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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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1. What is the embryological background for enamel?
Enamel organ invaginates into the dental papilla
Epithelial rests of Malassez
Osteocytes
Enamel organ

2. What is macrodontia?
The enamel organ - dental papilla - dental sac
Cementoblasts
Only dentinal tubules with processes
Abnormally large teeth

3. What is an enamel pearl?
Sphere of enamel on root
The enamel organ - dental papilla - dental sac
The tooth germ
The stellate reticulum

4. What processes are involved with the apposition stage?
May be confused as calculus deposit on root
Induction - proliferation
The permanent molars
Ameloblasts

5. What type of tissue is dentin - cementum - and alveolar bone?
Cementocytes
Cementocytes
Connective
The ectomesenchyme

6. What is the primordium of the tooth?
Induction - proliferation
Imbrication lines of von Ebner
The tooth germ
The cervical loop

7. What are the formative cells for dentin?
Local or systemic or hereditary
Odontoblasts
Induction - proliferation
Epithelial rests of Malassez

8. How is the dentinocemental junction formed?
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
As a result of the apposition of cementum over dentin
The bud stage
Only dentinal tubules with processes

9. What is the main process involved in initiation?
Future dentin and pulp tissue
Induction
Cementoblasts
The ectomesenchyme - which was influenced by the neural crest cells

10. When the inner epithelial epithelium columnar cells elongate and repolarize they differentiate into what?
Maturation
Preameloblasts
There is unequal growth in different parts of the tooth bud
Enamel organ

11. What stage does anodontia occur?
8th week
As a result of the apposition of cementum over dentin
Initiation stage
Enamel secreting cells (ameloblasts)

12. What are the incremental lines for dentin?
Compressed layer of flat to cuboidal cells
Imbrication lines of von Ebner
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
Dental papilla

13. What is tubercle?
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
Hereditary in localized form. endocrine dysfunction is complete
Connective
Extra cusp due to effects on enamel organ

14. What is anodontia?
Dental papilla
Arrest and reversal lines
Enamel
Absence of single or multiple teeth

15. What happens during the maturation stage?
Hereditary in localized form. endocrine dysfunction is complete
Osteoblasts
The ameloblasts
Dental tissues fully mineralize to their mature levels.

16. What happens during the bell stage?
During the cap stage
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.

17. What is matrix?
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Cementoid
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

18. What is cementogenisis?
Dens in dente - gemination - tubercle - and fusion
Imbrication lines of von Ebner
The cementum - PDL - and alveolar bone
Apposition of the cementum

19. When root formation is completed the portion of the basement membrane disintegrates its cells may become what?
Common on permanent molars or cingulum of anterior teeth
Epithelial rests of Malassez
Enamel organ invaginates into the dental papilla
Odontogenesis

20. What conveys communications between the cells of the enamel organ - the dental papilla - and the dental sac allowing tissue interactions?
The basement membrane
When the gingiva recedes and no actual tooth movement takes place
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
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.

21. What will the dental sac give rise to?
The dental lamina
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion
The cementum - PDL - and alveolar bone
Sphere of enamel on root

22. What is another name for the dental sac?
Outer
Dental follicle
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
In the cap stage

23. What processes are involved in the bell stage?
Only dentinal tubules with processes
The enamel organ is compressed
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
Differentiation - proliferation - morphogenesis

24. The stellate reticulum is located inner or outer?
Sphere of enamel on root
Outer
The outer cells of the dental papilla and the central cells of the dental papilla
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel

25. What are the clinical ramifications?
Common on permanent molars or cingulum of anterior teeth
Bud stage
Cementoblasts
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

26. What is the function of the Hertwig's epithelial root sheath?
Into odontoblasts
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
The outer cells of the dental papilla and the central cells of the dental papilla
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin

27. What will the outer cells of the dental lamina differentiate into?
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Dentin secreting cells (odontoblats)
Imbrication lines of von Ebner
Union of 2 adjacent tooth germs

28. What are the major components of the tooth germ?
The enamel organ - dental papilla - dental sac
Tooth germ tries to divide
Enamel organ invaginates into the dental papilla
Maturation

29. How is the reduced enamel epithelium created?
The enamel organ is compressed
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
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 stellate reticulum

30. What is the time span for initiation?
6th to 7th weeks
There are none - they are lost with eruption
Maturation
Cementocytes

31. The remaining ectomesenchyme surrounding the outside of the enamel organ condenses into what?
Future dentin and pulp tissue
Dental papilla
Cementoblasts
The dental sac

32. What are the mature cells for cementum?
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Cementocytes
The enamel organ is compressed
Odontoblasts

33. What will the inner cells of the dental lamina differentiates into?
Enamel secreting cells (ameloblasts)
The primordium of the pulp
Bud stage
Dental papilla

34. What are the etiological factors for anodontia?
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Preameloblasts
Abnormally large teeth
Development of one or more extra teeth

35. What are the formative cells for enamel?
As a result of the apposition of cementum over dentin
Ameloblasts
The cementum - PDL - and alveolar bone
Osteoblasts

36. What are the developmental disturbances of the cap stage?
Initiation stage
8th week
Ameloblasts
Dens in dente - gemination - tubercle - and fusion

37. What are the mature cells for dentin?
May be confused as calculus deposit on root
Hereditary
Only dentinal tubules with processes
The stellate reticulum

38. What are the incremental lines for cementum and alveolar bone?
Tall columnar cells
The ameloblasts place an acellular dental cuticle on the new enamel surface
Connective
Arrest and reversal lines

39. The stratum intermediate is located inner or outer?
The stellate reticulum
Trauma - pressure or metabolic disease
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion
Inner

40. Odontoblasts leave attached cellular extensions in the length of the predentin called what?
Union of 2 adjacent tooth germs
The enamel organ - dental papilla - dental sac
Odontoblastic process
Imbrication lines of von Ebner

41. What kind of cells occur in the outer enamel epithelium in the bell stage?
Cuboidal cells
The cementum - PDL - and alveolar bone
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
The stellate reticulum

42. When the undifferentiated cells of the dental sac come into contact with the root dentin they differentiate into what?
The tooth germ
Cementoblasts
Preameloblasts
The apposition of the enamel matrix

43. What is the time span for the cap stage?
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
There are none - they are lost with eruption
9th to 10th weeks

44. What do the odontoblasts do?
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
8th week
Odontoclasts
Initiation stage

45. What does the cervical loop consist of?
The outer cells of the dental papilla and the central cells of the dental papilla
Cementoblasts
The basement membrane
A bilayer rim that consists only IEE and OEE

46. What happens during initiation?
Into odontoblasts
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
The outer cells of the dental papilla and the central cells of the dental papilla

47. What is enamel dysplasia?
Arrest and reversal lines
Hereditary
Faulty development of enamel from interference involving ameloblasts
Commonly involves permanent maxillary lateral incisor and 3rd molars

48. Where is the dental sac originally derived from?
During the cap stage
Only dentinal tubules with processes
The ectomesenchyme
The enamel organ - dental papilla - dental sac

49. What is microdontia?
As a result of the apposition of cementum over dentin
Enamel secreting cells (ameloblasts)
Abnormally small teeth
Hereditary in localized form. endocrine dysfunction is complete

50. What type of tissue is enamel?
Osteocytes
Tooth germ
Cementocytes
Epithelial