FCPS-1 Prep Golden File Acquisition Notes - Dentistry

Key Philosophical Principles & Overview

• Foundation Motto for Academic & Professional Excellence: "Study while others are sleeping. Work while others are loafing. Prepare while others are playing. And dream while others are wishing."

• Core Target Examination: FCPS-1 Prep (Dentistry) — Golden File Acquisition Viewer.

Head and Neck Nerve Anatomy & Clinical Neuropathies

Lingual Nerve

• Functional Components:

  • General somatic afferent (GSA): General sensation (pain, touch, temperature) to the anterior two-thirds of the tongue.

  • Special visceral afferent (SVA): Carries taste fibers from the anterior two-thirds of the tongue via the chorda tympani nerve (branch of CN VII).

• Clinical Vulnerability & Damage:

  • Most commonly injured during mandibular third molar ($3^{\text{rd}}$ molar) extraction surgery.

  • Damage results in loss of both general sensation and taste perception on the ipsilateral anterior two-thirds of the tongue.

Inferior Alveolar Nerve (IAN)

• Functional Supply: Mandibular teeth, labial and buccal gingivae of anterior/premolar teeth, lower lip, and chin.

• Clinical Vulnerability & Damage:

  • Most commonly injured during mandibular canal fractures, inferior alveolar nerve block anesthesia, third molar impaction surgery, and dental implant placement.

  • Damage results in unilateral numbness/paresthesia of the mandibular teeth, lower lip, and chin.

Mental Nerve

• Anatomical Course: Emerges from the mental foramen on the lateral surface of the mandible (near the apices of mandibular premolars).

• Functional Supply: Skin of the chin, as well as the skin and mucosa of the lower lip.

• Clinical Vulnerability & Damage:

  • Frequently injured during periapical surgery or traumatic injuries near the mandibular premolars, or from direct compression by an overextended/resorbed mandibular complete denture base.

  • Damage results in localized numbness/paresthesia restricted strictly to the lower lip and chin (no dental numbness).

Mylohyoid Nerve

• Branching & Functions:

  • Motor branch of the IAN arising prior to entry into the mandibular foramen.

  • Motor innervation: Mylohyoid muscle and the anterior belly of the digastric muscle.

  • Sensory innervation: Occasionally provides sensory fibers to the mandibular incisors.

• Clinical Significance: Injury is rarely noted clinically except for minor collateral sensory disturbances.

Auriculotemporal Nerve

• Functional Supply: Sensory innervation to the temporomandibular joint (TMJ), auricle, and external auditory meatus. Also carries postganglionic parasympathetic secretomotor fibers from the otic ganglion to the parotid gland.

• Clinical Vulnerability & Damage:

  • Injury results in TMJ pain and preauricular anesthesia.

  • Aberrant regeneration following parotidectomy results in Frey's syndrome (gustatory sweating and flushing over the cheek during mealtime/mastication).

Glossopharyngeal Nerve (CN IX)

• Sensory & Autonomic Supply: Sensory to the posterior one-third of the tongue, tonsillar fossa, and upper pharynx; secretomotor to the parotid gland via the otic ganglion.

• Eagle's Syndrome: Elongation of the styloid process or calcification of the stylohyoid ligament causes irritation of CN IX, presenting as persistent throat pain, dysphagia, and referred otalgia.

Hypoglossal Nerve (CN XII)

• Motor Supply: Innervates all intrinsic and extrinsic muscles of the tongue (except palatoglossus, innervated by CN X).

• Surgical Vulnerability: Injury to the genioglossus muscle or CN XII during ranula excision or floor-of-mouth surgery leads to an inability to protrude the tongue, with deviation toward the side of the lesion.

Nerve Injury Classifications & Pain Dysfunctions

• Neuropraxia: Mildest form of nerve injury. Temporary conduction block without structural axonal breakdown; complete spontaneous recovery.

• Axonotmesis: Axonal degeneration occurs distal to the lesion (Wallerian degeneration), but the connective tissue sheath (epineurium/perineurium) remains intact; recovery is possible.

• Neurotmesis: Most severe form of injury; complete severance of the nerve trunk and connective tissue sheath; no spontaneous recovery without surgical intervention.

• Neuralgia: Sudden, severe, brief, stabbing/electric shock-like pain along the anatomical course of a nerve (e.g., Trigeminal Neuralgia).

• Causalgia: Severe, persistent, burning pain following nerve injury, frequently accompanied by sympathetic overactivity.

• Hyperalgesia: Increased sensitivity and lowered threshold to a normally painful stimulus.

• Hypoesthesia: Reduced sensitivity to touch, temperature, or painful stimuli.

• Paresthesia: Abnormal, non-painful spontaneous sensation (e.g., tingling, prickling, or numbness).

• Dysesthesia: Unpleasant, abnormal, and often painful spontaneous sensation.

Salivary Glands: Anatomy, Histology, Physiology, & Pathology

Major Salivary Glands & Ducts

• Parotid Gland:

  • Saliva Characteristics: Watery, purely serous, rich in salivary amylase ($\alpha$\text{-amylase}); highly effective in initiating starch digestion.

  • Anatomical Duct: Stensen's duct.

  • Autonomic Ganglion: Parasympathetic secretomotor relay occurs at the Otic ganglion.

• Submandibular Gland:

  • Saliva Characteristics: Mixed (seromucous), accounting for the majority of resting saliva volume.

  • Anatomical Duct: Wharton's duct; opens into the sublingual caruncle.

  • Pathological Predilection: Most common site for sialolithiasis (salivary stone formation).

• Sublingual Gland:

  • Saliva Characteristics: Predominantly mucous, highly viscous.

  • Anatomical Ducts: Bartholin's duct (major) and Rivinus ducts (minor).

  • Pathological Predilection: Primary origin of ranulas.

Minor Salivary Glands

• Distribution: Present throughout the oral cavity except on the gingiva and anterior hard palate.

• Palatine Glands: Purely mucous type; situated in the posterior hard palate and soft palate.

• Labial Glands: Upper and lower lips; mixed secretion, mainly mucous.

• Von Ebner's Glands: Purely serous glands located adjacent to the circumvallate papillae on the dorsum of the tongue.

• Buccal Glands: Cheeks; mixed secretion.

• Glossopalatine Glands: Posterior lateral tonsillar pillar; mucous type.

• Blandin-Nuhn Glands: Anterior ventral surface of the tongue; mixed secretion.

• Retromolar Glands: Mucous glands located behind the last molar.

Histology & Duct Architecture

• Duct Sequence: Secretory end pieces (acini) $\rightarrow$ Intercalated ducts $\rightarrow$ Striated ducts $\rightarrow$ Excretory / Interlobular ducts.

• Histology of Mucous Cells: Lightly stained, pyramidal cells containing abundant mucinogen granules, with flattened nuclei compressed against the basal cell membrane, arranged in tubular patterns.

• Cell-Free Zone of Weil (in Dental Pulp): Contains nerve fibers (Plexus of Raschkow) and capillaries, but strictly lacks lymphatics.

Salivary Function & Caries Dynamics

• Viscosity vs. Caries: Viscosity is directly proportional to caries susceptibility (thicker, mucin-dense saliva impedes self-cleansing and increases plaque retention).

• Flow Rate vs. Caries: Inversely proportional ($\downarrow$ flow rate $\rightarrow \uparrow$ caries risk).

• Salivary pH vs. Caries: Inversely proportional (lower pH $\rightarrow \uparrow$ caries risk).

• Buffering Capacity vs. Caries: Inversely proportional (weak buffering capacity $\rightarrow \uparrow$ caries risk).

• Critical pH Thresholds:

  • Enamel dissolution: $\text{pH} = 5.5$

  • Dentin dissolution: $\text{pH} = 6.2-6.5$

  • Fluorapatite dissolution: $\text{pH} = 4.5$

Clinical Salivary Diseases

• Ranula:

  • Definition: Mucous extravasation cyst arising from the sublingual gland due to ductal rupture.

  • Simple Ranula: Translucent, bluish, painless, soft, fluctuant swelling restricted to the floor of the mouth, lateral to the midline.

  • Plunging Ranula: Herniation of mucin through the mylohyoid muscle into the upper cervical neck region.

  • Histology: Extravasation pseudocyst lined by compressed connective tissue and granulation tissue filled with mucin and histiocytes, lacking a true epithelial lining.

• Sjögren's Syndrome:

  • Clinical Triad: Keratoconjunctivitis sicca (dry eyes/xerophthalmia) + Xerostomia (dry mouth) + Autoimmune connective tissue disease.

  • Serological Markers: Anti-SS-A (Ro) and Anti-SS-B (La) autoantibodies.

  • Diagnostic Modalities: Schirmer test ( tear flow assessment), salivary gland scintigraphy, and lip biopsy demonstrating dense lymphocytic infiltration.

  • Risk Factor: Significant long-term predisposition to non-Hodgkin B-cell lymphoma.

• Pleomorphic Adenoma:

  • Most common benign tumor of both major and minor salivary glands.

  • Classically presents as a slow-growing, firm, painless swelling at the junction of the hard and soft palate.

Oral Potentially Malignant Disorders (OPMDs) & Oral Oncology

Potentially Malignant Disorders

• Oral Submucous Fibrosis (OSMF):

  • Primary Etiology: Chewing betel nut / Areca nut (alkaloid exposure).

  • Earliest Clinical Symptom: Burning sensation upon consuming spicy foods.

  • Hallmark Features: Blanching of the mucosa, palpable fibrous bands in the buccal mucosa, loss of tongue papillae, and progressive trismus (restricted mouth opening).

  • Histopathology: Juxtaepithelial hyalinization and dense collagenous fibrosis of the lamina propria.

  • Malignant Transformation Rate: $7-13\%$

• Leukoplakia:

  • Definition: A predominantly white patch or plaque that cannot be scraped off and cannot be characterized clinically or pathologically as any other disease.

  • Clinical Forms: Homogenous (smooth, thin, low dysplasia risk) vs. Non-homogenous (speckled/erythroleukoplakia, nodular, verrucous; significantly higher malignant risk).

  • Malignant Transformation Rate: $5-15\%$

  • Histopathology: Epithelial dysplasia of variable degrees.

• Erythroplakia:

  • Definition: A fiery red, velvety patch of the oral mucosa that cannot be attributed to any other mucosal pathology.

  • Malignant Potential: Highest among all OPMDs; $50-70\%$ show severe dysplasia, carcinoma in situ, or invasive squamous cell carcinoma at the time of initial biopsy.

• Leukoedema:

  • Clinical Presentation: Diffuse, grayish-white opalescent appearance of the buccal mucosa.

  • Pathognomonic Test: Disappears completely when the affected mucosa is stretched.

• Nicotinic Stomatitis:

  • Etiology: Heavy pipe smoking (thermal and chemical irritation).

  • Clinical Appearance: Diffuse white, hyperkeratotic palate studded with multiple red dots (inflamed orifices of minor salivary gland ducts).

• Frictional Keratosis:

  • Etiology: Chronic mechanical trauma (e.g., sharp fractured tooth cusp, rough denture border).

  • Histopathology: Hyperorthokeratosis without cellular dysplasia; completely resolves upon removal of the traumatic source.

Oral Squamous Cell Carcinoma (SCC)

• Predilection Site: Lateral border and ventral surface of the tongue (most common site overall in Western populations).

• Gold Standard Diagnostic Test: Biopsy (Incisional biopsy for large lesions; Excisional biopsy for small lesions $<1\,\text{cm}$). Must contain both the lesion and adjacent normal tissue edge.

• Auxiliary Diagnostic Modalities:

  • Brush Biopsy: Cytological screening test only; non-confirmatory.

  • Fine Needle Aspiration Cytology (FNAC): Ideal for cervical lymph nodes and salivary gland masses, but not the primary gold standard for oral mucosal lesions.

  • MRI: Superior for soft tissue delineation, muscle invasion, and perineural spread.

  • CT Scan: Superior for detecting bony cortical invasion of the mandible or maxilla.

Odontogenic & Non-Odontogenic Cysts and Tumors

Odontogenic Cysts

• Dentigerous Cyst (Follicular Cyst):

  • Pathogenesis: Encloses the crown of an unerupted/impacted tooth, attached precisely at the cementoenamel junction (CEJ).

  • Target Teeth: Mandibular third molars > Maxillary permanent canines.

  • Features: Straw-colored fluid aspirate; lined by thin (2–4 cell layers) non-keratinized stratified squamous epithelium.

• Odontogenic Keratocyst (OKC):

  • Target Site: Posterior body and ramus of the mandible.

  • Radiographic Features: Unilocular or multilocular radiolucency expanding anteroposteriorly within medullary bone without significant cortical expansion.

  • Aspirate & Histology: Straw-colored fluid with low soluble protein content ($<4\,\text{g}/100\,\text{ml}$) containing parakeratin debris. Lined by uniform parakeratinized stratified squamous epithelium with a palisaded basal cell layer.

  • Clinical Note: High recurrence rate ($\sim 30\%$); multiple OKCs are a component of Gorlin-Goltz syndrome (Nevoid Basal Cell Carcinoma Syndrome).

• Radicular Cyst:

  • Etiology: Most common odontogenic cyst overall; arises from the cell rests of Malassez in response to pulpal necrosis at the apex of a non-vital tooth.

• Lateral Periodontal Cyst:

  • Arises between the roots of vital teeth; most common in the mandibular premolar-canine region.

Non-Odontogenic Cysts

• Nasopalatine Duct Cyst (Incisive Canal Cyst):

  • Most common non-odontogenic cyst; presents as a classic heart-shaped radiolucency in the anterior maxillary midline.

• Globulomaxillary Cyst:

  • Radiographic Feature: Classic pear-shaped radiolucency situated between the roots of the maxillary lateral incisor and canine; adjacent teeth remain vital.

• Nasolabial Cyst:

  • Soft tissue extraosseous cyst occurring in the nasolabial fold, clinically causing elevation of the ala of the nose.

• Dermoid Cyst:

  • Midline floor of mouth swelling; histologically contains dermal appendages (hair follicles, sebaceous glands, sweat glands).

Odontogenic & Non-Odontogenic Tumors

• Ameloblastoma:

  • Origin: Odontogenic epithelium (enamel organ remnants, rests of Malassez, or rests of Serres).

  • Radiograph: Classic "soap bubble" or "honeycomb" multilocular radiolucency causing extensive root resorption and cortical expansion in the posterior mandible.

• Cementoblastoma:

  • Pathognomonic Radiograph: Distinct mixed radiolucent-radiopaque mass attached directly to the root apex of a vital tooth (most commonly the mandibular first molar), surrounded by a thin radiolucent halo.

• Fibrous Dysplasia:

  • Radiograph: Classic "ground-glass" or "orange-peel" appearance with ill-defined borders; most commonly affects the maxilla over the mandible.

  • Etiology: Somatic gain-of-function mutation in the GNAS-1 gene.

• Cherubism:

  • Autosomal dominant disorder appearing in early childhood; presents with bilateral, symmetrical painless cheek swellings and bilateral multilocular radiolucencies of the mandible/maxilla, causing an eyes-upward-to-heaven ("cherubic") appearance.

• Paget's Disease of Bone (Osteitis Deformans):

  • Features: Marked osteoclastic and osteoblastic remodelling leading to progressive bone expansion (increasing skull size, dentures no longer fitting).

  • Radiograph: Classic "cotton-wool" radiopacities.

  • Laboratory Diagnostics: Significantly elevated Serum Alkaline Phosphatase (ALP) and elevated urinary hydroxyproline, with completely normal serum calcium and phosphate levels.

• Central Giant Cell Granuloma (CGCG):

  • Radiolucent multilocular lesion of the anterior mandible, frequently crossing the anatomical midline.

• Calcifying Epithelial Odontogenic Tumor (Pindborg Tumor):

  • Features: Radiographic "driven snow" calcifications; histologically demonstrates Liesegang rings.

Bone Pathologies, Syndromes, & Craniofacial Anomalies

Craniofacial & Genetic Syndromes

• Pierre Robin Sequence:

  • Clinical Tetrad / Triad: Micrognathia + Glossoptosis + Cleft palate + Severe neonatal airway obstruction.

• Treacher Collins Syndrome (Mandibulofacial Dysostosis):

  • Features: Zygomatic hypoplasia, severe micrognathia, downward-slanting palpebral fissures, coloboma of lower eyelids, and external ear anomalies.

• Crouzon Syndrome:

  • Features: Craniosynostosis, severe midface hypoplasia, ocular exophthalmos, and a pathognomonic "copper-beaten skull" radiograph.

• Apert Syndrome:

  • Features: Craniosynostosis + Midface hypoplasia + Severe syndactyly of hands and feet ("mitten hands").

• Cleidocranial Dysplasia:

  • Features: Hypoplasia or complete absence of clavicles (enabling shoulder approximation), delayed closure of fontanelles, multiple impacted permanent teeth, and numerous supernumerary teeth.

• DiGeorge Syndrome:

  • Pathogenesis: Developmental failure of the $3^{\text{rd}}$ and $4^{\text{th}}$ pharyngeal (branchial) pouches.

  • Features: Thymic hypoplasia (T-cell immunodeficiency), parathyroid hypoplasia causing severe hypocalcemia and neonatal tetany, cardiac malformations, mandibular hypoplasia, and hypomineralized enamel/teeth.

• Melkersson-Rosenthal Syndrome:

  • Pathognomonic Triad: 1. Persistent/recurrent orofacial edema (lip swelling/cheilitis granulomatosa), 2. Fissured tongue (lingua plicata), 3. Recurrent unilateral or bilateral facial nerve palsy.

Cleft Lip and Palate Embryology

• Unilateral / Bilateral Cleft Lip: Failure of fusion between the Maxillary Process and the Median Nasal Process.

• Isolated Cleft Palate: Failure of fusion between the two Palatine Shelves.

• Midline Upper Lip Cleft: Failure of fusion between the two Median Nasal Processes.

• Teratogenic Triggers: Maternal administration of Phenytoin, Diazepam, or exposure to Cigarette smoke during early pregnancy (Excess Vitamin D is NOT teratogenic for cleft formation).

Dental Embryology, Histology, & Hard Tissue Anomalies

Embryological Derivations

• Ameloblasts & Enamel Organ: Derived strictly from Ectoderm (Inner Enamel Epithelium $\rightarrow$ Ameloblasts).

• Odontoblasts, Dentin, & Pulp: Derived from Neural Crest cells (via Dental Papilla).

• Cementum, Periodontal Ligament (PDL), & Alveolar Bone: Derived from the Dental Follicle (Neural Crest origin).

• Primary Tooth Bud Timing: The dental lamina initiates first primary tooth buds at the $6^{\text{th}}$ week of intrauterine life (IUL).

• Hertwig's Epithelial Root Sheath (HERS): Extension of the inner and outer enamel epithelium at the cervical loop; guides root size, shape, and number, and induces differentiation of root odontoblasts. Leaves behind epithelial rests of Malassez.

Histology of Dental Tissues

• Enamel:

  • Composition: Hardest biological tissue; $96\%$ inorganic (Hydroxyapatite crystals), $4\%$ water and organic matrix.

  • Structural Features: Enamel rods extend perpendicular to the Dentinoenamel Junction (DEJ). Tomes' processes are responsible for enamel matrix secretion. Incremental growth lines of Retzius manifest externally on the enamel surface as shallow furrows called Perikymata.

  • Unique Status: Enamel is the ONLY mineralized structure in the human body derived from epithelial origin.

• Dentin:

  • Primary Organic Matrix: Type I Collagen ($\sim 90\%$ of organic matrix).

  • Continual Production: Intratubular (peritubular) dentin deposition occurs continuously throughout life.

  • Mantle Dentin: The very first layer of dentin formed adjacent to the DEJ.

• Cementum:

  • Vascular Status: Cementum is completely AVASCULAR, whereas bone is highly VASCULAR.

  • Acellular Cementum: Covers the cervical two-thirds of the root; formed prior to eruption.

  • Cellular Cementum: Covers the apical one-third of the root; contains trapped cementocytes.

  • Eruption Function: Deposition of cementum at the root apex allows continuous tooth eruption to compensate for incisal/occlusal wear.

Anomalies of Structure, Shape, & Number

• Amelogenesis Imperfecta: Hereditary enamel defect affecting primary and permanent dentitions. Characterized by thin (hypoplastic), soft (hypocalcified), or porous (hypomature) enamel. Dentin and pulp remain structure-normal.

• Dentinogenesis Imperfecta: Autosomal dominant defect; teeth present with an opalescent amber color, bulbous crowns, marked cervical constrictions, short roots, and early obliteration of pulp chambers. Extremely prone to severe enamel fracture/wear, but NOT more susceptible to dental caries.

• Regional Odontodysplasia ("Ghost Teeth"): Localized non-hereditary anomaly showing marked reduction in enamel and dentin density with extremely wide pulp chambers.

• Turner's Tooth (Turner's Hypoplasia): Localized enamel hypoplastic defect on a permanent tooth caused by periapical infection or trauma from its overlying deciduous predecessor.

• Hutchinson's Incisors & Mulberry Molars: Pathognomonic features of Congenital Syphilis. Incisors are screwdriver-shaped with incisal notches; molars show multiple poorly developed berry-like cusps.

• Dental Fluorosis: Endemic hypomineralization caused by excess fluoride intake during enamel formation, producing opaque, mottled, brownish enamel.

• Fusion: Union of two individual tooth buds during the initiation/proliferation stage, resulting in a reduced total tooth count.

• Gemination: Single tooth bud attempts to split into two; results in a normal tooth count (if counted as one enlarged bifid crown).

• Concrescence: Union of two fully formed adjacent teeth by cementum ONLY; most common in maxillary permanent molars.

• Dilaceration: Abnormal angulation or bend in the root or crown caused by trauma during root formation.

• Taurodontism: Elongation of the pulp chamber with apical displacement of the furcation; commonly observed in Down syndrome and Klinefelter syndrome.

• Tooth Wear Modalities:

  • Attrition: Physiological wear resulting from direct tooth-to-tooth contact.

  • Abrasion: Pathological wear from mechanical friction by an external object (e.g., hard toothbrushing).

  • Erosion: Pathological chemical dissolution of enamel/dentin by non-bacterial acids (e.g., gastric reflux, acidic drinks).

  • Abfraction: Wedge-shaped cervical loss of tooth structure caused by heavy occlusal flexure forces.

Periodontal Diseases, Microbiology, & Immunology

Periodontal Microbiology & Pathogenesis

• Plaque Adherence: Bacterial synthesis of Dextran (extracellular glucan polymer) is primarily responsible for dental plaque adherence to the tooth surface.

• Invasive Tissue Spread: Hyaluronidase ("spreading factor") is the enzyme responsible for bacterial invasion through fascial planes in deep dental infections.

• Primary Bone Loss Pattern: Horizontal bone loss is the earliest and most common pattern of periodontal bone destruction.

Specific Periodontal Entities

• Localized Aggressive Periodontitis (LAP):

  • Primary Pathogen: Aggregatibacter actinomycetemcomitans (Aa).

  • Predilection Sites: Classic attachment loss restricted to Permanent First Molars and Incisors.

  • Features: Minimal local plaque/calculus relative to severe bone destruction; strong familial predilection.

  • Initial Clinical Sign: Pathological tooth migration and development of a midline diastema.

• Generalized Aggressive Periodontitis:

  • Affects at least 3 permanent teeth other than first molars and incisors.

  • Pathogens: Red Complex Bacteria (Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia).

• Necrotizing Ulcerative Gingivitis (NUG / Vincent's Angina):

  • Etiology: Fusospirochetal complex (Fusiform bacilli + Treponema denticola).

  • Pathognomonic Features: Severe localized pain, spontaneous bleeding, punched-out/cratered interdental papillae covered by a greyish pseudomembrane, and extreme fetid odor ("woody/pasty gum"). Non-contagious.

Endodontics, Pulp Biology, & Restorative Dentistry

Pulp Histology & Inflammatory Dynamics

• Pulp Zones:

  1. Odontoblastic Layer (innermost to dentin).

  2. Cell-Free Zone of Weil (contains capillary network and Raschkow's plexus; no lymphatics).

  3. Cell-Rich Zone (high density of fibroblasts and undifferentiated mesenchymal cells).

  4. Pulp Core (innermost vascular core; initiates acute inflammatory vasodilation and leukocyte extravasation in deep caries).

• Defense Response: Deep caries triggers secondary/tertiary (reparative) dentin deposition directly beneath affected dentinal tubules.

Endodontic Procedures & Materials

• First Pulp Extirpation Instrument: Barbed Broach.

• Standard Working Length Range: $21-25\,\text{mm}$.

• Endodontic Irrigants & Chelators:

  • Sodium Hypochlorite (NaOCl): Primary organic tissue solvent and bactericidal irrigant. Extrusion causes severe tissue necrosis.

  • Ethylenediaminetetraacetic Acid (EDTA 17%): Chelating agent that dissolves inorganic dentin mineral to effectively remove the smear layer.

• Primary Microorganism in Retreatment Failure: Enterococcus faecalis (highly resistant to Calcium Hydroxide; sensitive to $2\%$ Chlorhexidine).

• GP Solvent: Chloroform.

• Root Perforation Repair Gold Standard: Mineral Trioxide Aggregate (MTA).

• Irreversible Pulpitis Emergency Management: Complete biomechanical instrumentation of the canal (pulpectomy).

• Cracked Tooth Syndrome: Intermittent sharp pain on chewing and rebound release, with localized cusp tenderness and normal periapical radiographs.

Restorative Dentistry & Adhesion

• Acid-Etched Composite Bonding: Micro-mechanical interlocking via resin tag formation inside etched enamel microporotic structures.

• Deep Caries Pulp Protection: Glass Ionomer Cement (GIC) with a Zinc Oxide Eugenol (ZOE) base.

• Toothpaste Abrasives: Hydrated Silica.

• Water Fluoridation: Classic example of Primary Disease Prevention.

Dental Materials & Prosthodontics

Impression Materials

• Zinc Oxide Eugenol (ZOE) Impression Paste:

  • Major Accelerator Component: Zinc Acetate.

  • Properties: Rigid, highly dimensionally stable. Contraindicated in patients with severe xerostomia due to painful mucosal irritation.

• Polysulfide Impression Material:

  • Can be electroplated safely without any risk of dimensional distortion.

• Alginate (Irreversible Hydrocolloid):

  • Main Powder Component: Sodium Alginate.

  • Reactor: Calcium Sulfate; Retarder: Trisodium Phosphate.

  • Main Bulk Filler ($60-70\%$): Diatomaceous Earth (Silica).

  • Setting Reaction: Sol $\rightarrow$ Gel transition forming Calcium Alginate.

  • Distortion Factors: Syneresis (water evaporation causing shrinkage) vs. Imbibition (water absorption causing swelling).

  • Storage Protocol: Wrap in damp paper towel/gauze inside a sealed plastic bag; pour within $5-10\,\text{minutes}$. Deteriorates rapidly under high storage temperatures.

Prosthodontic Clinical Neuropathies

• Denture Base Nerve Compression: Severe resorption of the mandibular alveolar ridge causes direct compression of the mental nerve by the complete denture flange over the mental foramen, resulting in persistent lip/chin hypoesthesia.

Oral Surgery, Fascial Spaces, & Radiation Effects

Dry Socket (Fibrinolytic Alveolitis)

• Pathogenesis: Extraction complication (highest incidence in mandibular third molars) occurring 2–4 days post-op. Characterized by premature degradation of the blood clot via elevated localized fibrinolysis.

• Responsible Mediator: Plasmin (destroys the fibrin network).

• Analgesic Timing: Pain medication should ideally be administered before local anesthesia wears off.

Fascial Spaces & Infection Spread

• Submasseteric Space Abscess: Most commonly originates from an infected mandibular third molar; located between the masseter muscle and the lateral surface of the mandibular ramus. Characterized by severe trismus, angle pain, and minimal intraoral swelling.

• Anatomical Barrier to Deep Neck Infection: Mylohyoid Muscle forms the primary anatomical floor barrier preventing mandibular root apex infections from plunging into deep neck spaces.

• Maxillary Sinusitis vs. Pulpitis: Sinusitis presents as diffuse, dull pressure across ALL upper posterior teeth that worsens upon bending forward, accompanied by nasal discharge and clouding of the sinus on Waters' view radiograph.

Radiation Effects on Oral Structures

• Mucositis: Acute, EARLY effect of head and neck radiotherapy (erythema, painful sloughing/ulceration).

• Endarteritis Obliterans: The primary vascular pathology (progressive occlusion of small blood vessels) responsible for tissue hypoxia, poor healing, and non-healing necrotic tissue in irradiated structures.

• Osteoradionecrosis (ORN): Chronic, LATE complication; occurs far more frequently in the Mandible than the maxilla due to dense cortical bone structure, single blood supply, and higher absorbed radiation doses.

• Radiation Rampant Caries: Rapidly progressive caries secondary to radiation-induced salivary gland destruction and subsequent severe Xerostomia.

Complete Multiple Choice Questions & Clinical Scenarios

1. A baby refuses breastfeeding but accepts bottle feeding easily. Which defect is most likely present?

   • A) Tongue tie

   • B) Hard palate defect

   • C) Soft palate defect

   • D) Cleft lip

   • Answer: C) Soft palate defect

2. A patient complains of severe pain in extractions days after tooth removal. Which mediator is mainly responsible for the premature blood clot degradation?

   • A) Histamine

   • B) Bradykinin

   • C) Plasmin

   • D) Prostaglandin

   • Answer: C) Plasmin

3. During mandibular $3^{\text{rd}}$ molar surgery, the patient lost sensation in the anterior two-thirds of the tongue. Which nerve is injured?

   • A) Glossopharyngeal

   • B) Lingual

   • C) Hypoglossal

   • D) Inferior alveolar

   • Answer: B) Lingual

4. A patient shows white interlacing striae on the buccal mucosa (Wickham's striae). Which condition is most likely present?

   • A) Pemphigus vulgaris

   • B) Oral candidiasis

   • C) Oral lichen planus

   • D) Leukoplakia

   • Answer: C) Oral lichen planus

5. Patient presents with unilocular radiolucency around a $3^{\text{rd}}$ molar crown, aspirate is straw-colored fluid. What is the diagnosis?

   • A) Radicular cyst

   • B) Ameloblastoma

   • C) Dentigerous cyst

   • D) OKC

   • Answer: C) Dentigerous cyst

6. The most susceptible site for oral cancer is:

   • A) Tip of tongue

   • B) Lateral border & ventral tongue

   • C) Hard palate

   • D) Gingiva

   • Answer: B) Lateral border & ventral tongue

7. A 30-year-old male presents with pain, swelling, and multiple draining sinuses on the mandibular region 2 weeks after intermaxillary wiring for a mandibular fracture. The discharge is yellowish with sulfur granules. What is the most likely causative organism?

   • A) Streptococcus viridans

   • B) Staphylococcus aureus

   • C) Actinomyces

   • D) Klebsiella

   • Answer: C) Actinomyces

8. A patient complains of taste and a numb sensation in the left half of his tongue after removal of his left lower wisdom tooth. Which nerve was injured?

   • A) Facial nerve

   • B) Glossopharyngeal nerve

   • C) Inferior alveolar nerve

   • D) Lingual nerve

   • Answer: D) Lingual nerve

9. Disturbance of saliva production from the parotid gland is likely to result from damage to which ganglion?

   • A) Gasserian

   • B) Geniculate

   • C) Otic

   • D) Pterygopalatine

   • Answer: C) Otic

10. A 20-year-old man falls down and chips the incisal edge of his maxillary central incisor, reducing crown length. The tooth erupts slightly to compensate. This movement results in an increase in size of which tissue?

    • A) Cementum

    • B) Dentin

    • C) Enamel

    • D) Periodontal ligament

    • Answer: A) Cementum

11. The position of maximum intercuspation of upper & lower teeth is referred to as:

    • A) Centric position

    • B) Centric occlusion

    • C) Centric relation

    • D) Centric bite

    • Answer: B) Centric occlusion

12. A person eats a starch-rich diet. Saliva from which gland is most effective in digestion?

    • A) Von Ebner's

    • B) Minor Salivary

    • C) Parotid glands

    • D) Submandibular glands

    • Answer: C) Parotid glands

13. At nine years of age, the mandibular permanent first molar has its distal contact with which tooth?

    • A) First premolar

    • B) No distal contact

    • C) Second molar

    • D) Second premolar

    • Answer: B) No distal contact

14. A deep carious lesion reaches the pulp, causing vasodilation and white blood cell migration. This response is initiated by cells in which zone?

    • A) Cell-free zone

    • B) Cell-rich zone

    • C) Odontoblast layer

    • D) Pulp core

    • Answer: D) Pulp core

15. Which type of dentin is continuously produced throughout life?

    • A) Interglobular dentin

    • B) Intertubular dentin

    • C) Intratubular dentin

    • D) Mantle dentin

    • Answer: C) Intratubular dentin

16. Which ducts arise directly from secretory end pieces of salivary glands?

    • A) Striated ducts

    • B) Excretory ducts

    • C) Intercalated ducts

    • D) Interlobular ducts

    • Answer: C) Intercalated ducts

17. Histology of a salivary gland section shows lightly stained pyramidal cells with flattened nuclei arranged in tubular patterns. What are these cells?

    • A) Ductal cells

    • B) Fibroblasts

    • C) Mucous cells

    • D) Serous cells

    • Answer: C) Mucous cells

18. Shallow furrows (perikymata) on the enamel surface under microscope are due to:

    • A) Toothbrush abrasion

    • B) Attrition from occlusal forces

    • C) Cracks in enamel

    • D) Incremental formation of enamel

    • Answer: D) Incremental formation of enamel

19. Which term indicates the dentin formed first in the tooth?

    • A) Granular Dentin

    • B) Hyaline Dentin

    • C) Mantle Dentin

    • D) Primary Dentin

    • Answer: C) Mantle Dentin

20. A 9-year-old child presents with a permanent maxillary central incisor showing localized enamel hypoplasia. History reveals an abscessed primary predecessor at age 5. Diagnosis?

    • A) Hutchinson's tooth

    • B) Amelogenesis imperfecta

    • C) Turner's tooth

    • D) Dental Fluorosis

    • Answer: C) Turner's tooth

21. A chronic smoker presents with a non-healing indurated ulcer on the lateral border of the tongue for 3 months. Gold standard test?

    • A) MRI

    • B) Biopsy

    • C) CT scan

    • D) FNAC

    • Answer: B) Biopsy

22. A betel nut chewer presents with restricted mouth opening (trismus). Diagnosis?

    • A) Oral candidiasis

    • B) Leukoplakia

    • C) Oral submucous fibrosis

    • D) Erythroplakia

    • Answer: C) Oral submucous fibrosis

23. Which feature differentiates a benign tumor from hyperplasia?

    • A) Benign tumors are encapsulated

    • B) Hyperplasia is always malignant

    • C) Hyperplasia infiltrates tissues

    • D) Benign tumors lack capsule

    • Answer: A) Benign tumors are encapsulated

24. Two weeks post third molar extraction, a patient reports severe persistent burning pain along the IAN distribution with sympathetic features. Diagnosis?

    • A) Neuropraxia

    • B) Neuralgia

    • C) Causalgia

    • D) Hyperalgesia

    • Answer: C) Causalgia

25. A 16-year-old with asymmetric mandibular growth needs assessment of active growth. Best investigation?

    • A) CT scan

    • B) OPG

    • C) Scintigraphy

    • D) Lateral cephalogram

    • Answer: C) Scintigraphy

26. A 12-year-old presents with painless jaw swelling; radiograph shows ground glass appearance. Diagnosis?

    • A) Ossifying fibroma

    • B) Fibrous dysplasia

    • C) Ameloblastoma

    • D) Osteosarcoma

    • Answer: B) Fibrous dysplasia

27. Earliest and most common bone loss pattern in periodontitis is:

    • A) Vertical bone loss

    • B) Horizontal bone loss

    • C) Angular bone loss

    • D) Fenestration

    • Answer: B) Horizontal bone loss

28. Radiograph required for a suspected sialolith swelling in the floor of the mouth?

    • A) OPG

    • B) Mandibular occlusal view

    • C) Lateral ceph

    • D) PA mandible

    • Answer: B) Mandibular occlusal view

29. Mealtime floor of mouth swelling near sublingual caruncle involves which duct?

    • A) Bartholin's duct

    • B) Wharton's duct

    • C) Stensen's duct

    • D) Rivinus duct

    • Answer: B) Wharton's duct

30. A mother taking cyclosporine gives birth. Effect on baby's teeth?

    • A) Enamel defect

    • B) Dentin defect

    • C) No effect

    • D) Pulp defect

    • Answer: C) No effect

31. Most appropriate investigation to assess salivary gland function:

    • A) CT scan

    • B) Ultrasound

    • C) Scintigraphy

    • D) MRI

    • Answer: C) Scintigraphy

32. Vital mandibular first molar with mixed radiolucent-radiopaque lesion attached to root. Diagnosis?

    • A) Periapical cemental dysplasia

    • B) Cementoblastoma

    • C) Ossifying fibroma

    • D) Ameloblastoma

    • Answer: B) Cementoblastoma

33. Which muscle forms the main barrier preventing lower molar root infections from spreading into deep neck spaces?

    • A) Buccinator

    • B) Mylohyoid

    • C) Masseter

    • D) Medial pterygoid

    • Answer: B) Mylohyoid

34. A 4-year-old presents with cleft palate, airway obstruction, glossoptosis, and micrognathia. Diagnosis?

    • A) Treacher Collins

    • B) Pierre Robin syndrome

    • C) Ectodermal dysplasia

    • D) Down syndrome

    • Answer: B) Pierre Robin syndrome

35. Which of the following is NOT a feature of amelogenesis imperfecta?

    • A) Thin enamel

    • B) Hypoplastic enamel

    • C) Mottled Teeth

    • D) Hypocalcified enamel

    • Answer: C) Mottled Teeth

36. Local anesthetics cross the placenta via:

    • A) Facilitated diffusion

    • B) Active transport

    • C) Simple diffusion

    • D) Pinocytosis

    • Answer: C) Simple diffusion

37. LA administered to a patient taking calcium channel blockers increases the risk of:

    • A) Hypertension

    • B) Hypotension

    • C) Tachycardia

    • D) Seizures

    • Answer: B) Hypotension

38. Profuse pulpal hemorrhage during access in a young permanent molar is best controlled with:

    • A) Ferric sulfate

    • B) Calcium hydroxide

    • C) Sodium hypochlorite

    • D) Epinephrine

    • Answer: C) Sodium hypochlorite

39. What epithelium lines the oropharynx?

    • A) Cuboidal

    • B) Columnar

    • C) Non-keratinized stratified squamous

    • Answer: C) Non-keratinized stratified squamous

40. 6-year-old with ghost-like teeth and enlarged pulps in right maxilla. Diagnosis?

    • A) Amelogenesis imperfecta

    • B) Regional odontodysplasia

    • C) Dentinogenesis imperfecta

    • D) Ectodermal dysplasia

    • Answer: B) Regional odontodysplasia

41. Bacterial polysaccharide responsible for plaque adherence to teeth:

    • A) Lipopolysaccharide

    • B) Dextran

    • C) Hyaluronic acid

    • D) Glucagon

    • Answer: B) Dextran

42. Enzyme facilitating infection spread in lower molar infections:

    • A) Collagenase

    • B) Hyaluronidase

    • C) Elastase

    • D) Dextranase

    • Answer: B) Hyaluronidase

43. Ameloblasts differentiate from:

    • A) Dental papilla

    • B) Outer enamel epithelium

    • C) Stellate reticulum

    • D) Internal enamel epithelium

    • Answer: D) Internal enamel epithelium

44. Primary pathogen in Localized Aggressive Periodontitis:

    • A) Actinomyces israelii

    • B) Aggregatibacter actinomycetemcomitans

    • C) Porphyromonas gingivalis

    • D) Treponema denticola

    • Answer: B) Aggregatibacter actinomycetemcomitans

45. Initial clinical sign of juvenile / localized aggressive periodontitis:

    • A) Pathological tooth migration and midline diastema

    • B) Tooth mobility and bone loss

    • C) Gingival enlargement

    • D) Pain and bleeding

    • Answer: A) Pathological tooth migration and midline diastema

46. Deficient dentin, opalescent teeth, bulbous crowns, pulpal obliteration:

    • A) Amelogenesis imperfecta

    • B) Dentinogenesis imperfecta

    • C) Enamel hypoplasia

    • D) Fluorosis

    • Answer: B) Dentinogenesis imperfecta

47. Submasseteric space abscess usually originates from:

    • A) Upper molars

    • B) Lower premolars

    • C) Lower $3^{\text{rd}}$ molars

    • D) Lower canines

    • Answer: C) Lower $3^{\text{rd}}$ molars

48. Vermilion zone of lips is characterized by:

    • A) Capillary loops near surface

    • B) Lymphatics

    • C) Sweat glands

    • D) Pigmented cells

    • Answer: A) Capillary loops near surface

49. Odontoblasts are derived from:

    • A) Ectoderm

    • B) Neural crest

    • C) Mesoderm

    • D) Endoderm

    • Answer: B) Neural crest

50. Palatine glands are located in:

    • A) Hard palate only

    • B) Soft palate only

    • C) Both hard & soft palate

    • D) Uvula

    • Answer: C) Both hard & soft palate

51. Zone of Weil contains all EXCEPT:

    • A) Lymphatics

    • B) Capillaries

    • C) Nerve plexus of Raschkow

    • D) Fibroblasts

    • Answer: A) Lymphatics

52. Nerve fibers first enter the dental papilla at which stage?

    • A) Bud stage

    • B) Cap stage

    • C) Bell stage

    • D) Eruption stage

    • Answer: C) Bell stage

53. Oral mucosa lacks which histology layer?

    • A) Stratum basale

    • B) Stratum spinosum

    • C) Stratum lucidum

    • D) Stratum superficiale

    • Answer: C) Stratum lucidum

54. Main organic component of bone and dentin:

    • A) Elastin

    • B) Collagen (Type I)

    • C) Glycoprotein

    • D) Keratin

    • Answer: B) Collagen (Type I)

55. Present in dentin and bone but NOT in enamel:

    • A) Hydroxyapatite

    • B) ACP (Amorphous calcium phosphate)

    • C) Fluorapatite

    • D) Dicalcium phosphate

    • Answer: B) ACP (Amorphous calcium phosphate)

56. First instrument used to extirpate pulp:

    • A) Reamer

    • B) File

    • C) Barbed broach

    • D) Spreader

    • Answer: C) Barbed broach

57. Standard length of instruments used in routine root canal procedures:

    • A) $15\,\text{mm}$

    • B) $25\,\text{mm}$

    • C) $30\,\text{mm}$

    • D) $40\,\text{mm}$

    • Answer: B) $25\,\text{mm}$

58. Solvent used to dissolve gutta-percha during retreatment:

    • A) Eugenol

    • B) Chloroform

    • C) Sodium hypochlorite

    • D) Hydrogen peroxide

    • Answer: B) Chloroform

59. Major accelerator constituent in ZOE impression paste:

    • A) Zinc acetate

    • B) Zinc chloride

    • C) Calcium sulfate

    • D) Barium sulfate

    • Answer: A) Zinc acetate

60. Which impression material can be electroplated without risk of distortion?

    • A) Polysulfide

    • B) Condensation silicone

    • C) Addition silicone

    • D) Polyether

    • Answer: A) Polysulfide

61. Obtundants act by which mechanism?

    • A) Blocking dentinal tubules

    • B) Anesthetizing dentinal tubules

    • C) Precipitating proteins in dentinal tubules

    • D) Promoting secondary dentin formation

    • Answer: C) Precipitating proteins in dentinal tubules

62. Alginate impression powder deteriorates rapidly at:

    • A) Low temperature

    • B) High temperature

    • C) Room temperature

    • D) Refrigerated temperature

    • Answer: B) High temperature

63. To prevent distortion before pouring, an alginate impression is best kept:

    • A) In open air

    • B) Immersed in water

    • C) Wrapped in damp paper towel in a sealed plastic bag

    • D) In hot oven

    • Answer: C) Wrapped in damp paper towel in a sealed plastic bag

64. Oral vesicles with positive Nikolsky sign and linear IgG/C3 along basement membrane. Diagnosis?

    • A) Pemphigus vulgaris

    • B) Mucous membrane pemphigoid

    • C) Lichen planus

    • D) Erythema multiforme

    • Answer: B) Mucous membrane pemphigoid

65. Unilateral soft floor of mouth swelling traced through the mylohyoid into the neck. Diagnosis?

    • A) Plunging ranula

    • B) Thyroglossal cyst

    • C) Cystic hygroma

    • D) Lymphangioma

    • Answer: A) Plunging ranula

66. Cobblestone buccal mucosa, lip swelling, non-caseating granulomas with giant cells. Diagnosis?

    • A) Ulcerative colitis

    • B) Crohn's disease

    • C) Sarcoidosis

    • D) Tuberculosis

    • Answer: B) Crohn's disease

67. Dull posterior maxillary tooth pain worsening on bending forward, cold history, clouding on Waters' view. Diagnosis?

    • A) Periapical abscess

    • B) Maxillary sinusitis

    • C) Osteomyelitis

    • D) Irreversible pulpitis

    • Answer: B) Maxillary sinusitis

68. Major mineral component providing hardness in enamel and bone:

    • A) Collagen fibers

    • B) Hydroxyapatite crystals

    • C) Keratin

    • D) Elastin

    • Answer: B) Hydroxyapatite crystals

69. Approximate percentage of water present in enamel:

    • A) $4\%$

    • B) $10\%$

    • C) $12\%$

    • D) $20\%$

    • Answer: A) $4\%$

70. Function of Tomes' process during enamel formation:

    • A) Secretion of enamel matrix proteins

    • B) Resorption of enamel

    • C) Formation of dentin

    • D) Regulation of minerals

    • Answer: A) Secretion of enamel matrix proteins

71. Direction of enamel rod extension:

    • A) Parallel to the DEJ

    • B) Perpendicular to the DEJ

    • C) Oblique to the DEJ

    • D) Circular around the DEJ

    • Answer: B) Perpendicular to the DEJ

72. Multilocular posterior mandibular radiolucency, straw aspirate, protein $<4\,\text{g}/100\,\text{ml}$, parakeratin. Diagnosis?

    • A) Ameloblastoma

    • B) Odontogenic keratocyst

    • C) Dentigerous cyst

    • D) Radicular cyst

    • Answer: B) Odontogenic keratocyst

73. Dry mouth and dry eyes with salivary autoantibodies Anti-SS (Ro/La). Diagnosis?

    • A) Lupus

    • B) Sjögren's syndrome

    • C) Scleroderma

    • D) Rheumatoid arthritis

    • Answer: B) Sjögren's syndrome

74. Progressively enlarging skull, lumbar vertebrae enlargement, hearing loss, elevated urinary hydroxyproline. Diagnosis?

    • A) Osteopetrosis

    • B) Osteogenesis imperfecta

    • C) Paget's disease of bone (Osteitis deformans)

    • D) Rickets

    • Answer: C) Paget's disease of bone (Osteitis deformans)

75. Edentulous 68-year-old man, dentures fit poorly, cotton-wool bone, high serum ALP, normal Ca/PO4. Diagnosis?

    • A) Fibrous dysplasia

    • B) Paget's disease of bone

    • C) Osteopetrosis

    • D) Osteogenesis imperfecta

    • Answer: B) Paget's disease of bone

76. 6-year-old child with bilateral symmetrical swelling of mandible ramus, soap bubble radiolucency, cherubic face. Diagnosis?

    • A) Fibrous dysplasia

    • B) Ameloblastoma

    • C) Central giant cell granuloma

    • D) Cherubism

    • Answer: D) Cherubism

77. Most common dental manifestation of rickets:

    • A) Microdontia

    • B) Enamel hypoplasia

    • C) Hypercementosis

    • D) Taurodontism

    • Answer: B) Enamel hypoplasia

78. Most useful test to confirm active unilateral condylar hyperplasia:

    • A) OPG

    • B) Lateral cephalogram

    • C) Bone scintigraphy

    • D) CT scan

    • Answer: C) Bone scintigraphy

79. Main function of flux in dental casting:

    • A) Increase alloy hardness

    • B) Remove oxides from metal surface

    • C) Reduce shrinkage

    • D) Act as binder

    • Answer: B) Remove oxides from metal surface

80. Flux used for stainless steel:

    • A) Borax

    • B) Fluoride

    • C) Sodium chloride

    • D) Calcium carbonate

    • Answer: B) Fluoride

81. Recurrent lip swelling, fissured tongue, facial nerve palsy. Diagnosis?

    • A) Heerfordt's syndrome

    • B) Melkersson-Rosenthal syndrome

    • C) Frey's syndrome

    • D) Myasthenia gravis

    • Answer: B) Melkersson-Rosenthal syndrome

82. Modern toothpaste abrasive agent:

    • A) Hydrated silica

    • B) Sorbitol

    • C) Sodium lauryl sulfate

    • D) Glycerin

    • Answer: A) Hydrated silica

83. Asymptomatic bulbous enlargement of root outline with intact PDL space and lamina dura. Diagnosis?

    • A) Cementoblastoma

    • B) Hypercementosis

    • C) Condensing osteitis

    • D) Periapical granuloma

    • Answer: B) Hypercementosis

84. Where is the highest gingival contour level normally found on anterior teeth?

    • A) Distal

    • B) Mesial

    • C) Mid-facial

    • D) Lingual

    • Answer: B) Mesial

85. Lead apron blocks approximately what percentage of scattered X-ray radiation?

    • A) $50\%$

    • B) $75\%$

    • C) $96\%$

    • D) $100\%$

    • Answer: C) $96\%$

86. Short stature, sloping shoulders, impacted teeth, absent clavicles. Diagnosis?

    • A) Dentinogenesis imperfecta

    • B) Cleidocranial dysplasia

    • C) Osteogenesis imperfecta

    • D) Hypophosphatasia

    • Answer: B) Cleidocranial dysplasia

87. Acute osteomyelitis after tooth extraction is most commonly caused by:

    • A) Staphylococcus aureus

    • B) Streptococcus mutans

    • C) Pseudomonas

    • D) Candida

    • Answer: A) Staphylococcus aureus

88. When is the best time to administer an analgesic for post-extraction pain?

    • A) 1 day after extraction

    • B) After anesthesia wears off

    • C) Before anesthesia wears off

    • D) Only if pain develops

    • Answer: C) Before anesthesia wears off

89. HIV-positive male with white corrugated lesions on lateral tongue. Pathogen?

    • A) HPV

    • B) Epstein-Barr virus (EBV)

    • C) Candida albicans

    • D) HSV

    • Answer: B) Epstein-Barr virus (EBV)

90. Hormone most important for normal tooth eruption:

    • A) Insulin

    • B) Thyroxine (T4)

    • C) Parathyroid hormone

    • D) Cortisol

    • Answer: B) Thyroxine (T4)

91. Bronze pigmentation of oral mucosa is associated with:

    • A) Cushing's syndrome

    • B) Addison's disease

    • C) Grave's disease

    • D) Acromegaly

    • Answer: B) Addison's disease

92. Pink spot/discoloration in a carious tooth indicates:

    • A) Pulpal necrosis

    • B) Internal resorption

    • C) Tetracycline stain

    • D) Fluorosis

    • Answer: B) Internal resorption

93. Intermittent sharp chewing pain, single cusp tenderness, no radiolucency. Diagnosis?

    • A) Acute apical periodontitis

    • B) Cracked tooth syndrome

    • C) Pulpal necrosis

    • D) Occlusal trauma

    • Answer: B) Cracked tooth syndrome

94. Cusp of Carabelli is located on which tooth?

    • A) Maxillary incisor

    • B) Mandibular first molar

    • C) Maxillary first molar

    • D) Maxillary 1st premolar

    • Answer: C) Maxillary first molar

95. Most prominent pulp horns are present in which deciduous tooth?

    • A) Deciduous maxillary first molar

    • B) Deciduous mandibular first molar

    • C) Deciduous maxillary second molar

    • D) Deciduous mandibular second molar

    • Answer: B) Deciduous mandibular first molar

96. Saw-tooth rete ridges histopathology is characteristic of:

    • A) Pemphigus vulgaris

    • B) Lichen planus

    • C) Psoriasis

    • D) Leukoplakia

    • Answer: B) Lichen planus

97. Primary vascular pathology causing poor healing in irradiated oral tissues:

    • A) Thrombophlebitis

    • B) Endarteritis obliterans

    • C) Capillary proliferation

    • D) Vasospasm

    • Answer: B) Endarteritis obliterans

98. Sudden severe electric-shock pain in right maxillary region lasting seconds. Diagnosis?

    • A) Postherpetic neuralgia

    • B) Trigeminal neuralgia

    • C) Dental abscess

    • D) TMJ disorder

    • Answer: B) Trigeminal neuralgia

99. Newborn with tetany, hypocalcemia, decreased PTH, cardiac defect, hypomineralized teeth. Diagnosis?

    • A) Down syndrome

    • B) DiGeorge syndrome

    • C) Crouzon syndrome

    • D) Pierre Robin

    • Answer: B) DiGeorge syndrome

100. DiGeorge syndrome is due to failure of development of which structures?

     • A) $1^{\text{st}}$ & $2^{\text{nd}}$ branchial arches

     • B) $2^{\text{nd}}$ & $3^{\text{rd}}$ pharyngeal pouches

     • C) $3^{\text{rd}}$ & $4^{\text{th}}$ pharyngeal pouches

     • D) $1^{\text{st}}$ & $4^{\text{th}}$ branchial clefts

     • Answer: C) $3^{\text{rd}}$ & $4^{\text{th}}$ pharyngeal pouches

101. Monro's microabscesses are seen in:

     • A) Lichen planus

     • B) Pemphigus vulgaris

     • C) Psoriasis

     • D) Bullous pemphigoid

     • Answer: C) Psoriasis

102. Elongated styloid process with throat pain, dysphagia, and referred otalgia. Diagnosis?

     • A) TMJ disorder

     • B) Glossopharyngeal neuralgia

     • C) Eagle's syndrome

     • D) Ludwig's angina

     • Answer: C) Eagle's syndrome

103. Which nerve is irritated in Eagle's syndrome?

     • A) Lingual nerve

     • B) Glossopharyngeal nerve

     • C) Hypoglossal nerve

     • D) Facial nerve

     • Answer: B) Glossopharyngeal nerve

104. Gustatory sweating and flushing over the cheek during mealtime post-parotidectomy (Frey's syndrome) occurs due to:

     • A) Regeneration of parasympathetic fibers of auriculotemporal nerve

     • B) Irritation of glossopharyngeal nerve

     • C) Elongated styloid process

     • D) Lesion of hypoglossal nerve

     • Answer: A) Regeneration of parasympathetic fibers of auriculotemporal nerve