Test your basic knowledge |

Dentistry Tooth Development And Eruption

Subjects : health-sciences, dentistry

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

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. When the inner epithelial epithelium columnar cells elongate and repolarize they differentiate into what?
Preameloblasts
Epithelial rests of Malassez
Hereditary
Absence of single or multiple teeth

2. When does macro/microdontia occur?
The ameloblasts place an acellular dental cuticle on the new enamel surface
Bud stage
Osteocytes
The actual vertical movement of the tooth

3. Where is the dental sac originally derived from?
The ectomesenchyme
The outer cells of the dental papilla and the central cells of the dental papilla
Epithelial rests of Malassez
Osteoblasts

4. When root formation is completed the portion of the basement membrane disintegrates its cells may become what?
Epithelial rests of Malassez
A mineralized cylinder - the dentinal tubule
The enamel organ - dental papilla - dental sac
Cuboidal cells

5. What happens during the apposition stage?
Enamel
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
There are none - they are lost with eruption
Dental tissues secreted as matrix in successive layers.

6. What happens during the cap stage?
The tooth germ
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 ameloblasts
Inner

7. What are the clinical ramifications of concrescence?
Union of 2 adjacent tooth germs
Local or systemic or hereditary
The dental sac
Common with permanent maxillary molars

8. What are the clinical ramifications of enamel dysplasia?
Odontoblastic process
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin
Occurs commonly between the maxillary centrals - distal to the 3rd molars and premolar region. may cause crowding - failureof normal eruption and disruption of occlusion
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics

9. What are the etiological factors for anodontia?
May cause disruption of occlusion and aesthetic problems - may need partial or full dentures - bridges - and/or implants
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Trauma - pressure or metabolic disease
Enamel organ

10. 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
Abnormally small teeth
A bilayer rim that consists only IEE and OEE
Compressed layer of flat to cuboidal cells

11. Do odontoblasts start their secretion of matrix before the ameloblasts?
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Preameloblasts
Yes - this is why the dentin is thicker in the mature tooth structure than the enamel
6th to 7th weeks

12. What is matrix?
An extracellular substance that is partially calcified - yet serves as a framework for later calcification
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
The primordium of the pulp
Displacement of ameloblasts to root surface

13. What are the mature cells for alveolar bone?
Osteocytes
Proliferation - differentiation - morphogenesis
Osteoblasts
Dental follicle

14. What hard tissue has vascularity?
The dental lamina
Apposition of the cementum
There is unequal growth in different parts of the tooth bud
Alveolar bone

15. What are the incremental lines for dentin?
Imbrication lines of von Ebner
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
Odontoblasts
Preameloblasts

16. What are the clinical ramifications of dens in dente?
Maturation
Tooth germ tries to divide
Enamel
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy

17. In the cap stage the tooth bud does not grow - what happens?
There are none - they are lost with eruption
Displacement of ameloblasts to root surface
There is unequal growth in different parts of the tooth bud
Hereditary

18. What happens to the thickened non tooth producing portions of the dental lamina eventually?
The enamel organ is compressed
Pressure on the area
It disintegrates as the developing oral mucosa comes to line the oral cavity
Induction - proliferation

19. The oral epithelium is induced by the ectomesenchyme to produce what?
The dental lamina
A mineralized cylinder - the dentinal tubule
Sphere of enamel on root
6th to 7th weeks

20. What are the major components of the tooth germ?
Tooth germ
Union of root structure of two or more teeth by cementum
Differentiation
The enamel organ - dental papilla - dental sac

21. What is the important acelluar structure that seperates the oral epithelium and the ectomesenchyme?
The basement membrane
6th to 7th weeks
Pitting or intrinsic color changes in enamel. changes in thickness of enamel possible. problems in function and aesthetics
Pressure on the area

22. What are the formative cells for cementum?
8th week
Cementoblasts
Enamel secreting cells (ameloblasts)
Development of one or more extra teeth

23. What is the main process involved in initiation?
Induction
The permanent molars
Maturation
Alveolar bone

24. What is an enamel pearl?
Enamel
Sphere of enamel on root
Tall columnar cells
Future dentin and pulp tissue

25. Where is the dental papilla originally derived from?
Osteoblasts
The ectomesenchyme - which was influenced by the neural crest cells
Hereditary - endocrine dysfunction - systemic disease - excess radiation exposure
Differentiation of enamel organ into bell with four cell types and dental papilla into two cell types.

26. The buds of the dental lamina - together with the surrounding ecto mesenchyme - will develop into what?
Trauma - pressure or metabolic disease
Only dentinal tubules with processes
Cementoblasts
Tooth germ

27. What are the processes involved in the cap stage?
Proliferation - differentiation - morphogenesis
Abnormally large teeth
There is unequal growth in different parts of the tooth bud
Osteoblasts

28. What is fusion?
Compressed layer of flat to cuboidal cells
Cuboidal cells
Union of 2 adjacent tooth germs
Dental papilla

29. What is the function of the Hertwig's epithelial root sheath?
Osteoblasts
Traumatic injury or crowding of teeth
4 types
To shape the root (or roots) and induce dentin formation in the root area so that it is continuous with coronal dentin

30. What is the embryological background for dentin - cementum and alveolar bone?
Imbrication lines of von Ebner
Induction
Commonly involves permanent maxillary lateral incisor and 3rd molars
Dental papilla

31. What are the etiological factors for dens in dente and gemination?
Cementoid
Connective
The permanent molars
Hereditary

32. What is the predominate process of the cap stage?
The dental sac
In the cap stage
Morphogenesis
The ectomesenchyme

33. What are the incremental lines for enamel?
Lines of Retzuis
Hereditary
Abnormally large teeth
The basement membrane that seperates the enamel organ and dental papilla

34. The stage named for extensive proliferation of the dental lamina into oval masses penetrating into the ectomesenchyme?
The ectoderm
The basement membrane that seperates the enamel organ and dental papilla
The bud stage
Osteoblasts

35. What are the cell layers found in the enamel organ in the bell stage?
Initiation stage
Enamel organ
There are none - they are lost with eruption
The outer enamel epithelium - the inner enamel epithelium - the stellate reticulum - and the stratum intermedium

36. What are succedaneous teeth?
Initiation
After the crown is completely shaped and the tooth is starting to erupt into the oral cavity
Odontoblastic process
Permanent teeth formed with primary predecessors - the anterior teeth and the premolars

37. What conveys communications between the cells of the enamel organ - the dental papilla - and the dental sac allowing tissue interactions?
Union of root structure of two or more teeth by cementum
Maturation
Morphogenesis
The basement membrane

38. What is amelogenisis?
Osteoblasts
Faulty development of enamel from interference involving ameloblasts
Odontoclasts
The apposition of the enamel matrix

39. What is macrodontia?
Local or systemic or hereditary
The basement membrane
Trauma - pressure or metabolic disease
Abnormally large teeth

40. What cell bodies are involved in the eruption and mineralization process but will be lost after eruption?
Alveolar bone
The ameloblasts
Tooth germ
Into odontoblasts

41. What is dens in dente?
Hereditary in localized form. endocrine dysfunction is complete
Preameloblasts
Enamel organ invaginates into the dental papilla
The ameloblasts

42. What are the formative cells for dentin?
Maturation
Dentin and alveolar bone
Odontoblasts
Bud stage

43. What are the 2 layers in the dental papilla within the concavity of the enamel organ?
The outer cells of the dental papilla and the central cells of the dental papilla
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 actual vertical movement of the tooth
Cementoblasts

44. How many types of cells are found in the enamel organ in the bell stage?
4 types
Enamel pearl - enamel dysplasia - and concresence
Common on permanent molars or cingulum of anterior teeth
There are none - they are lost with eruption

45. What layer serves as protection for the enamel organ?
When the gingiva recedes and no actual tooth movement takes place
Arrest and reversal lines
The outer enamel epithelium
Proliferation - differentiation - morphogenesis

46. What is the time span for the bud stage?
In the cap stage
8th week
The actual vertical movement of the tooth
Sphere of enamel on root

47. What processes are involved in the bell stage?
Differentiation - proliferation - morphogenesis
The actual vertical movement of the tooth
Common on permanent molars or cingulum of anterior teeth
Commonly affects the permanent maxillary lateral incisor. tooth may have deep lingual pit and need endodontic therapy

48. What are the formative cells for enamel?
Odontoblasts
Ameloblasts
Dentinogenesis - Which is the apposition of dentin matrix - or predentin - on the other side of the basement membrane
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing

49. What are the clinical ramifications of micro/macrodontia?
The dental lamina
Extra cusp due to effects on enamel organ
The actual vertical movement of the tooth
Commonly involves permanent maxillary lateral incisor and 3rd molars

50. The preameloblasts induce dental papilla cells to differentiate into what?
Large tooth with two pulp cavities. one fewer tooth in dentition. may cause problems in appearance and spacing
The enamel organ - dental papilla - dental sac
Into odontoblasts
Growth of the dental lamina into bud that penetrates growing ectomesenchyme