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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 mature cells for dentin?
8th week
Ameloblasts
Enamel
Only dentinal tubules with processes

2. What is matrix?
Cementoblasts
Connective
Tooth germ
An extracellular substance that is partially calcified - yet serves as a framework for later calcification

3. What is tubercle?
Arrest and reversal lines
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.
Extra cusp due to effects on enamel organ
Induction

4. When does macro/microdontia occur?
Faulty development of enamel from interference involving ameloblasts
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Bud stage
There is unequal growth in different parts of the tooth bud

5. What are the clinical ramifications of enamel dysplasia?
The cementum - PDL - and alveolar bone
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
The ectomesenchyme - which was influenced by the neural crest cells
Union of 2 adjacent tooth germs

6. When root formation is completed the portion of the basement membrane disintegrates its cells may become what?
9th to 10th weeks
Epithelial rests of Malassez
A mineralized cylinder - the dentinal tubule
Union of root structure of two or more teeth by cementum

7. What are the formative cells for dentin?
Odontoblasts
The basement membrane
The stellate reticulum
As a result of the apposition of cementum over dentin

8. What will the dental papilla eventually form?
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.
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Future dentin and pulp tissue
Arrest and reversal lines

9. What is the time span for the bell stage?
Enamel secreting cells (ameloblasts)
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy
11th to 12th weeks
Odontoblastic process

10. What are the clinical ramifications of supernumerary teeth?
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
4 types
Odontogenesis
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion

11. What stage does anodontia occur?
The permanent molars
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Pressure on the area
Initiation stage

12. What are the mature cells for enamel?
11th to 12th weeks
Maturation
Cementocytes
There are none - they are lost with eruption

13. What is fusion?
The dental sac
Union of 2 adjacent tooth germs
Commonly involves permanent maxillary lateral incisor and 3rd molars
Into odontoblasts

14. What happens during initiation?
A mineralized cylinder - the dentinal tubule
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
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion

15. What are the etiological factors for micro/macrodontia?
Epithelial
Odontoclasts
Hereditary in localized form. endocrine dysfunction is complete
The outer enamel epithelium

16. What cell bodies are involved in the eruption and mineralization process but will be lost after eruption?
Initiation stage
11th to 12th weeks
A bilayer rim that consists only IEE and OEE
The ameloblasts

17. The remaining ectomesenchyme surrounding the outside of the enamel organ condenses into what?
The dental sac
The ectomesenchyme - which was influenced by the neural crest cells
The basement membrane
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity

18. What is microdontia?
Cementoblasts
Abnormally small teeth
Faulty development of enamel from interference involving ameloblasts
Union of 2 adjacent tooth germs

19. How many types of cells are found in the enamel organ in the bell stage?
The outer enamel epithelium
4 types
Common on permanent molars or cingulum of anterior teeth
Bud stage

20. What kind of cells occur in the outer enamel epithelium in the bell stage?
Cuboidal cells
Osteocytes
The stellate reticulum
Outer

21. What is the important acelluar structure that seperates the oral epithelium and the ectomesenchyme?
The basement membrane
Enamel organ invaginates into the dental papilla
Preameloblasts
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.

22. What are the etiological factors for supernumerary teeth?
Faulty development of enamel from interference involving ameloblasts
The outer cells of the dental papilla and the central cells of the dental papilla
In the cap stage
Hereditary

23. What are the etiological factors of tubercle?
Cementoblasts
Trauma - pressure or metabolic disease
The enamel organ - dental papilla - dental sac
The permanent molars

24. The oral epithelium is induced by the ectomesenchyme to produce what?
The dental lamina
Induction
The ectoderm
Common on permanent molars or cingulum of anterior teeth

25. The preameloblasts induce dental papilla cells to differentiate into what?
It disintegrates as the developing oral mucosa comes to line the oral cavity
Into odontoblasts
Union of 2 adjacent tooth germs
The dental sac

26. What are the processes involved in the cap stage?
The ectomesenchyme - which was influenced by the neural crest cells
Differentiation
Proliferation - differentiation - morphogenesis
Initiation

27. When does the tooth bud become a tooth germ?
Osteocytes
It disintegrates as the developing oral mucosa comes to line the oral cavity
Displacement of ameloblasts to root surface
In the cap stage

28. What is the embryological background for enamel?
Enamel organ
Epithelial rests of Malassez
Hereditary
Abnormally small teeth

29. What do the odontoblasts do?
Tooth germ tries to divide
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
The primordium of the pulp
Dental papilla

30. What will the dental sac give rise to?
Osteoblasts
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
The cementum - PDL - and alveolar bone
Proliferation - differentiation - morphogenesis

31. What layer serves as protection for the enamel organ?
The outer enamel epithelium
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
Initiation
Outer

32. What is dens in dente?
Epithelial
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
A bilayer rim that consists only IEE and OEE
Enamel organ invaginates into the dental papilla

33. What is the outer portion of the ectoderm in the initiation stage?
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane
Oral epithelium
When the gingiva recedes and no actual tooth movement takes place

34. When does the process of root development take place?
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
The primordium of the pulp
6th to 7th weeks
Cementoid

35. When the inner epithelial epithelium columnar cells elongate and repolarize they differentiate into what?
Preameloblasts
Enamel
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
Connective

36. What are the clinical ramifications of micro/macrodontia?
8th week
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.
Commonly involves permanent maxillary lateral incisor and 3rd molars

37. What are the clinical ramifications of concrescence?
Future dentin and pulp tissue
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
Absence of single or multiple teeth
Common with permanent maxillary molars

38. What happens to the thickened non tooth producing portions of the dental lamina eventually?
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
Enamel organ invaginates into the dental papilla
It disintegrates as the developing oral mucosa comes to line the oral cavity
Common with permanent maxillary molars

39. What are supernumerary teeth?
The ectomesenchyme
The bud stage
Development of one or more extra teeth
Dentin and alveolar bone

40. What is the embryological background for dentin - cementum and alveolar bone?
Dental papilla
The dental lamina
The enamel organ
Enamel secreting cells (ameloblasts)

41. What are the mature cells for alveolar bone?
Apposition of the cementum
The dental lamina
Maturation
Osteocytes

42. What happens during the apposition stage?
Tooth germ tries to divide
Epithelial rests of Malassez
Cementocytes
Dental tissues secreted as matrix in successive layers.

43. When the undifferentiated cells of the dental sac come into contact with the root dentin they differentiate into what?
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
Cementoblasts
Differentiation - proliferation - morphogenesis
The successional dental lamina - an extension of the dental lamina that extends out lingually to the primary tooth germs

44. What else undergoes proliferation in the bud stage besides the dental lamina?
Permanent teeth formed with primary predecessors - the anterior teeth and the premolars
Union of 2 adjacent tooth germs
The stellate reticulum
The ectomesenchyme

45. What are the resorptive cells for enamel - dentin - cementum and alveolar bone?
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy
Odontoclasts
Commonly involves permanent maxillary lateral incisor and 3rd molars
Enamel organ

46. What are the clinical ramifications of fusion?
May be confused as calculus deposit on root
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing

47. Tooth development
Union of root structure of two or more teeth by cementum
Cementoblasts
Odontogenesis
The bud stage

48. What kind of cells reside in the stratum intermediate?
The dental lamina
A mineralized cylinder - the dentinal tubule
The outer cells of the dental papilla and the central cells of the dental papilla
Compressed layer of flat to cuboidal cells

49. What stage does the dental tissues subsequently fully mineralize
Hereditary in localized form. endocrine dysfunction is complete
Cementocytes
Common on permanent molars or cingulum of anterior teeth
Maturation

50. What wll the inner enamel epithelium differentiate into?
Cementoid
Future dentin and pulp tissue
Epithelial rests of Malassez
Enamel secreting cells (ameloblasts)