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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 incremental lines for enamel?
Lines of Retzuis
The dental sac
Osteoblasts
The actual vertical movement of the tooth

2. What is another name for the dental sac?
Dental follicle
Oral epithelium
Permanent teeth formed with primary predecessors - the anterior teeth and the premolars
The basement membrane

3. What are the formative cells for dentin?
Differentiation - proliferation - morphogenesis
The bud stage
Odontoblasts
May be confused as calculus deposit on root

4. What kind of cells reside in the stratum intermediate?
Proliferation - differentiation - morphogenesis
Compressed layer of flat to cuboidal cells
11th to 12th weeks
Osteocytes

5. What processes are involved with the apposition stage?
Arrest and reversal lines
The apposition of the enamel matrix
Induction - proliferation
Faulty development of enamel from interference involving ameloblasts

6. The remaining ectomesenchyme surrounding the outside of the enamel organ condenses into what?
Hereditary
Apposition of the cementum
The dental sac
Connective

7. What is the time span for initiation?
6th to 7th weeks
Dental tissues secreted as matrix in successive layers.
Only dentinal tubules with processes
Differentiation

8. In the cap stage the tooth bud does not grow - what happens?
There is unequal growth in different parts of the tooth bud
Hereditary
Trauma - pressure or metabolic disease
Odontoblasts

9. What are the mature cells for alveolar bone?
Maturation
Dental papilla
Osteocytes
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion

10. What hard tissue is innervated by nerves?
Osteocytes
Future dentin and pulp tissue
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
Dentin and alveolar bone

11. What are the incremental lines for cementum and alveolar bone?
Arrest and reversal lines
Odontoclasts
The outer cells of the dental papilla and the central cells of the dental papilla
Displacement of ameloblasts to root surface

12. When the inner epithelial epithelium columnar cells elongate and repolarize they differentiate into what?
11th to 12th weeks
Preameloblasts
It disintegrates as the developing oral mucosa comes to line the oral cavity
Initiation

13. What type of tissue is dentin - cementum - and alveolar bone?
Dentin secreting cells (odontoblats)
Connective
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane
Dental tissues fully mineralize to their mature levels.

14. What are the cell layers found in the enamel organ in the bell stage?
Dental papilla
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
Extra cusp due to effects on enamel organ
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin

15. What are the etiological factors for anodontia?
The ectomesenchyme
Tooth germ tries to divide
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
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure

16. What is the function of the Hertwig's epithelial root sheath?
The ectomesenchyme
Tooth germ tries to divide
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
Dental follicle

17. What is dens in dente?
The ameloblasts
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Enamel organ invaginates into the dental papilla
Sphere of enamel on root

18. What causes the induction of the preameloblasts to differentiate into ameloblasts?
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
Permanent teeth formed with primary predecessors - the anterior teeth and the premolars
Arrest and reversal lines
Differentiation - proliferation - morphogenesis

19. What is the important acelluar structure that seperates the oral epithelium and the ectomesenchyme?
The basement membrane
Dental tissues secreted as matrix in successive layers.
The ameloblasts
Osteocytes

20. What are supernumerary teeth?
Commonly involves permanent maxillary lateral incisor and 3rd molars
Future dentin and pulp tissue
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
Development of one or more extra teeth

21. What is anodontia?
Absence of single or multiple teeth
The primordium of the pulp
Cementocytes
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

22. What hard tissue has vascularity?
Alveolar bone
Cementoblasts
Oral epithelium
Displacement of ameloblasts to root surface

23. Active eruption
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
8th week
Outer

24. What do the odontoblasts do?
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
Common with permanent maxillary molars
Faulty development of enamel from interference involving ameloblasts
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy

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

26. Which layer in the bell stage has star shaped cells?
Dentin secreting cells (odontoblats)
The dental lamina
Imbrication lines of von Ebner
The stellate reticulum

27. When the undifferentiated cells of the dental sac come into contact with the root dentin they differentiate into what?
Proliferation
Cementoblasts
Outer
When the gingiva recedes and no actual tooth movement takes place

28. After the enamel apposition ceases the crown area of each primary or permanent tooth what happens?
Outer
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
The ameloblasts place an acellular dental cuticle on the new enamel surface

29. 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
Apposition of the cementum
The primordium of the pulp
Tooth germ tries to divide

30. What are entrapped cementoblasts called?
Trauma - pressure or metabolic disease
Future dentin and pulp tissue
The enamel organ is compressed
Cementocytes

31. What will the outer cells of the dental lamina differentiate into?
Future dentin and pulp tissue
Cementoid
Dentin secreting cells (odontoblats)
Dental tissues fully mineralize to their mature levels.

32. What kind of cells occur in the inner enamel epithelium?
Local or systemic or hereditary
The enamel organ is compressed
The stellate reticulum
Tall columnar cells

33. Which teeth are nonsuccedaneous?
The 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.
11th to 12th weeks
The permanent molars

34. The stage named for extensive proliferation of the dental lamina into oval masses penetrating into the ectomesenchyme?
Initiation stage
Lines of Retzuis
The bud stage
Union of 2 adjacent tooth germs

35. What is gemination?
Only dentinal tubules with processes
Tooth germ tries to divide
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion
Osteoblasts

36. When root formation is completed the portion of the basement membrane disintegrates its cells may become what?
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
Epithelial rests of Malassez
Proliferation - differentiation - morphogenesis
Differentiation

37. What happens during the cap stage?
The cementum - PDL - and alveolar bone
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.
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
The outer enamel epithelium

38. How is the dentinocemental junction formed?
As a result of the apposition of cementum over dentin
Differentiation
Dental papilla
The basement membrane that seperates the enamel organ and dental papilla

39. The preameloblasts induce dental papilla cells to differentiate into what?
The primordium of the pulp
Osteoblasts
Into odontoblasts
Tooth germ tries to divide

40. Tooth development
6th to 7th weeks
Dental follicle
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Odontogenesis

41. Where is the dental papilla originally derived from?
The ectomesenchyme - which was influenced by the neural crest cells
Outer
The enamel organ is compressed
Proliferation - differentiation - morphogenesis

42. What is an enamel pearl?
Sphere of enamel on root
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.
A mineralized cylinder - the dentinal tubule
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics

43. When does the tooth bud become a tooth germ?
Bud 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.
Hereditary in localized form. endocrine dysfunction is complete
In the cap stage

44. Where does the primordium of the permanent dentition develop?
Tall columnar cells
Common with permanent maxillary molars
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs
It disintegrates as the developing oral mucosa comes to line the oral cavity

45. What are the processes involved in the cap stage?
Cementoid
Proliferation - differentiation - morphogenesis
Cementoblasts
Common on permanent molars or cingulum of anterior teeth

46. What is the predominate process in the bell stage?
Differentiation
Osteocytes
Epithelial
The actual vertical movement of the tooth

47. What is the main process involved in initiation?
Dentin secreting cells (odontoblats)
Induction
Common on permanent molars or cingulum of anterior 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

48. What conveys communications between the cells of the enamel organ - the dental papilla - and the dental sac allowing tissue interactions?
Commonly involves permanent maxillary lateral incisor and 3rd molars
The basement membrane
The dental sac
There are none - they are lost with eruption

49. What is the embryological background for dentin - cementum and alveolar bone?
Sphere of enamel on root
Cementoid
Dental papilla
Dentin secreting cells (odontoblats)

50. What is the time span for the bell stage?
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
Union of 2 adjacent tooth germs
11th to 12th weeks