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Tooth Eruption and Movement

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Tooth Eruption and Movement Tooth eruption and movement Dr. Krisztián Nagy CÍM beírása!!! DÁTUM Diphydont dentition Deciduous dentition – primary dentition CÍM beírása!!! DÁTUM Diphydont dentition Permanent dentition – secondary dentition CÍM beírása!!! DÁTUM Mixed Dentition: Presence of both dentitions CÍM beírása!!! DÁTUM Tooth eruption CÍM beírása!!! DÁTUM • Teeth are formed in relation to the alveolar process. • Epithelial thickening: Dental lamina • Enamel organs: Series of 10 local thickenings on dental lamina in each alveolar process. • Each thickening forms one milk tooth. CÍM beírása!!! DÁTUM Stages in the formation of a tooth germ CÍM beírása!!! DÁTUM Formation of enamel organs CÍM beírása!!! DÁTUM Stages Bud stage : • Characterized by formation of a tooth bud. • The epithelial cells begin to proliferate into the ectomesenchyme of the jaw. CÍM beírása!!! DÁTUM Cap stage : • Formation of dental papilla. • The enamel organ & dental papilla forms the tooth germ. • Formation of ameloblasts. • Formation of odontoblasts. CÍM beírása!!! DÁTUM Bell stage: The cells on the periphery of the enamel organ separate into three important layers: • Cuboidal cells on the periphery of the dental organ form the outer enamel epithelium. • The cells of the enamel organ adjacent to the dental papilla form the inner enamel epithelium. • The cells between the inner enamel epithelium and the stellate reticulum form a layer known as the stratum intermedium. The dental lamina begin to disintegrates, leaving the developing teeth completely separated from the epithelium of the oral cavity. CÍM beírása!!! DÁTUM Crown stage : 1. Mineralization of hard tissues occur. 2. The inner enamel epithelial cells change in shape from cuboidal to columnar. The nuclei of these cells move closer to the stratum intermedium and away from the dental papilla. 3. The adjacent layer of cells in the dental papilla suddenly increases in size and differentiates into odontoblasts, which form dentin. 4. The inner enamel epithelium and the formation of odontoblasts continue from the tips of the cusps. CÍM beírása!!! DÁTUM Preeruption phase- crown phase CÍM beírása!!! DÁTUM Origin of germs of permanent teeth CÍM beírása!!! DÁTUM Preeruption phase CÍM beírása!!! DÁTUM Preeruption phase CÍM beírása!!! DÁTUM Root formation CÍM beírása!!! DÁTUM Root formation CÍM beírása!!! DÁTUM Eruption phase – movement CÍM beírása!!! DÁTUM CÍM beírása!!! DÁTUM Eruption phase – movement CÍM beírása!!! DÁTUM Eruption phase – breakthrough CÍM beírása!!! DÁTUM Eruption phase – breakthrough CÍM beírása!!! DÁTUM Eruption phase – breakthrough CÍM beírása!!! DÁTUM Eruption phase – occlusal contact CÍM beírása!!! DÁTUM Eruption cascade CÍM beírása!!! DÁTUM Eruption cascade CÍM beírása!!! DÁTUM Sequence of tooth eruption CÍM beírása!!! DÁTUM Sequence of tooth eruption CÍM beírása!!! DÁTUM Sequence of tooth eruption CÍM beírása!!! DÁTUM Sequence of tooth eruption CÍM beírása!!! DÁTUM 05/1985 04/1987 11/1989 04/1991 09/1996 02/1999 CÍM beírása!!! DÁTUM Sequence of tooth eruption Age Tooth Girls Boys 6 y 6 - 6 5,94 6,21 6 + 6 6,22 6,40 1 - 1 6,26 5,54 7 y 1 + 1 7,20 7,47 2 - 2 7,34 7,70 8 y 2 + 2 8,20 8,26 10 y 3 - 3 9,86 10,79 4 + 4 10,03 10,40 4 - 4 10,18 10,82 11 y 5 + 5 10,88 11,18 5 - 5 10,89 11,47 3 + 3 10,98 11,69 12 y 7 - 7 11,66 12,12 7 + 7 12,27 12,68 18 - 22 y 8 +/- 8 CÍM beírása!!! DÁTUM Eruption phase – occlusal contact 5 months At birth 1 year CÍM beírása!!!2 years 3.5 years 4.5 years DÁTUM Posteruption phase 7 years-functional occlusion attained 15 years – incisal wear but root apex is still not fully formed CÍM beírása!!! DÁTUM Some data The rate of tooth eruption depends on the phase of movement Intraosseous phase: 1 to 10 µm/day Extraosseous phase: 75 μm/day CÍM beírása!!! DÁTUM Presurgical naso-alvolear molding CÍM beírása!!! DÁTUM Bilateral cleft lip, alveolus and palate CÍM beírása!!! DÁTUM Secondary cases 18 months 2 years CÍM beírása!!! DÁTUM Abnormalities 1. Dentitio tarda 2. External resorption 3. General resorption disorders 4. Ankylotic primary teeth 5. Aplasia, oligodontia, hypodontia 6. Remaining primary teeth 7. Eruption disorders CÍM beírása!!! DÁTUM Dentitio tarda CÍM beírása!!! DÁTUM Dentitio tarda 6.5 year 9 year 10.5 year 12 year CÍM beírása!!! DÁTUM External resorption CÍM beírása!!! DÁTUM General resorption disorders CÍM beírása!!! DÁTUM Eruption disorders – hormonal Familial, nonsyndromic PFE is caused by heterozygous mutations in the gene encoding the G protein-coupled receptor for parathyroid hormone and parathyroid hormone-like hormone (PTHR1) - Decker et al., 2008 CÍM beírása!!! DÁTUM Submerged primary teeth CÍM beírása!!! DÁTUM Ankylosis CÍM beírása!!! DÁTUM Retained primary teeth CÍM beírása!!! DÁTUM Aplasia / oligodontia Anodontia = primary dental aplasia Total anodontia ectodermal dysplasia Partial anodontia (oligodontia) Hypodontia (last missing) M3 10-25% P2 3-4% I2 2% CÍM beírása!!! DÁTUM Congenitally Missing Teeth CÍM beírása!!! DÁTUM Natal and Neonatal Teeth CÍM beírása!!! DÁTUM Eruption disoders Frontal region Canine region Premolar region Molar region Wisdom tooth region CÍM beírása!!! DÁTUM Supporting zone CÍM beírása!!! DÁTUM Lost of support CÍM beírása!!! DÁTUM Maintain space! Space maintainer Lip-bumper Transpalatinal-arch Lingual-arch CÍM beírása!!! DÁTUM Tooth movement CÍM beírása!!! DÁTUM Eqilibrium theory BITE TONGUE LIP, BUCCAL TISSUES ERUPTION CÍM beírása!!! DÁTUM Dental movement Physiological: Eruption Pathological: Early primary or secondary tooth extraction Tumor Thumb sucking Muscular dysfunction Therapeutical: Orthodontics CÍM beírása!!! DÁTUM Guidance with functional apparatus Fränkel III CÍM beírása!!! DÁTUM Guidance with functional apparatus Lip bumper CÍM beírása!!! DÁTUM Basic principles of orthodontics • Bony appositon by traction and resorption on pressure • Too much pressure will cause capillary compression and hyalinization • Effective orthodontic force correlates with root surface • Newton III. rule: Action=Reaction. It is impossible to move only one tooth, only with skeletal anchorage CÍM beírása!!! DÁTUM Guided extrusion of impacted tooth CÍM beírása!!! DÁTUM Box-loop CÍM beírása!!! DÁTUM Skeletal anchorage Headgear CÍM beírása!!! DÁTUM Skeletal anchorage Palatinal mini- implant Vestibular mini-implant CÍM beírása!!! DÁTUM Forced extrusion in periodontally lost case Only traction – bony apposition CÍM beírása!!! DÁTUM Thank you very much for your kind attention! [email protected] CÍM beírása!!! DÁTUM Histology – Surrounding tissues The surrounding fibers change from being parallel to the tooth surface to bundles that are attached to the tooth surface and extending towards the periodontium (bone) The periodontal ligament have contractile properties and changes drastically during eruption During eruption, collagen fiber formation and turnover are rapid enabling fibers to attach and release and attach in rapid succession. Some fibers may attach and reattach later while the tooth moves occlusally as new bone forms around it and the fibers will organize and increase in number and density as the tooth erupts rxdentistry.net CÍM beírása!!! DÁTUM Histology – Underlying tissues As the tooth moves occlusally it creates space underneath the tooth to accommodate root formation Fibroblasts around the root apex form collagen that attach to the newly formed cementum Bone trabeculae fill in the space left behind as the tooth erupts in the pattern of a ladder which gets denser as the tooth erupts After tooth reaches functional occlusion periodontal fibers attach to the apical cementum and extend into the adjacent alveolar bone CÍM beírása!!! DÁTUM Mechanisms of Eruptive Tooth Movement Eruption is a multifactorial process The accepted theories of tooth eruption are: 1. Root Formation. Should be an obvious cause of tooth eruption. But studies have not provided evidence for this. If a tooth that is continuously erupting (rodent incisor and guinea pig molar) is prevented the root still forms by causing bone resorption. Rootless tooth still erupt, some teeth erupt more than the total length of the roots and the teeth still erupt after completion of root formation. Therefore root formation is accommodated during eruption and may not be the cause of tooth eruption. One point of importance is that, the tissue beneath the growing root resists the apical movement of the developing root. This resistance results in the occlusal movement of the tooth crown as the root lengthens. CÍM beírása!!! DÁTUM Mechanisms of Eruptive Tooth Movement 2. Bone Remodeling. Major proof is when a mand PM is removed without disturbing its follicle or you wire down the tooth germ, an eruptive pathway still forms within bone as osteoclasts widen the gubernacular canal. If the dental follicle is also removed no eruption path develops. So not sure if bone remodeling plays a significant role but is involved. One point to remember: Bone formation also occurs apical to the developing tooth • Dental Follicle. Studies have shown that the reduced dental epithelium initiates a cascade of intercellular signals that recruit osteoclasts to the follicle. By providing a signal and chemoattractant for osteoclasts, it is possible that the dental follicle can initiate bone remodeling which goes with tooth eruption. Teeth eruption is delayed or absent in animal models and human diseases that cause a defect in osteoclast differentiation. CÍM beírása!!! DÁTUM Mechanisms of Eruptive Tooth Movement 4. Periodontal ligament. Formation and renewal of PDL can be a factor in tooth eruption because of the traction power
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