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Dentistry Tooth Development And Eruption

Subjects : health-sciences, dentistry

Instructions:

Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What happens when the reduced enamel epithelium is created?
The primary tooth can now erupt into the oral cavity - the REE fuses with the oral epithelium - then enzymes from the REE disintegrate the central portion of the epithelial tissue leaving an epithelial tunnel for the tooth to erupt
Ameloblasts
Absence of single or multiple teeth
Enamel organ invaginates into the dental papilla

2. What are the odontoblastic processes is contained in what?
Imbrication lines of von Ebner
Dentin and alveolar bone
The basement membrane that seperates the enamel organ and dental papilla
A mineralized cylinder - the dentinal tubule

3. What are the resorptive cells for enamel - dentin - cementum and alveolar bone?
The stellate reticulum
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
Enamel organ forms into cap - surrounding mass of dental papilla from the ectomesenchyme and surrounded by mass of dental sac also from the ectomesenchyme. Formation of the tooth germ.
Odontoclasts

4. The buds of the dental lamina - together with the surrounding ecto mesenchyme - will develop into what?
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Initiation
The dental sac
Tooth germ

5. What happens during the apposition stage?
The outer enamel epithelium
Preameloblasts
Epithelial rests of Malassez
Dental tissues secreted as matrix in successive layers.

6. What are the mature cells for dentin?
Common with permanent maxillary molars
Only dentinal tubules with processes
11th to 12th weeks
Large single rooted tooth with one pulp cavity and exhibits 'twinning' in crown area. normal number of teeth in dentition. may cause problems in appearance and spacing

7. What is the time span for initiation?
The primordium of the pulp
Odontoblasts
As a result of the apposition of cementum over dentin
6th to 7th weeks

8. What happens during initiation?
Ectoderm lining stomodeum gives rise to the oral epithelium and then to the dental lamina - adjacent to deeper ectomesenchyme - Which is influenced by the neural crest cells. Both tissues are seperated by a basement membrane
Maturation
Lines of Retzuis
The ameloblasts

9. What are the clinical ramifications of fusion?
Common on permanent molars or cingulum of anterior teeth
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane
Initiation

10. Where is the dental sac originally derived from?
8th week
Absence of single or multiple teeth
The ectomesenchyme
Only dentinal tubules with processes

11. What are the developmental disturbances of the cap stage?
The outer enamel epithelium
Union of root structure of two or more teeth by cementum
Dentin and alveolar bone
Dens in dente - gemination - tubercle - and fusion

12. What causes the induction of the preameloblasts to differentiate into ameloblasts?
Tall columnar cells
Abnormally large teeth
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
Compressed layer of flat to cuboidal cells

13. The oral epithelium is induced by the ectomesenchyme to produce what?
The bud stage
Compressed layer of flat to cuboidal cells
Development of one or more extra teeth
The dental lamina

14. What is fusion?
Inner
Union of 2 adjacent tooth germs
The ameloblasts
Dental tissues fully mineralize to their mature levels.

15. What stage does the dental tissues subsequently fully mineralize
Maturation
The ectomesenchyme - which was influenced by the neural crest cells
Induction - proliferation
The enamel organ - dental papilla - dental sac

16. What are the 2 layers in the dental papilla within the concavity of the enamel organ?
The dental sac
Inner
Cementocytes
The outer cells of the dental papilla and the central cells of the dental papilla

17. What stage does supernumerary teeth occur?
The ectoderm
The stellate reticulum
Initiation
Connective

18. In the cap stage the tooth bud does not grow - what happens?
The cementum - PDL - and alveolar bone
There is unequal growth in different parts of the tooth bud
4 types
May be confused as calculus deposit on root

19. What happens during the bell stage?
Hereditary
Common on permanent molars or cingulum of anterior teeth
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy

20. What are the development disturbances of the apposition and maturation stages?
Dental follicle
Enamel pearl - enamel dysplasia - and concresence
The outer cells of the dental papilla and the central cells of the dental papilla
There are none - they are lost with eruption

21. What is the site for the future dentioenamel junction?
Cementoblasts
The basement membrane that seperates the enamel organ and dental papilla
Bud stage
The tooth germ

22. What is concrescence?
The primordium of the pulp
Union of root structure of two or more teeth by cementum
Apposition of the cementum
Preameloblasts

23. How is the dentinocemental junction formed?
As a result of the apposition of cementum over dentin
Proliferation - differentiation - morphogenesis
Dens in dente - gemination - tubercle - and fusion
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel

24. When does the tooth bud become a tooth germ?
May be confused as calculus deposit on root
In the cap stage
The bud stage
The stellate reticulum

25. What is the time span for the bud stage?
Common with permanent maxillary molars
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
8th week
Union of 2 adjacent tooth germs

26. The stratum intermediate is located inner or outer?
Enamel
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Hereditary
Inner

27. What are the etiological factors of enamel dysplasia?
Dental tissues secreted as matrix in successive layers.
Local or systemic or hereditary
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
The ectomesenchyme

28. When does the process of root development take place?
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
Future dentin and pulp tissue
Enamel

29. What are the processes involved in the cap stage?
Proliferation - differentiation - morphogenesis
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
Enamel organ forms into cap - surrounding mass of dental papilla from the ectomesenchyme and surrounded by mass of dental sac also from the ectomesenchyme. Formation of the tooth germ.
Cementoid

30. What are the clinical ramifications of enamel pearl?
Dental tissues fully mineralize to their mature levels.
May be confused as calculus deposit on root
Enamel organ
Commonly involves permanent maxillary lateral incisor and 3rd molars

31. What do the odontoblasts do?
When the gingiva recedes and no actual tooth movement takes place
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
Ameloblasts
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy

32. What are the clinical ramifications?
Dental tissues fully mineralize to their mature levels.
Bud stage
Common on permanent molars or cingulum of anterior teeth
Union of root structure of two or more teeth by cementum

33. What are the etiological factors for micro/macrodontia?
Cementocytes
Proliferation - differentiation - morphogenesis
Ameloblasts
Hereditary in localized form. endocrine dysfunction is complete

34. What are the formative cells for cementum?
Induction - proliferation
Cementoblasts
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
9th to 10th weeks

35. What is tubercle?
Displacement of ameloblasts to root surface
The stellate reticulum
Extra cusp due to effects on enamel organ
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane

36. What is microdontia?
The permanent molars
Proliferation
May be confused as calculus deposit on root
Abnormally small teeth

37. What are entrapped cementoblasts called?
The primary tooth can now erupt into the oral cavity - the REE fuses with the oral epithelium - then enzymes from the REE disintegrate the central portion of the epithelial tissue leaving an epithelial tunnel for the tooth to erupt
There is unequal growth in different parts of the tooth bud
Cementocytes
The ameloblasts

38. What will the dental papilla eventually form?
Odontogenesis
11th to 12th weeks
Future dentin and pulp tissue
Maturation

39. What is the important acelluar structure that seperates the oral epithelium and the ectomesenchyme?
Hereditary in localized form. endocrine dysfunction is complete
The basement membrane
The permanent molars
Initiation stage

40. What type of tissue is enamel?
Osteoblasts
The ectoderm
Ectoderm lining stomodeum gives rise to the oral epithelium and then to the dental lamina - adjacent to deeper ectomesenchyme - Which is influenced by the neural crest cells. Both tissues are seperated by a basement membrane
Epithelial

41. What processes are involved with the apposition stage?
Dentin and alveolar bone
Enamel secreting cells (ameloblasts)
Induction - proliferation
Enamel organ forms into cap - surrounding mass of dental papilla from the ectomesenchyme and surrounded by mass of dental sac also from the ectomesenchyme. Formation of the tooth germ.

42. What are the etiological factors for anodontia?
Ameloblasts
Lines of Retzuis
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Enamel organ

43. After the enamel apposition ceases the crown area of each primary or permanent tooth what happens?
Arrest and reversal lines
The ameloblasts place an acellular dental cuticle on the new enamel surface
Maturation
Enamel

44. What are the formative cells for enamel?
Ameloblasts
Displacement of ameloblasts to root surface
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Commonly involves permanent maxillary lateral incisor and 3rd molars

45. What will the dental sac give rise to?
Initiation
Arrest and reversal lines
The cementum - PDL - and alveolar bone
Initiation stage

46. What is amelogenisis?
The dental sac
The apposition of the enamel matrix
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
Imbrication lines of von Ebner

47. What is macrodontia?
Cementoid
Compressed layer of flat to cuboidal cells
Osteocytes
Abnormally large teeth

48. When does dens in dente occur?
During the cap stage
Initiation stage
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
The stellate reticulum

49. Do odontoblasts start their secretion of matrix before the ameloblasts?
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
The ectomesenchyme
The enamel organ

50. The remaining ectomesenchyme surrounding the outside of the enamel organ condenses into what?
The dental sac
Into odontoblasts
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Bud stage