Term
| Discuss and explain the two dentitions and when they occur |
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Definition
Primary Dentition - develop during prenatal (20 teeth. Eventually lost.
Permanent - 32 teeth replaces primary and is permanent. |
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Term
| Name and explain 3 dentition periods |
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Definition
Primary - Baby teeth
Permanent - Adult teeth
Mixed - Permanenet and mixed |
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Term
| What is odontogenisis and how does the process occur? |
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Definition
| Tooth development, in stages - initiantion, bud, cap, bell, apposition, maturation |
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Term
| What occurs during initiation stage, and what tissues are involved? |
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Definition
| 6-7 weeks - Induction - Ectoderm lining stomodeum gives rise to oral epithelium and then to dental lamina. |
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Term
| What developmental disturbances can occur in initiantion. |
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Definition
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Term
| What occurs during bud stage and what tissues are involved? |
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Definition
| Proliferation - 8th week - dental lamina grows penetrating into ectomessenchyme. ectoderm and messenchyme become ectomessencyme because of neural crest cells |
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Term
| what developmental disturbances occur during bud stage? |
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Definition
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Term
| What occurs during the cap stage and what tissues are involved? |
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Definition
| 9-10th week - proliferation - lamina holds on growing and a cap is formed around the bud. A lot of differentiation is going on. Enamel organ is formed (produced from ectoderm). Ectomessenchyme produces a dental papilla - future dentin and pulp. ectomessenchyme condenses producing dental sac which becomes cementum, alveolar bone and periodontal ligament |
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Term
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Definition
| during the 7th week oral epithilium grows deep into ectomessenchyme producing the dental lamina. This occurs to grow where the 2 jaws will eventually be. bascially both arches |
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Term
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Definition
| derived from ectomessenchyme influenced by neural crest cells. will create future dentin and pulp. |
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Term
| What does the tooth germ consist of? |
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Definition
| dental papilla, enamel organ and dental sac |
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Term
| what is succesional dental lamina? and what does it provide? |
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Definition
| dental lamina that will provide a space for succedaneous permanent teeth. |
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Term
| What is the difference between succedaneous and nonsuccedaneous teeth? |
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Definition
| succendaneous teeth are replaced with new teeth nonsuc are just new teeth that wont replace any teeth. |
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Term
| What development disturbance can occur during cap stage? |
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Definition
| dens in dente, gemination, fusion, tubercle |
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Term
| What occurs during the bell stage and what tissues are involved? |
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Definition
| 11-12th week - inner enamel epithelium(becomes enamel secreting cells ameloblasts) , OEE (protective barrier 4 enamel organ), stellate reticulum(form star shaped network), stratum intermedium. both support production of enamel. outer/inner dental papilla forms (inner - pulp)(outer - odontoblasts) |
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Term
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Definition
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Term
| What does enamel organ consist of and function of each layer? |
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Definition
| OEE - protect, IEE - ameloblasts, Stellate reticulum - network for enamel organ, Stratum intermedium - support prodection of enamel. |
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Term
| Describe dental sac and its function? |
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Definition
| looks like a sac around tooth germ. produces periodontium (supporting tooth tissues): cementum, periodontal ligament and alveolar bone |
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Term
| Explain stages of appostion and maturation during tooth development |
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Definition
| apposition - dentin, enamel, cementum - secreted in layers as a matrix for calcification. Maturation is reached when these tissues finally mineralize. |
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Term
| Describe the process of induction in tooth development? |
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Definition
| interaction between the embryological tissues. One tissue influences another tissue in order for a process to happen. |
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Term
| How do preameloblasts form? |
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Definition
| IEE differentiates into preameloblasts. Nucleus moves away from basement membrane during repolarization. These will induce dental papilla cells and IEE differentiates into cells that secrete enamel matrix |
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Term
| How do odontoblasts form and what do they produce? |
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Definition
| preameloblasts induce OEE to differentiate into odontoblasts. after repolarization the cells begin dentinogenisis creating dentin matrix or predentin (happens b4 enamel matrix secretion) |
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Term
| How do ameloblasts form and what do they produce? |
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Definition
| membrane between preameloblasts and odontoblasts disintigrates preameloblasts come in contact with newly formed dentin and differentiate into ameloblasts. This starts amelogenisis or formation of enamel matrix |
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Term
| Explain dentoenamel juction in relation to tomes process, odontoblasts, and ameloblasts |
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Definition
| enamel matrix secreted from tomes process. basement membrane now gone the enamel and dentin come together as the dentinoenamel junction. |
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Term
| apposition maturation disturbances? |
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Definition
| enamel pearl - extra enamel, enamel dysplasia - faulty enamel, concresence - roots joined |
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Term
| Describe the process of root development? |
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Definition
| crown forms the root down to the apices. cervical root (cervical portion of enamel matrix that consists of IEE and OEE) grows deeper into ectomessenchyme of dental sac encompassing some dental papilla this is called Hertwigs root sheath or HERS. |
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Term
| Whats hertwigs epithelial root sheath? |
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Definition
| membrane encompassing dental papilla that forms dentin for the roots of the teeth. |
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Term
| How does root dentin form? |
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Definition
| Influence of IEE on HERs lacking stellate reticulum and stratum intermedium creates odontoblastic differentiation. |
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Term
| What are the epithelial rests of malessez, and what complication is associated with them? |
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Definition
| root dentin complete HERS and basement membrane disintegrate. The cells left are the rests of malassez. become located in the periodontal ligament and can become cystic. |
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Term
| What disturbances happen during root development? |
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Definition
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Term
| discuss process of cementogenisis |
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Definition
| cells in dental sac come in contact with newly formed root dentin. Induces to become cementoblasts. Covers root dentin area and begins cementinogenisis |
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Term
| Where is the dentinocemental junction located, and what is its relationship to the pulp and other tissues? |
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Definition
| cementum over dentin create dentinocemental junction. central cells of dental papilla are forming pulp at same time. |
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Term
| How does periodontal ligament develop? |
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Definition
| ectomessenchyme from the dental sac forms periodontal ligament. Collagen fibers organized and inserted into outer portion of cementum and alveolar bone |
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Term
| How does alveolar bone develop? |
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Definition
| ectomessenchyme of the dental sac begin to mineralize to form tooth sockets or alveoli of alveolar bone surrounding PDL |
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Term
| disturbances for cementum and rooth formation? |
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Definition
| concrescence, dilaceration, accesory roots |
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Term
| What portion of the tooth is considered rooth trunk? |
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Definition
| Area before the roots branch |
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Term
| How do multirooted teeth develop? |
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Definition
| differential growth of HERS causes rooth trunk of multirooted teeth to divide into 2 or 3 roots |
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Term
| epithelial extension or root flaps |
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Definition
| during formation of enamelorgan onmultirooted teeth elongation of the cervical loop occurs producing long extensions for each root |
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Term
| What is the difference between active and passive eruption |
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Definition
active eruption - vertical movement of the tooth
Passive eruption - gingiva recedes no actual tooth movement occurs |
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Term
What occurs during active eruption?
describe REE and its role in tooth eruption. |
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Definition
Tooth moves vertically,
REE is formed and binds to oral epithelium, enzymes disitegrate the central portion of fused tissue. |
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Term
| what is an odontoclast, and what is its role in tooth shedding? |
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Definition
| cause resorption or removal of portions of the primary tooth root dentin and cementum as well as small portions of enamel crown. makes tooth loose. |
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Term
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Definition
| REE and oral epithelium on new enamel surface. Easily picks up stain and debri but can be cleaned and polished away |
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Term
| How does a permanent tooth erupt in the oral cavity and what process is involved? |
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Definition
| REE fuses with oral epithilium to create tissue that degenerates leaving an epithelial lined eruption tunnel |
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Term
| what can happen with traumatic injury in the oral cavity during eruption of permanent dentition, how can it be prevented? |
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Definition
| the roots are not completely formed traumatic injury could knock them out. use mouth guards. |
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Term
| describe developmental disturbances that happen during eruption |
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Definition
| dentigerous cyst - REE causes tooth can become larger preerruption. |
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