Dental Anatomy

  1. Structure responsible for root development
    cervical loop
  2. Where is the cervical loop located? And what structures/cells does it consist of?
    • most cervical portion of enamel organ
    • IEE and OEE
  3. As the cervical loop continues to grow deeper into the ectomesenchyme of the dental sac and enclosing more of the dental papilla, it forms what?
    Hertwig's epithelial root sheath (HERS)
  4. functions to shape the root (s) and induces dentin formation, so it is continueous with coronal dentin
  5. HERS induces ___________ ____ in the root area
    dentin formation
  6. What induces the ondontoblastic differentiation in the roots?
  7. Why doesn't enamel form in the roots of the teeth?
    because they don't have their support structure and intermediate layers (stellate reticulum and stratum intermedium)
  8. What happens to the basement membrane and HERS when root dentin formation is completed?
    they disintegrate
  9. HERS root sheath disintegrates and may become these groups of epithelial cells located in the mature perio ligament. They may become cystic and cause future problems
    Epithelial rests of malessez
  10. misplaced ameloblasts migrating to the root area, abnormally forming enamel on the root surface
    enamel pearls
  11. small spherical enamel projections found on root surface, especially at CEJ or in furcation areas on molars where root divides
    enamel pearls
  12. How do enamel pearls appear radiographically?
  13. enamel pearls may be confused as what? But cannot be removed.
    calculus upon exploration
  14. apposition of cementum
  15. When does cementogenesis occur?
    when HERS disintegrates allowing undifferentiated cells of the dental sac come in contact with the newly formed root dentin
  16. What induces the cells of the dental sac to differentiate into cementoblasts?
    coming in contact with the newly formed root dentin
  17. cells of the dental sac become what type of cells when they come in contact with the newly formed root dentin?
  18. move to cover the root dentin laying down cementum matrix
  19. cementum matrix
  20. cementoblasts entrapped in the cementum
  21. matured, calcified cementoid surrounding the cementocytes
  22. formed as a result of the apposition of cementum over the dentin
    dentinocemental junction
  23. excess cementum formation; union of the root structure of two or more teeth through the cementum only
  24. In what teeth do concrescence usually occur?
    permanent maxillary molars
  25. as the crown and root develop, the ectomesenchyme from the dental sac begins to form the___________, and also begins to mineralize to form the _____________
    • PDL
    • alveoli of alveolar bone surrounding the PDL
  26. The ends of collagen fibers connect in what 2 structures?
    • outer portion of cementum
    • surrounding alveolar bone
  27. base of the crown where roots of multirooted molars and premolars originates
    root trunk
  28. WHat causes the root trunk to divide into two or three roots?
    differential growth of HERS
  29. distorted roots or crown angulation in a formed tooth; results from distortion of HERS caused by injury or pressure
  30. deviation or bend restricted to only the root portion of the tooth, usually less than 90*, may be a result of trauma to the developing tooth
  31. extra roots or supernumerary roots; may be due to trauma, injury, or pressure affecting HERS
    accessory roots
  32. What teeth do accessory roots usually affect?
    permanent 3rd molars, it is rare in incisors
  33. actualy vertical movement of the teeth
    active eruption
  34. occurs as we age, as gingia recedes, no actual tooth movement occurs
    passive eruption
  35. Do mandibular or maxillary teeth usually erupt first?
    mandibular usually precedes maxillary
  36. teeth in both jaws erupt in _____
  37. do permanent teeth usually erupt first in boys or girls?
  38. eruption of primary central incisors
    6.5-8 months
  39. eruption of primary lateral incisors
    7-9 months
  40. eruption of primary first molars
    12-16 months
  41. eruption of primary canines
    6-21 months
  42. eruption of primary second molars
    21-30 months
  43. tissue that covers newly formed enamel, but fuses with oral epithelium as it erupts
    Reduced enamel epithelium (REE)
  44. residue formed on newly erupted tooth consisting of the fused tissue of the REE and oral epithelium as well as the dental cuticle placed by ameloblasts on new enamel. easily removed with polishing
    Nasmyth's membrane
  45. absorb alveolar bone between shedding primary teeth and erupting permanent teeth
  46. cause resorption or removal of portions of the primary root of dentin and cementum, as well as small portions of the enamel crown
  47. Why is it so important to keep primary teeth as long as possible?
    they servce as place holders for permanent teeth
  48. tendency of the permanent molars to have an eruptive force toward the midline
    mesial drift
Card Set
Dental Anatomy
root formation