Gingival Anatomy

• Attached Gingiva Width: Greatest in maxillary incisors (3.5 – 4.5mm) and mandibular incisors (3.3 – 3.9mm)
• Least Width: Maxillary 1st premolars (1.9mm) and mandibular premolars (1.8mm)
• Biological Width: Connective tissue attachment (1.07mm) + Epithelial attachment (0.97mm) = ~2mm
• Oral Epithelium: 0.2 – 0.3mm thick, can be keratinized/parakeratinized

Junctional Epithelium (JE)

• Attached to enamel by hemidesmosomes
• Keratinocytes attached by desmosomes
• Internal basal lamina → tooth surface
• External basal lamina → gingival connective tissue

Cementum

• Maximum thickness: Apical third & furcation (150 – 200μm)
• Coronal half: 16 – 60μm
• Acellular cementum: First formed, covers cervical third
• Cellular cementum: Forms when tooth reaches occlusal plane

PERIODONTAL LIGAMENT (PDL) FIBERS

Principal Fibers (Type I Collagen)

1. Oblique fibers: Largest group, bear vertical forces
2. Alveolar crest fibers: Prevent tooth extrusion
3. Transseptal fibers: Only fibers reconstructed after bone destruction (considered gingival fibers)

Key Point

• Reticular fibers: Type III collagen

🧂 Sodium Imbalance

• SIADH: Hyponatremia, convulsions
• Osmotic demyelination syndrome → too rapid correction
• Pseudohyponatremia: Seen in hyperlipidemia

⚖️ Acid-Base Disorders

• Normal pH: 7.36 – 7.44
• Metabolic alkalosis seen in mineralocorticoid excess

🔻 Anemia Types

🔸 Microcytic

🔸 Macrocytic

• Pernicious anemia: ↓ intrinsic factor
• MCH ↑, MCHC normal
• Hypokalemia during treatment
• Causes: Dietary folate deficiency, celiac disease
• Thiamine deficiency → Lactic acidosis

🔸 Sideroblastic

• Causes: Hypothyroidism, INH therapy
• Treatment: Pyridoxine
• Genetic variant: Pearson syndrome

Stippling of the Gingiva

• Stippling refers to the textured surface of the gingiva that resembles the skin of an orange. This characteristic is best observed when the gingiva is dried.

• Characteristics:

  • Location:
    • The attached gingiva is typically stippled, while the marginal gingiva is not.
    • The central portion of the interdental gingiva may exhibit stippling, but its marginal borders are usually smooth.
  • Surface Variation:
    • Stippling is generally less prominent on the lingual surfaces compared to the facial surfaces and may be absent in some individuals.
  • Age-Related Changes:
    • Stippling is absent in infancy, begins to appear around 5 years of age, increases until adulthood, and may start to disappear in old age.

Attached Gingiva

• Definition: The attached gingiva is the portion of the gingiva that is firmly bound to the underlying alveolar bone and extends from the free gingival groove to the mucogingival junction, where it meets the alveolar mucosa.

• Characteristics:

  • Structure:
    • The attached gingiva is classified as a mucoperiosteum, tightly bound to the underlying alveolar bone.
  • Width:
    • The width of the attached gingiva is greatest in the incisor region, measuring approximately:
      • 3.5 – 4.5 mm in the maxilla
      • 3.3 – 3.9 mm in the mandible
    • It is narrower in the posterior segments, measuring about:
      • 1.9 mm in the maxillary first premolars
      • 1.8 mm in the mandibular first premolars.
  • Histological Features:
    • The attached gingiva is thick and keratinized (or parakeratinized) and is classified as masticatory mucosa.
    • Masticatory mucosa is characterized by a keratinized epithelium and a thick lamina propria, providing resistance to mechanical forces.

Masticatory vs. Lining Mucosa

• Masticatory Mucosa:

  • Found in areas subject to high compression and friction, such as the gingiva and hard palate.
  • Characterized by keratinized epithelium and a thick lamina propria, making it resistant to masticatory forces.

• Lining Mucosa:

  • Mobile, distensible, and non-keratinized.
  • Found in areas such as the lips, cheeks, alveolus, floor of the mouth, ventral surface of the tongue, and soft palate.

• Specialized Mucosa:

  • Found on the dorsum of the tongue, adapted for specific functions such as taste.