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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. What is the embryological background for dentin - cementum and alveolar bone?
Dental papilla
6th to 7th weeks
The outer cells of the dental papilla and the central cells of the dental papilla
The enamel organ

2. What are the etiological factors for supernumerary teeth?
The apposition of the enamel matrix
Dental papilla
Abnormally large teeth
Hereditary

3. What are the major components of the tooth germ?
The enamel organ - dental papilla - dental sac
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
Pressure on the area
It disintegrates as the developing oral mucosa comes to line the oral cavity

4. What happens during the cap stage?
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
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.
Enamel
Future dentin and pulp tissue

5. What is the predominate process in the bell stage?
Imbrication lines of von Ebner
Differentiation
The ectoderm
Cementocytes

6. What happens during initiation?
Abnormally small teeth
Inner
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
The actual vertical movement of the tooth

7. What happens during the appositional stage?
Future dentin and pulp tissue
Local or systemic or hereditary
The enamel - dentin - and cementum are secreted in successive layers
Ameloblasts

8. What is the important acelluar structure that seperates the oral epithelium and the ectomesenchyme?
6th to 7th weeks
The dental sac
Permanent teeth formed with primary predecessors - the anterior teeth and the premolars
The basement membrane

9. The stage named for extensive proliferation of the dental lamina into oval masses penetrating into the ectomesenchyme?
Osteoblasts
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane
The bud stage

10. What is the time span for initiation?
The dental sac
A mineralized cylinder - the dentinal tubule
6th to 7th weeks
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin

11. What are the mature cells for enamel?
Initiation stage
The basement membrane that seperates the enamel organ and dental papilla
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
There are none - they are lost with eruption

12. What kind of cells reside in the stratum intermediate?
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy
Apposition of the cementum
Osteocytes
Compressed layer of flat to cuboidal cells

13. What is the time span for the cap stage?
Commonly involves permanent maxillary lateral incisor and 3rd molars
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
9th to 10th weeks
Maturation

14. What are the etiological factors for dens in dente and gemination?
Hereditary
The bud stage
Enamel pearl - enamel dysplasia - and concresence
Commonly involves permanent maxillary lateral incisor and 3rd molars

15. Tooth development
Odontogenesis
Maturation
Abnormally small teeth
9th to 10th weeks

16. What processes are involved in the bell stage?
Differentiation - proliferation - morphogenesis
Initiation stage
9th to 10th weeks
Development of one or more extra teeth

17. What does the cervical loop consist of?
Trauma - pressure or metabolic disease
A bilayer rim that consists only IEE and OEE
The permanent molars
Union of 2 adjacent tooth germs

18. What are the incremental lines for dentin?
When the gingiva recedes and no actual tooth movement takes place
Hereditary
Imbrication lines of von Ebner
Inner

19. What are the incremental lines for enamel?
Odontoblasts
May be confused as calculus deposit on root
Cementoid
Lines of Retzuis

20. What are supernumerary teeth?
Odontogenesis
Dental papilla
Development of one or more extra teeth
When the gingiva recedes and no actual tooth movement takes place

21. What causes the induction of the preameloblasts to differentiate into ameloblasts?
A bilayer rim that consists only IEE and OEE
The cervical loop
Bud stage
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin

22. What do the odontoblasts do?
Compressed layer of flat to cuboidal cells
Tooth germ tries to divide
Dental papilla
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane

23. What is enamel dysplasia?
When the gingiva recedes and no actual tooth movement takes place
Faulty development of enamel from interference involving ameloblasts
The ectomesenchyme
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin

24. Where is the dental sac originally derived from?
Absence of single or multiple teeth
The ectomesenchyme
The permanent molars
The enamel organ - dental papilla - dental sac

25. Passive eruption
Cementocytes
Maturation
Cementoid
When the gingiva recedes and no actual tooth movement takes place

26. What will the outer cells of the dental lamina differentiate into?
Dentin secreting cells (odontoblats)
A bilayer rim that consists only IEE and OEE
Absence of single or multiple teeth
Hereditary

27. Which teeth are nonsuccedaneous?
The permanent molars
Differentiation
Hereditary in localized form. endocrine dysfunction is complete
Enamel

28. What stage does the dental tissues subsequently fully mineralize
It disintegrates as the developing oral mucosa comes to line the oral cavity
Maturation
Lines of Retzuis
The enamel organ is compressed

29. What is anodontia?
Induction
Tooth germ tries to divide
Maturation
Absence of single or multiple teeth

30. What are the formative cells for alveolar bone?
Inner
Osteoblasts
Induction
Cuboidal cells

31. What are the clinical ramifications of dens in dente?
Into odontoblasts
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
Dental tissues secreted as matrix in successive layers.
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy

32. What are the clinical ramifications of micro/macrodontia?
The enamel - dentin - and cementum are secreted in successive layers
Commonly involves permanent maxillary lateral incisor and 3rd molars
Compressed layer of flat to cuboidal cells
The basement membrane

33. What is gemination?
Tooth germ tries to divide
Sphere of enamel on root
The outer enamel epithelium
Dentin and alveolar bone

34. 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 disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
There are none - they are lost with eruption
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing

35. What hard tissue is innervated by nerves?
Dental tissues fully mineralize to their mature levels.
There are none - they are lost with eruption
Dentin and alveolar bone
Only dentinal tubules with processes

36. How is the reduced enamel epithelium created?
Displacement of ameloblasts to root 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
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.
The enamel organ is compressed

37. What happens when the reduced enamel epithelium is created?
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion
The outer cells of the dental papilla and the central cells of the dental papilla
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
Future dentin and pulp tissue

38. What is the predominate process of the cap stage?
Morphogenesis
Trauma - pressure or metabolic disease
Absence of single or multiple teeth
There is unequal growth in different parts of the tooth bud

39. What are entrapped cementoblasts called?
Tooth germ tries to divide
The enamel organ
Cementocytes
Into odontoblasts

40. When does dens in dente occur?
Traumatic injury or crowding of teeth
During the cap stage
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
Dental papilla

41. What are the clinical ramifications?
Common on permanent molars or cingulum of anterior teeth
Trauma - pressure or metabolic disease
The outer enamel epithelium
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

42. What kind of cells occur in the outer enamel epithelium in the bell stage?
Preameloblasts
Cuboidal cells
Union of root structure of two or more teeth by cementum
It disintegrates as the developing oral mucosa comes to line the oral cavity

43. What are the incremental lines for cementum and alveolar bone?
The dental sac
Tall columnar cells
The outer enamel epithelium
Arrest and reversal lines

44. What is microdontia?
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion
Faulty development of enamel from interference involving ameloblasts
Growth of the dental lamina into bud that penetrates growing ectomesenchyme
Abnormally small teeth

45. What happens during the maturation stage?
The enamel - dentin - and cementum are secreted in successive layers
Dental tissues fully mineralize to their mature levels.
Cementoblasts
Dental papilla

46. What is an enamel pearl?
4 types
Cementoid
Sphere of enamel on root
Osteoblasts

47. Do odontoblasts start their secretion of matrix before the ameloblasts?
The basement membrane that seperates the enamel organ and dental papilla
Maturation
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
The outer cells of the dental papilla and the central cells of the dental papilla

48. What are the cell layers found in the enamel organ in the bell stage?
Tooth germ tries to divide
There is unequal growth in different parts of the tooth bud
9th to 10th weeks
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium

49. What is the process involved in the maturation stage?
Induction
Maturation
Initiation stage
Odontoblastic process

50. When the inner epithelial epithelium columnar cells elongate and repolarize they differentiate into what?
The dental lamina
Preameloblasts
Common on permanent molars or cingulum of anterior teeth
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel