PRC Dentist Licensure cheat sheet

Trigeminal nerve: V1 (ophthalmic) exits superior orbital fissure; V2 (maxillary) exits foramen rotundum; V3 (mandibular) exits foramen ovale and carries motor fibers to muscles of mastication.

Facial nerve (VII) exits via stylomastoid foramen; branches temporal, zygomatic, buccal, marginal mandibular, cervical - injury above the parotid causes ipsilateral lower-motor-neuron facial palsy including forehead.

Lingual nerve carries general sensation from anterior two-thirds of tongue and chorda tympani taste fibers; hypoglossal (XII) lesion deviates tongue toward the weak side on protrusion.

Henderson–Hasselbalch: pH = pKa + log([HCO3-]/(0.03 x PaCO2)); normal pH 7.35–7.45, PaCO2 35–45 mmHg, HCO3- 22–26 mEq/L.

Local anesthetic mechanism: uncharged base crosses the axon membrane, is protonated intracellularly, and blocks the inner pore of voltage-gated Na+ channels in a use-dependent manner; inflamed acidic tissue reduces the uncharged fraction and slows onset.

Epinephrine in local anesthetic causes vasoconstriction via alpha-1 receptors, prolonging duration and reducing systemic absorption; maximum epinephrine dose commonly cited as 0.2 mg (cardiac) to 0.04 mg/kg.

Penicillin allergy is mediated by the beta-lactam ring hapten; cross-reactivity with cephalosporins is low (<2%) except for shared side chains (e.g., amoxicillin–cefalexin).

Coagulase-positive Staphylococcus aureus is the most common cause of suppurative odontogenic soft tissue infection; obligate anaerobes (Prevotella, Porphyromonas, Fusobacterium) dominate in necrotic pulp space.

Warfarin inhibits vitamin K epoxide reductase, reducing factors II, VII, IX, X; INR 2.0–3.0 is the usual therapeutic target and dental extraction generally proceeds when INR is below 3.5 with local hemostatic measures.

Enamel is 96% mineral by weight, formed by ameloblasts that are lost at eruption, so enamel cannot regenerate; hydroxyapatite crystals are largest and most densely packed at the surface.

Dentin is 70% mineral, 20% organic (mostly type I collagen), 10% water; dentinal tubules run from pulp to DEJ with S-shaped curvature and are widest near the pulp.

Dental pulp is innervated mainly by A-delta fibers (sharp, fast, myelinated) and C fibers (dull, slow, unmyelinated); A-delta fibers respond to hydrodynamic fluid movement in tubules.

Periodontal ligament principal fibers: dentogingival, dentoalveolar, transseptal, horizontal, oblique (most numerous, resists axial load), apical, interradicular.

Saliva flow: unstimulated 0.3–0.4 mL/min, stimulated 1.5–2.0 mL/min; resting pH around 6.7–7.4; bicarbonate rises with flow to buffer acids.

Streptococcus mutans and Streptococcus sobrinus are the principal cariogenic bacteria; they synthesize glucans from sucrose via glucosyltransferase and adhere to the pellicle.

Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola form the red complex associated with periodontitis; Aggregatibacter actinomycetemcomitans is linked to aggressive periodontitis.

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

Ameloblastoma: benign but locally aggressive odontogenic epithelial tumor, most common in mandibular posterior region, with follicular or plexiform patterns and peripheral palisading with reverse polarity.

DMFT counts decayed, missing (due to caries), and filled permanent teeth; dmft applies to primary teeth; DMFS counts surfaces.

Caries prevalence = number with caries / total examined; incidence = new cases / population at risk over a period.

Sensitivity = TP/(TP+FN); specificity = TN/(TN+FP); positive predictive value depends on prevalence, so screening in low-prevalence groups yields more false positives.

Community Periodontal Index (CPI) uses a WHO probe with a 3.5 mm ball tip and scores sextants 0–4; code 4 means pocket depth 6 mm or more.

Water fluoridation at 0.7–1.0 mg/L reduces caries by about 20–40%; fluorosis risk rises above 1.5 mg/L; optimal concentration depends on climate and water intake.

Fluoride varnish (5% NaF, 22,600 ppm) is applied 2–4 times yearly for high-risk patients; silver diamine fluoride (38%) arrests cavitated lesions in primary teeth.

Hill's criteria for causality include strength, consistency, specificity, temporality, biological gradient, plausibility, coherence, experiment, and analogy; temporality is essential.

Sealing pits and fissures is indicated for deep, retentive fissures with caries risk; sealants on early non-cavitated lesions reduce progression; sealant retention is highest with isolation and 4-handed technique.

Oral health education should target behavior change using the Health Belief Model (perceived susceptibility, severity, benefits, barriers, self-efficacy, cue to action).

Pulp diagnosis: reversible pulpitis is provoked sharp pain relieved by stimulus removal; irreversible pulpitis is spontaneous or lingering pain, often worse at night and with cold.

Working length is determined by apex locator and confirmed radiographically 0.5–1.0 mm short of the radiographic apex; apical patency is maintained with a small file.

Irrigants: sodium hypochlorite 0.5–5.25% dissolves necrotic tissue and is antimicrobial but cytotoxic; EDTA 17% removes smear layer; chlorhexidine 2% is a final rinse alternative.

Endodontic success depends on cleaning, shaping, and three-dimensional obturation with a coronal seal; crown-down preparation and rotary NiTi reduce ledging but risk file separation.

Periodontal disease classification uses clinical attachment loss (CAL), probing depth (PD), bleeding on probing (BOP), and radiographic bone loss; staging (I–IV) reflects severity and complexity, grading (A–C) reflects progression rate.

Scaling and root planing is the initial therapy for periodontitis; adjunctive systemic antibiotics (e.g., amoxicillin + metronidazole) may be used in aggressive or grade C cases.

Recurrent aphthous stomatitis: painful round ulcers with yellow-white fibrinous centers and erythematous halos; minor (<1 cm), major (>1 cm), and herpetiform types; treat with topical corticosteroids.

Oral lichen planus: bilateral white striae (Wickham striae), erosive forms painful; a premalignant potential is debated but long-term follow-up is advised; biopsy atypical areas.

Oral candidiasis: pseudomembranous (thrush) wipes off leaving erythema; treat with topical nystatin or systemic fluconazole; check for predisposing factors such as diabetes, steroids, or xerostomia.

Inferior alveolar nerve block targets the pterygomandibular space; landmarks are the coronoid notch, pterygomandibular raphe, and occlusal plane; aspirate before injecting to avoid intravascular injection.

Maxillary infiltration anesthesia at the apex of the tooth; the greater palatine and nasopalatine blocks anesthetize the palate; the anterior superior alveolar nerve block covers anterior maxillary teeth.

Extraction forceps choice: maxillary central incisors use #1, maxillary molars use #18R/#18L, mandibular molars use #151 or #23, mandibular premolars use #151.

Mandibular fracture: most common site is the angle, then condyle and body; bilateral parasymphyseal fractures may cause a widened arch and airway compromise.

Le Fort classification: I is low transverse (Guérin), II is pyramidal (nasal bones spared), III is craniofacial disjunction with mobility of the entire midface.

Odontogenic infection spread: submandibular, sublingual, buccal, canine, and infratemporal spaces; Ludwig's angina is bilateral submandibular and sublingual cellulitis with elevation of the tongue and airway risk.

Antibiotic regimen for odontogenic infection: amoxicillin 500 mg every 8 hours or amoxicillin-clavulanate; penicillin-allergic patients receive clindamycin or metronidazole plus a macrolide.

Temporomandibular joint dislocation: condyle anterior to the articular eminence; reduce with downward and backward pressure; chronic recurrent dislocation may require eminectomy or botulinum toxin.

Ameloblastoma, squamous cell carcinoma, and osteosarcoma are key jaw tumors; any nonhealing ulcer or radiolucency with paresthesia requires biopsy and imaging.

Complete denture retention depends on adhesion, cohesion, surface tension, atmospheric pressure, and border seal; the neutral zone is where forces from tongue and cheek balance.

Posterior palatal seal is placed at the junction of the hard and soft palate, providing a valve seal; it should not extend beyond the vibrating line.

Occlusal vertical dimension is assessed by facial proportions, freeway space (2–4 mm), and phonetic tests; excessive VDO causes soreness and clicking.

Fixed partial denture abutment selection requires a crown-to-root ratio of at least 1:1 (ideally 2:3) and a common path of insertion; cantilever length should be minimized in posterior regions.

Implant osseointegration requires primary stability and a titanium surface; minimum bone width about 5–6 mm and height about 8–10 mm for standard implants; resonance frequency analysis measures stability.

Implant loading: immediate loading is possible with high insertion torque (≥35 Ncm) and splinted implants; delayed loading is typically 3–6 months in the maxilla and 2–4 months in the mandible.

Peri-implant mucositis is reversible inflammation without bone loss; peri-implantitis involves bone loss and requires decontamination, possible explantation, or surgical access.

Removable partial denture: rests direct forces along the long axis of abutment teeth; clasps provide retention; major connector should be rigid and cover minimal tissue.

Occlusal scheme for complete dentures: bilateral balanced occlusion in eccentric movements reduces tipping; monoplane or lingualized occlusion is used when ridge resorption is severe.

Angle classification: Class I is normal mesiobuccal cusp of maxillary first molar in the buccal groove of the mandibular first molar; Class II is distal, Class III is mesial.

Cephalometric landmarks: SNA normal about 82 degrees, SNB about 80 degrees, ANB about 2 degrees; ANB >4 suggests skeletal Class II, negative ANB suggests Class III.

Leeway space: about 1.5 mm per side in the maxilla and 2.5 mm per side in the mandible; use of this space affects crowding resolution.

Eruption timing: first primary tooth at 6–10 months, primary dentition complete by 2.5–3 years, first permanent molar at 6 years, permanent canine at 11–12 years.

Space maintenance: band-and-loop or crown-and-loop for primary molars; space regain with a lingual arch or removable appliance when space loss has occurred.

Early childhood caries affects maxillary anterior teeth first; prevention includes fluoride varnish, dietary counseling, and no bottle at bedtime; first dental visit by age 1.

Pulpotomy in primary teeth uses formocresol, ferric sulfate, or MTA; pulpectomy is indicated when radicular pulp is involved; stainless steel crowns restore badly broken primary molars.

Class II division 1 has proclined maxillary incisors; division 2 has retroclined central incisors with deep overbite; treatment may use functional appliances or headgear in growing patients.

Habit correction: digit sucking beyond age 4 may cause anterior open bite and maxillary constriction; appliance therapy with a palatal crib or reminder is used when counseling fails.

Periapical radiograph: bisecting-angle technique or paralleling technique; paralleling with a film holder gives less distortion and is preferred.

Panoramic radiograph: focal trough is the image layer; patient positioning errors cause ghost images, magnification of about 20–30%, and overlap of anterior teeth.

Cone beam computed tomography (CBCT) provides three-dimensional imaging with lower dose than medical CT; effective dose for a small field of view is roughly 10–100 microsieverts.

Radiographic features: radiolucent lesions include cysts and tumors; radiopaque lesions include odontoma, cementoblastoma, and osteosclerosis; mixed lesions include ameloblastoma and odontogenic myxoma.

Caries detection: bitewing radiographs are best for interproximal caries; radiolucency must reach the dentin to be visible; digital subtraction and fluorescence aids (DIAGNOdent) are adjuncts.

Periodontal radiographs: bone loss is measured from the CEJ to the alveolar crest; normal crest is 1–2 mm apical to the CEJ; furcation involvement is graded I–III.

TMJ imaging: panoramic and transcranial views are screening; CBCT or MRI is used for disc displacement and degenerative changes; MRI is best for soft tissue.

Radiation protection: ALARA principle, lead apron and thyroid collar, rectangular collimation, and fastest image receptor; avoid retakes and use digital sensors.

Foreign bodies and fractures: radiopaque materials include amalgam, gutta-percha, and metal; a fracture line may appear as a radiolucent line and requires multiple views.

Informed consent requires capacity, disclosure of material risks and alternatives, understanding, and voluntariness; documentation in the record is essential.

Confidentiality may be breached only with patient consent, legal requirement (e.g., reportable infectious disease), or serious public health risk; minimum necessary disclosure applies.

Mandatory reporting includes child abuse, elder abuse, and certain communicable diseases; failure to report may carry legal liability.

Scope of practice: a dentist may perform procedures within licensed training; delegation to dental assistants and hygienists is governed by local regulations and supervision levels.

Record keeping: retain complete records for the period required by law (commonly 5–10 years, longer for minors); records must be accurate, contemporaneous, and legible.

Negligence requires duty, breach, causation, and damages; the standard of care is that of a reasonably competent practitioner in similar circumstances.

Advertising and professional conduct: avoid false or misleading claims, guarantee of results, or solicitation of vulnerable patients; maintain professional boundaries.

Infection control standard precautions: hand hygiene, gloves, masks, eye protection, and sterilization of instruments by autoclave at 121°C for 15 minutes or 134°C for 3–4 minutes.

Emergency preparedness: maintain oxygen, epinephrine, antihistamines, and a defibrillator; syncope is managed with supine position and leg elevation; anaphylaxis requires intramuscular epinephrine.