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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. The oral epithelium is induced by the ectomesenchyme to produce what?
Proliferation - differentiation - morphogenesis
Cementocytes
Cementoblasts
The dental lamina

2. What are the etiological factors of tubercle?
Trauma - pressure or metabolic disease
Hereditary
The cementum - PDL - and alveolar bone
The basement membrane

3. What is the structure responsible for root development?
Osteocytes
11th to 12th weeks
The cervical loop
Tooth germ

4. What hard tissue has vascularity?
The ameloblasts place an acellular dental cuticle on the new enamel surface
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
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Alveolar bone

5. What does the cervical loop consist of?
The outer enamel epithelium
Connective
Alveolar bone
A bilayer rim that consists only IEE and OEE

6. What will the outer cells of the dental lamina differentiate into?
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
The ameloblasts
Dentin secreting cells (odontoblats)
Commonly involves permanent maxillary lateral incisor and 3rd molars

7. What happens during the cap stage?
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 ameloblasts place an acellular dental cuticle on the new enamel surface
Differentiation
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium

8. What is fusion?
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy
Oral epithelium
Union of 2 adjacent tooth germs
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

9. What stage does the dental tissues subsequently fully mineralize
Pressure on the area
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
Maturation
The enamel organ

10. What will the inner cells of the dental lamina differentiates into?
The primordium of the pulp
Imbrication lines of von Ebner
Enamel secreting cells (ameloblasts)
Cementocytes

11. What is another name for the dental sac?
Dental follicle
Differentiation - proliferation - morphogenesis
Traumatic injury or crowding of teeth
Common with permanent maxillary molars

12. What is enamel dysplasia?
Initiation
Abnormally large teeth
Faulty development of enamel from interference involving ameloblasts
Ameloblasts

13. What is the process involved in the maturation stage?
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
There are none - they are lost with eruption
Maturation

14. What is the function of the Hertwig's epithelial root sheath?
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
The enamel organ is compressed
Only dentinal tubules with processes
Bud stage

15. What is tubercle?
Displacement of ameloblasts to root surface
Extra cusp due to effects on enamel organ
Induction - proliferation
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

16. What is the embryological background for dentin - cementum and alveolar bone?
A bilayer rim that consists only IEE and OEE
The dental sac
Dental papilla
Cuboidal cells

17. When does macro/microdontia occur?
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
The outer cells of the dental papilla and the central cells of the dental papilla
Bud stage
During the cap stage

18. What are the clinical ramifications of enamel dysplasia?
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
There is unequal growth in different parts of the tooth bud
Connective
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel

19. What is amelogenisis?
The apposition of the enamel matrix
Oral epithelium
The basement membrane
Osteoblasts

20. When the undifferentiated cells of the dental sac come into contact with the root dentin they differentiate into what?
Cementoblasts
The ameloblasts
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
Imbrication lines of von Ebner

21. What kind of cells reside in the stratum intermediate?
Bud stage
Compressed layer of flat to cuboidal cells
Into odontoblasts
Abnormally large teeth

22. 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
During the cap stage
May be confused as calculus deposit on root
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics

23. The remaining ectomesenchyme surrounding the outside of the enamel organ condenses into what?
The dental sac
Alveolar bone
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
Into odontoblasts

24. What is the main process involved in the bud stage?
Enamel secreting cells (ameloblasts)
The ameloblasts
Proliferation
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

25. What are the clinical ramifications of fusion?
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
The bud stage
Initiation
9th to 10th weeks

26. What is the important acelluar structure that seperates the oral epithelium and the ectomesenchyme?
Only dentinal tubules with processes
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
The basement membrane
Local or systemic or hereditary

27. What is matrix?
Lines of Retzuis
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Dental papilla
Compressed layer of flat to cuboidal cells

28. What hard tissue is innervated by nerves?
The apposition of the enamel matrix
Absence of single or multiple teeth
Dentin and alveolar bone
The tooth germ

29. What wll the inner enamel epithelium differentiate into?
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy
Tooth germ
Enamel secreting cells (ameloblasts)
The outer enamel epithelium

30. What are the incremental lines for cementum and alveolar bone?
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
It disintegrates as the developing oral mucosa comes to line the oral cavity
Arrest and reversal lines

31. What are the mature cells for enamel?
Dental papilla
Pressure on the area
There are none - they are lost with eruption
The primordium of the pulp

32. What do the odontoblasts do?
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Development of one or more extra teeth
The basement membrane that seperates the enamel organ and dental papilla

33. How is the reduced enamel epithelium created?
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
A mineralized cylinder - the dentinal tubule
Proliferation
The enamel organ is compressed

34. What are the etiological factors for anodontia?
9th to 10th weeks
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
The apposition of the enamel matrix
Development of one or more extra teeth

35. Where is the dental sac originally derived from?
The ectomesenchyme
Cementoblasts
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
8th week

36. What are supernumerary teeth?
May be confused as calculus deposit on root
Induction
Development of one or more extra teeth
Local or systemic or hereditary

37. What cell bodies are involved in the eruption and mineralization process but will be lost after eruption?
The ameloblasts
Initiation
The basement membrane
Enamel pearl - enamel dysplasia - and concresence

38. What is the predominate process in the bell stage?
It disintegrates as the developing oral mucosa comes to line the oral cavity
The dental sac
Odontoblastic process
Differentiation

39. Tooth development
The basement membrane
Odontogenesis
The enamel - dentin - and cementum are secreted in successive layers
Local or systemic or hereditary

40. What happens during the appositional stage?
Differentiation - proliferation - morphogenesis
Development of one or more extra teeth
The enamel - dentin - and cementum are secreted in successive layers
Bud stage

41. What layer serves as protection for the enamel organ?
The outer enamel epithelium
Abnormally small teeth
Dens in dente - gemination - tubercle - and fusion
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy

42. What is the outer portion of the ectoderm in the initiation stage?
Commonly involves permanent maxillary lateral incisor and 3rd molars
9th to 10th weeks
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
Oral epithelium

43. What are the formative cells for enamel?
4 types
Ameloblasts
Dental tissues fully mineralize to their mature levels.
Maturation

44. What happens during the apposition stage?
Enamel secreting cells (ameloblasts)
The actual vertical movement of the tooth
Dental tissues secreted as matrix in successive layers.
It disintegrates as the developing oral mucosa comes to line the oral cavity

45. The stellate reticulum is located inner or outer?
Outer
The enamel organ
Dental papilla
Odontoblasts

46. What is the time span for the cap stage?
Arrest and reversal lines
The enamel - dentin - and cementum are secreted in successive layers
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
9th to 10th weeks

47. What kind of cells occur in the outer enamel epithelium in the bell stage?
Hereditary
Morphogenesis
Cuboidal cells
Dental papilla

48. When does the process of root development take place?
A mineralized cylinder - the dentinal tubule
Initiation stage
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
11th to 12th weeks

49. What processes are involved with the apposition stage?
Preameloblasts
Apposition of the cementum
Osteocytes
Induction - proliferation

50. Where is the enamal organ originally derived from?
Enamel organ
The outer cells of the dental papilla and the central cells of the dental papilla
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.
The ectoderm