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Dissertations / Theses on the topic 'Tooth development'
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1
Courtney, Jo-Maree. "TNF signalling in tooth development." Thesis, King's College London (University of London), 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424467.
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Modino, Sonie Alix Carmen. "Stem cells and tooth development." Thesis, King's College London (University of London), 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.444559.
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Alfaqeeh, Sarah Ahmad A. "Characterisation and regulation of the tooth-bone interface during tooth development." Thesis, King's College London (University of London), 2018. https://kclpure.kcl.ac.uk/portal/en/theses/characterisation-and-regulation-of-the-toothbone-interface-during-tooth-development(c9272f5d-7401-4f4c-8933-7c087c775802).html.
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The tooth is closely related to the periodontium in which it sits, with a soft tissue interface forming between the alveolar bone and hard tissues of the tooth. This is known as the tooth-bone interface (TBI). In functional teeth, the TBI houses the periodontal ligament, while during development the TBI creates a space into which the tooth can grow. This project aims to provide an understanding of how the formation of the tooth and bone are coordinated during development and characterise the underlying factors and mechanisms that prevent bone formation and invasion at the interface between the tooth and bone. Using murine mandibular first molar (M1) TRAP stained histological sections, osteoclasts were found to be closely associated with the border of the developing bone, lining the TBI, but not within the TBI itself. Slice culture was used to follow tooth development in explant culture as it provided an excellent opportunity for manipulation and lineage tracing. DiI labelling experiments showed the contribution of two sources of cells in the formation of alveolar bone namely, dental follicle cells from around the tooth and, bone cells from the margins of the dentary. Isolation experiments were used to investigate the impact of the tooth on the bone and bone on the tooth. Isolation of E14.5 mandibular first molar (M1) tooth germ from the surrounding mesenchyme and alveolar bone resulted in tooth germ expansion while removing the tooth epithelium did not change the normal layout of osteoclasts at E14.5. The effect of manipulating the BMP signalling pathway on the differentiation of cells in the TBI during tooth development was studied. A local reduction in the TBI was observed next to the BMP-4 beads whereas a local widening in the TBI was observed when Noggin beads were implanted. The effect of manipulating the RANK-RANKL signalling pathway was investigated next. In situ hybridisation revealed the presence of OPG, RANK, and RANKL in the alveolar bone but OPG and RANKL only in the dental epithelium. Addition of exogenous RANKL to tooth explants in culture resulted in a statistically significant increase in osteoclast numbers and a widening of the TBI. On the other hand, the results obtained after exogenous OPG addition were regarded as inconsistent due to high variability. However, correlation of the difference in bone growth within a cultured tooth germ with the presence of osteoclasts showed absence of osteoclasts in areas of bone encroachment and the opposite, presence of osteoclasts, in areas devoid of bone. The TBI then was analysed in c-Fos mutants, a knockout mouse known to have a defect in osteoclastogenesis, resulting in lack of osteoclast production. Genotyping showed that the c-Fos mutant embryos were displaying the expected Mendelian ratio, but almost all the homozygotes died after birth, and the heterozygotes viability was found to be compromised. Micro-CT analysis of a 3 week old c-Fos homozygote showed a strong osteopetrotic phenotype. Defects in the midline diastema, tooth impaction, and lack of roots were also observed. The TBI showed signs of bone invasion, encroaching on the M1. TRAP assay revealed few positive-stained mononucleated cells, which were probably macrophages. In conclusion this thesis demonstrates that the formation and maintenance of the TBI appears to be a finely regulated two-pronged process with control of osteoclast differentiation used to remove the bone (osteoclastogenesis), combined with inhibition of bone induction (osteogenesis). Together these two processes create a bone-free zone around the tooth. By changing either of these processes the TBI is disrupted and tooth development is altered.
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Vaahtokari, Anne. "Molecular mechanisms in embryonic tooth development." Helsinki : Dept. of Dentistry, Division of Pedodontics and Orthodontics, Institute of Biotechnology and Dept. of Biosciences, Division of Biochemistry, University of Helsinki, 1996. http://catalog.hathitrust.org/api/volumes/oclc/35253532.html.
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Brodarac, Andreja. "Impaired tooth development in Periostin deficient mice." [S.l.] : [s.n.], 2006. http://www.sub.uni-hamburg.de/opus/volltexte/2006/3106/index.html.
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Armfield, Brooke Autumn. "The Evolution and Development of Mammalian Tooth Class." Kent State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=kent1276693144.
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Key, Darren J. "Pax9 function in mammalian craniofacial and tooth development." Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417528.
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Hardcastle, Zoe. "The Sonic Hedgehog signalling pathway in tooth development." Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368160.
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Panpisut, P. "Development of composites for tooth and bone repair." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1571903/.
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Currently used composites for tooth and bone repair share a similar composition. A major issue with dental composites is polymerisation shrinkage leading to bond damage and increased risk of bacterial microleakage. Concerns with bone composites for vertebral fracture repair (vertebroplasty) include low monomer conversion, high stiffness, and lack of antibacterial agent release. The aim of this study was to develop novel dental composites and injectable bone composites to overcome these limitations. The effects of components on various properties of the materials were also examined. The main components of experimental composites consisted of dimethacrylate monomers mixed with dental glass, mono calcium phosphate monohydrate (MCPM), tristrontium phosphate (TSrP), and polylysine (PLS). The experimental dental composites exhibited higher monomer conversion than a commercial material. The addition of MCPM with TSrP and PLS promoted hygroscopic expansion, apatite precipitation, and early polylysine release. These properties are expected to reduce bacterial microleakage. The incorporation of these additives reduced the monomer conversion and strength of the composites but these were still within an acceptable range. To produce bone composites, the dental composites were modified by replacing a light activated initiator with a chemically activated initiator and decreasing powder to liquid ratio. The pre-cured bone composites exhibited viscoelastic properties and shear- thinning behaviour which are desirable for injectable materials. The use of high molecular weight diluent monomer (polypropylene glycol dimethacrylate, PPGDMA) increased monomer conversion and shelf life of the bone composites. The addition of MCPM and PPGDMA increased strontium release, which is known to promote in vivo bone formation. The use of small glass fillers and fibres improved mechanical properties of the composites. Furthermore, the composites showed fatigue properties that compared favourably with commercially available materials. Modulus of elasticity of the experimental bone composites was, however, too high compared with that of cancellous bone. This could potentially lead to increased adjacent vertebral fracture risk. An attempt was made to decrease the modulus by raising the level of PPGDMA, phosphates, and polylysine. Increasing of PPGDMA improved monomer conversion and reduced the injection force required for the composites. Furthermore, the increase of PPGDMA and phosphates enhanced surface apatite precipitation which is known to enable in vivo bone bonding. The increase of these components also increased polylysine release. This may reduce postoperative infection, which is a life-threatening complication of vertebroplasty. Increasing PPGDMA and phosphates, however, reduced metabolic activity of mesenchymal stem cells limiting optimal levels.
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Wedenberg, Cecilia. "Development and morphology of internal resorption of teeth a study in humans, monkeys and rats /." Stockholm : Kongl Carolinska Medico Chirurgiska Institutet, 1987. http://catalog.hathitrust.org/api/volumes/oclc/16149996.html.
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Wise, Sarah B. "Bone morphogenetic proteins in teleost tooth development and evolution." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3256386.
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Mitchell, Michaela Grace. "Convergent Evolution in Tooth Morphology of Filter Feeding Lamniform Sharks." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1478543402652077.
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Liversidge, Helen Mary. "Human tooth development in an archaeological population of known age." Thesis, University College London (University of London), 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318134.
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This thesis documents dental maturation in a mid C18, early C19 population where age at death is known (N=63, age range birth and 5.4 years). Emphasis is placed on the mineralization of individual deciduous and certain permanent teeth. In the first part of this thesis, the literature on dental maturation is reviewed with special reference to radiographic studies of populations, methodology and statistical analysis. Quantitative data on developing teeth, population differences and age estimation are also reviewed. In the second part of the thesis the Spitalfields material is described and used to investigate the accuracy of five types of age estimating methods that make use of the developing dentition. It emerges that the atlas method of Schour and Massler (1941) predicted age best. The third part of the thesis documents dental development in the Spitalfields Collection. New data for human deciduous anterior teeth and early stages of permanent anterior teeth are presented. In this study, few permanent anterior tooth crowns were complete before 5 years of age, contrary to published data from radiographic studies. Alveolar eruption of deciduous teeth and measurements of tooth length and weight are presented and discussed in context with published standards. The fourth part of this thesis is a preliminary investigation of cranial and postcranial development in this population. The fifth part is an appendix of data.
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Cobourne, Martyn Timothy. "The role of sonic hedgehog signalling during early tooth development." Thesis, King's College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397177.
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Togo, Yumiko. "Antagonistic functions of USAG-1 and RUNX2 during tooth development." Kyoto University, 2017. http://hdl.handle.net/2433/218004.
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Hu, Bing. "From molar development in the mouse to tooth tissue engineering." Université Louis Pasteur (Strasbourg) (1971-2008), 2006. https://publication-theses.unistra.fr/restreint/theses_doctorat/2006/HU_Bing_2006.pdf.
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Chez l’embryon, le germe dentaire est constitué d’un épithelium dérivé de l’ectoderme et d’un ecto-mésenchyme dérivé des crêtes neurales céphaliques. L’existence d’interactions continues et réciproques entre ces deux composantes fait de la dent un modèle unique pour étudier la nature et le rôle des interactions épithélio-mésenchymateuses dans le contrôle de l’organogenèse. Le développement dentaire fait intervenir les étapes successives d’initiation, de morphogenèse, d’histogenèse épithéliale et de cytodifférenciations. La morphogenèse, hautement spécifique pour la couronne, va conditionner la fonctionnalité de la dentition. L’histogenèse épithéliale va conduire à l’apparition de quatre compartiments cellulaires : les épithéliums dentaires interne et externe, le réticulum stellaire et le stratum intermedium. A cela s’ajoute un compartiment transitoire, le nœud de l’émail primaire (NEP), qui exprime les transcrits des quatre grandes familles de molécules de signalisation (BMPs, FGFs, WNTs et SHH). Du côté mésenchymateux dans la couronne, les cellules au contact de la membrane basale se différencient en odontoblastes (sécrétant la prédentine/dentine). En face, du côté épithélial, les cellules de l’épithélium dentaire interne se différencient en améloblastes sécrétant les composants de l’émail. Au niveau de la racine, cette interface dentine/émail est remplacée par une interface dentine/cément. L’origine des cémentoblastes n’est pas clairement définie. Du fait de la transcription de messagers codant pour des molécules de signalisation au niveau des cellules du NEP, on prête à cette structure un rôle important dans le contrôle de la morphogenèse. En fait, des expériences de dissociations/réassociations tissulaires ont montré que la morphogenèse dentaire est spécifiée par le mésenchyme, où l’on retrouve les molécules de signalisation. La question à l’origine de ce travail de Thèse visait à déterminer si le mésenchyme dentaire était aussi susceptible de contrôler l’histogenèse épithéliale. Nous avons par ailleurs cherché à tester le rôle du NEP dans la spécification du mésenchyme et à évaluer le rôle possible d’informations de position au niveau des cellules de l’épithélium dentaire. Ce travail s’est ensuite orienté vers l’ingénierie tissulaire, la reconstitution d’une dent entière étant actuellement un défi majeur de la médecine régénérative. Nous avons mis au point un ensemble d’approches expérimentales et une stratégie globale visant à obtenir, à partir de réassociations tissus/cellules ou cellules/cellules, la formation d’une dent entière (couronne, racine et périodonte). Nous avons enfin recherché des sources cellulaires non-dentaires dans la perspective d’une ingénierie tissulaire dentaire. Initialement, nous avons utilisé des ébauches de premières molaires inférieures au stade capuchon, prélevées au 14ème jour embryonnaire (E14) chez la souris. A ce stade, le NEP est fonctionnel. L’épithélium a été dissocié du mésenchyme par traitement à la trypsine. L’absence de contamination d’un compartiment par l’autre a été vérifiée en histologie, par microscopie à balayage, hybridation in situ et RT-PCR (les sondes utilisées étaient Pax9 et Fgf10 pour le mésenchyme, Fgf4, Pitx2, et Shh pour l’épithélium). L’épithélium qui comporte alors quatre populations cellulaires a été dissocié de manière à avoir des cellules individuelles. Ces cellules qui ont perdu toute information de position initiale ont été centrifugées et réassociées à un mésenchyme intact. En culture sur milieu semi-solide d’agar, les réassociations montrent la reconstitution d’une membrane basale continue à l’interface épithélio-mésenchymateuse puis le passage par les étapes successives de morphogenèse dentaire conduisant au développement d’une couronne de type molaire. Le développement de plusieurs cuspides a été visualisé par reconstruction 3D assistée par ordinateur. Parallèlement à ces étapes de morphogenèse, l’histogenèse épithéliale se restaure avec la caractérisation des différents compartiments caractérisant la transition d’un épithélium dentaire vers un organe de l’émail. En particulier, le mésenchyme induit la formation d’un NEP transitoire avec toutes ses caractéristiques : agencement histologique, sortie du cycle cellulaire (vérifié par incorporation de BrdU), expression de Shh et Fgf4, et apoptoses (ssDNA) au niveau de ses cellules internes. La rapidité du processus démontre la très forte plasticité des cellules épithéliales. Il ne semble pas y avoir de mémorisation de l’information de position, provenant d’interactions cellules-cellules et cellules-matrice. Enfin le développement de ces réassociations in vitro conduit à la différenciation fonctionnelle des odontoblastes et à la différenciation cytologique des améloblastes. Ces expériences ont été reprises à un stade plus précoce (E13) alors que le NEP est seulement en voie de formation et donc non-fonctionnel. Dans ces réassociations, le développement de structures dentaires montre que les potentialités du mésenchyme ne sont pas spécifiées par le NEP. L’ensemble de ces résultats a été publié. Nous avons cherché à savoir si, pour être actif, le mésenchyme devait être intact ou pouvait lui-aussi être dissocié en cellules isolées. A côté de l’aspect mécanistique, la question a un intérêt en vue de développer des techniques transposables à l’ingénierie tissulaire dentaire, actuellement à l’étude dans plusieurs laboratoires. Nous avons donc comparé le devenir de réassociations entre mésenchyme intact et cellules épithéliales avec celui de réassociations entre cellules mésenchymateuses et cellules épithéliales. Les réassociations entre les deux types cellulaires conduisent aussi à la formation de structures dentaires in vitro, mais cela se produit avec un certain retard par rapport aux réassociations où le mésenchyme avait été conservé intact et surtout, la forme des dents est perturbée. Par contre, l’histogenèse épithéliale est bien restaurée et, de part et d’autre de la membrane basale, les cellules se différencient en odontoblastes et améloblastes [. . . ]
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Hu, Bing Lesot Adeline. "From molar development in the mouse to tooth tissue engineering." Strasbourg : Université Louis Pasteur, 2006. http://eprints-scd-ulp.u-strasbg.fr:8080/00000543.
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Beaumont, Julia. "The whole tooth and nothing but the tooth: or why temporal resolution of bone collagen may be unreliable." Wiley, 2020. http://hdl.handle.net/10454/17648.
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YesThe carbon (δ13C) and nitrogen (δ15N) isotope ratios of human bone collagen have been used extensively over the last 40 years to investigate the diet of past populations. It has become apparent that bone collagen can give an unreliable temporal dietary signature especially in juveniles. With higher temporal resolution sampling of collagen from tooth dentine, it is possible to identify short‐term changes in diet previously invisible in bone. This paper discusses the inherent problems of using bone collagen for dietary studies and suggests better sample choices which can make our interpretations more robust, using breastfeeding and weaning as an example.
The modern data was collected and analysed using funding from the Rank Prize Funds New Investigator Award and sponsorship from DB Orthodontics, Bradford. The Tooth Fairy team acknowledges the support of the National Institute for Health Research Clinical Research Network (NIHR CRN).
The full-text of this article will be released for public view at the end of the publisher embargo on 06 Feb 2022.
Research Development Fund Publication Prize Award winner, February 2020.
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Harila, V. (Virpi). "The effect of preterm birth on the development of the dentition." Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514274393.
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Abstract
The aim of this study was to examine the effect of preterm birth on the development of the dentition. The spesific aims were to examine the effect on deciduous and permanent tooth crown dimensions, the eruption of permanent teeth and the sagittal occlusal relationships within the dentition.
The subjects consisted of 328 prematurely born (< 37 gestational weeks ) white and black children and 1804 control children, who participated in the cross-sectional study of the Collaborative Perinatal Project (USA) in the 1960's and 1970's.
Dental examinations, including dental casts were performed at the age of 6–12 years. Tooth crown size measurements, recording of the sagittal occlusal relationships and tooth eruption stages were performed by examining the dental casts.
In general larger permanent tooth crown dimensions were found in preterm white boys and black girls and smaller permanent tooth crown dimensions in preterm white girls and black boys. There were both increased and decreased deciduous tooth crown dimensions in preterm children compared to controls, but no significant differences were found. Boys had larger tooth crown sizes than girls within all preterm and control groups showing sexual dimorphism. The results showed earlier eruption of permanent incisors and first molars in all preterm children compared to controls and also according to sex and race. Concerning the sagittal occlusal relationships, the results showed greater prevalence of prenormal canine relationships in preterm group than in the controls. When the molar relationships were concerned, the prevalence of mesial molar occlusion was greater in the preterm group. The incidence of bilateral symmetrical canine relationship was the same in both preterm and control groups, but inside the preterm group the girls had better symmetry than the boys.
The findings of this research suggest that short gestation is not associated with reduced permanent and deciduous tooth crown dimensions in prematurely born children and also confirm the presence of the sexual dimorphism in tooth crown size. The studies also indicate that the clinical tooth eruption is accelerated in all observable permanent teeth in prematurely born children. The findings of occlusal morphology indicated that premature birth may effect the sagittal occlusal development. General health condition, neonatal and postnatal factors like intubation, postnatal molding of head shape and the importance of catch-up growth and early functional activity should be considered as possible influencing factors. Preterm birth may also interfere with the development of symmetry and lateralization.
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Jowett, Adrian K. "Glycosylation patterns during development of mouse molar teeth." Thesis, University of Manchester, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304035.
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Alkhamis, Abdulaziz M. "Investigation of the signaling [i.e. signalling] networks regulating early tooth development." Thesis, King's College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405510.
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Mandarakas, Melissa Rivkah. "Development and validation of the Charcot-Marie-Tooth disease Infant Scale." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/19659.
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Charcot-Marie-Tooth disease (CMT) is the most commonly inherited neuropathy. Many genetic subtypes of CMT show signs of symptomatic disease during the earliest years of life. This might be the ideal time to intervene before progression of clinical sequelae due to demyelination and axonal loss. No outcome measures have been validated for infants <3 years with CMT, a barrier to conducting trials for disease-modifying interventions, as well as running natural history studies (Chapter One). Existing outcome measures for the assessment of disease severity for infants with neuromuscular disease were systematically reviewed (Chapter Two). No CMT-specific outcome measures were identified, yet several items were appropriate to contribute to a new outcome measure: the CMT Infant Scale (CMTInfS). Peer review by 12 experts in the NIH-funded Inherited Neuropathies Consortium, and pilot testing of 22 infants confirmed the 31-item preliminary CMTInfS to undergo validation studies across 7 international sites (Chapter Three). In Chapter Four, excellent intra-rater and inter-rater reliability of CMTInfS total scores showed acceptable agreement both within (ICC3,1 0.994, 95% CI3,1 0.985 – 0.997) and between (ICC2,10.997, 95% CI 0.993 – 0.999) evaluators. Validation studies were conducted based on data from 128 infants: 26 confirmed CMT cases, 7 ‘at risk’ cases of CMT and 95 healthy controls (Chapter Five). Item, Factor and Rasch analyses produced a psychometrically robust 15-item functional outcome measure. The CMTInfS can be completed in 20min, requiring minimal training for experienced paediatric clinicians/researchers. Using age-matched z-scores to account for normal growth and development, the CMTInfS can discriminate between infants with CMT and controls. There was good agreement with the CMT Pediatric Scale. With further longitudinal data collection of different CMT genetic subtypes (Chapter Six), the CMTInfS will be trial-ready to evaluate potential treatments for CMT.
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Preston, Kate Patricia. "The development of model systems to study root caries." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367552.
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Reed, Helen Elizabeth. "Calcium transport mechanisms in rat incisor odontoblasts." Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367822.
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Alfawaz, Shurog Abdulrahman. "The genotypic and phenotypic features of familial tooth agenesis in consanguineous families." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8632.
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An evolution in methods of identifying the causal mutations and candidate genes for Mendelian disorders has occurred recently. Though several studies have reported the causative mutations in non syndromic tooth agenesis, there are only two reports on autosomal recessive nonsyndromic tooth agenesis in consanguineous families. Since the consanguinity rate is high in tribal population of Saudi and Pakistan, this study identified consanguineous families in these populations to investigate the molecular basis of tooth agenesis. This study aimed to study the phenotype of familial tooth agenesis in Saudi and Pakistani families of consanguineous marriage, and to identify the causative mutations. A further aim was to investigate the influence of the agenesis gene on tooth size in one large Saudi family. Sixteen families with non-syndromic tooth agenesis, were clinically characterised for the pattern of inheritance, tooth agenesis severity and type of teeth affected. Genetic analysis including homozygosity mapping and exome sequencing was performed in eight families. Hand measurements of Saudi family tooth dimensions were made on dental study models. The most affected tooth type in studied families were the lower second premolar and upper lateral incisors. The homozygosity mapping approach failed to identify the regions of the diseased mutations in these families. The exome sequencing data revealed a heterozygous novel frameshift mutation in exon 2 of the MSX1 gene, c.750_751insACCGGCTGCC (p.A250fs) in one Saudi family and a homozygous novel mutation in exon 8 of the SMOC2 gene, c.681T>A (p.C227X), in the Pakistani family. It was found that there was a significant (p <.0.05) trend of reduction in the crown sizes both in the tooth agenesis group and their family members with no tooth agenesis compared to the control group. It is concluded that homozygosity mapping was not sensitive to identify the elusive tooth agenesis gene and whole exome sequencing technique is needed in future studies. The tooth measurement study indicates and confirms that crown size is closely related to tooth agensis.
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Thomas, Bethan Louise. "The role of Dix-2 in the early development of murine dentition." Thesis, King's College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286738.
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O'Connell, Daniel Joseph. "An Epithelial-Mesenchymal Gene Regulatory Network that Controls Tooth Organogenesis." Thesis, Harvard University, 2011. http://dissertations.umi.com/gsas.harvard:10024.
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Many vertebrate organs form via the sequential, reciprocal exchange of signaling molecules between juxtaposed epithelial (E) and mesenchymal (M) tissues. For example, the instructive signaling potential for tooth development (odontogenesis) resides in the dental epithelium at the initiation-stage, and subsequently shifts to the dental mesenchyme one day later at the bud-stage. However, the properties of the gene regulatory networks (GRNs) that control the signaling dynamics during epithelial-mesenchymal (E-M) interactions in organogenesis are largely unknown. This dissertation describes an interdisciplinary effort between developmental and systems biology to elucidate the E-M GRN that controls early odontogenesis. The results provide a molecular mechanism for the longstanding paradigm of sequential, reciprocal E-M tissue interactions in development. We generated large-scale spatiotemporal gene expression data for the developing mouse tooth. Surprisingly, the shift in signaling molecule expression from E to M is accompanied by a striking concordance in genome-wide expression changes in both E-M compartments as development proceeds. We hypothesized that since diffusible signaling molecules can act on either E or M independent of their tissue site of synthesis, signaling molecules are uniquely able to simultaneously synchronize and couple the transcriptional dynamics and hence the developmental progression of E and M. To identify the unifying mechanism behind concordant E and M genome-wide expression changes in the face of the discordant expression changes in signaling molecule expression, we developed a novel probabilistic technique that integrates regulatory evidence from microarray gene expression data and the literature to determine the E-M GRN for early tooth development. This GRN contains a uniquely configured E-M Wnt/Bmp feedback circuit in which the Wnt and Bmp signaling pathways in E cross-regulate the expression of Wnt and Bmp4 signaling molecules, whereas both pathways jointly regulate Bmp4 expression in M. We validated the Wnt/Bmp feedback circuit in vivo using compound genetic mutations in mice that either short-circuit or break the circuit, and used mathematical modeling to show how the structure of the Wnt/Bmp feedback circuit can account for reciprocal signaling dynamics. Collectively, these results provide a simple mechanistic framework for how simultaneous signal transduction in E-M compartments can account for the signaling dynamics in organogenesis.
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Ramahi, Munzer. "Temporo-spatial expression of Ets1 and Ets2 transcription factors during murine tooth development." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63005.pdf.
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Rasch, Liam. "An ancestral gene network regulates continuous tooth regeneration and denticle development in elasmobranchs." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/8572/.
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Sharks and rays (elasmobranchs) regenerate their teeth via a novel system in which multiple teeth develop in advance of function as a dental conveyor belt. Given their ancestral phylogenetic position, extant elasmobranchs therefore provide ideal models to study the ancient state of gnathostome tooth regeneration (polyphyodonty). Despite this potential, they have received little attention, leaving a significant gap in knowledge. The research presented here addresses this by using suitable species of catshark and ray as comparative models to investigate conserved gene expression during elasmobranch tooth development and regeneration. In both sharks and rays, the conserved expression patterns of the dental stem cell marker Sox2 first identifies a putative dental stem cell niche (SCN). Using the catshark as a primary model, PCNA is then used to define cell proliferation dynamics, followed by further investigation of the expression of genes representative of the Wnt-β-catenin, BMP, FGF and hedgehog signaling pathways. Their expression patterns, and those of additional regulatory genes, imply deeply conserved roles in the elasmobranch dentition. This is particularly apparent in tooth morphogenesis in which the expression of several genes identifies a putative signaling center comparable to the mammalian enamel knot. PCNA and gene expression further define a continuous epithelial connection between the dental and oral epithelium, adding further experimental evidence to support the role of a dental SCN in elasmobranch tooth regeneration. These studies inspire the production of the first hypothetical elasmobranch dental gene regulatory network (GRN) models. This research further addresses the role of conserved genes in the development of dermal denticles, which in chondrichthyans enhance hydrodynamic efficiency and function as dermal body armour. These gene expression patterns imply similar regulatory roles to those in teeth, suggesting their evolution by a mechanism of gene network co-option. This further inspires the production of a denticle GRN model. When considered in light of existing theories of tooth and denticle evolution, this comparative expression data adds renewed perspective regarding their possible origins, as implied by their respective developmental similarities and differences.
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Khaddam, Mayssam. "Role of EMMPRIN and MMPs in tooth development, dental caries and pulp-dentin regeneration." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05T046/document.
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Le développement dentaire est orchestré par une série de signalisations inductives réciproques entre l'épithélium dentaire et le mésenchyme, qui conduit à la formation de la dentine et de l'émail. EMMPRIN/CD147 est un INducteur des MetalloPRoteinases de la Matrice Extracellulaire (MMPs) qui régule les interactions épithélio-mésenchymateuses dans le cancer et d'autres processus pathologiques et est exprimé lors du développement dentaire. Ainsi, nous avons utilisé des souris KO pour EMMPRIN pour déterminer le rôle d'EMMPRIN dans la formation des tissus dentaires. Nous avons démontré que l’absence d’EMMPRIN conduisait dans le germe dentaire à une diminution de l’expression de MMP-3 et de MMP-20, à un retard de la dégradation de la membrane basale, à un retard de la formation de l’émail bien visible dans l'incisive à croissance continue, à une diminution du volume et de l'épaisseur d'émail, mais à une maturation amélaire normale. Ces résultats indiquent qu'EMMPRIN est impliqué dans le dialogue épithélio-mésenchymateuse pendant le développement dentaire, principalement par la régulation de l'expression de certaines MMPS. Nous avons ensuite essayé d'évaluer le rôle potentiel d'EMMPRIN dans le processus de réparation dentaire en comparant la cicatrisation de blessures pulpaires des souris KO pour EMMPRIN à des souris WT. Enfin, dans un souci de transfert vers la clinique, nous avons évalué la capacité d’extraits de pépin de raisin (connu pour être des inhibiteurs naturels de MMPs) à empêcher la dégradation de la matrice dentinaire humaine déminéralisée et traitée par MMP-3Tooth development is regulated by a series of reciprocal inductive signalings between the dental epithelium and mesenchyme, which culminates with the formation of dentin and enamel. EMMPRIN/CD147 is an Extracellular Matrix MetalloPRoteinase (MMP) INducer that mediates epithelial-mesenchymal interactions in cancer and other pathological processes and is expressed in developing teeth. Here we used EMMPRIN knockout (KO) mice to determine the functional role of EMMPRIN on dental tissues formation. We demonstrated that EMMPRIN deficiency results in decreased in MMP-3 and MMP-20 expressions, delayed in basement membrane degradation in tooth germ, delayed in enamel formation well distinguishable in incisor, and in decreased enamel volume and thickness but normal maturation. These results indicate that EMMPRIN is involved in the epithelial-mesenchymal cross-talk during tooth development by regulating the expression of MMPs. Then we tried to investigate the potential role of EMMPRIN in the pulp dentin repair process by comparing the healing of injured pulps of EMMPRIN KO and WT mice. Finally, we evaluated the capacity of grape-seed extracts (known to be natural inhibitors of MMPs and used in new daily mouthrinse) to prevent the degradation of human demineralized dentin matrix by MMP-3
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Al-Abdallah, Mariam. "The development of a new digital method of analysing three dimensional orthodontic tooth movement." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493436.
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Aim: To develop a method to study linear, angular and rotational tooth movements in three dimensions using a surface laser scanning technique. Design: An experimental methodological study. Material and methods: The Konica Minolta Vivid 910 non-contact surface laser scanner was used to convert plaster models into digital data, which were then analysed by Rapidform™2006 software.
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Tsitrou, Effrosyni A. "Development of new tooth preparation guidelines forminimal CAD-CAM fabricated resin bonded indirect restorations." Thesis, University of Sheffield, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.444242.
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Yu, Wenjie. "A Pitx2-Irx1 regulatory network controls dental epithelial stem cell differentiation during tooth development." Diss., University of Iowa, 2017. https://ir.uiowa.edu/etd/6020.
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Tooth development is precisely controlled by epithelium-mesenchyme interactions, coordinated signaling pathways and associated transcription factors. Although the processes involved in tooth development are well established, details of the cellular and molecular mechanisms that control tooth development are not fully understood. One of the primary unknown mechanisms is the regulation of dental epithelial stem cells (DESCs), including DESC specification, proliferation and differentiation. In this dissertation, I have addressed this gap in knowledge by studying the role of Pituitary homeobox 2 (Pitx2) and Iroquois 1 (Irx1) in teeth at the cellular and molecular level in mice. PITX2 contains mutations of which are associated for Axenfeld-Rieger syndrome (ARS) in humans and is also required for early tooth development. All the background knowledge is included in Chapter I. In Chapter II, I describe the conditional ablation of Pitx2 in the dental epithelium using a Krt14Cre driver line (Pitx2cKO mice). Knocking out Pitx2 in teeth led to delayed epithelial invagination at bud stage and disruption of tooth morphogenesis at cap stage. At the cellular level, Pitx2 mediates DESC differentiation, daughter cell proliferation in bud stage tooth and regulates enamel knot formation in cap stage tooth. At the molecular level, Pitx2 acts as an upstream regulator of the sonic hedgehog (Shh) signaling pathway by regulating the expression of Shh in the dental epithelial signaling center during early tooth development. In addition, I demonstrated that Pitx2 directly controls the transcription of Irx1. In Chapter III, I determined the cellular and molecular mechanisms of Irx1 in mice. Irx1 general knockout mice were generated by replacing the entire Irx1 gene body with a LacZ reporter gene. Irx1 null mice are neonatal lethal and this lethality is due to pulmonary immaturity with defective surfactant protein secretion. In teeth, Irx1 is expressed in the outer enamel epithelium (OEE) and stratum reticulum (SR) and mediates DESC to OEE and SR differentiation through regulation of Forkhead box protein J1 (Foxj1) and Sex determining region Y-box9 (Sox9).
In summary, I identified a Pitx2-Irx1 regulatory network that controls DESC differentiation in teeth, which provided the field with a better understanding of tooth development and tooth regeneration.
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Kadavy, Kevan Daniel. "A longitudinal study of the relationship between childhood BMI and timing of dental development." Thesis, University of Iowa, 2017. https://ir.uiowa.edu/etd/5529.
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Introduction: Prevalence of childhood obesity is at an all-time high. The effect of childhood obesity on dental development and eruption is a widespread topic today in the dental field. Several cross-sectional studies over the past decade have found an association between advanced dental development and eruption and childhood obesity. The purpose of this study is to examine the longitudinal relationship between childhood Body Mass Index (BMI), and the development of the permanent dentition. Methods: 76 subjects from a longitudinal dataset (Iowa Facial Growth Study 1946-1960) were selected to examine the relationship between BMI and dental development during childhood. Periapical and lateral cephalometric radiographs were used to provide a dental maturity score for each subject using the Demirjian et al. (1973) method at three separate time points (age 4, 8, and 12). BMI was calculated using subjects’ height and weight at each time point. Results: Children with higher BMI’s at all three time points (4, 8 and 12) tended to have advanced dental development compared to children who were of normal weight status. Children who were considered underweight (< 5th BMI percentile) were more likely to be dentally delayed. BMI at age 4 was predictive of dental development status at age 8 and 12. Conclusion: Our results add to the growing body of evidence that childhood obesity is associated with advanced dental development. This is important in the dental and orthodontic fields, as early eruption has been hypothesized to be associated with increased dental caries, crowding, and malocclusions.
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Edge, Jonathan Culmer. "Design and development of a system for three dimensional periodontal probing measurement." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322066.
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Wahab, Fuad Kadim. "Factors influencing the solubility of dental enamel and the development of carious lesions." Thesis, University of Bristol, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279717.
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Li, Xiao. "The molecular mechanisms of PITX2 in tooth development and enamel defects in Axenfeld-Rieger Syndrome." Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/5014.
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Patients with Axenfeld-Rieger Syndrome (ARS) present various dental abnormalities. ARS is genetically associated with mutations in the PITX2 gene, which encodes one of the earliest transcription factors to initiate tooth development. Thus, Pitx2 has long been considered as an upstream regulator of the transcriptional hierarchy in tooth development. However, it is unclear how its mutant forms cause ARS dental anomalies. In this report, we outline the transcriptional mechanism that is defective in ARS. We demonstrate that during normal tooth development Pitx2 activates Amelogenin (Amel) expression, whose product is required for enamel formation, and that this regulation is perturbed by missense PITX2 mutations found in ARS patients. We further show that Pitx2-mediated Amel activation is enhanced and controlled by co-factors and target genes of Pitx2. These co-factors include cooperative transcription factors such as Dlx2 and FoxJ1; chromatin-associated remodeler factor Hmgn2; and Wnt signaling components such as Lef-1, β-catenin and Dact2. We also unveil a novel Pitx2 target gene Irx1 that functions in dental epithelium differentiation. Consistent with a physiological significance to these modulations, we show that FoxJ1, Dact2, Irx1 knockout mice and K14-Hmgn2 transgenic mice display various types of amelogenesis defects including enamel hypoplasia - consistent with the human ARS phenotype. Collectively, these findings define transcriptional mechanisms and multi-level regulations involved in normal tooth development and shed light on the molecular underpinnings of the enamel defect observed in ARS patients who carry PITX2 mutations. Moreover, our findings validate the etiology of the enamel defect in novel mouse models of enamel hypoplasia. The impact of this study on current understanding of the dental epithelium development and the translational value lie in the gene network we identified. By manipulating components of the network, pluripotent dental cells can be reprogrammed and serve as new source for tooth regeneration. Our findings brought insights of novel gene therapy approach that can alleviate the dental problems of patients with ARS and other developmental anomalies.
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Ödman, Jan. "Implants in orthodontics an experimental and clinical study /." [Göteborg] : Dept. of Orthodontics, Faculty of Odontology, University of Göteborg, 1994. http://books.google.com/books?id=fn1qAAAAMAAJ.
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Blenkin, Matthew Robert Barclay. "Forensic Dentistry and its Application in Age Estimation from the Teeth using a Modified Demirjian System." Thesis, The University of Sydney, 2005. http://hdl.handle.net/2123/669.
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The estimation of age at time of death is often an important step in the identification of human remains. If this age can be accurately estimated, it will significantly narrow the field of possible identities that will have to be compared to the remains in order to establish a positive identification. Some of the more accurate methods of age estimation, in the juvenile and younger adult, have been based on the assessment of the degree of dental development as it relates to chronological age. The purpose of this current study was to test the applicability of one such system, the Demirjian system, to a Sydney sample population, and to develop and test age prediction models using a large sample of Sydney children (1624 girls, 1637 boys). The use of the Demirjian standards resulted in consistent overestimates of chronological age in children under the age of 14 years by as much as a mean of 0.97 years, and underestimates of chronological age in children over 14 years by as much as a mean of 2.18 years in 16 year-old females. Of the alternative predictive models derived from the Sydney sample, those that provided the most accurate age estimates are applicable for the age ranges 2-14 years, with a coefficient of determination value of R-square=0.94 and a 95% confidence interval of ±1.8 years. The Sydney based standards provided significantly different and more accurate estimates of age for that sample when compared to the published standards of Demirjian.
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Blenkin, Matthew Robert Barclay. "Forensic Dentistry and its Application in Age Estimation from the Teeth using a Modified Demirjian System." University of Sydney. Community Oral Health and Epidemiology, 2005. http://hdl.handle.net/2123/669.
Full textAbstract:
The estimation of age at time of death is often an important step in the identification of human remains. If this age can be accurately estimated, it will significantly narrow the field of possible identities that will have to be compared to the remains in order to establish a positive identification. Some of the more accurate methods of age estimation, in the juvenile and younger adult, have been based on the assessment of the degree of dental development as it relates to chronological age. The purpose of this current study was to test the applicability of one such system, the Demirjian system, to a Sydney sample population, and to develop and test age prediction models using a large sample of Sydney children (1624 girls, 1637 boys). The use of the Demirjian standards resulted in consistent overestimates of chronological age in children under the age of 14 years by as much as a mean of 0.97 years, and underestimates of chronological age in children over 14 years by as much as a mean of 2.18 years in 16 year-old females. Of the alternative predictive models derived from the Sydney sample, those that provided the most accurate age estimates are applicable for the age ranges 2-14 years, with a coefficient of determination value of R-square=0.94 and a 95% confidence interval of �1.8 years. The Sydney based standards provided significantly different and more accurate estimates of age for that sample when compared to the published standards of Demirjian.
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AlQahtani, Sakher Jaber. "The London Atlas : developing an atlas of tooth development and testing its quality and performance measures." Thesis, Queen Mary, University of London, 2012. http://qmro.qmul.ac.uk/xmlui/handle/123456789/3363.
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Aim: To develop a comprehensive, validated, evidence based, practical, user-friendly atlas of dental age estimation and compare its performance with two widely used atlases. Methods: Based on the radiographic appearance of tooth development in 528 individuals aged 2-23 years and 176 neonates, the median stage of tooth development for each tooth in each age category/chronological year was used to construct diagrams representing ages between 28 weeks in-utero and 23 years were developed (The London Atlas) Accuracy was determined by ageing skeletal remains/radiographs of 1514 individuals (aged 32 weeks in-utero to 23 years) using The London Atlas (LA), the Schour and Massler (SM) and Ubelaker (Ub) atlases. Estimated age was compared to real age. Bias, absolute mean difference and proportion of individuals correctly assigned by age were calculated. Intra-observer variation (Kappa) was measured by re-assessment of 130 radiographs. To test the application of The London Atlas, a questionnaire was used to validate its use. Ninety 3rd year dental students were divided randomly into three subgroups, and blinded from the researcher. Each group used one of the 3 atlases to estimate the radiographic age of 6 individuals and complete a questionnaire focussed on the design, clarity, simplicity and self-explanation of the three atlases. Results: Excellent reproducibility was observed for all three atlases (Kappa: LA 0.879, SM 0.838 and Ub 0.857). LA showed no bias (P=0.720) and correctly estimated 53% of cases. SM and Ub showed significant bias by consistently underestimating age (P=0.026 and P=0.002) with 35% and 36% correctly estimated for SM and Ub respectively. The mean absolute difference for LA (0.72 years) was smaller than SM (1.15 years) and Ub (1.17 years). LA was preferred over the other two atlases in all quality measures tested (clarity, design, simplicity and self-explanation). Conclusion: The London Atlas represents a substantial improvement on existing atlases facilitating accurate age estimation from developing teeth. Development of interactive online and mobile app versions is complete.
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Näsman, Margareta. "Effects of anti-neoplastic therapy on tooth and bone formation : clinical and experimental studies /." Stockholm, 1998. http://diss.kib.ki.se/1998/91-628-3282-4/.
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Morrow, J. M. "Development of quantitative MRI as an outcome measure in Charcot-Marie-Tooth disease and inclusion body myositis." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1546503/.
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Lack of sensitive outcome measures is a major obstacle to clinical trials in many neuromuscular diseases (NMD). Lower limb muscle MRI allows non-invasive visualisation of acute and chronic pathology in NMD. This thesis aims to assess the reliability, validity and responsiveness of quantitative MRI in chronic neuromuscular diseases. A comprehensive quantitative MRI protocol of lower limb muscles was developed including T1, T2, fat fraction and magnetisation transfer ratio (MTR) measurements. The protocol was assessed for reliability and sensitivity to physiological variation in 47 healthy volunteers with 15 rescanned at a two week interval. This protocol was then performed together with detailed clinical assessments and isokinetic/isometric dynamometry in 20 patients with inclusion body myositis (IBM), 20 patients with Charcot-Marie-Tooth disease (CMT) and matched health volunteers twice at a 12 month interval. In the healthy volunteers, the inter-scan and inter-observer reliability was high (ICC 0.62-0.99) despite small observed physiological variation between subjects. Fat fraction, T2 and MTR showed significant correlations with subject age in thigh and calf muscles and with subject weight in thigh muscles whereas gender did not influence quantitative parameters. Cross-sectional analysis showed strong correlations with both muscle strength and clinical severity measures demonstrating validity of MRI measurements as outcome measures. Longitudinal assessment demonstrated excellent sensitivity to change of MRI measures; in particular muscle fat fraction quantification exceeded that of myometry and clinical measurements with standardised response mean (SRM) over 12 months of 1.1 in IBM and 0.8 in CMT indicating a high level of responsiveness. Annual change in fat fraction could be predicted based on baseline MRI measurements, providing the opportunity to improve SRM further. This thesis demonstrates the reliability, validity and responsiveness of quantitative MRI as an outcome measure providing a comprehensive practical protocol for clinical trials in NMD.
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Chen, Donglei. "The Origin of Tooth Replacement : Three-dimensional Synchrotron Histology Visualizes the Dental Development of Silurian Stem Osteichthyans." Doctoral thesis, Uppsala universitet, Evolution och utvecklingsbiologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-315885.
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Mechanisms of tooth replacement distribute incongruently among extant gnathostomes (jawed vertebrates): a permanent tooth-generating dental lamina exists in chondrichthyans (cartilaginous fish) and tetrapods but not teleosts, whereas tooth shedding by basal hard tissue resorption occurs in tetrapods and teleosts but not chondrichthyans. Theories about the evolution of tooth development have been biased towards the chondrichthyan conveyor-belt replacement, since there has been no fossil evidence for the origin of osteichthyan (bony fish and tetrapods) tooth replacement until now. 3D virtual dissections with submicron-scale resolution, based on propagation phase contrast synchrotron microtomography (PPC-SRµCT), reveal the growth history of the dentitions of Andreolepis and Lophosteus, 423-Myr-old Silurian stem osteichthyans close to the common ancestor of tetrapods and teleosts. Their marginal jawbones and “tooth cushions” (possible homologues of coronoids) shed teeth by in situ cyclic basal resorption, the earliest examples of osteichthyan-style tooth replacement. The replacement cycles were site-autonomic, and occurred in broad irregular multi-row tooth fields, including at sites separated from the margin of the bone by intervening teeth, showing that the production of replacement teeth did not occur in a single deep dental lamina, but in pockets associated with each tooth, as in many teleosts. It suggests that the functionally and anatomically similar laminae of chondrichthyans and tetrapods are convergent. The marginal jaw bones of both genera carry an initial non-shedding dentition arranged in alternate transverse files, labial to the shedding tooth field, overgrown by later dermal ornament and probably not belonging to the oral domain, but bearing in vivo biting damage showing that they functioned as teeth. The most lingual of these odontodes have been resorbed apically and are overlain by shedding teeth. The first-generation teeth on the tooth cushions display basal resorption in Andreolepis, but semi-basal resorption in Lophosteus. The latter leaves a basal dentine ring from each tooth, implying only odontoclasts are involved in the semi-basal resorption, which is probably the first step towards evolving a site-specific resorption. The polarized displacement of each generation of resorption surfaces reflects the fact that the cyclic replacement, as well as the sequential addition of tooth sites, is closely related to bone growth. Resorption surfaces and growth arrest surfaces also record the life history and the replacement rate. These data provide unique insights into the origin of osteichthyan tooth replacement.
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Sulieman, Munther Affram Matti. "The development and evaluation of a method in-vitro to study the effectiveness and safety of tooth bleaching." Thesis, University of Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422612.
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De, Angelis Daniel. "Syndecan-1 expression during postnatal tooth and oral mucosa development in 2 day to 6 week old rats." Title page, contents and abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09DM/09dmd284.pdf.
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Includes bibliographical references (leaves 68-76) Aims to observe changes in the expression of syndecan-1 in both the developing epithelium of the rat oral mucosa, and in epithelial cell rests of Malassez in the developing periodontium of normal rat molars, from late crown development through to early eruption.
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Spence, Jennifer Emily Spence. "Deciduous Tooth Emergence, Maternal and Infant Condition, and Infant Feeding Practices in the Brazilian Amazon." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu151211453566353.
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Liu, He. "Development of a novel system to measure and calculate tooth movements for studying the properties of the periodontal ligament." Thesis, Cardiff University, 2006. http://orca.cf.ac.uk/54584/.
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Motion analysis techniques have been widely used in biomechanics for measuring large-scale motions such as gait, posture etc, but have not yet been significantly explored for measuring smaller movements such as tooth movement under load. In principle, very accurate measurements could be possible and this could provide a valuable tool in many engineering applications. The aim of this study was to develop a novel system to measure and calculate tooth movements with 6DOF in 3D space for studying the properties of the periodontal ligament. The Qualisys ProReflex-MCU120 motion capture system has been developed to measure micro-movements. The calibration frame was designed and made for the system calibration. The system accuracy was 1.17%, 1.67% and 1.31% for diamond markers 1.81%, 2.37% and 1.39% for spherical markers in x, y and z directions in the range of 20 - 200pm. These results demonstrated that the system is accurate enough to measure small-scale movements. To measure tooth movement, two retroreflective marker clusters, two pointers and one plane for the pointer calibration were created. The two marker clusters were fixed on the measured tooth and the reference tooth for measurements. The pointer was used to identify the three landmarks for identifying anatomical coordinate system of tooth. Data analysis software was developed and evaluated for calculating tooth movement in 6DOF. In the data analysis software, the three coordinate systems method was used with transformation matrices to give 6DOF results. The evaluation results of a complete system were 3.2%, 2.8% and 2.4% for rotations 5.3%, 7.7% and 4.7% for translations in x, y and z directions in the term of accuracy. For producing tooth measurements, loading devices and loading control system were designed and tested. The experiments were carried out on human volunteers in clinical setting. Loads of 0.196N, 0.294N and 0.49N were separately applied to the measured tooth in the buccal direction and the intrusive direction for 10s and 30s, respectively. The experimental results demonstrated that, with the buccal loading, the tooth translations were 32pm for load of 0.294N, and 41pm for load of 0.49N in the y direction of the anatomical coordinate system, tooth rotations were 0.09 and 0.07 for load of 0.294N, and 0.1 and 0.06 for load of 0.49N in the x and z directions with the intrusive loading, tooth movements were 37pm, 15pm and 54pm for load of 0.196N, and 140pm, 51pm and 25pm for load of 0.49N in the x, y and z directions, tooth rotations were 0.04 , 0.07 and 0.2 for load of 0.196N, and 0.26 , 0.195 and 0.35 for load of 0.49N about the x, y and z directions. Overall, a novel system of measuring and calculating tooth movement has been developed. It could be useful in applications in many other engineering fields.
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Kolivand, Mohsen. "DEVELOPMENT OF TOOTH CONTACT AND MECHANICAL EFFICIENCY MODELS FOR FACE-MILLED AND FACE-HOBBED HYPOID AND SPIRAL BEVEL GEARS." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1245266082.
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Marin, Riera Miquel. "Studying the genotype-phenotype map through general mathematical models of embryonic development and its application on tooth morphogenesis and evolution." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/399225.
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Entendre com les especies canvien al llarg de les generacions es un dels principals desafiaments de la biologia evolutiva. Per tal d'entendre el canvi evolutiu a nivell del fenotip és necessari conèixer quina variació fenotípica heretable és present a cada generació i com la seleccio natural actua sobre el fenotip. La variació genètica heretable s'associa a la variació fenotípica corresponent a través del mapa genotip-fenotip (MGF). En el cas de l'evolució morfològica, el MGF ve donat pel desenvolupament embrionari, que consisteix en xarxes d'interacció complexes i dinàmiques entre gens, cèl·lules i teixits. El MGF ens indica el conjunt de fenotips que el desenvolupament pot produir i també les mutacions genètiques especiífiques que es requereixen per aconseguir un determinat fenotip. En aquesta tesi utilitzem l'aproximació computacional per tal de generar prediccions teòriques sobre com la complexitat del MGF influeix en la variació morfològica resultant del desenvolupament i quin efecte té en les dinàmiques evolutives de les poblacions. Utilitzem la dent de mamífer com a sistema model a causa de la seva alta complexitat morfològica i la seva rellevància ecològica i evolutiva. Per mitjà de la simulació d'evolució in silico trobem que els règims selectius que es centren en tots els detalls del fenotip no aconsegueixen portar les poblacions a l'optimalitat fenotípica. També desenvolupem un model general de desenvolupament animal que és capaç de reproduir un ampli ventall de mecanismes de desenvolupament. Després utilitzem aquest model per extendre el model de desenvolupament de dents i explorem la variacio morfològica provinent d'alteracions en l'adhesió i biomecànica cel·lulars. Per mitjà de la simulació del desenvolupament de dents amb models matemàtics hem pogut fer prediccions sobre com un MGF complex afecta la distribució de la variació fenotípica i l'efecte de la selecció natural durant l'evolució adaptativa.One of the main challenges of evolutionary biology is to understand how species change over generations. Phenotypic evolutionary change can only be understood by knowing how natural selection acts on the phenotype and which heritable phenotypic variation arises in each generation within populations. Heritable genetic variation is associated to the correspondent phenotypic variation by means of the genotype-phenotype map (GPM). In the case of morphological evolution, the GPM is determined by embryonic development which consists on complex and dynamic networks of interaction between genes, cells and tissues. The nature of the GPM tells us the ensemble of phenotypes that can be produced by development and also the specific genetic mutations that are required to reach a certain phenotype. In this thesis we use the computational approach to generate theoretical predictions on how the complexity of the GPM influences morphological variation arising from development and what effect has that on the evolutionary dynamics of populations. We use the mammalian tooth as a model system due to its high morphological complexity and ecological and evolutionary relevance. By performing in silico evolution we find that selective regimes that focus on all the details of the phenotype fail to drive populations to phenotypic optimality. We also develop a general model of animal development that is able to reproduce a wide range of developmental mechanisms. We then use this general model to extend the tooth development model and we explore the morphological variation arising from alterations in cell-cell adhesion and biomechanics. By simulating tooth development and evolution by means of mathematical models we have been able to make predictions on how a complex GPM arising from development affects the distribution of phenotypic variation and the effective of natural selection during adaptive evolution.