Embryology Chapter Six

  1. The first stage of tooth development and eruption
  2. What is the physiological process that occurs during the initiation stage of tooth development?
  3. The Pow wow, let's get this party started, cells decide who they are going to be, the part we don't understand.
  4. controlled levels of cellular growth
  5. cells start to be structurally and functionally different
  6. the tissues start to become structures
  7. growing up in form function and size
  8. tooth development
  9. Dentition
  10. 20 baby teeth that develop during the prenatal period. Will be shed.
    primary dentition
  11. True or False. flouridation matters when teeth are forming in the womb.
  12. 32 adult teeth that develop during the fetal period-though they mature for years after birth. Will replace baby teeth.
    secondary dentition
  13. Does flouridation help adults?
    not really
  14. overlapping of time between primary and secondary dentitions.
    mixed dentition
  15. What other 2 physiological processes take place during the initiation stage of tooth development, but not as prevelant as induction?
    • proliferation
    • differentiation
  16. What layers exist on the maxillary and mandibular arches during the initiation stage of tooth development?
    • Oral epithelium
    • Ectomesenchyme
    • basement membrane
  17. top layer that comes from the ectoderm
    oral epithelium
  18. bottom layer of mesoderm that originally came from the ectoderm
  19. the "velcro" separating the oral epithelium from the ectomesenchyme
    basement membrane
  20. describe the development of the dental lamina layer.
    for each tooth, the oral epithelium grows deeper into the ectomesenchyme (into a "finger-like projection") and forms the new layer called the dental lamina
  21. starts as oral epithelium and grows down to a new layer with "fingerlike projection"
    Dental Lamina
  22. what are 3 developmental disturbances that occur during the initiation stage of tooth development?
    • anodontia
    • hypodontia
    • supernumerary teeth
  23. absence of teeth. Nobody told them to grow. lack of initiation
    anodontia; initiation stage
  24. Less than normal amounts of teeth
    hypodontia; initiation stage
  25. extra teeth, somebody told them wrong
    supernumerary teeth; initiation stage
  26. the second stage of tooth development
    bud stage
  27. What physiological process occurs during the bud stage?
    proliferation only
  28. What happens during the bud stage of tooth development? The reason for the name of the stage.
    The finger like projection full of dental lamina undergoes extensive proliferation, starts to fatten up and look like a bud.
  29. What are some developmental disturbances that may take place during the bud stage?
    • Macrodontia
    • Microdontia
  30. Big teeth
    Macrodontia; bud stage
  31. little teeth
    microdontia; bud stage
  32. third stage of tooth development
    cap stage
  33. what physiological processes occur during the cap stage?
    • proliferation
    • morphogenesis
    • differentiation
  34. The predominant physiological process during the cap stage
  35. What causes the Cap shape of the dental lamina during the cap stage?
    unequal proliferation
  36. During the cap stage, the cells start differentiating to become____________and___________different
    • structurally
    • functionally
  37. Name the 3 layers that are formed during the cap stage.
    • enamel organ
    • dental papilla
    • dental sac
  38. comes from the dental lamina and will produce enamel
    enamel organ
  39. comes from ectomesenchyme and will be the future pulp and dentin
    dental papilla
  40. ectomesenchyme that will be the periodontium (cementum, periodontal ligament, and alveolar bone) the support structure
    dental sac
  41. enamel organ, dental papilla, and dental sac combined
    tooth germ
  42. the finger-like projection that will be the adult tooth
    succesional dental lamina
  43. the adult teeth that replace the baby teeth
  44. the adult teeth that don't replace the baby teeth, they form brand new with out a previous tooth, not successors
  45. what are 3 developmental disturbances that occur during the cap stage?
    • dens in dente
    • gemination
    • fusion
  46. tooth within a tooth the enamel organ gets lost in the dental papilla
    dens in dente; cap stage
  47. single tooth unsuccessfully tries to split in two. Large single rooted tooth with two crowns, may look like macrodontia, but we only count roots
    gemination; cap stage
  48. two tooth germs that fuse together. It looks like macrodontia, or even some anodontia because you can't see enough crowns, but count the roots
    fusion; cap stage
  49. What is the 4th stage of tooth development?
    Bell stage
  50. What physiological stages are occuring during the bell stage?
    • proliferation
    • differentiation
    • morphogenesis
  51. what physiological process is occuring to its furthest extent during the bell stage? And what forms as a result of it?
    • differentiation
    • many new layers
  52. What are the new layers that form during the bell stage as a result of extensive differentiation?
    • outer enamel epithelium
    • stellate reticulum
    • stratum intermedium
    • inner enamel epithelium
    • basement membrane
    • outer cells of dental papilla
    • inner cells of dental papilla
  53. protective barrier during enamel formation
    outer enamel epithelium
  54. star shaped cells that support enamel production
    stellate reticulum
  55. compressed layer of flat cells that support enamel production
    stratum intermedium
  56. will become enamel secreting cells (ameloblasts)
    inner enamel epithelium
  57. the velcro between inner enamel epithelium and outer cells of dental papilla, will become the dentinoenamel junction
    basement membrane
  58. will become the dentin secreting cells (odontoblasts)
    outer cells of dental papilla
  59. will become the dental pulp
    inner cells of dental papilla
  60. What stages of teeth development follow the bell stage?
    apposition and maturation stages
  61. growth by layers, layers of dentin, cementum, and enamel to be exact
  62. enamel secreting cells that retreat to the north (away from the basement membrane)
  63. dentin secreting cells that retreat to the south (away from the basement membrane)
  64. describe the formation of the matrix.
    The layers on either side of the basement membrane, the ameloblasts and odontoblasts, retreat and leave a slimy trail, the matrix
  65. structure of ameloblasts that secretes the actual enamel matrix
    tome's process
  66. during which stage is the matrix, the structural foundation, mineralized?
    maturation stage
  67. what happens to ameloblasts with tooth eruption?
    they are discarded
  68. attached cellular extensions left by odontoblasts
    odontoblastic processes.
  69. Odontoblastic processes that are contained and protected in mineralized cylinders of dentin
    dentinal tubules
  70. what happens to the cell bodies of odontoblasts with tooth eruption?
    they remain in the dental pulp
  71. faulty development of enamel. pitting and grooves in the enamel
    enamel dysplasia; apposition and maturation stages
  72. decreased quantity of enamel matrix
    • enamel hypoplasia; apposition and maturation stages
    • (could result from flourosis
  73. plenty of enamel matrix, but the quality was bad because it didn't fully mineralize
    enamel hypocalcification; apposition and maturation stages
  74. What are the 2 main metabolic or hereditary causes of enamel hypoplasia and enamel hypocalcification?
    • syphilis
    • flourosis
  75. too much fluoride during mineralization
  76. very thin or no enamel. hereditary, results in extreme attrition
    amelogenesis imperfecta; apposition and maturation stages
  77. faulty development of dentin. hypoplasia or hypocalcification
    dentin dysplasia
  78. blue-grey or brown teeth because the dentin didn't form correctly. the enamel (though healthy) chips off because it doesn't have support. results in attrition
    dentinogenesis imperfecta
  79. When does root development start?
    when crown is complete and erupting
  80. The IEE and OEE squished together - without the stellate reticulum or stratum intermedium.
    Cervical loop
  81. As the cervical loop extends deeper into the ectomesenchyme it becomes the____________.
    Hertwig's epithelial Root Sheath (HERS)
  82. HERS_____________the dental papilla to____________________ into odontoblasts.
    • induces
    • differentiate
  83. How come enamel doesn't form during root formation of the tooth?
    because there is no stratum intermedium or stellate reticulum, so ameloblasts cannot form
  84. what do the odontoblasts do once they are formed?
    they undergo dentinogenesis and begin to secrete predentin, the dentin matrix
  85. What happens to the HERS when root dentin formation is completed?
    it disintegrates, because of lack of ameloblasts
  86. lost epithelial cells that fail to disintegrate with the rest of the HERS that can become cystic and cause problems
    epithelial rests of Malassez
  87. What is it that induces the cells of the dental sac to become cementoblasts?
    After the disintegration of HERS, when the undifferentiated cells of the dental sac come in contact with the newly formed surface of root dentin.
  88. cementum producers
  89. cementum production
  90. enamal production
  91. dentin production
  92. slimy trail left by cementoblasts, or cementum matrix
  93. cell bodies left in the matrix by cementoblasts
  94. Why are the cell bodies of cementoblasts left in the matrix, or cementoid?
    because the matrix was laid so quickly that the cell bodies got trapped or caught in the matrix
  95. why do the cementoblasts line up with the periodontal ligament upon finishing the matrix?
    so they are ready to lay more cementum if it ever gets broken down
  96. the dental papilla is formed into the pulp of the tooth through____________.
  97. ectomesenchyme from the dental sac_____________into the _______________ adjacent to the cementum
    • differentiates
    • periodontal ligament (PDL)
  98. Where does the periodontal ligament anchor itself?
    into the cementum and alveolar bone
  99. How are multirooted teeth formed?
    cervical loop splits into multiple roots
  100. ameloblasts get lost and start forming enamel in abnormal places, they may be confused with calculus on the root surface
    enamel pearls; root formation
  101. two teeth get stuck together by the cementum. Can be caused by trauma or crowding of teeth. Really hard to extract
    concrescence; root development
  102. because of injury or pressure, HERS gets distorted and makes the roots bend. Hard to extract
    dilaceration; root development
  103. extra roots because of injury, pressure, or metabolic disease of HERS
    accessory roots; root development
  104. actual vertical movement of tooth
    active eruption
  105. gingiva recedes around tooth
    passive eruption
  106. enamel organ squished together, fuses to the oral epithelium of the oral cavity, and disintegrates some of the oral epithelium to make a tunnel of eruption
    Reduced Enamel Epithelium (REE)
  107. inflammatory response caused by the disintegration of oral epithelium because of the REE.
  108. symptoms of teething
    • bleeding
    • inflammed gums
    • slight fever
  109. portion where the epithelial tissues peel back, but remain intact around the cervical portion of the tooth during tooth eruption that creates a seal between the tissue and the tooth surface
    initial junctional epithelium
  110. dissolve the bone around the tooth
  111. dissolve the roots of the tooth (break down dentin)
  112. Why do kids teeth feel really loose and then suddenly tighten up again sometimes?
    because sometimes the tooth is not ready to come out, so the osteoblasts, odontoblasts, and cementoblasts will replace the resorbed bone and root
  113. left over REE and oral epithelium that sticks to the newly erupted teeth and catches stain
    Nasmyth's membrane
  114. All succedaneous teeth form and erupt__________________to the primary teeth, except the maxillary incisors that erupt______________to the primary teeth.
    • lingually
    • facially
  115. the REE forms a cyst around the completely formed crown. It can displace teeth and cause pain. Must be removed surgically
    dentigerous cyst; eruption
  116. a dentigerous cyst formed around the developing crown. When the tooth erupts it will go away.
    eruption cyst; eruption
Card Set
Embryology Chapter Six
Odontogenesis 1