INI-CET MDS cheat sheet

Permanent maxillary first molar: 5 cusps (MB, DB, ML, DL, distolingual/cusp of Carabelli), 3 roots (MB, DB, palatal), rhomboidal occlusal outline.

Permanent mandibular first molar: 5 cusps, 2 roots (mesial, distal); mesial root has two canals, distal usually one; crown wider mesiodistally than buccolingually.

Permanent maxillary first premolar: 2 cusps, 2 roots (buccal and palatal) in ~60% of cases; mesial marginal groove present; first premolar to erupt after first molar.

Permanent mandibular first premolar: 2 cusps with small lingual cusp, single root; lingual cusp is non-functional; occlusal outline diamond-shaped.

Universal numbering: 1-16 maxillary (1 = maxillary right third molar, 16 = maxillary left third molar); 17-32 mandibular (17 = mandibular left third molar, 32 = mandibular right third molar).

FDI two-digit system: first digit = quadrant (1 max right, 2 max left, 3 mand left, 4 mand right); second digit = tooth position 1-8 from midline.

Permanent maxillary central incisor: widest mesiodistal crown of any anterior tooth; crown:root ratio ~1:1.2; lingual fossa and cingulum prominent; incisal edge nearly straight.

Primary teeth: markedly constricted cervical region, prominent cervical ridge, thin enamel (~0.5-1 mm), bulbous crown; primary molar roots flare to accommodate developing permanent tooth.

Enamel organ stages: bud (initiation), cap (proliferation), bell (histodifferentiation and morphodifferentiation), apposition, maturation.

Amelogenesis: Tomes' process creates enamel rods; rod direction roughly perpendicular to dentin surface; Hunter-Schreger bands are alternating rod decussation seen in ground sections.

Dentinogenesis: odontoblasts secrete predentin, which mineralizes; peritubular dentin is more mineralized than intertubular dentin; S-shaped curvature of tubules in coronal dentin.

Cementum: acellular extrinsic fiber cementum on cervical third; cellular intrinsic fiber cementum in apical third and furcation; cementum is more permeable than dentin and continues to be deposited with age.

Periodontal ligament: principal fibers are dentogingival, dentoalveolar, alveologingival, interdental, transseptal; oxytalan fibers resist tensile forces.

Salivary glands: parotid is serous (rich in amylase), submandibular mixed (serous predominant), sublingual mostly mucous; myoepithelial cells are contractile and located between acini and basal lamina.

Taste buds: foliate papillae on lateral tongue, circumvallate on anterior sulcus, fungiform scattered on dorsum; filiform papillae lack taste buds and are keratinized.

Tooth eruption timeline: primary dentition begins ~6 months (mandibular central incisor), completes ~24-30 months; permanent first molar erupts at ~6 years (first permanent tooth).

Ameloblastoma: most common clinically significant odontogenic tumor; classic radiolucency is multilocular 'soap bubble' in posterior mandible; histology shows peripheral palisading and reverse polarity.

Odontogenic keratocyst (OKC): parakeratinized stratified squamous lining with corrugated surface, palisaded basal layer; high recurrence; associated with PTCH1 mutation and nevoid basal cell carcinoma syndrome.

Squamous cell carcinoma of oral cavity: most common site is lateral border of tongue; risk factors include tobacco, areca nut, alcohol, HPV (oropharyngeal), and chronic irritation.

Oral lichen planus: T-cell mediated; Wickham striae, reticular pattern on buccal mucosa; histology shows band-like lymphocytic infiltrate at epithelial-connective tissue interface and saw-tooth rete ridges.

Periapical pathology: radicular cyst is most common odontogenic cyst, lined by non-keratinized stratified squamous epithelium with inflammation; develops from epithelial rests of Malassez.

Streptococcus mutans: primary cariogenic organism; produces glucosyltransferase to synthesize insoluble glucans; adheres to pellicle via antigen I/II; acidogenic and aciduric.

Aggregatibacter actinomycetemcomitans: Gram-negative capnophilic rod associated with aggressive periodontitis; produces leukotoxin and cytolethal distending toxin.

Porphyromonas gingivalis: black-pigmented anaerobe; major pathogen in chronic periodontitis; possesses gingipains (cysteine proteases), fimbriae, and capsule.

Recurrent aphthous stomatitis: minor (<1 cm, heals in 7-10 days without scar), major (>1 cm, heals with scar), herpetiform (multiple small, coalescing); first-line therapy is topical corticosteroid.

Oral candidiasis: pseudomembranous form has removable white plaques; chronic hyperplastic form is non-removable; predisposing factors include xerostomia, immunosuppression, inhaled corticosteroids, and denture wearing.

Oral submucous fibrosis: juxta-epithelial fibrosis, restricted mouth opening, burning sensation; strongly associated with areca nut chewing; premalignant.

Pemphigus vulgaris: intraepithelial (suprabasal) split; Nikolsky sign positive; IgG against desmoglein 3; oral lesions often precede skin involvement.

Mucous membrane pemphigoid: subepithelial split; linear IgG and C3 along basement membrane; gingival desquamation and conjunctival involvement possible.

Trigeminal neuralgia: paroxysmal lancinating pain in V2/V3 distribution triggered by touch, chewing, or cold; carbamazepine is first-line therapy.

Sjögren syndrome: autoimmune exocrinopathy; xerostomia, keratoconjunctivitis sicca, bilateral parotid enlargement; anti-Ro/SSA and anti-La/SSB antibodies; lip biopsy shows focal lymphocytic sialadenitis.

Oral hairy leukoplakia: corrugated white plaque on lateral tongue in HIV-positive patients; caused by Epstein-Barr virus; does not respond to antifungal therapy.

Radiolucent vs radiopaque: radiolucent structures (pulp, PDL space, soft tissue, air) absorb fewer X-rays; radiopaque structures (enamel, dentin, bone, metal) absorb more.

Periapical radiograph: bisecting-angle technique or paralleling technique; paralleling with long-cone is preferred for accuracy; use E-speed or F-speed film or digital sensor to reduce dose.

Panoramic radiograph: shows maxilla, mandible, TMJ, and antral regions; not indicated for caries detection or fine periapical pathology; focal trough limitations cause ghost images.

Cone beam computed tomography (CBCT): three-dimensional imaging for implant planning, impacted teeth, endodontic anatomy, and maxillofacial trauma; effective dose is higher than panoramic but lower than medical CT.

Radiographic features of periapical cyst vs granuloma: both show well-defined periapical radiolucency; cyst is >1 cm with sclerotic border; definitive distinction requires histopathology.

Caries detection: bitewing radiographs are best for interproximal caries; early enamel caries appears as radiolucency at the enamel-dentin junction; occlusal caries is often missed on radiographs.

Sialography: injection of contrast into Stensen's or Wharton's duct; contraindicated in acute infection or iodine allergy; shows ductal strictures and sialoliths.

TMD imaging: MRI is the modality of choice for disc displacement; panoramic and CBCT assess osseous changes; arthrography is largely replaced by MRI.

G.V. Black cavity classification: Class I pits and fissures; Class II proximal posterior; Class III proximal anterior; Class IV proximal anterior involving incisal angle; Class V cervical third; Class VI incisal edge/cusp tip.

Working length determination: electronic apex locator combined with periapical radiograph; working length is ~0.5-1 mm short of the radiographic apex.

Root canal irrigants: sodium hypochlorite (0.5-5.25%) dissolves organic tissue and is antimicrobial; EDTA (17%) chelates smear layer; chlorhexidine has substantivity but can form precipitate with NaOCl.

Rotary NiTi instrumentation: uses crown-down technique; NiTi files have shape memory and superelasticity; torque control and glide path reduce file separation.

Obturation: gutta-percha with sealer; warm vertical compaction or single-cone with bioceramic sealer; length should be within 0.5-1 mm of radiographic apex.

Dental amalgam: high copper (>6%) is gamma-2 free and more corrosion resistant; low copper contains gamma-2 phase (Sn8Hg) which is weak and prone to corrosion.

Composite resin: Bis-GMA (base), TEGDMA (diluent), silane coupling agent, photoinitiator (camphorquinone); polymerization shrinkage is greatest in bulk; incremental layering reduces stress.

Endodontic emergencies: irreversible pulpitis presents with sharp, lingering pain to thermal stimuli; necrotic pulp with acute apical periodontitis presents with pain on percussion and biting.

Gingival sulcus depth: healthy 1-3 mm; probing depth ≥4 mm with bleeding suggests periodontitis; clinical attachment level = probing depth + recession.

Periodontal disease classification (2017 World Workshop): Stages I-IV based on severity and complexity; Grades A-C based on rate of progression; staging uses interdental CAL, radiographic bone loss, and tooth loss.

Plaque-induced gingivitis: reversible inflammation confined to gingiva; no attachment loss; treated by mechanical plaque control and professional debridement.

Scaling and root planing: nonsurgical therapy for periodontitis; re-evaluation at 4-6 weeks; adjunctive antibiotics (amoxicillin + metronidazole) reserved for aggressive or refractory cases.

Guided tissue regeneration: barrier membrane excludes epithelium and gingival connective tissue to allow PDL and bone regeneration; indications include intrabony defects and furcation involvement.

Implant osseointegration: direct bone-to-implant contact without intervening soft tissue; success requires primary stability, adequate bone volume, and avoidance of overheating during drilling (>47°C for 1 minute causes bone necrosis).

Peri-implant mucositis vs peri-implantitis: mucositis is reversible inflammation without bone loss; peri-implantitis includes progressive bone loss and is treated with debridement, decontamination, and possible surgical resection.

Sinus lift: maxillary sinus pneumatization limits posterior implant placement; lateral window approach or crestal approach; membrane perforation is the most common complication.

Third molar extraction indications: recurrent pericoronitis, caries, cyst formation, orthodontic need, and pathology; contraindications include uncontrolled systemic disease and high risk of nerve injury.

Inferior alveolar nerve injury risk: highest with mandibular third molar extraction, especially when roots are close to the canal; signs include lip and chin paresthesia; most resolve within 6 months.

Local anesthesia: 2% lidocaine with 1:100,000 epinephrine provides ~60 minutes pulpal anesthesia; maximum dose is 7 mg/kg (or 4.4 mg/kg without epinephrine).

Mandibular fracture: most common site is the angle, then condyle; clinical signs include malocclusion, step deformity, and paresthesia of the lower lip.

Le Fort fractures: I (low transverse, above apices), II (pyramidal, through maxilla and nasal bones), III (craniofacial disjunction); all may present with midface mobility and airway compromise.

Odontogenic infection spread: most common source is mandibular molars; submandibular space, sublingual space, and buccal space are common; Ludwig's angina involves bilateral submandibular and sublingual spaces and is a surgical emergency.

Orthognathic surgery: Le Fort I osteotomy for maxillary repositioning; bilateral sagittal split osteotomy (BSSO) for mandibular advancement or setback; genioplasty for chin contour.

TMJ ankylosis: restricted jaw opening due to fibrous or bony fusion; managed by gap arthroplasty or costochondral graft reconstruction.

Complete denture impression: primary impression with irreversible hydrocolloid; final impression with border molding using modeling compound and elastomeric material; posterior palatal seal provides retention.

Occlusal vertical dimension (OVD): distance between maxilla and mandible when teeth are in occlusion; excessive OVD causes soreness and speech difficulty; reduced OVD causes angular cheilitis and loss of lip support.

Crown preparation: full veneer crown requires 1.0-1.5 mm axial reduction and 1.5-2.0 mm occlusal reduction; finish line options include chamfer, shoulder, and knife-edge.

Fixed partial denture (bridge) indications: missing teeth with sound abutments; contraindications include long-span edentulous areas, mobile abutments, and poor crown-root ratio.

Dental implants: two-stage vs one-stage placement; healing period 3-6 months in mandible and 4-6 months in maxilla; provisionalization must avoid occlusal overload.

Removable partial denture (RPD): Kennedy classification (I bilateral posterior edentulous, II unilateral posterior, III unilateral bounded, IV anterior); Applegate's rules modify classification.

Occlusion: centric relation is the maxillomandibular relationship with condyles in anterior-superior position against articular eminence; centric occlusion is maximum intercuspation.

Denture stomatitis: chronic erythematous candidiasis under denture; predisposing factors include nocturnal wear, poor hygiene, and ill-fitting dentures; treated with antifungal therapy and denture hygiene.

Angle's classification: Class I (normal molar relationship with malocclusion), Class II (mandibular first molar distal to maxillary first molar), Class III (mandibular first molar mesial to maxillary first molar).

Cephalometric landmarks: Sella (S), Nasion (N), A-point, B-point, Gonion, Menton; SNA ~82°, SNB ~80°, ANB ~2°; ANB indicates skeletal discrepancy.

Growth assessment: cervical vertebral maturation (CVM) stages indicate pubertal growth spurt; peak growth occurs around CVM stage III-IV.

Fixed appliance biomechanics: archwire sequence from NiTi (leveling) to stainless steel (working); bracket slot 0.022 or 0.018 inch; anchorage control determines tooth movement.

Functional appliances: Twin Block, Herbst, and activator advance the mandible in Class II patients; best results during active growth.

Extraction decisions: impacted third molars, severe crowding, and bimaxillary protrusion often require premolar extraction; anchorage planning is critical.

Retention: fixed lingual retainer or removable Hawley/essix retainer; relapse risk highest in the first year; long-term retention often needed.

Cleft lip and palate: multidisciplinary care includes presurgical orthopedics, alveolar bone grafting (~8-12 years), and orthodontic treatment; timing of surgery affects maxillary growth.

Eruption timeline: primary teeth begin ~6 months; first permanent molar at ~6 years; permanent incisors at 6-7 years; canine at 9-12 years; second molar at 12 years.

Early childhood caries (ECC): any caries on primary teeth in children under 6; severe ECC (S-ECC) involves smooth surfaces or ≥4 surfaces; associated with bottle feeding and poor oral hygiene.

Fluoride: topical fluoride varnish 5% NaF for caries prevention; systemic fluoride supplements only in non-fluoridated areas; fluorosis risk with excessive ingestion.

Pit and fissure sealants: indicated for deep pits and fissures in caries-prone children; resin-based sealants require isolation; glass ionomer sealants are moisture-tolerant.

Space maintenance: band-and-loop or crown-and-loop maintain space after premature primary molar loss; space loss is greatest in the first 6 months.

Pulpectomy in primary teeth: indicated for irreversible pulpitis or necrosis; use rotary or hand files; obturate with zinc oxide eugenol or iodoform-based paste.

Behavior management: tell-show-do, positive reinforcement, and distraction are first-line; protective stabilization only when necessary and with consent.

Teething: typically begins at 6 months; symptoms include drooling and irritability; teething rings and cold compresses are first-line; avoid benzocaine in infants under 2 years.

DMFT/dmft index: D = decayed, M = missing, F = filled; DMFT for permanent teeth, dmft for primary teeth; used to measure caries prevalence.

Community Periodontal Index (CPI): scores 0 (healthy) to 4 (pocket ≥6 mm); used in WHO surveys; requires a special probe.

Oral health survey design: cross-sectional surveys estimate prevalence; longitudinal studies assess incidence; sampling methods include simple random, stratified, and cluster.

Water fluoridation: optimal level 0.7-1.0 ppm depending on climate; reduces caries by ~25-40%; monitored by fluoride concentration and dental fluorosis prevalence.

Health education: uses the PRECEDE-PROCEED model for planning; behavior change theories include Health Belief Model and Transtheoretical Model.

National oral health programs: in India, the National Oral Health Programme focuses on school children and rural populations; integration with primary health centers.

Epidemiological measures: incidence = new cases/population at risk/time; prevalence = existing cases/total population; relative risk and odds ratio compare groups.

Dental manpower planning: dentist-to-population ratio; in India approximately 1:10,000; maldistribution between urban and rural areas is a major challenge.

Diabetes mellitus: HbA1c ≥6.5% diagnostic; periodontal disease is a bidirectional risk factor; poor glycemic control increases infection risk; elective surgery requires HbA1c <8%.

Hypertension: ≥140/90 mmHg; dental management includes stress reduction, monitoring blood pressure, and avoiding epinephrine-containing local anesthetics in severe uncontrolled cases.

Antibiotic prophylaxis: indicated for infective endocarditis in high-risk cardiac patients before invasive dental procedures; amoxicillin 2 g orally 30-60 minutes before procedure.

Anticoagulants: warfarin (INR monitoring), DOACs (dabigatran, rivaroxaban); dental extraction may require INR check; local hemostatic measures are usually sufficient.

Asthma: avoid aspirin and NSAIDs in aspirin-sensitive patients; use bronchodilator before appointment; avoid lying flat in acute exacerbation.

Epilepsy: phenytoin can cause gingival hyperplasia; avoid triggering factors; have suction and airway support available.

Hepatitis B and C: bloodborne transmission; standard precautions; needlestick injury requires post-exposure prophylaxis for HBV.

HIV: oral manifestations include candidiasis, hairy leukoplakia, Kaposi sarcoma, and periodontal disease; universal precautions apply.

Wound healing: primary intention (clean surgical wound), secondary intention (open wound with granulation), tertiary intention (delayed closure); phases are hemostasis, inflammation, proliferation, and remodeling.

Suture materials: absorbable (catgut, Vicryl, Monocryl) vs non-absorbable (silk, nylon, Prolene); monofilament reduces infection risk; braided sutures have higher tensile strength.

Local anesthetics: amide-type (lidocaine, bupivacaine) metabolized in liver; ester-type (procaine, benzocaine) metabolized by plasma pseudocholinesterase; allergy more common with esters.

Hemostasis: primary hemostasis (platelet plug), secondary (coagulation cascade), tertiary (fibrinolysis); vitamin K-dependent factors are II, VII, IX, X.

Shock: hypovolemic, cardiogenic, distributive, obstructive; management includes ABCs, fluid resuscitation, and vasopressors in distributive shock.

Fluid and electrolyte balance: normal serum sodium 135-145 mEq/L, potassium 3.5-5.0 mEq/L; hyponatremia causes confusion and seizures; hyperkalemia causes arrhythmias.

Sterilization: autoclave at 121°C, 15 psi for 15-20 minutes; dry heat at 160°C for 2 hours; chemical sterilization with glutaraldehyde or ethylene oxide.

Infection control: standard precautions apply to all patients; hand hygiene, PPE, and sharps disposal are essential; post-exposure prophylaxis for HBV, HIV, and HCV.

Cell injury: reversible injury shows swelling and fatty change; irreversible injury shows membrane damage, mitochondrial dysfunction, and nuclear changes (pyknosis, karyolysis, karyorrhexis).

Inflammation: acute inflammation involves vasodilation, increased permeability, and neutrophil infiltration; chronic inflammation involves lymphocytes, plasma cells, and macrophages.

Neoplasia: benign tumors are well-differentiated and non-invasive; malignant tumors show anaplasia, invasion, and metastasis; TNM staging describes tumor size, nodes, and metastasis.

Pharmacokinetics: absorption, distribution, metabolism, excretion; first-order kinetics vs zero-order; half-life determines dosing interval.

Antibiotics: beta-lactams inhibit cell wall synthesis; aminoglycosides inhibit protein synthesis; fluoroquinolones inhibit DNA gyrase; resistance mechanisms include beta-lactamase production.

Fluid compartments: total body water ~60% of body weight; intracellular ~40%, extracellular ~20%; plasma ~5%; maintenance fluids 30-35 mL/kg/day.

Nutrition: protein-energy malnutrition impairs wound healing; vitamin C deficiency causes scurvy and poor collagen synthesis; zinc deficiency delays healing.

Medical emergencies in dental office: syncope (most common), hypoglycemia, angina, asthma, anaphylaxis; management includes positioning, oxygen, and emergency drugs (epinephrine, nitroglycerin, glucose).