oral_bio_SEQ.pdf

Page 1 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Total No. of SEQs: 15 Total Marks: 45...

Page 1 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Total No. of SEQs: 15 Total Marks: 45 Time 2 hours 15 min. Note: 3 Marks for each question. Q1. Name the embryological processes (prominences) that are responsible for the development of the face. Specify the processes that fail to fuse in cleft lip and cleft palate. (3) Topic: Oral Embryology Key: Processes Marks Face: (1) Frontonasal (medial and lateral nasal) Right and left Maxillary Right and left Mandibular Cleft lip: (1) Medial nasal and maxillary Cleft of primary palate: (0.5) Frontonasal (medical nasal) and maxillary (palatal shelf) Secondary palate: (0.5) Palatal shelves of left and right maxillary processes Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 3: Pages 30-53  Page 2 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q2. Draw and label the two different histological structures of ameloblasts at the stage of enamel maturation. (3) Topic: Oral Histology Key: Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 7: Page 174  Page 3 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q3. Indicate the origin and fate of the following cells: (3) (a) Odontoblasts (b) Cementoblasts (c) Ameloblasts (d) Periodontal ligament fibroblasts (e) Serous cells of salivary gla nds (f) Cells of the stratum spinosum of oral epithelium Topic: Oral Histology Key: Cell Origin Fate Marks Odontoblasts Dental papilla, Pulp periphery 0.5 ectomesenchyme, neural crest Cementoblasts Dental follicle, Cementocytes or in PDL 0.5 ectomesenchyme on the cementum surface Ameloblasts Internal enamel Reduced enamel 0.5 epithelium, Dental epithelium, junctional organ, Ectoderm epithelium PDL fibroblasts Dental follicle, In PDL, may undergo 0.5 ectomesenchyme cell death Serous cells Oral epithelium, In gland, may undergo 0.5 ectoderm cell death Cells of st. Basal cell layer, Lost in oral cavity 0.5 spinosum ectoderm Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapters 5, 7, 8, 9, 11 and 12  Page 4 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q4. Explain what you understand by (define) the following terms related to oral mucosa: (3) (a) Lamina propria (b) Masticatory mucosa (c) Attached gingiva (d) Vermillion zone (e) Junctional epithelium (f) Melanocyte Topic: Oral Histology Key: (0.5 marks for each) (a) Lamina propria: connective tissue underlying epithelium- further subdivided into papillary and reticular lamina propria. (b) Masticatory mucosa: moist lining of the oral cavity capable of withstanding masticatory stresses. Has keratinized epithelium. Covers gingive and hard palate. (c) Attached gingiva: part of masticatory mucosa firmly adherent to the underlying bone, present between free gingiva and alveolar mucosa. (d) Vermillion zone: transitional zone of mucosa present on the lips, between skin of the lips and oral labial mucosa. Redder than oral mucosa, lightly jeratinized. (e) Junctional epithelium: connects the tooth to the gingiva by a basal lamina (hemi-desmosomes)- thus forming the dento-gingival junction. Develops initially by cells of the reduced enamel epithelium. (f) Melanocyte: melanin pigment producing cell present in the deeper layer of epithelium. Distributes/injects melanosomes into adjacent cells. Ref: Ten Cate's Oral Histology: Development, St ructure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 12: Pages 329-375  Page 5 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q5. Enumerate 6 functions of saliva. Name the components of saliva that are responsible for each of these functions. (3) Topic: Oral Physiology Key: Function Components Marks Protection/lubrication Mucins, glycoproteins, water 0.5 Digestion Amylase, lipase 0.5 Tooth integrity Calcium, phosphate, fluoride 0.5 Taste Gustin, water 0.5 Buffering Bicarbonate, phosphate 0.5 Antibacterial Lactoferrin, lysozyme, Immunoglobilins, 0.5 peroxidase, histatins, aggultinins Tissue healing Peptides, proteins Pellicle formation Proteins Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 11: Pages 300-301  Page 6 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q6. Explain the changes/events that occur inside the temporomandibular joint during: (a) Wide opening of the mouth. (1.5) (b) Right lateral movement of the mandible. (1.5) Topic: Oral Anatomy Key: (a) Initial bilateral hinge movement of the condyle in the lower joint compartment. Followed by bilateral forward gliding movement of the condyle and disk in the upper compartment. (1.5 marks) (b) Rotational movement of the RIGHT condyle along a vertical axis in the lower joint compartment. Forward gliding movement of the LEFT condyle in the upper compartment. (1.5 marks) Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 13: Page 376-398  Page 7 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q7. List the age changes in the following dental tissues: (a) Enamel. (1) (b) Dentin. (1) (c) Pulp. (1) Topic: Oral Histology Key: (a) Attrition, wear facets Discolouration Reduced permeability, decreased caries Increased brittleness (1 mark) (b) Secondary dentin formation Intratubular dentin deposition – sclerotic dentin formation Increased brittleness Decreased permeability Dead tract formation (1 mark) (c) Decrease in volume of pulp chamber and root canal Reduced vascular supply Decrease in cell density Degeneration of nerves Dystrophic calcification (1 mark) Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapters 7 and 8  Page 8 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q8. Tabulate the origin of fibres, location and function of acellular (primary) and cellular (secondary) cementum. (3) Topic: Oral Histology Key: Type Origin of Location Function Marks fibres Acellular Mostly Cervical margin to Anchorage 0.5+0.5+ extrinsic apical third 0.5 Cellular Intrinsic Middle to apical third Adaptation and 0.5+0.5+ and furcations repair 0.5 Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 9: Page 248  Page 9 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q9. Draw and label the lingual view of the maxillary right permanent central incisor. (3) Topic: Tooth Morphology Key: Ref: Tooth Morphology. Fuller.  Page 10 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q10. Indicate how each of the following teeth are referred to in the Palmer notation, Universal numbering system and the FDI notation: (a) Maxillary right permanent lateral incisor. (0.5) (b) Maxillary left permanent second molar. (0.5) (c) Maxillary right deciduous first molar. (0.5) (d) Mandibular left first premolar. (0.5) (e) Mandibular right permanent canine. (0.5) (f) Mandibular left deciduous second molar. (0.5) Topic: Tooth Morphology Key: Tooth Palmer Universal FDI Marks Maxillary right permanent lateral 7 12 0.5 incisor Maxillary left permanent second 15 27 0.5 molar Maxillary right deciduous first B 54 0.5 molar Mandibular left first premolar 21 34 0.5 Mandibular right permanent canine 27 43 0.5 Mandibular left deciduous second K 75 0.5 molar Ref: Tooth Morphology. Fuller.  Page 11 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q11. During cavity preparation a patient feels pain during drilling and irrigation of the cavity. Explain the the mechanisms that may be responsible for this sensitivity. Which of these is the most likely explanation? (3) Topic: Oral Physiology Key: 1. Dentin contains nerve endings that respond when it is stimulated. (1 mark) 2. Odontoblasts serve as receptors and are coupled to nerves in the pulp. (1 mark) 3. Fluid movement in dentinal tubules due to stimulation is registered by nerves close to the dentin. Most likely mechanism. (1 mark) Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 8: Pages 233-236  Page 12 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q12. Explain the reasons why a tooth continues to move throughout its life after eruption. (3) Topic: Oral Anatomy Key: 1. Accommodation for jaw/bone growth- teeth move 2-3 mm occlusally between ages 14-18. (1 mark) 2. Compensation for occlusal wear/attrition. Teeth move occlusally resulting in cementum deposition. (1 mark) 3. Accommodation for interproximal wear. Mesial drift due to anterior component of occlusal force and contraction of transseptal ligament. (1 mark) Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 10: Pages 280-282  Page 13 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q13. Draw and label the histological structure of the pulp, clearly indicating the different zones of the pulp. (3) Topic: Oral Histology Key: Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 8: Page 216  Page 14 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q14. Tabulate the time of eruption, Number of cusps, names of the roots, and names of the root canals of the following teeth: a) Maxillary permanent first molar. (1) b) Mandibular permanent first molar. (1) c) Maxillary first premolar. (1) Topic: Tooth Morphology Key: Tooth Time of Number Name of roots Name of root Marks eruption of cusps canals Maxillary Palatal, Palatal, mesiobuccal. 0.25+0.25+ permanent 6-7 4-5 mesiobuccal. distobuccal 0.25+0.25 first molar distobuccal Mandibular Mesial, distal Mesiobuccal, 0.25+0.25+ permanent mesiolingual, distal 0.25+0.25 6-7 5 first molar (may be 2 distal canals) Maxillary Variable. One Variable. Buccal, 0.25+0.25+ first 9-11 2 or bifid (buccal, lingual 0.25+0.25 premolar lingual) Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 10: Pages 275-298 & Tooth Morphology. Fuller.  Page 15 of 15 BDS FIRST PROFESSIONAL EXAMINATION 2007 ORAL AND TOOTH MORPHOLOGY Model Paper (SEQs) Q15. There is accidental exposure of the pulp during cavity preparation. The dentist covers the exposed pulp using a calcium hydroxide cement. Explain the response of the pulp to this injury. (3) Topic: Oral Histology Key: Marks Initial response by tissue macrophages and neutrophils (1 mark) Inflammatory response initiated by lymphocytes and mast cells. (1 mark) Pulp may undergo necrosis Undifferentiated cells will turn into odontoblasts and produce reparative (tertiary) dentin calcific bridge. (1 mark) Ref: Ten Cate's Oral Histology: Development, Structure, Function. Antonio Nanci. 6th Edition. Mosby. Chapter 8: Pages 192-239