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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 is tubercle?
Extra cusp due to effects on enamel organ
Initiation
Compressed layer of flat to cuboidal cells
Preameloblasts

2. What does the cervical loop consist of?
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.
The enamel organ is compressed
A bilayer rim that consists only IEE and OEE
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants

3. When the undifferentiated cells of the dental sac come into contact with the root dentin they differentiate into what?
Cementoblasts
Alveolar bone
Local or systemic or hereditary
Traumatic injury or crowding of teeth

4. What are the incremental lines for dentin?
The outer cells of the dental papilla and the central cells of the dental papilla
Cementoblasts
The ectomesenchyme
Imbrication lines of von Ebner

5. What happens when the reduced enamel epithelium is created?
Tall columnar cells
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
Arrest and reversal lines
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

6. What processes are involved with the apposition stage?
The primordium of the pulp
Alveolar bone
Induction - proliferation
Enamel

7. What are the etiological factors for enamel pearl?
Displacement of ameloblasts to root surface
Hereditary in localized form. endocrine dysfunction is complete
Tooth germ tries to divide
The enamel organ is compressed

8. What stage does supernumerary teeth occur?
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
Cementocytes
9th to 10th weeks
Initiation

9. What is the important acelluar structure that seperates the oral epithelium and the ectomesenchyme?
Enamel organ
During the cap stage
The basement membrane
Preameloblasts

10. What happens during the appositional stage?
Dental follicle
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
The enamel - dentin - and cementum are secreted in successive layers
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion

11. The remaining ectomesenchyme surrounding the outside of the enamel organ condenses into what?
Connective
Osteocytes
The basement membrane
The dental sac

12. When does the tooth bud become a tooth germ?
In the cap stage
Abnormally large teeth
The enamel - dentin - and cementum are secreted in successive layers
Odontoclasts

13. What are the mature cells for enamel?
The ameloblasts
Cementoblasts
The primordium of the pulp
There are none - they are lost with eruption

14. What are the clinical ramifications of fusion?
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
Hereditary in localized form. endocrine dysfunction is complete
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
Cementocytes

15. What stage does anodontia occur?
As a result of the apposition of cementum over dentin
Dens in dente - gemination - tubercle - and fusion
Initiation stage
Dental tissues fully mineralize to their mature levels.

16. What happens to the thickened non tooth producing portions of the dental lamina eventually?
Union of 2 adjacent tooth germs
It disintegrates as the developing oral mucosa comes to line the oral cavity
Connective
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

17. What will the dental sac give rise to?
Dental tissues fully mineralize to their mature levels.
The ectomesenchyme
May be confused as calculus deposit on root
The cementum - PDL - and alveolar bone

18. What are the etiological factors of concrescence?
8th week
Cuboidal cells
Connective
Traumatic injury or crowding of teeth

19. What are the incremental lines for enamel?
Connective
Initiation stage
Tooth germ
Lines of Retzuis

20. What is the cementum matrix called?
Cementoid
Faulty development of enamel from interference involving ameloblasts
When the gingiva recedes and no actual tooth movement takes place
The enamel organ - dental papilla - dental sac

21. What is the structure responsible for root development?
Cementoblasts
Epithelial rests of Malassez
The cervical loop
Outer

22. What are the odontoblastic processes is contained in what?
Connective
Tall columnar cells
9th to 10th weeks
A mineralized cylinder - the dentinal tubule

23. Where is the enamel matrix secreted from by the ameloblasts?

24. The preameloblasts induce dental papilla cells to differentiate into what?
The outer enamel epithelium
The tooth germ
Into odontoblasts
Enamel organ invaginates into the dental papilla

25. What are the etiological factors of enamel dysplasia?
Local or systemic or hereditary
When the gingiva recedes and no actual tooth movement takes place
The ectomesenchyme - which was influenced by the neural crest cells
As a result of the apposition of cementum over dentin

26. What is the inner mass in the cap stage that forms a concavity of the enamel organ?
Dental papilla
Ameloblasts
Odontoblastic process
The basement membrane

27. What is the time span for the bell stage?
Sphere of enamel on root
A bilayer rim that consists only IEE and OEE
Hereditary in localized form. endocrine dysfunction is complete
11th to 12th weeks

28. What is the primordium of the tooth?
Enamel organ invaginates into the dental papilla
Bud stage
9th to 10th weeks
The tooth germ

29. In the cap stage the tooth bud does not grow - what happens?
Oral epithelium
There is unequal growth in different parts of the tooth bud
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
The dental lamina

30. Do odontoblasts start their secretion of matrix before the ameloblasts?
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
Dentin and alveolar bone
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
Displacement of ameloblasts to root surface

31. How many types of cells are found in the enamel organ in the bell stage?
The ectomesenchyme
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
4 types
Dental follicle

32. What kind of cells occur in the inner enamel epithelium?
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
Cementoid
Tall columnar cells
The permanent molars

33. What are the major components of the tooth germ?
Dental follicle
Cementoblasts
The enamel organ - dental papilla - dental sac
Tooth germ tries to divide

34. What will the outer cells of the dental lamina differentiate into?
Dentin secreting cells (odontoblats)
May be confused as calculus deposit on root
Cuboidal cells
Arrest and reversal lines

35. What is an enamel pearl?
The enamel organ
The dental lamina
Sphere of enamel on root
Dental papilla

36. When root formation is completed the portion of the basement membrane disintegrates its cells may become what?
Only dentinal tubules with processes
Apposition of the cementum
Epithelial rests of Malassez
When the gingiva recedes and no actual tooth movement takes place

37. What are the clinical ramifications?
The cementum - PDL - and alveolar bone
The ectoderm
Common on permanent molars or cingulum of anterior teeth
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion

38. What happens during the bell stage?
Proliferation - differentiation - morphogenesis
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.
Imbrication lines of von Ebner
Common on permanent molars or cingulum of anterior teeth

39. Active eruption
The primordium of the pulp
Hereditary
When the gingiva recedes and no actual tooth movement takes place
The actual vertical movement of the tooth

40. What is the outer portion of the ectoderm in the initiation stage?
Dental follicle
Common on permanent molars or cingulum of anterior teeth
Traumatic injury or crowding of teeth
Oral epithelium

41. The stratum intermediate is located inner or outer?
There is unequal growth in different parts of the tooth bud
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion
8th week
Inner

42. What are supernumerary teeth?
The dental sac
Sphere of enamel on root
Hereditary
Development of one or more extra teeth

43. What else undergoes proliferation in the bud stage besides the dental lamina?
Enamel organ invaginates into the dental papilla
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
Outer
The ectomesenchyme

44. What conveys communications between the cells of the enamel organ - the dental papilla - and the dental sac allowing tissue interactions?
In the cap stage
The apposition of the enamel matrix
The basement membrane
Epithelial

45. What is the time span for initiation?
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
The permanent molars
6th to 7th weeks
9th to 10th weeks

46. What are the clinical ramifications of anodontia?
Common on permanent molars or cingulum of anterior teeth
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
Displacement of ameloblasts to root surface
The enamel organ is compressed

47. What are the cell layers found in the enamel organ in the bell stage?
Preameloblasts
In the cap stage
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
Oral epithelium

48. How is the reduced enamel epithelium created?
The enamel organ
Abnormally large teeth
The enamel organ is compressed
Tall columnar cells

49. What happens during the apposition stage?
Cementoblasts
The enamel organ
In the cap stage
Dental tissues secreted as matrix in successive layers.

50. What is the time span for the bud stage?
Tall columnar cells
Induction
Outer
8th week