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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. The oral epithelium is induced by the ectomesenchyme to produce what?
Outer
The dental lamina
As a result of the apposition of cementum over 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

2. What are the odontoblastic processes is contained in what?
The enamel organ - dental papilla - dental sac
Dentin and alveolar bone
9th to 10th weeks
A mineralized cylinder - the dentinal tubule

3. What happens during initiation?
Trauma - pressure or metabolic disease
The ectomesenchyme
Compressed layer of flat to cuboidal cells
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

4. What is the structure responsible for root development?
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
Differentiation
The cervical loop
There are none - they are lost with eruption

5. What are the clinical ramifications of fusion?
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
Common with permanent maxillary molars
Dental tissues fully mineralize to their mature levels.
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing

6. What is the cementum matrix called?
Induction
The basement membrane that seperates the enamel organ and dental papilla
Compressed layer of flat to cuboidal cells
Cementoid

7. How is the dentinocemental junction formed?
The ameloblasts
As a result of the apposition of cementum over dentin
Initiation stage
9th to 10th weeks

8. What happens during the appositional stage?
The ectomesenchyme
Displacement of ameloblasts to root surface
Osteocytes
The enamel - dentin - and cementum are secreted in successive layers

9. Where is the enamal organ originally derived from?
The ectoderm
Arrest and reversal lines
In the cap stage
The outer cells of the dental papilla and the central cells of the dental papilla

10. Do odontoblasts start their secretion of matrix before the ameloblasts?
The cementum - PDL - and alveolar bone
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
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.
Proliferation - differentiation - morphogenesis

11. Where is the dental papilla originally derived from?
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 ectomesenchyme - which was influenced by the neural crest cells
Commonly involves permanent maxillary lateral incisor and 3rd molars
Into odontoblasts

12. Where does the primordium of the permanent dentition develop?
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
The dental sac
Tooth germ tries to divide
Epithelial

13. What is the time span for the cap stage?
9th to 10th weeks
Osteoblasts
Trauma - pressure or metabolic disease
Traumatic injury or crowding of teeth

14. What is the primordium of the tooth?
Cementocytes
The tooth germ
The ameloblasts place an acellular dental cuticle on the new enamel surface
Trauma - pressure or metabolic disease

15. What is amelogenisis?
Arrest and reversal lines
Into odontoblasts
Osteocytes
The apposition of the enamel matrix

16. Active eruption
Oral epithelium
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
The actual vertical movement of the tooth
Initiation

17. What is anodontia?
Cementoblasts
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Absence of single or multiple teeth
Enamel

18. When root formation is completed the portion of the basement membrane disintegrates its cells may become what?
Only dentinal tubules with processes
Epithelial rests of Malassez
Tall columnar cells
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion

19. What are the etiological factors for dens in dente and gemination?
Odontoblasts
The enamel organ
Morphogenesis
Hereditary

20. What is enamel dysplasia?
Connective
The enamel - dentin - and cementum are secreted in successive layers
Faulty development of enamel from interference involving ameloblasts
Cementocytes

21. What are the clinical ramifications of enamel pearl?
May be confused as calculus deposit on root
Odontogenesis
Development of one or more extra teeth
Displacement of ameloblasts to root surface

22. What conveys communications between the cells of the enamel organ - the dental papilla - and the dental sac allowing tissue interactions?
The ameloblasts
The bud stage
The basement membrane
There is unequal growth in different parts of the tooth bud

23. Which layer in the bell stage has star shaped cells?
The stellate reticulum
The outer cells of the dental papilla and the central cells of the dental papilla
The permanent molars
Connective

24. What layer serves as protection for the enamel organ?
Sphere of enamel on root
Cementoid
It disintegrates as the developing oral mucosa comes to line the oral cavity
The outer enamel epithelium

25. What is the time span for the bud stage?
Union of 2 adjacent tooth germs
Induction - proliferation
8th week
Initiation stage

26. Passive eruption
Oral epithelium
Differentiation
The outer cells of the dental papilla and the central cells of the dental papilla
When the gingiva recedes and no actual tooth movement takes place

27. What are the formative cells for alveolar bone?
Osteoblasts
Into odontoblasts
Sphere of enamel on root
The enamel - dentin - and cementum are secreted in successive layers

28. What are succedaneous teeth?
Permanent teeth formed with primary predecessors - the anterior teeth and the premolars
Dental tissues fully mineralize to their mature levels.
May be confused as calculus deposit on root
Future dentin and pulp tissue

29. What kind of cells occur in the outer enamel epithelium in the bell stage?
Pressure on the area
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
Cuboidal cells
Hereditary

30. What is microdontia?
The permanent molars
Common on permanent molars or cingulum of anterior teeth
Abnormally small teeth
The ectomesenchyme

31. What happens during the apposition stage?
Dental tissues secreted as matrix in successive layers.
Enamel pearl - enamel dysplasia - and concresence
Differentiation
8th week

32. What else undergoes proliferation in the bud stage besides the dental lamina?
Lines of Retzuis
The ectomesenchyme
Oral epithelium
Cementoid

33. What is fusion?
Dentin secreting cells (odontoblats)
The outer enamel epithelium
Union of 2 adjacent tooth germs
Dentin and alveolar bone

34. What are the mature cells for enamel?
Differentiation
There are none - they are lost with eruption
Dentin secreting cells (odontoblats)
Induction

35. In the cap stage the tooth bud does not grow - what happens?
The outer cells of the dental papilla and the central cells of the dental papilla
The dental sac
There is unequal growth in different parts of the tooth bud
The primordium of the pulp

36. What is the process involved in the maturation stage?
The cementum - PDL - and alveolar bone
Maturation
Tooth germ
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel

37. What are the etiological factors of enamel dysplasia?
The apposition of the enamel matrix
The ectomesenchyme
Local or systemic or hereditary
The outer cells of the dental papilla and the central cells of the dental papilla

38. What are the clinical ramifications of anodontia?
Commonly involves permanent maxillary lateral incisor and 3rd molars
The stellate reticulum
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
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants

39. What stage does the dental tissues subsequently fully mineralize
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
Tooth germ
Maturation

40. How is the reduced enamel epithelium created?
It disintegrates as the developing oral mucosa comes to line the oral cavity
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
Common on permanent molars or cingulum of anterior teeth
The enamel organ is compressed

41. What kind of cells occur in the inner enamel epithelium?
Enamel
The dental lamina
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
Tall columnar cells

42. What happens during the bell stage?
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
Common with permanent maxillary molars
Faulty development of enamel from interference involving ameloblasts

43. What are entrapped cementoblasts called?
The primordium of the pulp
Tooth germ tries to divide
Union of root structure of two or more teeth by cementum
Cementocytes

44. What is concrescence?
Union of root structure of two or more teeth by cementum
There are none - they are lost with eruption
Cementoblasts
The basement membrane that seperates the enamel organ and dental papilla

45. What are the formative cells for dentin?
Bud stage
Oral epithelium
Odontoblasts
Dental papilla

46. When does dens in dente occur?
Enamel organ invaginates into the dental papilla
Cuboidal cells
During the cap stage
Commonly involves permanent maxillary lateral incisor and 3rd molars

47. What processes are involved in the bell stage?
The ameloblasts
Inner
Differentiation - proliferation - morphogenesis
Ameloblasts

48. What are the resorptive cells for enamel - dentin - cementum and alveolar bone?
Odontoclasts
During the cap stage
Tooth germ tries to divide
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.

49. When does the tooth bud become a tooth germ?
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
In the cap stage
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
Induction - proliferation

50. What happens during the bud stage?
Imbrication lines of von Ebner
Hereditary in localized form. endocrine dysfunction is complete
The ectomesenchyme
Growth of the dental lamina into bud that penetrates growing ectomesenchyme