Gingiva Periodontology

Introduction

• Periodontium: Comprises investing and supporting tissues of the tooth, including:
  • Gingiva
  • Periodontal ligament
  • Cementum
  • Alveolar bone

Oral Mucosa Zones

• Masticatory mucosa: Gingiva and covering of the hard palate (25%)
• Specialized mucosa: Dorsum of the tongue (15%)
• Lining mucosa: Remainder of the oral cavity (60%)

Gingiva Definitions

• Carranza's Definition: Covers alveolar processes and surrounds necks of teeth
• AAP 1992: Fibrous tissue covered by keratinized epithelium surrounding teeth
• Schroeder's Definition: Part of oral mucosa attached to teeth and alveolar processes

Function of Gingiva

• Connects soft to hard tissue
• Provides sensation for chewing
• Controls oral microbes
• Protects periodontal ligament (PDL) and alveolar bone
• Adapts to oral conditions and supports teeth

Development of Gingival Epithelium

• Develops from ectoderm and mesoderm
• Ectoderm forms oral epithelium; mesoderm forms lamina propria

Clinical Anatomy of Gingiva

• Unattached Gingiva: Forms soft tissue wall of gingival sulcus
• Marginal Gingiva: Collar-like fashion around teeth
• Free Gingival Groove: Demarcates unattached gingiva in some regions
• Gingival Sulcus: Space between free gingiva and tooth surface
  • Normal depth: 0-3 mm

Attached Gingiva

• Firm and resilient gingiva tightly bound to periosteum
• Provides barrier to inflammation and supports esthetics

Interdental Gingiva

• Occupies gingival embrasures
• Shapes: Pyramidal and "col" shape

Microscopic Anatomy

Gingival Epithelium

• Stratified squamous epithelium
• Functions as a physical barrier
• Types:
  • Outer oral epithelium
  • Sulcular epithelium
  • Junctional epithelium

Junctional Epithelium

• Non-keratinized, stratified squamous epithelium
• Attaches to tooth surface and supports PDL
• Fast turnover rate (5 days)

Epithelial Cell Types

• Keratinocytes: 90% of gingival cells, main function in barrier action
• Non-keratinocytes: Include Langerhans cells, melanocytes, and Merkel cells

Connective Tissue

• Includes ground substance, gingival fibers, blood vessels, nerves, and lymphatics
• Gingival Fibers: Collagen, reticulin, and elastic fibers

Blood Supply

• Mainly from supraperiosteal vessels
• Anastomose with vessels from alveolar bone and PDL

Aging Changes

• Stippling and keratinization decrease with age
• Width of attached gingiva and collagen strength increase

Clinical Considerations

• Biological Width: Dimension of soft tissue attached to tooth above alveolar bone
  • Violation can lead to bone loss and gingival recession

Conclusion

• Gingival health is crucial for periodontal treatment success
• Proper function and interaction between periodontal tissues are essential