Tooth Development and Enamel Formation Quiz
40 Questions
3 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the percentage of hydroxylapatite in dentin by weight?

  • 70% (correct)
  • 50%
  • 80%
  • 90%

    • Where does the formation of coronal dentin begin?

  • Near the DEJ
  • In the root of the tooth
  • At the cervical loop of the enamel organ
  • In the papillary tissue adjacent to the inner enamel epithelium (correct)

    • What is the main difference between root dentin and coronal dentin?

  • The mineralization process
  • The rate of formation
  • The color of the dentin
  • The orientation of collagen fibers (correct)

    • What is the characteristic of Dentinogenesis Imperfecta (DGI) type I?

    <p>It is associated with osteogenesis imperfecta</p> Signup and view all the answers

    What is the appearance of teeth affected by Dentinogenesis Imperfecta?

    <p>Blue-gray to yellow-brown</p> Signup and view all the answers

    What is the function of dentin in relation to enamel?

    <p>It provides structural support</p> Signup and view all the answers

    What is a characteristic of dentin that is not true of enamel?

    <p>It continues to form throughout life</p> Signup and view all the answers

    What is the percentage of organic material in dentin by weight?

    <p>20%</p> Signup and view all the answers

    What is the function of the papillae that form between the folds of the outer enamel epithelium?

    <p>To provide nutritional supply for the enamel organ</p> Signup and view all the answers

    What is the name of the membrane that separates the enamel organ and the dental papilla before dentin formation?

    <p>Membrana preformativa</p> Signup and view all the answers

    During which stage of tooth development do hard tissues, including enamel and dentin, begin to form?

    <p>Advance bell stage</p> Signup and view all the answers

    What is the term for the process by which the inner enamel epithelium cells change shape from cuboidal to columnar during the crown stage?

    <p>Cell morphogenesis</p> Signup and view all the answers

    What is the name of the structure that forms from the dental papilla during tooth development?

    <p>Dental pulp</p> Signup and view all the answers

    What is the function of the dental sac during tooth development?

    <p>To give rise to the periodontal ligament</p> Signup and view all the answers

    What is the term for the stage of tooth development where the inner enamel epithelium cells stop dividing and begin to differentiate into pre-ameloblasts?

    <p>Advance bell stage</p> Signup and view all the answers

    What is the name of the structure that forms at the cuspal tip of the tooth germ during the advance bell stage?

    <p>Dentin</p> Signup and view all the answers

    What is the result of the growth of dentin with age?

    <p>Decrease in the size of the pulp chamber</p> Signup and view all the answers

    What type of dentin is deposited by odontoblasts in response to injury?

    <p>Tertiary dentin</p> Signup and view all the answers

    What is the purpose of reactionary dentin?

    <p>To slow down the progress of caries</p> Signup and view all the answers

    What type of dentin is secreted by undifferentiated mesenchymal cells?

    <p>Reparative dentin</p> Signup and view all the answers

    What is the characteristic of the tubular pattern of reactionary dentin?

    <p>Disordered and irregular</p> Signup and view all the answers

    What is the term used to describe reparative dentin deposited rapidly with a sparse and irregular tubular pattern?

    <p>Osteodentin</p> Signup and view all the answers

    What is the prognosis of a tooth that has undergone reparative dentin formation?

    <p>Poor</p> Signup and view all the answers

    What is the difference between reactionary and reparative dentin?

    <p>All of the above</p> Signup and view all the answers

    What is the shape of undifferentiated mesenchymal cells in the pulp?

    <p>Spindle shaped</p> Signup and view all the answers

    What is the function of histiocytes or macrophages in the pulp?

    <p>To develop characteristics in response to inflammation</p> Signup and view all the answers

    What is the origin of blood vessels in the pulp and periodontium?

    <p>Inferior or superior alveolar artery</p> Signup and view all the answers

    What happens to undifferentiated mesenchymal cells in old age?

    <p>They decrease in number</p> Signup and view all the answers

    What is the function of dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous teeth (SHED)?

    <p>To undergo proliferation and migrate to the site of injured odontoblasts and produce dentin</p> Signup and view all the answers

    What is the significance of the connections between the vessels of the pulp and the periodontium?

    <p>It allows for the spread of infection</p> Signup and view all the answers

    What is the primary function of the prong-like extensions of cementum?

    <p>To increase the surface area for attaching fibers and anchor the tooth to the surrounding alveolar bone</p> Signup and view all the answers

    What type of cells are found along pulp vessels, in the cell-rich zone and scattered throughout the central pulp?

    <p>Undifferentiated mesenchymal cells</p> Signup and view all the answers

    What is often observed in areas where enamel drops have developed on the dentin?

    <p>Localized hypercementosis</p> Signup and view all the answers

    What is the route taken by small arteries and arterioles in the pulp?

    <p>They enter the apical canal and pursue a direct route to the coronal pulp</p> Signup and view all the answers

    What are the knob-like projections designated as?

    <p>Excenceoses</p> Signup and view all the answers

    What is associated with chronic periapical inflammation?

    <p>Extensive deposition of cementum</p> Signup and view all the answers

    What is characterized by a reduction in the number of Sharpey's fibers embedded in the root?

    <p>Hypercementosis of cementum in non-functioning teeth</p> Signup and view all the answers

    What is the periodontium composed of?

    <p>Cementum, periodontal ligament, bone lining the tooth socket, and that part of the gingiva facing the tooth</p> Signup and view all the answers

    What is thicker around the apex of all teeth and in the furcation of multirooted teeth?

    <p>Cementum</p> Signup and view all the answers

    What is an irregular overgrowth of cementum characterized by?

    <p>Spike-like extensions and calcification of Sharpey's fibers</p> Signup and view all the answers

    Study Notes

    Tooth Development

    • At the advanced bell stage, the formerly smooth surface of the outer enamel epithelium is laid in folds, and papillae with capillary loops form between the folds, providing a nutritional supply for the avascular enamel organ.
    • The dental papilla is enclosed in the invaginated portion of the enamel organ, and its peripheral cells differentiate into odontoblasts under the organizing influence of the epithelium.
    • The dental papilla ultimately gives rise to dental pulp once dentin formation begins.

    Dental Sac

    • The dental sac shows a circular arrangement of its fibers and resembles a capsular structure before the formation of dental hard tissue begins.
    • With the development of the root, the fibers of the dental sac differentiate into periodontal ligament fibers that become embedded in the cementum and alveolar bone.

    Advance Bell Stage (Crown Stage)

    • Hard tissues, including enamel and dentin, develop during the advance bell stage.
    • Important cellular changes occur at this time, including the cessation of rapid division of inner enamel epithelial cells and their transformation into pre-ameloblasts.
    • The boundary between the inner enamel epithelium and odontoblasts outlines the future dentino-enamel junction.

    Dentin Formation

    • Dentin formation begins at the bell stage of tooth development in the papillary tissue adjacent to the inner enamel epithelium.
    • Root dentin forms at a slightly later stage of development and requires the proliferation of epithelial cells from the cervical loop of the enamel organ around the growing pulp to initiate the differentiation of root odontoblasts.

    Dentin

    • Dentin is a calcified tissue that, along with enamel, cementum, and pulp, is one of the four major components of teeth.
    • By weight, 70% of dentin consists of the mineral hydroxylapatite, 20% is organic material, and 10% is water.
    • Dentin is less mineralized and less brittle than enamel, and it continues to form throughout life in response to stimuli, such as tooth decay or attrition.

    Tertiary Dentin

    • Tertiary dentin is deposited by odontoblasts or replacement odontoblasts from the pulp at specific sites in response to injury.
    • Tertiary dentin can be divided into reactionary or reparative dentin, depending on the cells that secrete it and the reason for its formation.

    Pulp

    • The pulp organ is extensively vascularized, with blood vessels arising from the inferior or superior alveolar artery and draining through the same veins in both the mandibular and maxillary regions.
    • Pulpal stem cells, including dental pulp stem cells and stem cells from human exfoliated deciduous teeth, can undergo proliferation and migrate to the site of injured odontoblasts, producing dentin.

    Cementum

    • Cementum is a calcified tissue that covers the root of the tooth and is necessary for the attachment of the tooth to the surrounding alveolar bone through the periodontal ligament.
    • Cementum can undergo excessive deposition in response to chronic periapical inflammation, resulting in a thickening of the cementum around the root.
    • Hypercementosis of cementum can also occur in non-functioning teeth, resulting in a reduction in the number of Sharpey's fibers embedded in the root.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz covers the process of tooth development, focusing on the formation of enamel and the role of the dental papilla.

    More Like This

    Oral and Maxillofacial Surgery
    11 questions

    Oral and Maxillofacial Surgery

    BuoyantHamster avatar
    BuoyantHamster
    Dental Development Anatomy
    3 questions

    Dental Development Anatomy

    FancierPansy avatar
    FancierPansy
    12 Digestiu (I)
    40 questions

    12 Digestiu (I)

    SmilingBegonia avatar
    SmilingBegonia
    Dental Lamina and Enamel Organ Flashcards
    23 questions

    Dental Lamina and Enamel Organ Flashcards

    CalmingCornet avatar
    CalmingCornet
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser