OMS cheat sheet

Le Fort I fracture: horizontal fracture through maxilla above apices; Le Fort II: pyramidal involving orbital rim and nasal bone; Le Fort III: craniofacial disjunction.

Inferior alveolar nerve injury risk highest in third molar extraction with deep impaction, lingual plate perforation, and age >25; cone-beam CT used when nerve proximity <1 mm.

Odontogenic infection spread: submandibular space via mylohyoid; Ludwig's angina involves bilateral submandibular, sublingual, and submental spaces and requires urgent airway management.

Marsupialization or enucleation for odontogenic keratocyst; recurrence rate 25-60% with enucleation alone; adjunctive Carnoy's solution or peripheral ostectomy reduces recurrence.

TMJ dislocation reduction: apply downward and backward pressure on mandible; if chronic, consider eminectomy or botulinum toxin injection.

Orthognathic surgery: Le Fort I advancement >5 mm may require bone graft; mandibular setback >10 mm increases airway compromise risk.

Platelet-rich fibrin (PRF) used in third molar sockets to reduce dry socket incidence and improve soft tissue healing.

Antibiotic prophylaxis for infective endocarditis: amoxicillin 2 g orally 30-60 min before procedure for high-risk cardiac conditions.

Maximum recommended dose of lidocaine with epinephrine: 7 mg/kg (up to 500 mg); without epinephrine: 4.4 mg/kg (up to 300 mg).

Articaine 4% with epinephrine 1:100,000: maximum dose 7 mg/kg; contraindicated in patients with sulfite allergy.

Bupivacaine 0.5% with epinephrine 1:200,000 provides up to 8 hours anesthesia; maximum dose 1.3 mg/kg.

Inferior alveolar nerve block success rate ~80%; if bone contact fails, redirect needle 1-2 mm posteriorly and reinsert.

Local anesthetic systemic toxicity: first sign often circumoral numbness and tinnitus; treat with 20% lipid emulsion 1.5 mL/kg bolus.

Naloxone reverses opioid-induced respiratory depression: 0.4 mg IV/IM, repeat every 2-3 min as needed.

Flumazenil reverses benzodiazepine sedation: 0.2 mg IV over 15 sec, may repeat to max 1 mg.

Pain management multimodal: NSAIDs (ibuprofen 400-600 mg q6h) plus acetaminophen; avoid codeine in children <12 years due to CYP2D6 ultrarapid metabolism risk.

Leukoplakia: white patch not attributable to any other disease; dysplasia rate 10-20%; biopsy indicated for non-homogeneous lesions.

Erythroplakia: red patch with highest malignant transformation rate (up to 90%); urgent biopsy required.

Lichen planus: bilateral white striae (Wickham striae) on buccal mucosa; malignant transformation rate ~1%.

Aphthous ulcers: recurrent, painful, non-keratinized mucosa; major aphthous >1 cm and heals with scarring.

Pleomorphic adenoma: most common salivary gland tumor; parotid gland most frequent site; recurrence risk due to pseudopodia.

Mucoepidermoid carcinoma: most common malignant salivary gland tumor; MAML2 translocation; low-grade has cystic spaces.

Odontogenic keratocyst: parakeratinized epithelium with corrugated surface; PTCH1 mutation; high recurrence after enucleation.

Pemphigus vulgaris: intraepithelial IgG autoantibodies against desmoglein 3; Nikolsky sign positive; treated with corticosteroids and rituximab.

Cone-beam CT effective dose: 10-100 µSv for small FOV; panoramic radiograph ~10-15 µSv; bitewing ~1-5 µSv.

Radiolucent lesions: cyst, tumor, osteomyelitis; radiopaque lesions: odontoma, cementoblastoma, osteosclerosis.

Panoramic radiograph magnification: 20-30% vertical and horizontal; not for precise measurements.

CBCT voxel size: smaller voxel (0.075-0.2 mm) improves spatial resolution but increases dose and noise.

MRI is modality of choice for soft tissue tumors and TMJ disc displacement; T2-weighted images show fluid as bright.

Sialography is contraindicated in acute sialadenitis; use ultrasound or MRI instead.

Foreign body localization: two views at right angles; metal appears radiopaque with artifact on CT.

Caries detection: bitewing radiograph is gold standard; ICDAS scoring correlates with histology.

Periodontal disease classification (2017): staging I-IV based on severity and complexity; grading A-C based on progression rate.

Pocket depth ≥4 mm with bleeding on probing indicates active disease; ≥5 mm requires treatment.

Guided tissue regeneration (GTR) success requires primary closure, space maintenance, and infection control; membranes include collagen and PTFE.

Implant osseointegration: titanium surface roughness (Sa 1-2 µm) enhances bone apposition; healing 3-6 months depending on bone quality.

Peri-implantitis: progressive bone loss ≥0.5 mm beyond initial remodeling plus bleeding and suppuration; treated with decontamination and possible explantation.

Platform switching reduces crestal bone loss by shifting microgap away from bone.

Free gingival graft (FGG) increases keratinized tissue width; connective tissue graft (CTG) provides better esthetics and root coverage.

Antibiotic prophylaxis for implant placement not routinely recommended; consider in immunocompromised patients.

Working length determination: electronic apex locator accuracy ±0.5 mm; confirm with periapical radiograph.

Root canal irrigation: sodium hypochlorite 0.5-5.25% dissolves organic tissue; EDTA 17% removes smear layer.

Nickel-titanium rotary files: crown-down technique reduces ledging; torque-controlled motor prevents file separation.

Obturation: cold lateral condensation or warm vertical compaction; sealer thickness <0.1 mm ideal.

Post-endodontic pain: incidence 3-58%; premedication with NSAIDs reduces intensity.

Retreatment indications: persistent symptoms, new periapical lesion, inadequate obturation; remove gutta-percha with solvent or rotary instruments.

Vertical root fracture: J-shaped radiolucency; usually requires extraction.

Regenerative endodontics for immature necrotic teeth: induce blood clot, use triple antibiotic paste (minocycline, ciprofloxacin, metronidazole).

Occlusal vertical dimension (OVD) increase: 2-4 mm tolerated; greater requires provisional trial.

Complete denture retention: factors include adhesion, cohesion, atmospheric pressure, and border seal.

Zirconia crown: high flexural strength (900-1200 MPa); requires opaque liner for esthetics; minimal tooth reduction 1-1.5 mm.

Resin-bonded bridge: minimal preparation; survival rate ~80% at 5 years; contraindicated in parafunction.

Implant-supported fixed prosthesis: screw-retained preferred for retrievability; cement-retained for esthetics.

Marginal fit of crowns: acceptable gap ≤120 µm; die spacer improves seating.

Occlusal scheme for implant prostheses: mutually protected occlusion; avoid non-working side contacts.

Denture stomatitis: Candida albicans; treat with nystatin and denture hygiene; remove dentures at night.

Class II malocclusion: mandibular retrognathia; treat with functional appliance (Twin Block) during growth spurt.

Class III: maxillary deficiency; facemask therapy before age 10; orthognathic surgery after growth completion.

Eruption timeline: first primary tooth 6-10 months; first permanent molar 6 years; maxillary canine 11-12 years.

Space maintenance: band and loop for primary molar loss; space loss risk highest within 6 months.

Fluoride varnish: 5% NaF applied every 3-6 months for caries prevention; reduces caries by 30-40%.

Pulpotomy in primary teeth: formocresol or MTA; MTA has higher success rate.

Cephalometric analysis: SNA 82°, SNB 80°, ANB 2°; indicates skeletal class.

Early orthodontic treatment: interceptive for crossbite, crowding, and habits; phase I before age 9.

ASA classification: ASA I healthy; ASA II mild systemic disease; ASA III severe disease limiting activity; ASA IV incapacitating disease.

Informed consent: must include diagnosis, treatment options, risks, benefits, and alternatives; documented in writing.

Medical history: ask about bleeding disorders, allergies, medications (anticoagulants, bisphosphonates), and cardiac conditions.

Bisphosphonate-related osteonecrosis of jaw (BRONJ): risk increases with IV bisphosphonates and duration >3 years; avoid elective extraction.

Hypertension: elective dental care deferred if BP >180/110 mmHg; refer for medical management.

Diabetes: HbA1c >7% increases infection risk; schedule morning appointments and monitor glucose.

Pregnancy: second trimester safest for elective care; avoid supine position after 20 weeks to prevent supine hypotensive syndrome.

Differential diagnosis: use SOAP format (Subjective, Objective, Assessment, Plan) for documentation.

Syncope: place patient supine, elevate legs, administer oxygen; if no response, check glucose and vital signs.

Anaphylaxis: epinephrine 0.3-0.5 mg IM (1:1000) in thigh; repeat every 5-15 min; call emergency services.

Aspiration: position patient upright, encourage coughing; if obstruction, Heimlich maneuver; bronchoscopy if unresolved.

Local anesthetic overdose: stop injection, support airway, administer oxygen; lipid emulsion for cardiovascular collapse.

Standard precautions: hand hygiene, gloves, mask, eye protection; sterilize instruments with autoclave (121°C, 15 psi, 15-20 min).

Surface disinfection: use EPA-registered hospital disinfectant; blood spills cleaned with 1:10 bleach.

Needlestick injury: wash with soap and water, report immediately, test for HIV/HBV/HCV; post-exposure prophylaxis within 2 hours.

Medical emergency kit: include epinephrine, nitroglycerin, aspirin, glucose, albuterol, and oxygen.