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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 during the cap stage?
Epithelial
8th week
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.
Permanent teeth formed with primary predecessors - the anterior teeth and the premolars

2. What are the etiological factors for micro/macrodontia?
Hereditary in localized form. endocrine dysfunction is complete
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
The actual vertical movement of the tooth
When the gingiva recedes and no actual tooth movement takes place

3. What stage does supernumerary teeth occur?
Initiation
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Into odontoblasts
During the cap stage

4. How many types of cells are found in the enamel organ in the bell stage?
Odontogenesis
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane
4 types
An extracellular substance that is partially calcified - yet serves as a framework for later calcification

5. What is the cementum matrix called?
Cementoid
Only dentinal tubules with processes
Extra cusp due to effects on enamel organ
Tall columnar cells

6. What processes are involved with the apposition stage?
There is unequal growth in different parts of the tooth bud
Induction - proliferation
Into odontoblasts
During the cap stage

7. When does macro/microdontia occur?
Hereditary
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.
Bud stage
Enamel organ invaginates into the dental papilla

8. What is tubercle?
There are none - they are lost with eruption
The ameloblasts place an acellular dental cuticle on the new enamel surface
Extra cusp due to effects on enamel organ
Union of 2 adjacent tooth germs

9. What happens during initiation?
Tooth germ tries to divide
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
Osteoblasts
The ectoderm

10. What will the outer cells of the dental lamina differentiate into?
Cuboidal cells
The ectomesenchyme
The tooth germ
Dentin secreting cells (odontoblats)

11. What are the incremental lines for enamel?
A mineralized cylinder - the dentinal tubule
Lines of Retzuis
Dental tissues secreted as matrix in successive layers.
Extra cusp due to effects on enamel organ

12. What happens during the bud stage?
Enamel pearl - enamel dysplasia - and concresence
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Displacement of ameloblasts to root surface
Preameloblasts

13. What are the resorptive cells for enamel - dentin - cementum and alveolar bone?
Trauma - pressure or metabolic disease
Odontoclasts
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Future dentin and pulp tissue

14. What are the mature cells for alveolar bone?
Osteocytes
Dental follicle
6th to 7th weeks
Ameloblasts

15. What are the clinical ramifications of fusion?
As a result of the apposition of cementum over dentin
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
Bud stage
The tooth germ

16. What happens to the thickened non tooth producing portions of the dental lamina eventually?
Enamel pearl - enamel dysplasia - and concresence
It disintegrates as the developing oral mucosa comes to line the oral cavity
The stellate reticulum
Into odontoblasts

17. The remaining ectomesenchyme surrounding the outside of the enamel organ condenses into what?
Maturation
6th to 7th weeks
Development of one or more extra teeth
The dental sac

18. What are the developmental disturbances of the cap stage?
Dens in dente - gemination - tubercle - and fusion
Arrest and reversal lines
Tooth germ tries to divide
Commonly involves permanent maxillary lateral incisor and 3rd molars

19. What is the main process involved in the bud stage?
Displacement of ameloblasts to root surface
Proliferation
Ameloblasts
The basement membrane

20. What is the time span for initiation?
Dens in dente - gemination - tubercle - and fusion
6th to 7th weeks
Enamel
Bud stage

21. What does the cervical loop consist of?
Proliferation
A bilayer rim that consists only IEE and OEE
Induction - proliferation
Cuboidal cells

22. What is the embryological background for enamel?
Apposition of the cementum
Enamel organ
The dental sac
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs

23. What hard tissue is can not have tissue formation after eruption?
Enamel
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Cementocytes
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs

24. What processes are involved in the bell stage?
Trauma - pressure or metabolic disease
Differentiation - proliferation - morphogenesis
Hereditary
May be confused as calculus deposit on root

25. What wll the inner enamel epithelium differentiate into?
Preameloblasts
Enamel secreting cells (ameloblasts)
There are none - they are lost with eruption
The basement membrane

26. What is the time span for the bell stage?
The apposition of the enamel matrix
11th to 12th weeks
Displacement of ameloblasts to root surface
The basement membrane that seperates the enamel organ and dental papilla

27. How is the reduced enamel epithelium created?
The enamel organ is compressed
Dental follicle
Tall columnar cells
Odontoclasts

28. Where is the dental sac originally derived from?
The ectomesenchyme
Extra cusp due to effects on enamel organ
Tooth germ tries to divide
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy

29. What are succedaneous teeth?
The enamel - dentin - and cementum are secreted in successive layers
Permanent teeth formed with primary predecessors - the anterior teeth and the premolars
Proliferation
Dental tissues fully mineralize to their mature levels.

30. What are the mature cells for enamel?
Abnormally large teeth
Cementoid
Enamel organ invaginates into the dental papilla
There are none - they are lost with eruption

31. 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
Osteocytes
Tooth germ
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel

32. Do odontoblasts start their secretion of matrix before the ameloblasts?
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
There is unequal growth in different parts of the tooth bud
The bud stage

33. The stellate reticulum is located inner or outer?
Proliferation
Dental tissues fully mineralize to their mature levels.
Cementoblasts
Outer

34. What happens during the apposition stage?
It disintegrates as the developing oral mucosa comes to line the oral cavity
Initiation stage
Dental tissues secreted as matrix in successive layers.
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.

35. What are the cell layers found in the enamel organ in the bell stage?
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
The cervical loop
Displacement of ameloblasts to root surface

36. After the enamel apposition ceases the crown area of each primary or permanent tooth what happens?
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
The stellate reticulum
Odontogenesis
The ameloblasts place an acellular dental cuticle on the new enamel surface

37. What are entrapped cementoblasts called?
Cementocytes
Epithelial
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
Apposition of the cementum

38. What happens during the maturation stage?
Dental tissues fully mineralize to their mature levels.
Hereditary
Enamel
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing

39. What is fusion?
The permanent molars
Union of 2 adjacent tooth germs
When the gingiva recedes and no actual tooth movement takes place
Imbrication lines of von Ebner

40. 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
The basement membrane
Dentin secreting cells (odontoblats)
Tooth germ

41. What happens during the bell stage?
Initiation stage
Epithelial rests of Malassez
Alveolar bone
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.

42. What are the etiological factors for dens in dente and gemination?
Hereditary
The enamel - dentin - and cementum are secreted in successive layers
The ameloblasts
The basement membrane

43. What are the etiological factors of concrescence?
The basement membrane
As a result of the apposition of cementum over dentin
Traumatic injury or crowding of teeth
The permanent molars

44. The oral epithelium is induced by the ectomesenchyme to produce what?
The dental lamina
Proliferation - differentiation - morphogenesis
The stellate reticulum
Inner

45. What is the important acelluar structure that seperates the oral epithelium and the ectomesenchyme?
As a result of the apposition of cementum over dentin
The basement membrane
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
Tooth germ tries to divide

46. When the inner epithelial epithelium columnar cells elongate and repolarize they differentiate into what?
Preameloblasts
4 types
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
Dental papilla

47. What is gemination?
When the gingiva recedes and no actual tooth movement takes place
Dental tissues secreted as matrix in successive layers.
Tooth germ tries to divide
May be confused as calculus deposit on root

48. What are the clinical ramifications of micro/macrodontia?
Imbrication lines of von Ebner
Lines of Retzuis
Arrest and reversal lines
Commonly involves permanent maxillary lateral incisor and 3rd molars

49. What is the site for the future dentioenamel junction?
The basement membrane that seperates the enamel organ and dental papilla
The actual vertical movement of the tooth
Enamel organ invaginates into the dental papilla
Union of root structure of two or more teeth by cementum

50. What are the formative cells for enamel?
Union of 2 adjacent tooth germs
Dental papilla
Hereditary in localized form. endocrine dysfunction is complete
Ameloblasts