NEET MDS Lessons
Periodontology
Periodontics: Dental specialty deals with the supporting and surrounding tissues of the teeth.
1. Periodontium: tissues that invest and support teeth Includes Gingiva, Alveolar mucosa Cementum, Periodontal ligament, Alveolar bone, Support bone
2. Periodontal disease: changes to periodontium beyond normal range of variation
a. Specific plaque hypothesis: specific microorganisms cause periodontal disease; mostly anaerobes. Three implicated: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteriodes forsythus
b. Contributing factors: often a combination of factors
i. Local: calculus (tarter, home for bacteria, with age), traumatic occlusal forces, caries (root caries), overhangs and over-contoured restorations, open contacts with food impaction, missing/malaligned teeth
Invasion of biological width: from free gingival margin -> attached gingiva need ~ 3 mm. If enter this area -> problems (e.g., resorption)
ii. Host factors: exacerbate periodontal problems; e.g., smoking/tobacco use, pregnancy and puberty (hormonal changes, blood vessel permeability), stress, poor diet
iii.Medications: often -> tissue overgrowth; e.g., oral contraceptives, antidepressants, heart medicines, transplant anti-rejection drugs
iv.Systemic diseases: e.g., diabetes, immunosuppression
B. Gingivitis: inflammation of gingiva; with age; generally reversible
C. Periodontitis: inflammation of supporting tissues of teeth, characterized by loss of attachment (PDL) and bone; generally irreversible
D. Periodontal disease as risk factor for systemic diseases:
1. Causes difficulty for diabetics to control blood sugar
2. Pregnant women with periodontal disease ~ 7 times more likely to have premature and/or underweight baby
3. Periodontal diseased patients may be at risk for heart disease
Aggressive Periodontitis (formerly Juvenile Periodontitis)
- Historical Names: Previously referred to as periodontosis, deep cementopathia, diseases of eruption, Gottleib’s diseases, and periodontitis marginalis progressive.
- Risk Factors:
- High frequency of Actinobacillus actinomycetemcomitans.
- Immune defects (functional defects of PMNs and monocytes).
- Autoimmunity and genetic factors.
- Environmental factors, including smoking.
- Clinical Features:
- Vertical loss of alveolar bone around the first molars and incisors, typically beginning around puberty.
- Bone loss patterns often described as "target" or "bull" shaped lesions.
Gingival Crevicular Fluid (GCF) is a serum-like exudate found in the gingival sulcus. Initially considered a transudate in healthy gingiva, it transitions to an inflammatory exudate during disease states. GCF serves as a valuable diagnostic medium due to its dynamic composition, reflective of periodontal status.
Composition of GCF
GCF contains a variety of biochemical and cellular components that mirror periodontal health:
| Component | Characteristics & Clinical Importance |
|---|---|
| Glucose | 3–4 times higher than serum levels, indicating microbial metabolism and inflammation |
| Proteins | Albumin, IgG, enzymes like elastase, collagenase, myeloperoxidase |
| Electrolytes | Sodium, potassium, calcium — influence osmotic balance and tissue response |
| Cytokines | IL-1β, TNF-α, IL-6 — markers of inflammation and bone resorption |
| Prostaglandins | PGE2 — associated with tissue destruction and inflammation |
| Lymphocytes | T:B ratio is reversed (1:3) compared to serum (3:1), reflecting immune modulation |
| Microbial Products | Lipopolysaccharides, enzymes from plaque — triggers host response |
| Metabolic Products | Lactate, pyruvate — indicators of anaerobic bacterial activity |
Morphological Classification
Three-Wall Defect (Intrabony Defect)
- Description: Defect contained by three bony walls
- Prognosis: Best regenerative potential
- Treatment: Ideal candidate for GTR procedures
Two-Wall Defect (Crater)
- Description: Defect between two adjacent teeth
- Characteristics: Interdental bone loss
- Prevalence: Most common osseous defect in chronic periodontitis
One-Wall Defect (Hemiseptum)
- Description: Defect with only one remaining bony wall
- Prognosis: Poorest regenerative potential
- Treatment: Often requires resective therapy
Bone Loss Patterns
Horizontal Bone Loss
- Associated Pocket Type: Suprabony pocket
- Pattern: Uniform reduction in alveolar bone height
- Radiographic Appearance: Horizontal radiolucency
Vertical/Angular Bone Loss
- Associated Pocket Type: Infrabony pocket
- Pattern: Uneven bone destruction
- Clinical Significance: More complex treatment requirements
Treatment Phases
- Phase 1: Non – surgical
- Phase 2: Surgical
- Phase 3: Restorative
- Phase 4: Maintenance Must progress through Phase 1 → 4 before Phase 2 or 3
Merin's Classification
- Class A: 6 months – 1 year recall
- Class B: 3 – 4 months recall
- Class C: 1 – 3 months recall
COPD
- Reid's index: Used in chronic bronchitis
- Emphysema features: ↓DLCO, weight loss, pneumothorax risk
- Chronic bronchitis: Polycythemia
- GOLD criteria: COPD severity assessment
- BODE index: Lung transplant evaluation
Sleep Apnea
Definition: Breathing pause ≥10 seconds during sleep
ASTHMA
Diagnosis & Pathophysiology
- Best diagnostic test: Demonstration of reversible obstruction
- Small airways involved
- Idiosyncratic asthma: Normal IgE levels
- Aspirin-sensitive asthma: Associated with nasal polyps
Key Points
- Charcot-Leyden crystals: Eosinophil granules
- Nebulizer droplet size: <2.5 μm
- Most severe attack indicator: Bradycardia
- Montelukast: NOT useful in acute bronchial asthma
Automated Probing Systems
Automated probing systems have become increasingly important in periodontal assessments, providing enhanced accuracy and efficiency in measuring pocket depths and clinical attachment levels. This lecture will focus on the Florida Probe System, the Foster-Miller Probe, and the Toronto Automated Probe, discussing their features, advantages, and limitations.
1. Florida Probe System
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Overview: The Florida Probe System is an automated probing system designed to facilitate accurate periodontal assessments. It consists of several components:
- Probe Handpiece: The instrument used to measure pocket depths.
- Digital Readout: Displays measurements in real-time.
- Foot Switch: Allows for hands-free operation.
- Computer Interface: Connects the probe to a computer for data management.
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Specifications:
- Probe Diameter: The end of the probe is 0.4 mm in diameter, allowing for precise measurements in periodontal pockets.
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Advantages:
- Constant Probing Force: The system applies a consistent force during probing, reducing variability in measurements.
- Precise Electronic Measurement: Provides accurate and reproducible measurements of pocket depths.
- Computer Storage of Data: Enables easy storage, retrieval, and analysis of patient data, facilitating better record-keeping and tracking of periodontal health over time.
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Disadvantages:
- Lack of Tactile Sensitivity: The automated nature of the probe means that clinicians do not receive tactile feedback, which can be important for assessing tissue health.
- Fixed Force Setting: The use of a fixed force setting throughout the mouth may not account for variations in tissue condition, potentially leading to inaccurate measurements or patient discomfort.
2. Foster-Miller Probe
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Overview: The Foster-Miller Probe is another automated probing system that offers unique features for periodontal assessment.
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Capabilities:
- Pocket Depth Measurement: This probe can measure pocket depths effectively.
- Detection of the Cemento-Enamel Junction (CEJ): It is capable of coupling pocket depth measurements with the detection of the CEJ, providing valuable information about clinical attachment levels.
3. Toronto Automated Probe
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Overview: The Toronto Automated Probe is designed to enhance the accuracy of probing in periodontal assessments.
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Specifications:
- Probing Mechanism: The sulcus is probed with a 0.5 mm nickel titanium wire that is extended under air pressure, allowing for gentle probing.
- Angular Control: The system controls angular discrepancies using a mercury tilt sensor, which limits angulation within ±30 degrees. This feature helps maintain consistent probing angles.
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Limitations:
- Reproducible Positioning: The probe requires reproducible positioning of the patient’s head, which can be challenging in some clinical settings.
- Limited Access: The design may not easily accommodate measurements of second or third molars, potentially limiting its use in comprehensive periodontal assessments.