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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 are the cell layers found in the enamel organ in the bell stage?
Cementoblasts
There are none - they are lost with eruption
Proliferation
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium

2. Odontoblasts leave attached cellular extensions in the length of the predentin called what?
Morphogenesis
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
May be confused as calculus deposit on root
Odontoblastic process

3. What is the function of the Hertwig's epithelial root sheath?
The outer enamel epithelium
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
Connective
Epithelial rests of Malassez

4. After the enamel apposition ceases the crown area of each primary or permanent tooth what happens?
The ameloblasts place an acellular dental cuticle on the new enamel surface
Absence of single or multiple teeth
Odontoblasts
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.

5. What is the outer portion of the ectoderm in the initiation stage?
Oral epithelium
11th to 12th weeks
It disintegrates as the developing oral mucosa comes to line the oral cavity
Cementoid

6. What are the clinical ramifications of fusion?
The dental lamina
Extra cusp due to effects on enamel organ
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

7. What is an enamel pearl?
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy
Differentiation
Sphere of enamel on root
Odontoclasts

8. What will the dental papilla eventually form?
11th to 12th weeks
Oral epithelium
Future dentin and pulp tissue
Dentin secreting cells (odontoblats)

9. What are the etiological factors of tubercle?
8th week
The bud stage
Trauma - pressure or metabolic disease
May be confused as calculus deposit on root

10. What kind of cells occur in the outer enamel epithelium in the bell stage?
Cuboidal cells
There are none - they are lost with eruption
4 types
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.

11. What are the major components of the tooth germ?
Future dentin and pulp tissue
Dental papilla
Inner
The enamel organ - dental papilla - dental sac

12. The remaining ectomesenchyme surrounding the outside of the enamel organ condenses into what?
The dental sac
Compressed layer of flat to cuboidal cells
The enamel organ is compressed
Outer

13. What are the clinical ramifications of dens in dente?
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy
The basement membrane
Dentin and alveolar bone
Cementocytes

14. When does macro/microdontia occur?
Bud stage
Trauma - pressure or metabolic disease
Sphere of enamel on root
Initiation stage

15. What are the etiological factors for supernumerary teeth?
Ameloblasts
Maturation
Initiation stage
Hereditary

16. What are the odontoblastic processes is contained in what?
A mineralized cylinder - the dentinal tubule
The ectomesenchyme
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
Commonly involves permanent maxillary lateral incisor and 3rd molars

17. Which layer in the bell stage has star shaped cells?
The stellate reticulum
Extra cusp due to effects on enamel organ
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
The ectoderm

18. What wll the inner enamel epithelium differentiate into?
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Enamel secreting cells (ameloblasts)
Into odontoblasts

19. When does dens in dente occur?
Abnormally large teeth
The ectomesenchyme
During the cap stage
Cementoblasts

20. What are the etiological factors for fusion?
Pressure on the area
Tall columnar cells
Extra cusp due to effects on enamel organ
Enamel

21. Where is the enamal organ originally derived from?
The ectoderm
As a result of the apposition of cementum over dentin
Initiation
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics

22. What are the clinical ramifications of concrescence?
A bilayer rim that consists only IEE and OEE
Future dentin and pulp tissue
The outer enamel epithelium
Common with permanent maxillary molars

23. What kind of cells occur in the inner enamel epithelium?
Tall columnar cells
11th to 12th weeks
Enamel organ
Cementocytes

24. What processes are involved with the apposition stage?
9th to 10th weeks
Induction - proliferation
As a result of the apposition of cementum over dentin
Dental papilla

25. The stellate reticulum is located inner or outer?
The dental sac
Outer
Sphere of enamel on root
Development of one or more extra teeth

26. What is the embryological background for dentin - cementum and alveolar bone?
Dental papilla
Abnormally large teeth
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Dentin and alveolar bone

27. The stage named for extensive proliferation of the dental lamina into oval masses penetrating into the ectomesenchyme?
Outer
8th week
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
The bud stage

28. What are the incremental lines for enamel?
The ectomesenchyme
Lines of Retzuis
Arrest and reversal lines
Bud stage

29. What will the dental sac give rise to?
In the cap stage
Oral epithelium
The cementum - PDL - and alveolar bone
The outer enamel epithelium

30. What is the main process involved in initiation?
The enamel organ - dental papilla - dental sac
Dens in dente - gemination - tubercle - and fusion
Odontogenesis
Induction

31. What are the clinical ramifications of anodontia?
May be confused as calculus deposit on root
The basement membrane
Tooth germ
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants

32. What layer serves as protection for the enamel organ?
Traumatic injury or crowding of teeth
The outer enamel epithelium
The ectomesenchyme
Dental papilla

33. What are the etiological factors for dens in dente and gemination?
Hereditary
Common on permanent molars or cingulum of anterior teeth
The cementum - PDL - and alveolar bone
Dental tissues fully mineralize to their mature levels.

34. What are the clinical ramifications of supernumerary teeth?
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
The basement membrane
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 enamel organ is compressed

35. What happens during the maturation stage?
Faulty development of enamel from interference involving ameloblasts
Dental tissues fully mineralize to their mature levels.
Development of one or more extra teeth
During the cap stage

36. In the cap stage the tooth bud does not grow - what happens?
There is unequal growth in different parts of the tooth bud
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
Odontoblastic process
Proliferation - differentiation - morphogenesis

37. What is the time span for the bell stage?
11th to 12th weeks
Tooth germ
Alveolar bone
Compressed layer of flat to cuboidal cells

38. What do the odontoblasts do?
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
Enamel
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

39. What is the site for the future dentioenamel junction?
The basement membrane
Initiation stage
The basement membrane that seperates the enamel organ and dental papilla
Odontoclasts

40. How many types of cells are found in the enamel organ in the bell stage?
Dental papilla
4 types
Faulty development of enamel from interference involving ameloblasts
Dental follicle

41. What is anodontia?
A bilayer rim that consists only IEE and OEE
Absence of single or multiple teeth
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics

42. What is fusion?
Union of 2 adjacent tooth germs
The ameloblasts
Odontoblasts
The outer cells of the dental papilla and the central cells of the dental papilla

43. What are the etiological factors of concrescence?
Common with permanent maxillary molars
Proliferation
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
Traumatic injury or crowding of teeth

44. What is the important acelluar structure that seperates the oral epithelium and the ectomesenchyme?
Enamel secreting cells (ameloblasts)
The ectomesenchyme
The basement membrane
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

45. What will the outer cells of the dental lamina differentiate into?
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
Dentin secreting cells (odontoblats)
Odontoblastic process
Dental papilla

46. When does the process of root development take place?
Preameloblasts
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
May be confused as calculus deposit on root
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

47. What are the mature cells for dentin?
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane
The bud stage
Only dentinal tubules with processes
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

48. What is the embryological background for enamel?
A bilayer rim that consists only IEE and OEE
Enamel organ
The dental sac
Development of one or more extra teeth

49. What is the structure responsible for root development?
Traumatic injury or crowding of teeth
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
The cervical loop
Morphogenesis

50. What are the 2 layers in the dental papilla within the concavity of the enamel organ?
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Enamel secreting cells (ameloblasts)
The outer cells of the dental papilla and the central cells of the dental papilla
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