Podcast
Questions and Answers
Which type of gingival epithelium is non-keratinized and lines the gingival sulcus?
Which type of gingival epithelium is non-keratinized and lines the gingival sulcus?
Which layer of the oral epithelium is responsible for cell renewal?
Which layer of the oral epithelium is responsible for cell renewal?
Which of the following is NOT a characteristic of junctional epithelium?
Which of the following is NOT a characteristic of junctional epithelium?
Which type of cell is responsible for producing melanin in the gingival epithelium?
Which type of cell is responsible for producing melanin in the gingival epithelium?
Signup and view all the answers
What is the main function of desmosomes in the gingival epithelium?
What is the main function of desmosomes in the gingival epithelium?
Signup and view all the answers
Which component of the extracellular matrix is responsible for providing tensile strength and structural integrity?
Which component of the extracellular matrix is responsible for providing tensile strength and structural integrity?
Signup and view all the answers
Which type of glycosaminoglycan is found in the basement membrane and is important for cell signaling?
Which type of glycosaminoglycan is found in the basement membrane and is important for cell signaling?
Signup and view all the answers
Which type of collagen is found in the periodontal ligament and resists tensile forces?
Which type of collagen is found in the periodontal ligament and resists tensile forces?
Signup and view all the answers
During which phase of bone remodeling do osteoclasts degrade bone matrix?
During which phase of bone remodeling do osteoclasts degrade bone matrix?
Signup and view all the answers
Which molecule stimulates osteoclast differentiation and leads to bone resorption?
Which molecule stimulates osteoclast differentiation and leads to bone resorption?
Signup and view all the answers
Which of the following fiber groups in the periodontal ligament is responsible for primarily resisting lateral forces?
Which of the following fiber groups in the periodontal ligament is responsible for primarily resisting lateral forces?
Signup and view all the answers
What is the primary function of the cementum in the periodontium?
What is the primary function of the cementum in the periodontium?
Signup and view all the answers
Which part of the alveolar bone is directly involved in the formation of the tooth socket?
Which part of the alveolar bone is directly involved in the formation of the tooth socket?
Signup and view all the answers
What is the primary difference between acellular and cellular cementum?
What is the primary difference between acellular and cellular cementum?
Signup and view all the answers
Which of the following functions is NOT directly associated with the gingival tissue?
Which of the following functions is NOT directly associated with the gingival tissue?
Signup and view all the answers
Study Notes
Periodontal Structures and Components
-
Gingiva: A protective barrier against mechanical forces and immune defense. It's pink, keratinized, and exhibits a stippled appearance in healthy individuals.
- Free gingiva: Surrounds the tooth crown.
- Attached gingiva: Anchored to the bone and cementum.
- Interdental gingiva (papilla): Fills the space between teeth.
-
Periodontal Ligament (PDL): Acts as a shock absorber, providing sensory and proprioceptive function. Maintains homeostasis through fibroblast activity.
- Fiber Groups: Alveolar crest, horizontal, oblique, apical fibers (resist various tooth movements) and interradicular fibers (multi-rooted teeth).
-
Cementum: Anchors PDL fibers to the root surface. Compensates for tooth wear through continuous deposition occurring in layers.
- Acellular cementum: Majority of attachment in the cervical region.
- Cellular cementum: Contains cementocytes and found in the apical third and furcation areas.
-
Alveolar Bone: Provides structural support to teeth and has continuous remodeling responding to forces.
- Alveolar Bone Proper (Lamina Dura): Thin compact bone lining the tooth socket.
- Cortical bone: Outer layer of dense bone defining the bone contour.
- Cancellous bone: Spongy bone between cortical layers. More abundant in the maxilla.
Gingival Epithelium
-
Types:
- Oral epithelium: Keratinized for protection, four layers: stratum corneum, stratum granulosum, stratum spinosum, and stratum basale.
- Sulcular epithelium: Non-keratinized, lines the gingival sulcus.
- Junctional epithelium: Non-keratinized, directly attached to the tooth; more permeable, high turnover.
-
Cellular Elements:
- Keratinocytes: Primary cells producing keratin.
-
Non-keratinocytes:
- Melanocytes: Produce melanin.
- Langerhans cells: Antigen-presenting cells.
- Merkel cells: Involved in mechanoreception.
- Inflammatory cells: Participate in the immune response.
-
Cell Junctions:
- Desmosomes: Attach epithelial cells.
- Hemidesmosomes: Anchor cells to the basement membrane.
- Basement membrane: Composed of lamina lucida and lamina densa; connects epithelium to connective tissue.
Extracellular Matrix (ECM)
-
Components:
- Collagen: Provides tensile strength and integrity.
- Elastin: Contributions to tissue elasticity.
- Proteoglycans: Regulate hydration and signaling.
- Glycosaminoglycans (GAGs): Maintain tissue hydration and flexibility.
- Fibronectin & Laminin: Facilitate cell adhesion and migration.
-
GAGs and Proteoglycans: GAGs (linear polysaccharides) bind to proteins (proteoglycans) influencing hydration and signaling.
- Major Types of GAGs: Hyaluronic acid, dermatan sulfate, chondroitin sulfate, heparan sulfate, and keratan sulfate.
-
Collagen: Essential structural component (approx. 30% of total protein). In periodontium, type I (tensile resistance in gingiva, bone, cementum, PDL), type III (gingival CT integrity), type IV (basement membranes), and type V (connective tissues, cementum) are key.
Bone Remodeling and Collagen
-
Bone Remodeling: Bone undergoes continuous remodeling in response to mechanical forces and maintenance homeostasis.
- Phases: Resting, resorption (osteoclasts degrade matrix), reversal (prep for new matrix), formation (osteoblasts build matrix → mineralization).
-
Regulation:
- RANKL/OPG: RANKL stimulates osteoclasts, OPG blocks RANKL, influencing bone resorption.
- TGF-β & BMPs: Stimulate bone formation.
-
Periodontal Disease's Impact: Inflammation (periodontitis) leads to excessive RANKL activation → prolonged osteoclast activity → bone loss. Pro-inflammatory cytokines accelerate osteoclastogenesis, harming the balance between resorption and formation.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on the various structures and components of the periodontium. This quiz covers the roles and definitions of gingiva, periodontal ligament, and cementum, including their subtypes and functions. Perfect for students studying dental anatomy or periodontology.
