• Normal count + ↑ BT: Platelet functional defect
• Small platelets: Wiskott – Aldrich syndrome
• ITP: Antibody against platelets, ↑ bleeding time
• Platelet transfusion not indicated in immunologic thrombocytopenia
• Thrombocytopenia not seen in Henoch – Schönlein purpura

Epithelial Turnover Rates in Oral Tissues

Epithelial turnover is a critical process in maintaining the health and integrity of oral tissues. Understanding the turnover rates of different epithelial types in the oral cavity can provide insights into their regenerative capabilities and responses to injury or disease.

Turnover Rates of Oral Epithelial Tissues

1. Junctional Epithelium:

   • Turnover Rate: 1-6 days
   • Description:
     • The junctional epithelium is a specialized epithelial tissue that forms the attachment between the gingiva and the tooth surface.
     • Its rapid turnover rate is essential for maintaining a healthy seal around the tooth and for responding quickly to inflammatory changes or injury.

2. Palate, Tongue, and Cheeks:

   • Turnover Rate: 5-6 days
   • Description:
     • The epithelial tissues of the hard palate, tongue, and buccal mucosa (cheeks) have a moderate turnover rate.
     • This relatively quick turnover helps maintain the integrity of these surfaces, which are subject to mechanical stress and potential injury from food and other environmental factors.

3. Gingiva:

   • Turnover Rate: 10-12 days
   • Description:
     • The gingival epithelium has a slower turnover rate compared to the junctional epithelium and the epithelium of the palate, tongue, and cheeks.
     • This slower rate reflects the need for stability in the gingival tissue, which plays a crucial role in supporting the teeth and maintaining periodontal health.

Clinical Significance

• Wound Healing:

  • The rapid turnover of the junctional epithelium is particularly important in the context of periodontal health, as it allows for quick healing of any disruptions caused by inflammation or mechanical trauma.

• Response to Disease:

  • Understanding the turnover rates can help clinicians anticipate how quickly tissues may respond to treatment or how they may regenerate after surgical procedures.

• Oral Health Maintenance:

  • The varying turnover rates highlight the importance of maintaining good oral hygiene practices to support the health of these tissues, especially in areas with slower turnover rates like the gingiva.

• GTR Membrane Placement:
  • Apical border: 3 – 4 mm below defect margin.
  • Lateral extension: 2 – 3 mm beyond defect.
• Root Surface Biomodification: Citric acid (pH 1.0) for 2 – 5 min.
• Enamel Matrix Derivative: Emdogain (from porcine teeth).
• Cervical Enamel Projections: Seen in 8.6 – 28.6% of molars.
• Smoking: Preventable risk factor; damages cilia via hydrogen cyanide.

Pathophysiology

• Enzyme defect: Glucose-6-phosphate dehydrogenase deficiency
• Result: Impaired NADPH production → reduced glutathione → oxidative damage
• Inheritance: X-linked recessive (affects males predominantly)

Key Clinical Features

• Heinz bodies: Characteristic finding (precipitated denatured hemoglobin)
• Hemolytic episodes: Triggered by oxidative stress
• Chronic hemolysis: Usually absent between episodes
• Neonatal jaundice: May be severe

Important Clinical Points

• Estrogen does NOT induce hemolysis (unlike other conditions)
• Favism: Hemolysis after eating fava beans
• Drug-induced: Most common trigger for hemolytic crisis

Oxidative Stressors to Avoid

Medications

• Antimalarials: Primaquine, chloroquine
• Antibiotics: Sulfonamides, nitrofurantoin, chloramphenicol
• Analgesics: Aspirin (high doses), phenazopyridine
• Others: Methylene blue, naphthalene (mothballs)

Infections

• Bacterial infections
• Viral hepatitis
• Pneumonia
• Typhoid fever

Other Triggers

• Fava beans (favism)
• Diabetic ketoacidosis
• Severe illness/stress

Cushing's Syndrome

• Earliest feature: Loss of diurnal variation of cortisol
• High-dose dexamethasone suppression test: Differentiates pituitary adenoma vs ectopic ACTH

Adrenal Insufficiency (Addison's Disease)

• Most common cause in India: Tuberculosis
• Most common primary tumor metastasizing to adrenals: Melanoma
• Most confirmatory test: ACTH stimulation test
• Diagnostic: Low plasma cortisol (<3 mg/dL) at 8 AM + elevated ACTH (>200 pg/mL)
• Most common symptom: Asthenia (due to hypotension & hypoglycemia)

Blade Angulation Protocols

Scaling & Root Planing

• Angulation: 45-90 degrees to tooth surface
• Purpose: Effective calculus removal and root surface debridement

Gingival Curettage

• Angulation: >90 degrees
• Technique: Removal of infected soft tissue from pocket wall

Curette Sharpening

• Optimal Angle: 100-110 degrees
• Maintenance: Critical for effective instrumentation

Curette Design

Gracey Curettes

• Offset Angle: 60 degrees
• Specificity: Area-specific design for different tooth surfaces

Universal Curettes

• Angle: 90 degrees
• Application: Suitable for all tooth surfaces

After-Five Curettes

• Modification: Terminal shank extended by 3mm
• Purpose: Access to deep pockets (>5mm)

Probing Systems

CPITN Probe

• Tip Diameter: 0.5mm
• Markings: 3.5, 5.5, 8.5, 11.5mm
• Use: Community periodontal index assessment

Florida Probe

• Tip Diameter: 0.4mm (more precise)
• Technology: Computerized probing system

Implant Probing

• Maximum Force: 25N
• Probe Type: Plastic probes recommended to prevent implant surface damage