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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. How many types of cells are found in the enamel organ in the bell stage?
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
4 types
Hereditary
Growth of the dental lamina into bud that penetrates growing ectomesenchyme

2. What happens during the maturation stage?
Dental tissues fully mineralize to their mature levels.
The basement membrane that seperates the enamel organ and dental papilla
The dental sac
Enamel pearl - enamel dysplasia - and concresence

3. What are the clinical ramifications of micro/macrodontia?
Enamel
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
Commonly involves permanent maxillary lateral incisor and 3rd molars
Hereditary in localized form. endocrine dysfunction is complete

4. What are the major components of the tooth germ?
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium
The enamel organ - dental papilla - dental sac
Dentin and alveolar bone
Connective

5. What kind of cells occur in the outer enamel epithelium in the bell stage?
Initiation
Enamel secreting cells (ameloblasts)
Cuboidal cells
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy

6. What do the odontoblasts do?
Future dentin and pulp tissue
Local or systemic or hereditary
Inner
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane

7. What are the developmental disturbances of the cap stage?
Lines of Retzuis
Dens in dente - gemination - tubercle - and fusion
The permanent molars
Proliferation - differentiation - morphogenesis

8. What does the cervical loop consist of?
A bilayer rim that consists only IEE and OEE
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane
Enamel
The enamel organ - dental papilla - dental sac

9. What are the mature cells for dentin?
Induction - proliferation
Tall columnar cells
Local or systemic or hereditary
Only dentinal tubules with processes

10. After the enamel apposition ceases the crown area of each primary or permanent tooth what happens?
The cementum - PDL - and alveolar bone
The ameloblasts place an acellular dental cuticle on the new enamel surface
Displacement of ameloblasts to root surface
Cementocytes

11. What is the embryological background for dentin - cementum and alveolar bone?
Dental papilla
Inner
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
It disintegrates as the developing oral mucosa comes to line the oral cavity

12. The buds of the dental lamina - together with the surrounding ecto mesenchyme - will develop into what?
The permanent molars
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
Morphogenesis
Tooth germ

13. What happens during initiation?
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
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
Only dentinal tubules with processes
The ameloblasts place an acellular dental cuticle on the new enamel surface

14. What are the formative cells for dentin?
Maturation
Epithelial rests of Malassez
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Odontoblasts

15. What is the cap in the cap stage?
Permanent teeth formed with primary predecessors - the anterior teeth and the premolars
The enamel organ
In the cap stage
Initiation

16. What hard tissue is innervated by nerves?
Dentin and alveolar bone
The tooth germ
Dental papilla
The enamel - dentin - and cementum are secreted in successive layers

17. What is an enamel pearl?
Dental tissues secreted as matrix in successive layers.
Sphere of enamel on root
The ectoderm
Future dentin and pulp tissue

18. Tooth development
Odontoblastic process
Enamel organ
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.
Odontogenesis

19. What is gemination?
Initiation
Apposition of the cementum
11th to 12th weeks
Tooth germ tries to divide

20. What is the predominate process of the cap stage?
Lines of Retzuis
Common on permanent molars or cingulum of anterior teeth
Induction
Morphogenesis

21. What is the structure responsible for root development?
The cervical loop
Odontoblastic process
Into odontoblasts
Enamel organ invaginates into the dental papilla

22. What are succedaneous teeth?
The outer cells of the dental papilla and the central cells of the dental papilla
In the cap stage
Future dentin and pulp tissue
Permanent teeth formed with primary predecessors - the anterior teeth and the premolars

23. What are the clinical ramifications of enamel dysplasia?
Cementocytes
Abnormally large teeth
Absence of single or multiple teeth
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics

24. 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
Into odontoblasts
9th to 10th weeks
Tooth germ

25. What is concrescence?
Union of root structure of two or more teeth by cementum
Odontogenesis
Union of 2 adjacent tooth germs
The outer enamel epithelium

26. What happens during the bell stage?
Union of 2 adjacent tooth germs
Displacement of ameloblasts to root surface
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.
Odontoclasts

27. How is the reduced enamel epithelium created?
May be confused as calculus deposit on root
The enamel organ is compressed
The basement membrane
The ectomesenchyme - which was influenced by the neural crest cells

28. The oral epithelium is induced by the ectomesenchyme to produce what?
Displacement of ameloblasts to root surface
The dental lamina
6th to 7th weeks
The ameloblasts place an acellular dental cuticle on the new enamel surface

29. When the inner epithelial epithelium columnar cells elongate and repolarize they differentiate into what?
Into odontoblasts
The dental sac
Preameloblasts
Induction

30. What hard tissue has vascularity?
Oral epithelium
Enamel organ invaginates into the dental papilla
Alveolar bone
Enamel pearl - enamel dysplasia - and concresence

31. What processes are involved with the apposition stage?
Trauma - pressure or metabolic disease
The stellate reticulum
Induction - proliferation
The actual vertical movement of the tooth

32. What are the incremental lines for dentin?
Initiation
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
Imbrication lines of von Ebner
Induction - proliferation

33. What processes are involved in the bell stage?
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
Sphere of enamel on root
The enamel - dentin - and cementum are secreted in successive layers
Differentiation - proliferation - morphogenesis

34. When does the process of root development take place?
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
Outer
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
The Tomes' process - a tapered portion of each ameloblast that faces the disintegrating basement membrane

35. What is the time span for the cap stage?
Ameloblasts
Enamel organ invaginates into the dental papilla
9th to 10th weeks
Odontoblasts

36. What is the embryological background for enamel?
Traumatic injury or crowding of teeth
The disintegration of the basement membrane allows the preameloblasts to come into contact with the newly formed predentin
Enamel organ
The basement membrane

37. Where is the dental papilla originally derived from?
The ectomesenchyme - which was influenced by the neural crest cells
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
Traumatic injury or crowding of teeth
Hereditary

38. The stratum intermediate is located inner or outer?
Inner
Maturation
The actual vertical movement of the tooth
The enamel - dentin - and cementum are secreted in successive layers

39. What is the site for the future dentioenamel junction?
Epithelial
Development of one or more extra teeth
The basement membrane that seperates the enamel organ and dental papilla
Cementoid

40. Which teeth are nonsuccedaneous?
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 permanent molars
The dental lamina
Hereditary

41. When the undifferentiated cells of the dental sac come into contact with the root dentin they differentiate into what?
Cementoblasts
Tooth germ
The enamel - dentin - and cementum are secreted in successive layers
The stellate reticulum

42. What are the etiological factors for micro/macrodontia?
Enamel
Maturation
Cementoid
Hereditary in localized form. endocrine dysfunction is complete

43. What are the mature cells for alveolar bone?
Osteocytes
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
Arrest and reversal lines
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants

44. What is the time span for the bell stage?
11th to 12th weeks
Cementoblasts
Absence of single or multiple teeth
Proliferation

45. What hard tissue is can not have tissue formation after eruption?
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
Enamel
The basement membrane
Dental tissues fully mineralize to their mature levels.

46. What is the time span for initiation?
Tooth germ
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
6th to 7th weeks
9th to 10th weeks

47. What are the mature cells for cementum?
Future dentin and pulp tissue
Cementocytes
Into odontoblasts
Traumatic injury or crowding of teeth

48. What are the clinical ramifications of concrescence?
Compressed layer of flat to cuboidal cells
11th to 12th weeks
Common with permanent maxillary molars
May be confused as calculus deposit on root

49. How is the dentinocemental junction formed?
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
As a result of the apposition of cementum over dentin
Induction
11th to 12th weeks

50. What are the etiological factors for anodontia?
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Bud stage
Hereditary
Inner