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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 are the formative cells for dentin?
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
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
Dental follicle
Odontoblasts

2. Do odontoblasts start their secretion of matrix before the ameloblasts?
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
The basement membrane
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
Compressed layer of flat to cuboidal cells

3. The buds of the dental lamina - together with the surrounding ecto mesenchyme - will develop into what?
The ameloblasts
During the cap stage
Tooth germ
Ameloblasts

4. What are the clinical ramifications of enamel pearl?
The ectoderm
Cuboidal cells
May be confused as calculus deposit on root
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

5. What kind of cells occur in the outer enamel epithelium in the bell stage?
Odontoblasts
The enamel organ
Cuboidal cells
Odontogenesis

6. What are the resorptive cells for enamel - dentin - cementum and alveolar bone?
Odontoclasts
Abnormally small teeth
The dental sac
Differentiation - proliferation - morphogenesis

7. The stage named for extensive proliferation of the dental lamina into oval masses penetrating into the ectomesenchyme?
The bud stage
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
Apposition of the cementum
May be confused as calculus deposit on root

8. The stellate reticulum is located inner or outer?
Outer
Proliferation - differentiation - morphogenesis
The ectomesenchyme - which was influenced by the neural crest cells
Hereditary in localized form. endocrine dysfunction is complete

9. What are the mature cells for dentin?
Preameloblasts
Local or systemic or hereditary
A bilayer rim that consists only IEE and OEE
Only dentinal tubules with processes

10. What processes are involved with the apposition stage?
Dentin secreting cells (odontoblats)
Cementocytes
Union of root structure of two or more teeth by cementum
Induction - proliferation

11. What are the 2 layers in the dental papilla within the concavity of the enamel organ?
Alveolar bone
The outer cells of the dental papilla and the central cells of the dental papilla
The ameloblasts place an acellular dental cuticle on the new enamel surface
Lines of Retzuis

12. What is fusion?
Union of 2 adjacent tooth germs
Inner
Absence of single or multiple teeth
When the gingiva recedes and no actual tooth movement takes place

13. What happens during the appositional stage?
The enamel - dentin - and cementum are secreted in successive layers
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane
Cementoid
Dentin secreting cells (odontoblats)

14. Tooth development
The dental sac
Odontogenesis
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
There are none - they are lost with eruption

15. What is the predominate process of the cap stage?
Morphogenesis
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
Enamel organ
Enamel

16. What stage does supernumerary teeth occur?
Inner
Initiation
Common on permanent molars or cingulum of anterior teeth
A mineralized cylinder - the dentinal tubule

17. What kind of cells reside in the stratum intermediate?
Compressed layer of flat to cuboidal cells
Traumatic injury or crowding of teeth
Tooth germ
Odontoclasts

18. What are the incremental lines for enamel?
Only dentinal tubules with processes
Lines of Retzuis
Hereditary in localized form. endocrine dysfunction is complete
An extracellular substance that is partially calcified - yet serves as a framework for later calcification

19. What is microdontia?
There are none - they are lost with eruption
The cervical loop
Abnormally small teeth
Apposition of the cementum

20. What happens during the cap stage?
Maturation
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 primordium of the pulp
Common on permanent molars or cingulum of anterior teeth

21. How many types of cells are found in the enamel organ in the bell stage?
The enamel - dentin - and cementum are secreted in successive layers
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
4 types
Cementoblasts

22. What are the formative cells for cementum?
Epithelial rests of Malassez
May be confused as calculus deposit on root
Cementoblasts
The primordium of the pulp

23. What happens to the thickened non tooth producing portions of the dental lamina eventually?
A mineralized cylinder - the dentinal tubule
Connective
It disintegrates as the developing oral mucosa comes to line the oral cavity
The outer cells of the dental papilla and the central cells of the dental papilla

24. What cell bodies are involved in the eruption and mineralization process but will be lost after eruption?
Induction - proliferation
Dental follicle
The ameloblasts
Odontoblasts

25. What is the process involved in the maturation stage?
Initiation
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.
Only dentinal tubules with processes
Maturation

26. What type of tissue is enamel?
Inner
Epithelial
Dental papilla
Pressure on the area

27. What are the clinical ramifications of concrescence?
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Common with permanent maxillary molars

28. What are the clinical ramifications of fusion?
Outer
The tooth germ
Differentiation - proliferation - morphogenesis
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing

29. What happens during the bell stage?
A bilayer rim that consists only IEE and OEE
Tooth germ tries to divide
6th to 7th weeks
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.

30. What is the main process involved in initiation?
As a result of the apposition of cementum over dentin
Induction
Lines of Retzuis
Tall columnar cells

31. What is cementogenisis?
Enamel
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
Enamel organ invaginates into the dental papilla
Apposition of the cementum

32. What hard tissue is innervated by nerves?
Trauma - pressure or metabolic disease
The basement membrane
Only dentinal tubules with processes
Dentin and alveolar bone

33. What wll the inner enamel epithelium differentiate into?
Cementocytes
Alveolar bone
Enamel secreting cells (ameloblasts)
Enamel organ invaginates into the dental papilla

34. What is the outer portion of the ectoderm in the initiation stage?
During the cap stage
Cuboidal cells
Oral epithelium
Traumatic injury or crowding of teeth

35. What are the processes involved in the cap stage?
Apposition of the cementum
Proliferation - differentiation - morphogenesis
The basement membrane that seperates the enamel organ and dental papilla
Tall columnar cells

36. What is the cementum matrix called?
Cementoid
Cuboidal cells
4 types
The permanent molars

37. What is tubercle?
Extra cusp due to effects on enamel organ
There are none - they are lost with eruption
A bilayer rim that consists only IEE and OEE
Cementoblasts

38. What is the primordium of the tooth?
Abnormally large teeth
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
Cementocytes
The tooth germ

39. Active eruption
The actual vertical movement of the tooth
Osteoblasts
Extra cusp due to effects on enamel organ
Future dentin and pulp tissue

40. What kind of cells occur in the inner enamel epithelium?
Tall columnar cells
The dental sac
Displacement of ameloblasts to root surface
Connective

41. What are the major components of the tooth germ?
The outer enamel epithelium
The ectoderm
The enamel organ - dental papilla - dental sac
Absence of single or multiple teeth

42. What is matrix?
It disintegrates as the developing oral mucosa comes to line the oral cavity
Preameloblasts
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Cementocytes

43. What will the inner cells of the dental lamina differentiates into?
Dental tissues secreted as matrix in successive layers.
The primordium of the pulp
Tall columnar cells
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin

44. Which layer in the bell stage has star shaped cells?
Into odontoblasts
Maturation
The basement membrane
The stellate reticulum

45. What is the embryological background for dentin - cementum and alveolar bone?
The ectoderm
Dental papilla
Sphere of enamel on root
Cementoblasts

46. What are the etiological factors for supernumerary teeth?
The ectomesenchyme
Hereditary
Induction
The enamel organ is compressed

47. What are the etiological factors for anodontia?
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Hereditary
During the cap stage
Odontoblastic process

48. When does dens in dente occur?
Epithelial
Ameloblasts
Apposition of the cementum
During the cap stage

49. What are the clinical ramifications of supernumerary teeth?
Dental papilla
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion
Compressed layer of flat to cuboidal cells
Enamel secreting cells (ameloblasts)

50. What are the clinical ramifications?
Cementocytes
Common on permanent molars or cingulum of anterior teeth
A mineralized cylinder - the dentinal tubule
The apposition of the enamel matrix