NEET MDS Lessons
Periodontology
🧬 Risk Factors
- Increased homocysteine levels
- Raised lipoprotein(a)
- Nephrotic syndrome increases CAD risk
- Unsaturated fatty acid intake: Protective
- Best probability predictor in elderly: LDL/HDL ratio
⚕️ Diagnosis & Presentation
| Condition | Diagnostic Best Practice |
|---|---|
| Angina pectoris | History |
| Stable angina | Cardiac markers unchanged |
| Acute MI | Tall T wave (earliest ECG sign) |
| MI ≥12 hrs post-onset | Test of choice: Cardiac troponin |
| Prinzmetal’s angina | First-line agent: Nitrates |
| Intraoperative MI | Transesophageal echocardiography |
| Best biomarker of MI | Troponin T |
| WHO MI criteria | Echo not part of official criteria |
🧪 Enzymes & Drugs
- Enzyme ↑ at 4 – 6 hrs, ↓ in 3 – 4 days: CPK
- Stress ECHO agent: Dobutamine
- Intervention of choice: Streptokinase + Heparin
- Thrombolytics window: Within 12 hrs of MI
🚨 Prognosis & Complications
- Day 1: Maximum MI mortality
- Post-MI valvular lesion: Mitral regurgitation
- Best predictor of morbidity: LVEF
- Fatal thrombolysis complication: Intracranial hemorrhage
- LAD artery nicknamed: Widow’s artery
Electrosurgery
- Frequency: 1.5 – 7.5 million cycles/sec
Flap Incisions & Blades
- Internal bevel: #15 blade
- Crevicular: #12 blade
- Interdental: Orban's knife
Suturing Techniques
- Horizontal mattress: For diastema/wide spaces
- Anchor suture: For flap closure mesial/distal to tooth
Specific Procedures
- Modified Widman flap: Does not reduce pocket depth
- Apically displaced flap: Increases attached gingiva width
Osseous Surgery Sequence
- Osteoplasty: Vertical grooving, radicular blending
- Ostectomy: Flattening interproximal bone, gradualizing marginal bone
Bone Grafts
- FDBA: Osteoconductive
- DFDBA: Osteoinductive
- Hydroxyapatite: Ca:P ratio 1.67
- Beta – TCP: Ca:P ratio 1.5
Furcation Treatment
- Grade 2: "Cul – de – sac" defect
- Most common hemisection: Distobuccal root of maxillary 1st molar
Root Coverage Procedures
- Laterally displaced pedicle: Grupe & Warren technique
- Subepithelial connective tissue graft: Langer & Langer technique
- Papilla preservation flap: First choice for maxillary anterior (esthetics)
Healing Timeline
Scaling & Curettage
- Epithelialization: 2 – 7 days
- Immature collagen: 21 days
Gingivectomy
- Surface epithelialization: 5 – 14 days
- Complete repair: 1 month
Flap Surgery
- Epithelial attachment: 1 week
ANUG (Acute Necrotizing Ulcerative Gingivitis)
- Signs: Punched – out crater depressions of interdental papilla
- Symptoms: Metallic foul taste, pasty saliva
- Treatment: 3 visits (2nd visit: 1 – 2 days after 1st; 3rd visit: 5 days after 2nd)
NUG/NUP
- No pocket formation (destroys junctional epithelium)
Primary Herpetic Gingivostomatitis
- Cellular change: Ballooning degeneration → Tzanck cells
- Treatment:
- Within 3 days: Acyclovir 15 mg/kg × 5 times × 7 days
- After 3 days: Supportive care with NSAIDs
Leukemic Gingivitis
- Most common in acute monocytic leukemia
Lead Intoxication
- Steel gray linear pigmentation (Burton's line)
🧪 Glomerular Hematuria
| Urine Finding | Interpretation |
|---|---|
| >20% Dysmorphic RBCs | Suggests glomerular origin |
| RBC casts | Glomerular pathology |
| Creatinine clearance | Measures GFR |
💧 Nephrotic Syndrome
- Edema cause: Hypoalbuminemia
- Commonest cause (adults): Diabetes mellitus
- Lipid profile: ↓ HDL cholesterol
- Minimal change disease: No change on light microscopy
- Membranoproliferative GN: Tram-track appearance
- Membranous GN: Common in renal vein thrombosis
- Best test for renal vein thrombosis: CT angiography
Sharpening Stones
- Natural: India, Arkansas
- Artificial: Ruby, Carborundum, Ceramic
Surgical Equipment
- Dental loupes: 1.5 – 6× magnification
- Coe – pak working time: 15 – 20 minutes
Preventive Measures
- Calculus control toothpastes: Contain pyrophosphates
- Antibiotic prophylaxis: Amoxicillin 2.0g, 30 – 60 min before procedure
Abrasion Rates
- Dentin: 25× faster than enamel
- Cementum: 35× faster than enamel
- Chlorhexidine:
- Minimum: 0.12%; Optimum: 0.2%.
- Chip degrades in 7 – 10 days.
- Floss & Brushes:
- Preferred floss: Unwaxed thin.
- Floss length: 12 – 18 inches.
- Toothbrush: 2 – 4 rows, 5 – 12 tufts per row.
- Soft bristle diameter: 0.2 mm.
- Powered Brushes: Invented in 1939; use oscillating/rotating motion.
- Fones Technique: Circular brushing method.
- Antiplaque Agents:
- Bisbiguanides: 2nd generation.
- Pyrophosphate: Inhibits calculus formation.
- Gingival Conditions:
- Pregnancy gingivitis: Bleeding.
- Desquamative gingivitis: Fiery red, painful sloughing.
- Gingival hyperplasia: Most commonly caused by phenytoin.
- Gingival enlargement covering 3/4 of tooth: Grade III.
- ANUG:
- Organism: Spirochetes.
- Seen in: Young adults.
- First-day management: Avoid deep scaling.
- Stages: Superficial zone = bacterial contamination.
- Granulomatous Lesion: Pyogenic granuloma.
- Gingival Recession: Most commonly due to traumatic brushing.