
13.
Cleft Palate Craniofac J ; 36(4): 304-9, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10426595

ABSTRACT

OBJECTIVE: The objectives of the present study were (1) to investigate whether growth increments until 6 months of age are influenced by particular factors, (2) to analyze whether anterior cleft reduction is dependent on the extent of the cleft width at birth, and (3) to examine the correlation between maxillary measurements at birth and the anterior cleft width at 6 months of age. DESIGN: The study design was prospective and longitudinal. SETTING: Heidelberg University Hospital Interdisciplinary Cleft/Craniofacial Center. PATIENTS AND METHOD: The longitudinal records of 34 patients (24 male and 10 female) with complete unilateral cleft lip, alveolar ridge, and hard and soft palate were included in this study. All patients were treated with the same protocol. All participants were assessed at 0 and 6 months of age. Maxillary plaster casts of the patients were analyzed using a computer-controlled three-dimensional digitizing system. MAIN OUTCOME MEASURE: Maxillary models were measured and compared to putative factors influencing growth. RESULTS: No statistically significant differences were found between maxillary growth changes and increases in weight and length. Similarly, there was no significant interaction between the extent of the alveolar cleft width at birth and its reduction prior to lip closure. In contrast, significant differences of maxillary growth increments could be found between male and female patients. Stepwise regression analysis demonstrated a correlation between maxillary measurements at birth and growth increments. CONCLUSION: The results of the study indicate that gender plays a certain role in growth changes within the first 6 months of age.


Subject(s)
Aging/pathology , Cleft Lip/pathology , Cleft Palate/pathology , Dental Arch/growth & development , Maxilla/growth & development , Confidence Intervals , Dental Arch/pathology , Female , Humans , Infant , Infant, Newborn , Linear Models , Male , Maxilla/pathology , Models, Dental/statistics & numerical data , Prospective Studies , Reproducibility of Results , Sex Characteristics , Statistics, Nonparametric
14.
J Orofac Orthop ; 60(2): 77-86, 1999.
Article in English, German | MEDLINE | ID: mdl-10220976

ABSTRACT

Fibroblasts isolated from human periodontal ligament (PDL) were cultured under a medium supplemented with ascorbic acid, beta-glycerophosphate and dexamethasone. The cultures were assessed for their ability to elaborate a mineralized matrix. Cell cultures stained positive when analyzed for alkaline phosphatase activity throughout the culture period. After about 3 weeks in culture, the cells produced a calcified matrix. Light microscopy showed formation of clusters of different shapes and sizes. Von Kossa staining revealed mineral deposits as amorphous brown-black precipitates. Transmission electron microscopy showed cells in multilayers and mineralized formations in close association with a dense network of collagen fibers. Scanning electron microscopy revealed smooth formations rising over the cultures with an abundant fiber matrix. We conclude that human PDL fibroblasts can be induced to form a mineralized matrix which shares features with bone mineralized matrix but most likely represents a more immature type of in vitro mineralization. Moreover, the present study further supports the osteoblastic potential of these cells.


Subject(s)
Calcification, Physiologic , Periodontal Ligament/ultrastructure , Cell Culture Techniques/methods , Cells, Cultured , Culture Media , Extracellular Matrix/ultrastructure , Fibroblasts/ultrastructure , Humans , Microscopy, Electron/methods , Microscopy, Electron, Scanning/methods , Osteoblasts , Time Factors
15.
J Orofac Orthop ; 60(2): 95-107, 1999.
Article in English, German | MEDLINE | ID: mdl-10220978

ABSTRACT

In the context of orthodontic treatment planning, the decisions to be made are often affected by the assumption of future growth patterns, especially the direction of mandibular rotation. Using longitudinally available lateral cephalograms from the Belfast Growth Study, it was examined whether, on the basis of the cephalometric variables at the ages of 7, 9 and 11, the direction of mandibular rotation can be predicted in the respective subsequent 4-year intervals. For statistical analysis of this problem, logistic regression models were applied to describe and quantify the influence of potential explanatory variables on the direction of mandibular rotation (dependent variable). In addition, graphical methods taken from the field of medical diagnostics were applied for prediction and for determination of predictive accuracy. The use of logistic regression models revealed no relations between the explanatory variables SN-MeGo and S-Go/N-Me and the subsequent mandibular growth pattern. Only the upper and lower parts of the gonial angle showed a minor predictive impact. A graphical evaluation of their prognostic impact by means of "receiver operating characteristics" (ROC) curves, complemented by determination of the areas under the curves, confirmed the relations discovered. Nevertheless the prognostic limits of the lateral cephalogram emerged clearly for all variables investigated.


Subject(s)
Cephalometry/statistics & numerical data , Adolescent , Child , Child, Preschool , Humans , Logistic Models , Longitudinal Studies , Maxillofacial Development , Prognosis , ROC Curve , Sensitivity and Specificity
16.
Ann Anat ; 181(1): 127-32, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10081576

ABSTRACT

In stratified epithelia, integrins play a fundamental role in mediating basal cell attachment to a variety of extracellular matrix molecules. To assess whether keratinocyte-specific integrins are expressed in a similar way as in the normal situation also under in vivo related conditions, we processed oral mucosa equivalents consisting of keratinocytes and fibroblasts from non-cornified gingiva. In this model histomorphology, the expression of differentiation-specific keratins and keratinocyte-type integrins exhibited similarity to the tissue of origin. The stages of tissue normalization were assessed on frozen sections by indirect immunofluorescence. The initial activated stage (1 week) was characterized by (i) incomplete epithelial organization and a weak presence of the suprabasal mucosa type keratin K4, (ii) diffuse expression of the integrin chains beta 1 and alpha 6 and (iii) abundance of the wound healing-associated integrin alpha v throughout the whole epithelium. After 2 weeks, the increase in epithelial organization was characterized by (i) the presence of a basal and suprabasal cell compartment, (ii) extension of K4 in the suprabasal compartment, (iii) extended expression of the keratinocyte integrins beta 1 and alpha 6 and (iv) concentration of alpha v integrin underneath basal cells. Further normalization of tissue architecture was indicated by (i) a slight increase in K4 extension, (ii) appearance of keratinocyte integrins beta 1 and alpha 6 in basal and parabasal cells and (iii) interruption of the band-like alpha v integrin immunolocalization at the subepithelial site. The findings in the in vitro model system indicate that these oral mucosa equivalents exhibit similarities to the in vivo situation of non-cornified gingiva, thus rendering them a suitable model for the assessment of stages during epithelial reconstruction or in vivo relevant studies on material effects.


Subject(s)
Gingiva/cytology , Integrins/biosynthesis , Keratinocytes/cytology , Mouth Mucosa/cytology , Antigens, CD/biosynthesis , Cell Differentiation , Cells, Cultured , Coculture Techniques , Fibroblasts/cytology , Fibroblasts/physiology , Gingiva/physiology , Humans , Integrin alpha6 , Integrin alphaV , Integrin beta1/biosynthesis , Integrins/analysis , Keratinocytes/physiology , Keratins/biosynthesis , Mouth Mucosa/physiology , Organ Culture Techniques , Time Factors
17.
J Orofac Orthop ; 60(1): 39-52, 1999.
Article in English, German | MEDLINE | ID: mdl-10028787

ABSTRACT

The aim of this study was to analyze the dynamic development of Class II, Division 2 malocclusion with reference to the untreated patients from the Belfast Growth Study. As a second step, the influences of premolar extraction in all 4 quadrants and of maxillary second molar extraction in the upper jaw in Class II/2 patients were examined, focusing on the cephalometric variables in comparison to those of the untreated patients from the Belfast study. The longitudinal cephalometric values of 20 patients in each group were compared. In addition, the possibility of third molar eruption was evaluated in the extraction patients from the panoramic radiographs. The overbite based on study models at the beginning and end of treatment was calculated. Furthermore, renewed spacing after premolar extraction was assessed. The results derived from cephalometric analysis demonstrated that profile flattening was also observed in untreated Class II/2 patients during the growth period. Comparison of these data with those obtained from the extraction groups revealed a significantly marked recession of the upper lip after premolar extraction. In contrast, only slightly increased flattening after maxillary second molar extraction was observed compared with the untreated patients of the control group. Whereas the interincisal angle was reduced to a value approximating that of untreated Class I patients after maxillary second molar extraction, only a small decrease was recorded after premolar extraction. From our point of view, the claim that premolar extraction facilitates third molar eruption should be seen in an extremely critical light and should not contribute to the decision in favor of extraction. In addition, there is a problem of renewed spacing in the extraction area after premolar extraction.


Subject(s)
Malocclusion, Angle Class II/surgery , Tooth Extraction , Adolescent , Bicuspid/surgery , Cephalometry/statistics & numerical data , Child , Female , Humans , Male , Malocclusion, Angle Class II/diagnostic imaging , Mandible , Maxilla , Molar/surgery , Radiography , Statistics, Nonparametric
18.
Cell Tissue Res ; 292(2): 355-66, 1998 May.
Article in English | MEDLINE | ID: mdl-9560478

ABSTRACT

Cell-matrix interactions and the ordered deposition of basement membrane (BM) components are of major importance for the maintenance of tissue homeostasis in complex epithelia. This aspect was studied in vitro in a coculture system designed as an oral mucosa model. As crucial epithelial features the kinetics of proliferation, expression of site-specific keratins as well as integrin patterns in correlation to synthesis of BM components were assessed by immunohistochemistry and in situ hybridization. Comparison with non-cornified gingiva as tissue of origin revealed different stages of epithelial development, eventually leading to complete reconstruction within a time frame of 1-3 weeks. First, the initial activated stage up to 1 week was characterized by (a) high keratinocyte proliferation, (b) extended expression of the basal cell-specific keratin K5 and (c) a patchy pattern of the differentiation-specific keratins K4 and K13. Second, after 2 weeks the improvement of histoarchitecture correlated to (a) predominant K5 expression in the basal and (b) extension of K4 and K13 within the suprabasal cell compartment, (c) high expression of integrins alpha3 beta1 and alpha6 beta4 including their ligand laminin-5 and (d) accumulating deposition of basement membrane components. Third, virtually complete tissue normalization at 3 weeks was indicated by (a) restriction of K5 to the basal cell area, (b) regular suprabasal localization of K4 and K13, (c) polarization of integrins to basal and parabasal cells and (d) linear codistribution of collagen IV, "classical" laminin (-1 or -10) and laminin-5 underneath the basal cells. Thus, these organotypic cocultures represent relevant equivalents for non-keratinized oral mucosa with typical gingival differentiation features and in addition suitable models for preclinical trials such as prospective dental material testing.


Subject(s)
Epithelial Cells/metabolism , Mouth Mucosa/anatomy & histology , Mouth Mucosa/metabolism , Cell Differentiation , Cell Division , Cells, Cultured , Coculture Techniques , Epithelial Cells/cytology , Extracellular Matrix Proteins/metabolism , Fluorescent Antibody Technique, Indirect , Humans , Integrins/metabolism , Keratins/metabolism , Mouth Mucosa/growth & development , Phenotype , Time Factors
19.
Eur J Orthod ; 20(2): 111-4, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9633164

ABSTRACT

A non-surgical technique for the treatment of upper airway obstruction in oculoauriculovertebral dysplasia using an intra-oral orthopaedic appliance is described, which resulted in respiratory and feeding problems being solved without side-effects. This non-invasive management might also be of major benefit in the treatment of airway obstruction associated with Pierre Robin sequence, mandibular micrognathia in other craniofacial anomalies, or obstructive sleep apnoea.


Subject(s)
Airway Obstruction/therapy , Goldenhar Syndrome , Occlusal Splints , Airway Obstruction/etiology , Dental Care for Chronically Ill , Female , Goldenhar Syndrome/complications , Humans , Infant
20.
Am J Orthod Dentofacial Orthop ; 113(6): 641-6, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9637567

ABSTRACT

Functional treatment of condylar fractures in adult patients usually follows the closed reduction/maxillomandibular fixation approach. Some of the problems arising when functional appliances (i.e., activator) are used have been identified and presented here, especially in patients where fractured parts are dispositioned/dislocated. The cause is discussed and a different functional approach is proposed that yields good results.


Subject(s)
Activator Appliances , Joint Dislocations/therapy , Mandibular Condyle/injuries , Mandibular Fractures/therapy , Adolescent , Adult , Female , Humans , Jaw Fixation Techniques/instrumentation , Male , Occlusal Splints
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