OCB Qs

Question 1

1. Which of the following tissues is formed by the oral epithelium?
• Dentine
• Cementum
• Enamel
• Dental pulp
• Periodontal ligament

Answer 1

Enamel

Question 2

2. Which of the following statements is false?
   • Neural crest cells undergo ectodermal- to-mesenchymal transitions
   • Neural crest cells are multipotent
   • The initiation stage of tooth development is not part of morphogenesis
   • The thickening of the epithelium in the primary epithelial band is due to an
   increased rate of cell proliferation
   • If the mesenchymal condensation around the epithelial bud does not occur tooth development will stop at the bud stage

Answer 2

• The thickening of the epithelium in the primary epithelial band is due to an
increased rate of cell proliferation

Question 3

3. Which two of the following does the dental follicle not give rise to?
• The dentine
• The periodontal ligament
• The alveolar bone socket
• The cementum
• The dental pulp

Answer 3

• The dentine

* The dental pulp

Question 4

5. At which stage of tooth development do tooth buds for the permanent teeth
begin to form?
• Bud stage
• Early cap stage
• Late cap stage
• Early bell stage
• Late bell stage

Answer 4

• Late bell stage

Question 5

7. Which of the following statements is false?
   • The coronal two thirds of the root contain acellular cementum
   • The dental papilla controls alveolar bone metabolism during tooth eruption
   • The cervical loop is where the inner enamel epithelium joins the outer enamel
   epithelium
   • The breakdown of HERS causes cementum and periodontal ligament
   formation
   • HERS maps out the root shape 

Answer 5

• The coronal two thirds of the root contain acellular cementum

Question 6

10. Which of the follow statements is false?
    • The pulp is often called the dentine-pulp complex because the odontoblast processes extend at least one-third into the dentinal tubules
    • Enamel contains type 1 collagen fibres
    • In older patients the pulp reduces in size
    • Odontoblasts are post mitotic cells and therefore cannot divide
    • The nerves of the dental pulp are both myelinated and unmyelinated

Answer 6

• Enamel contains type 1 collagen fibres

Question 7

11. Which of the following is not a purpose of the dental pulp?
• To form dentine
• To form the periodontal ligament
• Defence against infection
• To repair dentine
• To form the root

Answer 7

• To form the periodontal ligament

Question 8

12. Which one of the following is not part of the periodontium?
• Gingiva
• Dentine
• Periodontal ligament
• Cementum
• Alveolar bone

Answer 8

• Dentine

Question 9

13. Which of the following statements is true about attached gingivae?
    • It is slightly loose
    • It is bound from the free gingival groove to the tooth
    • It is keratanised
    • It is always stippled

Answer 9

• It is keratanised

Question 10

15. Which tooth has the canine fossa?
• Maxillary first premolar
• Mandibular first premolar
• Maxillary canine
• Mandibular canine
• Mandibular second premolar

Answer 10

• Maxillary first premolar

Question 11

16. Which of the following is not a derivative of mesoderm?
• Skeleton
• Blood
• Kidney
• Nervous system
• Skeletal muscle

Answer 11

• Nervous system

Question 12

17. Incremental lines of Retzius are seen in:
• Enamel
• Dentine
• Cementum
• Pulp
• Periodontal ligament

Answer 12

• Enamel

Question 13

18. The 5th cusp on the lower permanent first molar is located where?
    - Mesio-buccally
    - Disto-buccally
    - Mesio-palatally
    - Disto-palatally
    - Occlusally

Answer 13

• Disto-buccally

Question 14

20. By weight how much inorganic material does dentine contain?
• 96 percent
• 70 percent
• 55 percent
• 84 percent
• 43 percent

Answer 14

• 96 percent

Question 15

21. Which of the following statements is false?
    • Coronal dentine consists only of mantle and circumpulpal dentine
    • Peritubular dentine is hypercalcified compared to intertubular dentine
    • There is often a neonatal line in dentine
    • Interglobular dentine is areas of highly calcified dentine formed by over fusion
    of the calcospherites
    • Tertiary dentine can be reactionary or reparative

Answer 15

• Interglobular dentine is areas of highly calcified dentine formed by over fusion

Question 16

23. Which type of cartilage lines the articular surfaces of the TMJ?
• Hyaline
• Fibrocartilage
• Elastic
• Fibroelastic
• Keratohyalin

Answer 16

• Fibrocartilage

Question 17

24. The proximal part of the mandible is divided into three processes; the
    coronoid process, the condylar process and the angular process. Which of the
    muscles listed below is the coronoid process a site of attachment for?
    • Temporalis muscle
    • Lateral Pterygoid
    • Medial Pterygoid
    • Mylohyoid
    • Digastric

Answer 17

• Temporalis muscle

Question 18

26. Which of the following is responsible for the development of the angular
process?
• RunX2
• Pax 9
• TGF – beta 2
• BMP4
• IHH

Answer 18

• TGF – beta 2

Question 19

27. Which of these below is the last deciduous tooth to erupt?
• lower second deciduous molar
• upper first deciduous molar
• upper first deciduous central incisor
• lower deciduous canine
• upper first lateral incisor

Answer 19

• lower second deciduous molar

Question 20

29. Dentinal tubules are calcified in:
    - translucent dentine
    - Primary dentine
    - secondary dentine
    - interglobular dentine

Answer 20

• translucent dentine

Question 21

30. Which of the following statements is false?
    - There is no 5th pharyngeal arch
    - The basic structure of each branchial arch consists of cartilage, a nerve and an artery
    - Within the maxillary process is located the Meckels cartilage
    - the nerve supply to the third pharyngeal arch is the glossopharyngeal nerve
    - The midbrain and rhombomeres 1 and 2 contribute to the face and the first branchial arch

Answer 21

• Within the maxillary process is located the Meckels cartilage