DHY 121 - Oral Histology & Embryology

1. Compare the three stages of tooth development, histological­ly
   1. Describe the stages of tooth development both morphologically and physiologically
   2. Describe the three components of the cap stage and the embryolog­ic tissue they come from.
   3. Describe the structures each of component of the tooth germ and what will produce
   4. Describe the cell shape and function of each cell layer in the Bell stage of development
   5. Explain the role of the inner enamel epithelium during the forma­tion process of enamel and dentin
   6. Compare the mineralization process of enamel, dentin and cemen­tum
   7. Describe the formation and function of the reduced dental epitheli­um and the structures it produces
   8. Describe root development incorporating the role of each of the following
2. Contrast the histological development and composition of enamel with that of dentin and cementum
   1. Describe the six stages in the life cycle of the ameloblast
   2. Explain the importance of dentin to enamel formation
   3. Describe the three relationships which occur at the CEJ between enamel and cementum including incidence
   4. Describe the orientation of enamel rods, their crystalline arrange­ment, and how their width differs from start to finish
   5. Describe the two stages of enamel mineralization
   6. Describe the structural features of enamel and their causes
   7. Explain how fluoride and acid etching work
   8. Explain the cause of enamel solubility
   9. List the major inorganic constituents of enamel and their percentag­es
3. Compare the histological development and composition of dentin with enamel and cementum
   1. Describe dentinogenesis from the late Bell Stage to eruption includ­ing the following
   2. Define the following types of dentin: primary, secondary, repara­tive, and sclerotic
   3. Statepercentages of organic vs. inorganic components of dentin
   4. Describe the makeup of the organic matrix
   5. Explain the three theories of dentin hypersensitivity
4. Contrast the histological development and composition of cementum with that of enamel and dentin
   1. Describe cementogenesis including the roles of Hertwig’s epithelial root sheath, cementoblasts, cementoid & resting lines
   2. State whether or not cementum can be deposited throughout life
   3. Define and describe cementum including its composition and function
   4. Compare cementum to enamel, dentin and bone in inorganic con­tent, vascularity, remodeling capacity and resistance to resorption
   5. Compare cellular and acellular cementum in regard to location and structural makeup
   6. Describe the histologic structure of cementum, including lamellae, cementocyte processes, canaliculi and lacunae
   7. State the importance of Sharpey’s fibers to cementum and the PDL
   8. Define cementicles and hypercementosis
5. Differentiate between the cellular and fibrous components of the pulp and periodontal ligament
   1. Define periodontium
   2. List and define the four fiber groups found in the lamina propria of the attached gingiva
   3. Describe the formation of the periodontal ligament
   4. List the cell types found in the PDL and the pulp and their func­tions
   5. Describe the five groups of principal fibers found in the PDL
   6. List and define four functions of the PDL and the pulp
   7. State the significance of ground substance in the PDL
   8. Describe the blood and nerve supply to the PDL and the pulp
   9. List the four zones of the pulp
   10. State the purpose of undifferentiated mesenchymal cells in the pulp
   11. Describe the extracellular components of the PDL and the pulp, and state their functions
   12. State the significance of alterations in fluid pressure within the pulp during dental procedures
   13. Apply knowledge of histology to the following procedures
6. Analyze the changes that occur within pulp, enamel, dentin, and the periodontal ligament during aging
   1. Describe the three classifications of pulp stones and explain their significance
   2. Describe four changes that occur within the pulp with increasing age
   3. Explain how bacteria can enter a tooth and its effect upon the pulp
   4. Discuss the significance of devitalization upon a tooth’s function
7. Demonstrate knowledge of cellular histology
   1. Describe the components of the cell, the cell membrane, cytoplasm, organelles, and inclusions
   2. Describe the extra cellular materials surrounding the cell and the cell’s intercellular junctions
   3. Describe cell division and the phases of mitosis that are involved
8. Examine the histology of the oral mucous membrane
   1. Describe oral epithelium
   2. Describe the lamina propria
   3. Describe the submucosa
   4. Describe histologically the lining mucosa covering the lip, vermil­lion border, soft palate, ventral surface of tongue, cheek and floor of the mouth
   5. Describe histologically the masticatory mucosa covering the gingiva and hard palate
   6. Describe histologically the four types of papillae found on the dorsal surface of the tongue
   7. Define nonkeratinocyte and describe the following cells: Langerhan’s cells, Merkel’s cells, melanocytes, lymphocytes
   8. Describe the composition, development and turn over of the dentogingival junction tissues
9. Differentiate the cellular and ductal components of the major salivary glands
   1. Describe and give the function of exocrine gland, serous, mucous and seromucous endpieces
   2. Describe the histological structure of the three major salivary glands, whether they are serous, mucous, or mixed, and the names of their ducts and where they open in the oral cavity
   3. Define minor salivary gland and list six of these and whether they are serous, mucous, or mixed
   4. Define intercalated ducts, striated ducts, terminal secretory ducts, and myoepithelial cells
   5. List the components of saliva.
   6. Describe the innervation of the salivary glands and the effects that the salivary glands and the effects that the sympathetic and para­sympathetic innervation have on the salivary flow
10. Synthesize the histological development of the fibrous and bony compo­nents of the temporomandibular joint
    1. Describe the formation of the mandible by endochondral and intramembranous ossification
    2. Diagram or identify on a diagram the adult TMJ including the glenoid fossa, condylodiscal cavity, articular disc, temporal distal cavity, head of the condyle, articular capsule and tubercle, and the external auditory meatus
    3. Describe the histology of the articulating surfaces of the condyle and glenoid fossa
11. Differentiate histologically the pre-eruptive and posteruptive phases of tooth movement
    1. Define eruption
    2. Differentiate pre-eruptive, eruptive and post-eruptive tooth move­ments
    3. Define excentric growth
    4. Outline tooth eruption including a description of reduced enamel epithelium and the role it and the oral epithelium play in tooth eruption
    5. State the four possible theories set forth in the explanation of the mechanism of tooth movement and state the theory or theories considered the most plausible
    6. State the significance of the gubernaculum dentis or cord and gubernacular foramina or canals
    7. Explain the remodeling role of the periodontal ligament during root formation and eruption
    8. Contrast these terms: clinical vs. anatomical crown; active vs. passive eruption
    9. Define mesial drift
    10. List the three causes of shedding of primary teeth
    11. Describe an odontoclast including the microscopic appearance and function
    12. Describe the mechanism of resorption of the bone, root, and soft tissues which result in shedding
12. Synthesize the embryological and histological development of the maxilla and mandible
    1. State the relationship of Merkel’s cartilage to the developing mandi­ble
    2. Describe the types of ossification which form the maxilla and the mandible
    3. Describe the maxillary sinus and define pneumatization.
    4. State the percentages of the organic and inorganic components of bone
    5. State the chemical formula for hydroxyapatite
    6. Define the following components of alveolar bone: lamina dura, interdental septum, interradicular bone, Haversian system bone, cribriform plate
    7. Describe the histology of bone including periosteum, endosteum, trabeculae, osteocytes, canaliculi, lamellae, osteons, and Haversian canals
13. Analyze the embryological development of the oral cavity.
    1. Compare the three primary embryonic layers and the structures which will eventually result from them
    2. Define the borders of the stomatodeum at the time of its formation; define buccopharyngeal membrane
    3. Discuss the fate of the first 4 branchial arches and their corresponding pharyngeal pouches
    4. Discuss which nerves innervate the first three branchial arches and their resulting anatomical structures
    5. Discuss the development of the tongue including which of the cranial nerves innervate which areas
    6. Discuss which processes fuse to form the maxilla and mandible
    7. Describe the processes which form the embryonic face
    8. List 2 glands which arise from embryonic oral epithelium
14. Contrast normal versus abnormal embryological development of the oral structures
    1. Define Trisomy 21 and list some of the prominent features of this illness as related to the face and oral cavity
    2. Define Treacher Collin’s Syndrome including the cause of and the diagnostic/clinical features in the face and oral cavity
    3. Define microstomia/macrostomia
    4. List the main etiologies for the formation of palatal clefts as well as facial and lip clefts