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৪৮তম স্পেশাল বিসিএস ডেন্টাল ⎯ মডেল টেস্ট [Archived]

পরীক্ষা৪৮তম স্পেশাল বিসিএস ডেন্টাল ⎯ মডেল টেস্ট [Archived]তারিখতারিখ অনির্ধারিতসময়40 minutes
মোট প্রশ্ন৮০
সিলেবাস
Exam – 10 Subject Final Topics: Conservative Dentistry & Dental Radiology, Oral surgery and Anaesthesia.
ঘনত্ব
উত্তর
উত্তরিতবর্তমানপুনরায় দেখুনঅসম্পূর্ণ

৪৮তম স্পেশাল বিসিএস ডেন্টাল ⎯ মডেল টেস্ট [Archived]

৪৮তম স্পেশাল বিসিএস ডেন্টাল ⎯ মডেল টেস্ট [Archived] · তারিখ অনির্ধারিত · ৮০ প্রশ্ন

.
When should finishing and polishing of composite restorations ideally be performed?
  1. Immediately after curing
  2. After 24 hours of placement
  3. Before curing
  4. After one week
সঠিক উত্তর:
After 24 hours of placement
উত্তর
সঠিক উত্তর:
After 24 hours of placement
ব্যাখ্যা
In clinical practice:

Some clinicians perform initial finishing immediately with very gentle instruments to remove gross excess, but the final polishing is best delayed (usually 24 hours) to optimize surface properties.
.
In apexogenesis, the pulp is:
  1. Necrotic
  2. Completely removed
  3. Partially removed
  4. Maintained vital
সঠিক উত্তর:
Maintained vital
উত্তর
সঠিক উত্তর:
Maintained vital
ব্যাখ্যা
Apexogenesis
Purpose:
Preserve pulp vitality
Promote continued root growth
Allow natural apical foramen closure
Strengthen root walls and prevent fracture

 Indications:
Vital pulp 
Immature tooth with open apex

Procedure Steps:
Remove inflamed coronal pulp (partial pulpotomy)
Place biocompatible dressing (e.g., calcium hydroxide, MTA, or Biodentine)
Seal with permanent restoration
Periodic radiographic monitoring to assess root development
.
Which material is contraindicated as a liner due to its strong acidity?
  1. Zinc phosphate cement
  2. Calcium hydroxide
  3. Polycarboxylate cement
  4. Glass ionomer cement
সঠিক উত্তর:
Zinc phosphate cement
উত্তর
সঠিক উত্তর:
Zinc phosphate cement
ব্যাখ্যা
Zinc Phosphate Cement 

Composition:

Powder:
Zinc oxide (main)
Magnesium oxide (minor)
Liquid:
Aqueous solution of phosphoric acid
Buffers (aluminum and zinc phosphates)

Uses in Dentistry:
Luting agent for crowns, bridges, inlays, onlays
Base material under restorations
Orthodontic band cementation

Properties:
Setting Time: ~5–9 minutes
Mixing: On a cool glass slab in increments
Initial pH low (~2) → acidic, but becomes neutral over time
Mechanical Strength: High compressive strength
No chemical bond to tooth (retention is mechanical)

Disadvantages:
Pulpal irritation due to low initial pH
Brittle under tensile forces
Lacks antibacterial properties
Not adhesive
.
The thickness of a base should ideally be:
  1. Less than 0.5 mm
  2. 1-2 mm
  3. More than 3 mm
  4. None of the above
সঠিক উত্তর:
1-2 mm
উত্তর
সঠিক উত্তর:
1-2 mm
ব্যাখ্যা
Base in Cavity 

Function of Base

Protect the pulp
Replace lost dentin
Provide thermal insulation
Offer mechanical support under restorative material

Indications:
Deep cavities near the pulp
Under metallic restorations (e.g., amalgam)
When dentin thickness is insufficient (<1 mm)

Common Base Materials:
Zinc phosphate cement
Zinc polycarboxylate
Glass ionomer cement (GIC) – has fluoride release
Calcium hydroxide – for pulp protection, but weak mechanically
Resin-modified GIC – stronger and adhesive

Thickness of base in restorative dentistry depends on the material used and the remaining dentin thickness. General guidelines:

- Calcium hydroxide liner: <0.5 mm (just a thin layer over deepest area near pulp)
- Base (like zinc phosphate, glass ionomer, resin-modified GIC): around 1–2 mm
- Not more than one-third of the cavity depth
- Enough to provide thermal protection and support over liner if needed

Too thick base may compromise strength of the restoration and increase the risk of failure.
.
Pulp polyp usually occurs in:
  1. Young patients with good pulp vitality
  2. Elderly patients with poor healing
  3. Patients with systemic illness
  4. All age groups equally
সঠিক উত্তর:
Young patients with good pulp vitality
উত্তর
সঠিক উত্তর:
Young patients with good pulp vitality
ব্যাখ্যা
Pulp Polyp (Chronic Hyperplastic Pulpitis) 
Key Features:

Seen in children and adolescents
More common in first permanent molars
Occurs when pulp remains vital and hyperplastic, open apex, not necrotic
Usually painless, unless secondarily infected

Clinical Appearance:

Pink or red fleshy mass protruding from the pulp chamber
May bleed on touch
Can be mistaken for gingival tissue or granuloma

Histology:

Granulation tissue with chronic inflammatory cells
Capillary proliferation
Covered with stratified squamous epithelium due to surface irritation
.
What is the correct sequence for placing materials in a deep cavity with potential pulp exposure under composite restoration?
  1. Etch → Adhesive → Composite
  2. Calcium hydroxide liner → GIC base → Etch → Adhesive → Composite
  3. GIC base → ZOE → Composite
  4. Etch → Calcium hydroxide → ZOE → Composite
সঠিক উত্তর:
Calcium hydroxide liner → GIC base → Etch → Adhesive → Composite
উত্তর
সঠিক উত্তর:
Calcium hydroxide liner → GIC base → Etch → Adhesive → Composite
ব্যাখ্যা
Pulp Protection Sequence in Cavity Preparation 

Goal:
To protect the pulp from thermal, chemical, mechanical, and bacterial irritation during restorative procedures.


Sequence (Deepest to most superficial):

1.Calcium Hydroxide (if near pulp):
Used as a liner for direct or indirect pulp capping
Stimulates reparative dentin formation

2.Base (if needed):
Materials: Glass Ionomer Cement (GIC), Zinc Polycarboxylate, or Zinc Phosphate
Provides thermal insulation and mechanical support

3.Cavity Liner (optional):
Thin coating to seal dentinal tubules (e.g., copal varnish for amalgam)
Not used under composites

4.Adhesive/Bonding Agent (for composites) 

5.Restorative Material:
Amalgam, composite, GIC, etc., placed on top

Example:
Shallow cavity: Only bonding agent + restorative
Moderate cavity: Liner (optional) + bonding/base + restorative
Deep cavity (near pulp): Calcium hydroxide → GIC base → bonding (if composite) → restorative
.
Main disadvantage of Zinc Polycarboxylate cement is:
  1. Poor biocompatibility
  2. Poor adhesion
  3. Short working time and low strength
  4. Contains fluoride
সঠিক উত্তর:
Short working time and low strength
উত্তর
সঠিক উত্তর:
Short working time and low strength
ব্যাখ্যা
Zinc Polycarboxylate Cement 
Composition:
Powder: Zinc oxide, magnesium oxide
Liquid: Aqueous solution of polyacrylic acid

Uses:
Luting agent for crowns, bridges, inlays
Base under restorations
Cementing orthodontic appliances

Properties:
Chemical bond to tooth structure (via calcium in enamel/dentin)
Biocompatible and less irritating to the pulp
Working time: ~2.5 minutes
Setting time: ~6 minutes
Compressive strength: Moderate
Film thickness: Acceptably thin

Advantages:
Chemically bonds to enamel and dentin
Low pulpal irritation
Good thermal insulation
Easy to mix and handle

Disadvantages:
Lower strength than resin cements
Moisture-sensitive during setting
Short working time
Not ideal under heavy occlusal loads
.
Miracle Mix is a combination of:
  1. Zinc oxide and calcium
  2. Glass ionomer and silver alloy
  3. Polycarboxylate and alumina
  4. Zinc phosphate and amalgam
সঠিক উত্তর:
Glass ionomer and silver alloy
উত্তর
সঠিক উত্তর:
Glass ionomer and silver alloy
ব্যাখ্যা
Miracle Mix is a metal-reinforced glass ionomer cement (GIC) used for core build-ups and restorations in stress-bearing areas.

Key Features:
Combines fluoride-releasing property of GIC with mechanical strength of metal
Self-cures chemically
Radiopaque

Uses:
Core build-up material
Temporary restorations in posterior teeth
Cervical or Class I cavities
Foundation for crowns

Advantages:
Better strength than conventional GIC
Fluoride release (anticariogenic)
Bonds to tooth structure chemically
Easy to use in bulk

Disadvantages:
Inferior esthetics due to silver content
Lower strength compared to composite or amalgam
Not polishable to a high gloss
Brittle in very thin layers
.
Which pulp therapy is preferred for a cariously exposed vital pulp in a primary molar without sign of infection?
  1. Pulpectomy
  2. Apexification
  3. Indirect pulp capping
  4. Pulpotomy
সঠিক উত্তর:
Pulpotomy
উত্তর
সঠিক উত্তর:
Pulpotomy
ব্যাখ্যা
Pulpotomy 

Definition:
Pulpotomy is a vital pulp therapy procedure involving the removal of the coronal portion of the dental pulp, while preserving the vitality of the radicular pulp.

Indications:
Primary teeth with reversible pulpitis
Permanent immature teeth (open apex) with vital pulp
Pulp exposure due to caries or trauma

Contraindications:
Signs of irreversible pulpitis (spontaneous pain, swelling, mobility)
Non-vital pulp or periapical pathology
Internal/external resorption

Procedure Steps:
Local anesthesia and isolation (rubber dam)
Remove caries and access pulp chamber
Excise coronal pulp using a sterile spoon excavator or bur
Control bleeding (moist cotton pellet for ~5 mins)
Place medicament (e.g., MTA, formocresol, ferric sulfate)
Seal with base (e.g., GIC)
Restore (usually with SSC in primary teeth)

Common Medicaments:
Formocresol (traditional, now less used due to toxicity concerns)
Mineral Trioxide Aggregate (MTA) – biocompatible, highly effective
Biodentine – newer alternative to MTA
Ferric sulfate – for hemostasis
১০.
Ellis Class III fracture involves:
  1. Enamel only
  2. Enamel and dentin
  3. Enamel, dentin and pulp
  4. Root only
সঠিক উত্তর:
Enamel, dentin and pulp
উত্তর
সঠিক উত্তর:
Enamel, dentin and pulp
ব্যাখ্যা
Ellis Fracture Classification 

Class I: Enamel Fracture
Class II: Enamel and Dentin Fracture
Class III: Enamel, Dentin, and Pulp Fracture
Class IV: Non-vital Tooth
Class V: Tooth Avulsion
Class VI: Root Fracture
Class VII: Tooth Displacement (Luxation)
১১.
The most appropriate storage medium for an avulsed tooth is:
  1. Tap water
  2. Dry tissue
  3. Milk
  4. Ice
সঠিক উত্তর:
Milk
উত্তর
সঠিক উত্তর:
Milk
ব্যাখ্যা
Avulsed Tooth Storage Medium 

Hank’s Balanced Salt Solution (HBSS) – Gold standard
Cold milk – Easily available, good for up to 3 hours
Saline solution – Acceptable short-term storage
Patient’s saliva (inside the mouth, e.g., buccal vestibule) – Temporary option
Tap water – Least ideal; causes cell swelling and damage
১২.
Which is the most cariogenic sugar?
  1. Glucose
  2. Lactose
  3. Galactose
  4. Sucrose
সঠিক উত্তর:
Sucrose
উত্তর
সঠিক উত্তর:
Sucrose
ব্যাখ্যা
Cariogenic Sugars 

Sucrose: Most cariogenic; used by bacteria to produce sticky glucans aiding plaque formation
Glucose
Fructose
Maltose and lactose: Less cariogenic 
.
১৩.
What is the most common space maintainer for premature loss of primary first molar?
  1. Lingual arch
  2. Nance appliance
  3. Band and loop
  4. Patial denture
সঠিক উত্তর:
Band and loop
উত্তর
সঠিক উত্তর:
Band and loop
ব্যাখ্যা
Space Maintainers – Types and Uses

1. Band and Loop:

Use: Maintains space after premature loss of a single primary molar

2. Lingual Arch:

Use: Maintains bilateral space in the mandibular arch after loss of multiple primary molars

3. Nance Appliance:

Use: Maintains space in the maxillary arch after loss of molars


4. Distal Shoe:

Use: Maintains space when primary second molar is lost before eruption of permanent first molar

5. Removable Space Maintainer:

Use: When multiple teeth lost and patient can cooperate
Appliance: Acrylic partial denture with clasps
১৪.
What is the earliest clinical sign of enamel caries?
  1. Brown discoloration
  2. Loss of enamel structure
  3. White spot lesion
  4. Cavitation
সঠিক উত্তর:
White spot lesion
উত্তর
সঠিক উত্তর:
White spot lesion
ব্যাখ্যা
Features of enamel caries :

Early lesion: White spot lesion (opaque, chalky) due to subsurface mineral loss

Progression: Enamel rods dissolve, surface may remain intact initially (subsurface decay)

Common sites: Pits and fissures of molars, smooth surfaces near gingiva, approximal areas

Appearance: May progress to brown or cavitated lesions if untreated
১৫.
What is the ideal mercury-to-alloy ratio in dental amalgam?
  1. 1:1
  2. 1:2
  3. 2:1
  4. 1:3
সঠিক উত্তর:
1:1
উত্তর
সঠিক উত্তর:
1:1
ব্যাখ্যা
Amalgam Composition 
Composition:

Mercury (Hg): ~50% by weight (liquid)
Alloy powder: ~50% by weight, mainly consisting of:
Silver (Ag): 40–70% (adds strength, corrosion resistance)
Tin (Sn): 12–30% (improves workability)
Copper (Cu): 12–30% (reduces corrosion, increases strength)
Minor elements: Zinc (Zn) (0–2%) for oxidation control

Types of amalgam:

Low-copper (traditional)
High-copper (most common today; less corrosion, better strength)
১৬.
Wedge placement during Class II restoration helps in:
  1. Establishing proper proximal contact
  2. Minimizing polymerization
  3. Preventing postoperative sensitivity
  4. Reducing occlusal load
সঠিক উত্তর:
Establishing proper proximal contact
উত্তর
সঠিক উত্তর:
Establishing proper proximal contact
ব্যাখ্যা
Wedge 
Purpose:
Separates adjacent teeth slightly to create space for restorative material (especially in Class II cavities)
Provides tight contact between restoration and adjacent tooth
Prevents overhangs
Helps adapt matrix bands tightly against the tooth

Types:
Wooden wedges (commonly used)
Plastic wedges (radiolucent, less traumatic)

Placement Tips:
Insert from the lingual side for better adaptation
Avoid excessive force to prevent trauma to the gingiva
১৭.
ZOE (Zinc Oxide Eugenol) is contraindicated under composite restorations because:
  1. It stains teeth
  2. It is not biocompatible
  3. It interferes with polymerization
  4. It causes thermal sensitivity
সঠিক উত্তর:
It interferes with polymerization
উত্তর
সঠিক উত্তর:
It interferes with polymerization
ব্যাখ্যা
Zinc Oxide Eugenol (ZOE) Cement is generally not recommended under composite restorations because:

Eugenol inhibits polymerization of resin composites, leading to poor bonding and restoration failure.
Causes softening or incomplete curing of the composite resin.

Exceptions:
Some eugenol-free ZOE formulations (e.g., intermediate restorative material - IRM without eugenol) can be used as a temporary base before composite placement.

Alternative Bases Under Composite:
Glass Ionomer Cement (GIC) or resin-modified GIC — compatible and bond well
Calcium hydroxide (for pulp protection) followed by GIC
১৮.
Cavo-surface angle for Class I amalgam restoration should be:
  1. 30–45°
  2. 90°
  3. More than 120°
  4. Less than 60°
সঠিক উত্তর:
90°
উত্তর
সঠিক উত্তর:
90°
ব্যাখ্যা
Cavosurface Margin 
Definition:
The cavosurface margin is the junction where the prepared cavity wall meets the unprepared tooth surface (enamel or dentin).

Importance:
Determines the marginal seal of a restoration
Affects retention, strength, and esthetic outcome
Influences the choice of cavity design and restorative material

Types of Cavosurface Margins:
Beveled: Usually on enamel to increase surface area for bonding
Butt Joint: Right angle margin, common with amalgam
Chamfer: Rounded shoulder, used in crown preparations
১৯.
Acid etching of enamel is done with:
  1. 10% Phosphoric acid
  2. 50% Nitric acid
  3. 20% Citric acid
  4. 37% Phosphoric acid
সঠিক উত্তর:
37% Phosphoric acid
উত্তর
সঠিক উত্তর:
37% Phosphoric acid
ব্যাখ্যা
Acid Etching 
A technique using acidic solution (usually 37% phosphoric acid) to microscopically roughen the enamel or dentin surface to enhance adhesion of restorative materials.

Purpose:
Removes the smear layer
Creates micro-porosities in enamel for mechanical interlocking
Improves bond strength of composites and sealants

Procedure:
Apply acid etchant (gel or liquid) to enamel for 15–30 seconds
For dentin, apply for 10–15 seconds (to avoid over-etching)
Rinse thoroughly with water
Dry enamel to a frosty white appearance; dentin should remain slightly moist
Apply bonding agent immediately

Effects:
Enamel surface becomes roughened and porous
Enhances resin penetration and hybrid layer formation in dentin
২০.
The most common cause of postoperative sensitivity in composite restorations is:
  1. Excess bonding agent
  2. Polymerization shrinkage
  3. Saliva contamination
  4. Incorrect finishing
সঠিক উত্তর:
Polymerization shrinkage
উত্তর
সঠিক উত্তর:
Polymerization shrinkage
ব্যাখ্যা
Sensitivity in Composite Restorations
Causes of Postoperative Sensitivity:

Polymerization Shrinkage:
Causes gap formation at the tooth-restoration interface leading to fluid movement in dentinal tubules (hydrodynamic theory) → sensitivity.

Microleakage:
Poor seal allows bacterial toxins and fluids to irritate pulp.

Inadequate Bonding:
Improper etching or bonding technique can result in weak adhesion and sensitivity.

Pulpal Inflammation:
Deep cavities may cause pulp irritation during or after restoration.

Thermal Insulation:
Thin or absent base under composite can lead to temperature changes transmitted to pulp.

Prevention Tips:
Use proper acid etching and bonding protocol
Incremental placement of composite to reduce shrinkage stress
Use of desensitizing agents or liners (e.g., calcium hydroxide, GIC base) in deep cavities
Ensure good isolation and moisture control
২১.
Which of the following best describes the "laws of orifice location" used in access cavity preparation?
  1. always located at the center of the pulp chamber
  2. at the junction of walls and floor of the pulp chamber and are equidistant from a line drawn mesiodistally
  3. randomly placed and cannot be predicted
  4. always on the mesial side of the pulp chamber
সঠিক উত্তর:
at the junction of walls and floor of the pulp chamber and are equidistant from a line drawn mesiodistally
উত্তর
সঠিক উত্তর:
at the junction of walls and floor of the pulp chamber and are equidistant from a line drawn mesiodistally
ব্যাখ্যা
Law of Orifice Location

This law states that root canal orifices are always located at the junction of the floor and walls of the pulp chamber.
২২.
In maxillary first molars, which canal orifice is most difficult to locate during access cavity preparation?
  1. MB1
  2. MB2
  3. Distobuccal
  4. Palatal
সঠিক উত্তর:
MB2
উত্তর
সঠিক উত্তর:
MB2
ব্যাখ্যা
MB2 Canal (Second Mesiobuccal) 
Key Facts:
Present in up to 90% of maxillary first molars
Often difficult to locate and negotiate due to small size and complex anatomy
Missing MB2 canal is a common cause of root canal treatment failure in these teeth

Identification Tips:
Use magnification (dental loupes or microscope)
Look for a small groove or developmental line between the MB1 canal and the palatal canal
Use ultrasonic tips to trough carefully
CBCT imaging helps detect MB2 presence and anatomy
২৩.
Most retentive feature in a Class II amalgam preparation is:
  1. Occlusal convergence
  2. Gingival seat
  3. Reverse curve
  4. Dovetail
সঠিক উত্তর:
Occlusal convergence
উত্তর
সঠিক উত্তর:
Occlusal convergence
ব্যাখ্যা
Amalgam Retention 

Amalgam does not bond chemically to tooth structure, so retention depends on mechanical factors in cavity design.


Key Retentive Features:

Parallel or Slightly Convergent Walls:
Provides resistance form; walls taper slightly toward occlusal to prevent dislodgment.

Retention Grooves or Boxes:
Small undercuts or grooves placed in dentin to lock restoration mechanically.

Beveled or Rounded Internal Line Angles:
Avoid stress concentration and improve adaptation.

Extension into Sound Tooth Structure:
Adequate depth and width to support restoration.

Amalgam Condensation:
Proper packing to eliminate voids and enhance physical retention.
২৪.
What is the main disadvantage of relying solely on radiographs for working length determination?
  1. Radiation exposure
  2. Two-dimensional image of three-dimensional structure
  3. Costly equipment
  4. Time-consuming procedure
সঠিক উত্তর:
Two-dimensional image of three-dimensional structure
উত্তর
সঠিক উত্তর:
Two-dimensional image of three-dimensional structure
ব্যাখ্যা
Working Length Determination from Radiograph

Purpose:
To ensure complete cleaning and shaping of the canal
To avoid over- or under-instrumentation
To guide obturation up to the correct length

Procedure:
Insert a small endodontic file (#15 or #20) into the canal
Take a periapical radiograph using the paralleling technique
Evaluate the file tip’s position relative to the radiographic apex
Adjust length to position the tip 0.5–1 mm short of the apex

Additional Tips:
Repeat radiograph if necessary
Use electronic apex locator (EAL) for confirmation
Combine both methods for best accuracy
২৫.
Balanced force technique uses:
  1. Alternating clockwise and counter-clockwise motions
  2. Clockwise only motion
  3. K-files Only
  4. Reaming motion throughout
সঠিক উত্তর:
Alternating clockwise and counter-clockwise motions
উত্তর
সঠিক উত্তর:
Alternating clockwise and counter-clockwise motions
ব্যাখ্যা
Balanced Force Technique
A canal instrumentation method using hand files (especially flexible NiTi K-files) that balances cutting and debris removal while maintaining canal shape, especially in curved canals.

Purpose:
Minimize canal transportation and ledging
Preserve canal curvature
Improve debris removal apically

Instruments Used:
NiTi K-files (0.04 or 0.02 taper)
Low-speed handpiece (optional)

Technique Steps:

Insertion (Engage):
Insert file with gentle clockwise rotation (~90°) to engage dentin.
Cutting (Cut):
Apply 360° counter-clockwise rotation with slight apical pressure to cut dentin.
Removal (Disengage):
Clockwise turn (~120°) without pressure to remove the file and debris.

Advantages:
Safer in curved canals
Reduces instrument separation
Less risk of canal distortion
২৬.
Crown-down technique involves:
  1. Using small files first
  2. Starting from apex and proceeding coronally
  3. Enlarging coronal third first, then progressing apically
  4. Bypassing curved canals
সঠিক উত্তর:
Enlarging coronal third first, then progressing apically
উত্তর
সঠিক উত্তর:
Enlarging coronal third first, then progressing apically
ব্যাখ্যা
Crown-Down Technique 
A root canal instrumentation method where coronal portions of the canal are prepared before the apical parts, using progressively smaller instruments.

Purpose:
Reduce coronal resistance
Improve irrigant penetration
Minimize debris extrusion and canal distortion
Safer navigation of curved canals

Steps:
Coronal Flaring:
Use larger files or Gates Glidden drills to widen coronal third first.
Middle Third Preparation:
Use medium-sized files to shape the middle portion.
Apical Preparation:
Finish with smaller files to shape and clean the apical third.

Advantages:
Enhanced access to apical region
Improved debris removal and irrigant flow
Reduced instrument stress and breakage
Better tactile control
২৭.
The recommended technique to avoid apical extrusion of irrigant is:
  1. Using high pressure syringe
  2. Binding needle to canal walls
  3. Using side-vented needle placed 2 mm short of working length
  4. Using wide gauge needle at apex
সঠিক উত্তর:
Using side-vented needle placed 2 mm short of working length
উত্তর
সঠিক উত্তর:
Using side-vented needle placed 2 mm short of working length
ব্যাখ্যা
Preventionof apical extrusion of irrigant:

Use side-vented needles
Keep needle 2–3 mm short of working length
Apply gentle pressure
Use rubber stopper for length control
Consider using negative pressure irrigation systems
২৮.
Which of the following statements is true regarding MTAD?
  1. It is primarily an oxidizing agent
  2. It contains tetracycline, acid, and a detergent
  3. It is contraindicated in children
  4. It dissolves pulp tissue effectively
সঠিক উত্তর:
It contains tetracycline, acid, and a detergent
উত্তর
সঠিক উত্তর:
It contains tetracycline, acid, and a detergent
ব্যাখ্যা
MTAD 
Full Form:
MTAD = Mixture of Tetracycline, Acid, and Detergent

Composition:
Tetracycline isomer (Doxycycline 3%) – antibacterial
Citric acid (4.25%) – smear layer removal
Detergent (Tween 80) – lowers surface tension for better penetration

Uses in Endodontics:
Final root canal irrigant after NaOCl
Removes smear layer
Kills resistant bacteria, especially Enterococcus faecalis
Enhances dentin bonding

Advantages:
Effective antimicrobial action
Biocompatible and less toxic than NaOCl
Promotes cleaner canal walls for obturation

Limitations:
More expensive than conventional irrigants
Requires correct sequence: NaOCl → MTAD
২৯.
Zinc oxide eugenol-based sealers are:
  1. Hydrophobic
  2. Non-resorbable
  3. Highly adhesive to dentin
  4. Resorbable when extruded
সঠিক উত্তর:
Resorbable when extruded
উত্তর
সঠিক উত্তর:
Resorbable when extruded
ব্যাখ্যা
ZOE Sealer –
ZOE = Zinc Oxide Eugenol sealer

Composition:
Powder: Zinc oxide, rosin, bismuth compounds (for radiopacity)
Liquid: Eugenol (acts as oil-based liquid and antimicrobial)

Uses:
As an endodontic sealer in root canal obturation
Used with gutta-percha to fill voids and seal canal walls

Advantages:
Long history of clinical success
Antimicrobial due to eugenol
Good flow and working time
Radiopaque

Disadvantages:
Soluble over time → potential leakage
Can be irritating to periapical tissues if extruded
No chemical bond to dentin
Shrinks slightly on setting
৩০.
The main drawback of lateral condensation is:
  1. Requires expensive equipment
  2. Excessive extrusion of gutta-percha
  3. Poor adaptation to irregular canal walls
  4. Inability to use gutta-percha
সঠিক উত্তর:
Poor adaptation to irregular canal walls
উত্তর
সঠিক উত্তর:
Poor adaptation to irregular canal walls
ব্যাখ্যা
Drawbacks of Lateral Condensation Technique 

Incomplete adaptation:
May not perfectly adapt to canal irregularities, especially in oval or curved canals.

Void formation:
Risk of creating voids between cones or at canal walls.

Vertical root fracture risk:
Excessive lateral pressure during condensation can fracture thin roots.

Time-consuming:
Technique-sensitive and requires multiple accessory cones.

Difficult in curved/narrow canals:
Inadequate condensation or spreader placement in apical regions.

Not ideal for wide canals:
Leaves unfilled spaces unless warm techniques or flowable sealers are used.
৩১.
Drawback of MTA includes:
  1. High solubility
  2. Lack of biocompatibility
  3. Tooth discoloration and long setting time
  4. No antibacterial property
সঠিক উত্তর:
Tooth discoloration and long setting time
উত্তর
সঠিক উত্তর:
Tooth discoloration and long setting time
ব্যাখ্যা
MTA (Mineral Trioxide Aggregate) – Concise Note

Definition:
MTA is a biocompatible, bioactive endodontic material used for pulp therapy, root repair, and perforation sealing.


Composition:
Tricalcium silicate
Dicalcium silicate
Tricalcium aluminate
Bismuth oxide (radiopacity)
Calcium sulfate (setting control)

Properties:
Sets in moisture
High pH (~12.5) → antimicrobial
Biocompatible and bioinductive (stimulates cementogenesis)
Radiopaque
Long setting time (~2–4 hours)

Uses:
Pulp capping / pulpotomy
Apexification
Perforation repair
Root-end filling (retrograde)
Regenerative endodontics

Disadvantages:
Long setting time
Expensive
Difficult handling
Can cause tooth discoloration (especially gray MTA)
৩২.
The most important factor in achieving successful RCT is:
  1. Length of obturation
  2. Type of sealer used
  3. Irrigant used
  4. Method of access cavity preparation
সঠিক উত্তর:
Length of obturation
উত্তর
সঠিক উত্তর:
Length of obturation
ব্যাখ্যা
Successful Root Canal Treatment (RCT) – Key Criteria

Clinical Signs of Success:
Absence of pain (spontaneous or on biting)
No swelling, sinus tract, or mobility
Normal function restored
No tenderness on percussion or palpation

Radiographic Signs of Success:
Proper obturation: Root canal filled 0.5–1 mm short of apex
No voids in filling
Healing of periapical radiolucency (if previously present)
Intact lamina dura and normal periodontal ligament space

Essential Factors for Success:
Accurate diagnosis and case selection
Proper working length determination
Complete cleaning and shaping
Effective irrigation and disinfection
Hermetic (leak-proof) obturation
Well-sealed coronal restoration
৩৩.
Which is the best method for determining working length in a tooth with apical resorption?
  1. Radiograph
  2. Digital Radiograph
  3. Tactile sense
  4. Electronic apex locator
সঠিক উত্তর:
Electronic apex locator
উত্তর
সঠিক উত্তর:
Electronic apex locator
ব্যাখ্যা
Advantages:

Highly accurate (especially newer models)

Useful in open apices, re-treatment, or distorted radiographs

Reduces radiation exposure (fewer X-rays needed)


Limitations:

Accuracy decreases in presence of metal restorations, perforations, or dry canals

Should always be verified with radiographs
৩৪.
A patient reports prolonged pain after thermal stimulus, especially at night. Likely diagnosis:
  1. Reversible pulpitis
  2. Symptomatic irreversible pulpitis
  3. Asymptomatic irreversible pulpitis
  4. Necrotic pulp
সঠিক উত্তর:
Symptomatic irreversible pulpitis
উত্তর
সঠিক উত্তর:
Symptomatic irreversible pulpitis
ব্যাখ্যা
Clinical Features:

Spontaneous pain (without stimulus)

Lingering pain after hot/cold stimulus

Throbbing or radiating pain

May be worse at night

Sometimes pain on percussion


Diagnosis Tests:

Thermal test: Prolonged pain to cold

Electric pulp test: Exaggerated or no response

Percussion: May be tender in advanced cases
৩৫.
Phoenix abscess is:
  1. A chronic abscess with sinus tract
  2. An acute flare-up of chronic periapical lesion
  3. A granulomatous lesion
  4. None of the above
সঠিক উত্তর:
An acute flare-up of chronic periapical lesion
উত্তর
সঠিক উত্তর:
An acute flare-up of chronic periapical lesion
ব্যাখ্যা
Cause:

Reactivation of chronic apical lesion (e.g., granuloma) due to:

New bacterial invasion

Trauma

Incomplete canal debridement

Lowered host resistance



Clinical Features:

Severe pain and tenderness

Tooth elevation or mobility

Swelling in adjacent soft tissues

Possible systemic signs (fever, malaise)
৩৬.
Which condition presents with sinus tract and is usually asymptomatic?
  1. Acute apical abscess
  2. Reversible pulpitis
  3. Chronic apical abscess
  4. Condensing osteitis
সঠিক উত্তর:
Chronic apical abscess
উত্তর
সঠিক উত্তর:
Chronic apical abscess
ব্যাখ্যা
Clinical Features:

Painless or mild discomfort

Visible opening on gingiva or oral mucosa (usually near involved tooth)

May have purulent discharge

Surrounding tissue may appear normal or slightly inflamed




Diagnosis:

Trace sinus tract with gutta-percha point on radiograph to identify source tooth

Vitality testing (usually non-vital pulp)

Radiograph shows periapical radiolucency at apex
৩৭.
Which bonding generation introduced self-etch adhesives?
  1. 3rd
  2. 4th
  3. 5th
  4. 6th
সঠিক উত্তর:
6th
উত্তর
সঠিক উত্তর:
6th
ব্যাখ্যা
Self-Etch Adhesive – Concise Note

Definition:
A self-etch adhesive is a dental bonding system that combines acid etching and primer application in one step without rinsing, simplifying bonding to enamel and dentin.


Types:

One-step (all-in-one): Etchant, primer and adhesive combined

Two-step: Separate self-etch primer and adhesive resin applied sequentially


Mechanism:

Acidic monomers partially dissolve smear layer and demineralize tooth surface

Simultaneously infiltrate collagen for hybrid layer formation

Creates micromechanical and chemical bond to tooth


Advantages:

Reduced postoperative sensitivity

Less technique-sensitive

Preserves dentin moisture better


Limitations:

Generally lower enamel bond strength than total-etch

Less effective smear layer removal in some cases
৩৮.
Which of the following causes elongation of the image in IOPA radiograph?
  1. Increased exposure time
  2. Excessive vertical angulation
  3. Insufficient vertical angulation
  4. Improper horizontal angulation
সঠিক উত্তর:
Insufficient vertical angulation
উত্তর
সঠিক উত্তর:
Insufficient vertical angulation
ব্যাখ্যা
Errors in Dental Radiography – Concise Note

Common Radiographic Errors:

Cone Cutting:

Partial image due to improper alignment of X-ray beam and film/sensor.
Overexposure / Underexposure:

Too dark or too light images caused by incorrect exposure settings.
Movement Blur:

Patient or tubehead movement causing blurred image.
Incorrect Film Placement:

Missing areas, overlapping, or distorted structures.
Elongation / Foreshortening:

Incorrect vertical angulation causing distorted tooth length.
Double Exposure:

Two images superimposed due to accidental re-exposure of film.
Artifacts:

Foreign objects, scratches, or debris on film/sensor
Prevention Tips:

Proper patient positioning
Correct exposure settings
Stabilize film/sensor and tubehead
Use paralleling technique
৩৯.
The most effective method to protect the operator from scatter radiation is:
  1. Wearing lead apron
  2. Standing at least 2 meters away and at an angle of 90–135°
  3. Standing behind the patient
  4. Using high-speed films
সঠিক উত্তর:
Standing at least 2 meters away and at an angle of 90–135°
উত্তর
সঠিক উত্তর:
Standing at least 2 meters away and at an angle of 90–135°
ব্যাখ্যা
Radiation Protection Measures:

1. For Patient:
- Use of lead apron and thyroid collar
- Use of high-speed films or digital sensors
- Proper collimation (preferably rectangular)
- Use of E/F-speed film
- Minimum exposure time
- Proper positioning and technique to avoid retakes

2. For Operator:
- Maintain distance of at least 6 feet from X-ray source
- Stand behind protective barrier or wall
- Never hold film in patient’s mouth
- Use dosimeter badges for exposure monitoring

3. Equipment Safety:
- Use of aluminum filters to absorb soft X-rays
- Regular equipment maintenance
- Use of appropriate exposure settings

4. Legal/Administrative Measures:
- Compliance with radiation safety norms
- Staff training on radiation hazards
- Record keeping of exposures and maintenance
৪০.
Cone beam computed tomography (CBCT) is most useful in:
  1. Detecting dental caries
  2. Assessing alveolar bone levels in gingivitis
  3. 3D assessment of impacted teeth
  4. Identifying pulp stones
সঠিক উত্তর:
3D assessment of impacted teeth
উত্তর
সঠিক উত্তর:
3D assessment of impacted teeth
ব্যাখ্যা
CBCT (Cone Beam Computed Tomography) 
CBCT is a specialized 3D imaging technique that provides detailed volumetric images of dental and maxillofacial structures with lower radiation than conventional CT.

Key Features:
3D visualization of teeth, bone, and soft tissues
High spatial resolution for accurate diagnosis
Smaller field of view (FOV) tailored for dental applications
Quick scan time (10-70 seconds)

Uses in Dentistry:
Implant planning
Evaluation of impacted teeth
Assessment of root canal anatomy and pathology
TMJ analysis
Detection of fractures and pathology

Advantages:
Lower radiation dose compared to medical CT
Precise anatomical detail
Improved treatment planning and outcomes

Limitations:
Costly equipment
Artifacts from metal restorations
Limited soft tissue contrast compared to medical CT
৪১.
Which of the following is the earliest and most consistent clinical sign of Ludwig’s angina?
  1. Trismus
  2. Submandibular swelling
  3. Tongue elevation
  4. Dysphagia
সঠিক উত্তর:
Tongue elevation
উত্তর
সঠিক উত্তর:
Tongue elevation
ব্যাখ্যা
Ludwig’s Angina

Etiology: Most commonly from infected mandibular molars (especially second and third molars).

Bacterial profile: Polymicrobial – Streptococcus viridans, Staphylococcus aureus,
anaerobes.

Clinical features:
Bilateral swelling of submandibular region
Elevated tongue → risk of airway obstruction
Firm, brawny swelling (not fluctuant)
Trismus, dysphagia, drooling, muffled voice
No abscess formation early on – it’s cellulitis, not a true abscess.

Airway compromise is the most dangerous complication.

Tx: Emergency airway management + high-dose IV antibiotics ± surgical drainage.
৪২.
A dental infection from the upper canine can spread to the cavernous sinus via which venous route?
  1. External jugular vein
  2. Facial vein via angular vein
  3. Retromandibular vein
  4. Inferior alveolar vein
সঠিক উত্তর:
Facial vein via angular vein
উত্তর
সঠিক উত্তর:
Facial vein via angular vein
ব্যাখ্যা
The facial vein communicates with the cavernous sinus via the angular vein. This is a fact of great clinical significance, because any infection of the region of the face drained by the facial vein can spread to the cavernous sinus, resulting in a serious condition called thrombosis of the cavernous sinus.
৪৩.
Which of the following is not a common space for dental infection spread?
  1. Submandibular space
  2. Retropharyngeal space
  3. Buccal space
  4. Pretracheal space
সঠিক উত্তর:
Pretracheal space
উত্তর
সঠিক উত্তর:
Pretracheal space
ব্যাখ্যা
Classification of Facial Spaces:

 A.Primary Spaces (Directly from dental origin)

Maxillary Infections
Canine space: From maxillary canine or 1st premolar
Buccal space: Molars/premolars above buccinator
Infratemporal space: Rare, upper 3rd molars

 Mandibular Infections
Submental space: From mandibular incisors
Sublingual space: Molars/premolars above mylohyoid
Submandibular space: Molars below mylohyoid
Buccal space: Crosses both jaws — molars usually

B.Secondary Spaces (Infection spreads from primary spaces)

Masticator space: Involves masseteric, pterygomandibular, and temporal spaces (from 3rd molars)

Lateral pharyngeal space: From submandibular/pterygomandibular

Retropharyngeal space: Danger space → can lead to mediastinitis

Prevertebral space: Deepest danger zone

Peritonsillar space: Infections can spread here from tonsils/dental origins
৪৪.
In periapical abscess, the spread of infection along the path of least resistance is often determined by:
  1. Tooth vitality
  2. Patient’s immune status
  3. Root length
  4. Position of muscle attachment relative to root apex
সঠিক উত্তর:
Position of muscle attachment relative to root apex
উত্তর
সঠিক উত্তর:
Position of muscle attachment relative to root apex
ব্যাখ্যা
Spread of Periapical Abscess 
A periapical abscess can spread beyond the apex depending on bone thickness, tooth location, and tissue resistance.

1. Through Bone to Soft Tissues: Infection perforates cortical bone, spreading into adjacent soft tissues. It commonly exits through the path of least resistance—usually the thinner buccal or lingual plate.

2. Sinus Tract Formation: 
Intraoral sinus: common in anterior maxilla or posterior mandible.
Extraoral sinus: can appear on the skin, especially in mandibular abscesses.

3. Fascial Space Involvement:
Primary spaces: Buccal, sublingual (above mylohyoid), submandibular (below mylohyoid), palatal.

Secondary spaces: Masticator, pterygomandibular, parapharyngeal, retropharyngeal—pose greater risk for complications.

4. Hematogenous Spread: Bacteria can enter the bloodstream, potentially causing bacterial endocarditis, septicemia, or distant abscesses (e.g. brain, lungs) in immunocompromised individuals.

5. Life-Threatening Complications:

Ludwig’s angina
Cavernous sinus thrombosis
৪৫.
A fluctuant, tender swelling in the upper neck below the angle of mandible with systemic signs of infection suggests:
  1. Reactive lymphadenopathy
  2. Parotid tumor
  3. Abscess secondary to odontogenic infection
  4. Cystic hygroma
সঠিক উত্তর:
Abscess secondary to odontogenic infection
উত্তর
সঠিক উত্তর:
Abscess secondary to odontogenic infection
ব্যাখ্যা
A neck abscess is a localized collection of pus in the cervical fascial spaces, often resulting from the spread of an odontogenic infection, especially from lower molars.
৪৬.
What causes trismus after tooth extraction?
  1. Alveolar bone fracture
  2. Damage to the TMJ
  3. Inflammation of masticatory muscles
  4. Oral candidiasis
সঠিক উত্তর:
Inflammation of masticatory muscles
উত্তর
সঠিক উত্তর:
Inflammation of masticatory muscles
ব্যাখ্যা
Trismus is the restricted mouth opening due to spasm or dysfunction of the muscles of mastication, commonly defined as interincisal opening <35 mm.

Etiology

Odontogenic Causes:
Pericoronitis (especially impacted mandibular third molars)
Pterygomandibular space infection
Masticator space abscess
Post-extraction infection

Traumatic Causes:
TMJ dislocation
Fracture of zygoma, mandible
Injection injury (e.g., inferior alveolar nerve block hematoma)

Other Causes:
Temporomandibular joint disorders
Oral submucous fibrosis
Radiation fibrosis (post-radiotherapy)
Tetanus
Tumors (infratemporal fossa, parotid, etc.)
৪৭.
Which of the following increases the risk of dry socket?
  1. Young age
  2. Use of oral contraceptives
  3. Low bone density
  4. Diabetes
সঠিক উত্তর:
Use of oral contraceptives
উত্তর
সঠিক উত্তর:
Use of oral contraceptives
ব্যাখ্যা
Dry Socket (Alveolar Osteitis)

Onset:
Typically occurs 2–4 days after tooth extraction (especially mandibular molars).

Etiology & Risk Factors:
Trauma during extraction
Smoking
Oral contraceptives (estrogen slows healing)
Poor oral hygiene
Previous dry socket history
Excessive rinsing/spitting post-op
Infection or bacterial fibrinolysis (e.g., Treponema denticola, Prevotella spp.)

Clinical Features:
Severe, throbbing pain (radiates to ear, temple, jaw)
Empty socket with exposed bone
Foul odor or taste
No swelling or pus
Halitosis
No systemic signs (fever uncommon)

Diagnosis:
Clinical (based on history + appearance)
No special investigations required unless to rule out infection/fracture

Management:
Irrigation with saline or chlorhexidine
Medicated dressing (e.g., zinc oxide-eugenol)
Analgesics (NSAIDs or opioids if severe)
Re-dress every 24–48 hrs as needed
Self-healing in 7–10 days with proper care
Avoid curettage—it delays healing

Prevention:
Atraumatic extraction technique
Avoid smoking post-op
Chlorhexidine rinse pre- and post-extraction
Good post-op instruction
৪৮.
Oroantral communication most commonly occurs following the extraction of which tooth?
  1. Mandibular molars
  2. Maxillary first molar
  3. Mandibular premolars
  4. Maxillary canines
সঠিক উত্তর:
Maxillary first molar
উত্তর
সঠিক উত্তর:
Maxillary first molar
ব্যাখ্যা
Oroantral Communication 

Etiology:
Extraction of maxillary molars/premolars (due to proximity to sinus floor), trauma, cysts, tumors, infections, or surgical procedures (e.g., implant placement).

Clinical Features:
Persistent nasal regurgitation of fluids during drinking
Altered voice or nasal speech
Oroantral fistula if communication persists
Pain or discomfort in maxillary region
Possible sinusitis symptoms: nasal congestion, discharge, foul smell

Diagnosis:
Clinical inspection of extraction site for visible opening
Valsalva test (patient exhales gently with nose pinched, air may escape through socket)
Radiographs (CBCT or panoramic) to assess defect size

Management:
Small communications (<2 mm) may heal spontaneously with sinus precautions
Larger defects require surgical closure via buccal advancement flap, palatal flap, or buccal fat pad graft
Pre- and post-operative antibiotics if sinusitis present
Sinus precautions: avoid nose blowing, sneezing with mouth closed, no smoking

Complications:
Chronic sinusitis
Oroantral fistula formation
Persistent infection
৪৯.
A dentigerous cyst typically envelops which part of an unerupted tooth?
  1. Apex
  2. Crown at cemento-enamel junction
  3. Mid root
  4. Entire root surface
সঠিক উত্তর:
Crown at cemento-enamel junction
উত্তর
সঠিক উত্তর:
Crown at cemento-enamel junction
ব্যাখ্যা
Dentigerous Cyst

Etiology:
Associated with impacted teeth, especially mandibular third molars and maxillary canines.

Pathogenesis:
Fluid accumulates between the crown and reduced enamel epithelium, causing cystic expansion.

Clinical Features:
Usually asymptomatic and discovered incidentally on radiographs
Swelling or painless jaw expansion if large
Delayed eruption or displacement of involved tooth
Occasionally pain or infection if secondarily infected

Radiographic Features:
Well-defined unilocular radiolucency surrounding the crown of an unerupted tooth
Radiolucent area attached at the cemento-enamel junction
Corticated border, may cause root resorption or displacement of adjacent teeth

Treatment:
Enucleation with removal of the associated tooth or
Marsupialization
৫০.
Which cyst may present cholesterol clefts and arcading epithelial patterns?
  1. Radicular cyst
  2. Nasolabial cyst
  3. Eruption cyst
  4. Gingival cyst of adult
সঠিক উত্তর:
Radicular cyst
উত্তর
সঠিক উত্তর:
Radicular cyst
ব্যাখ্যা
Histology of Radicular Cyst

1. Cyst Lining Epithelium:
Composed of non-keratinized stratified squamous epithelium
Usually 4–20 cell layers thick
Epithelium is derived from epithelial cell rests of Malassez
Often shows arcading pattern (epithelial proliferation forming arches)
May exhibit hyperplasia due to chronic inflammation

2. Cyst Wall (Fibrous Capsule):
Dense fibrous connective tissue
Contains chronic inflammatory infiltrate—mostly lymphocytes, plasma cells, and macrophages
Possible presence of cholesterol clefts and foreign-body giant cells due to breakdown of erythrocytes and cell debris

3. Additional Features:
Rushton bodies: Eosinophilic, linear or rounded hyaline structures occasionally found in the epithelium (thought to be keratin or hemoglobin-derived)
Microabscesses

4. Adjacent Bone:
Bone resorption seen around the cyst due to inflammatory mediators (prostaglandins, cytokines)
৫১.
A multilocular cyst in the jaw with high recurrence and possible daughter cysts suggests:
  1. Residual cyst
  2. Odontogenic keratocyst(OKC)
  3. Globulomaxillary cyst
  4. Dentigerous cyst
সঠিক উত্তর:
Odontogenic keratocyst(OKC)
উত্তর
সঠিক উত্তর:
Odontogenic keratocyst(OKC)
ব্যাখ্যা
Pathogenesis of OKC

-Arises from dental lamina remnants
-Exhibits aggressive behavior with potential for infiltration and recurrence due to daughter cysts and satellite microcysts
৫২.
In oral wounds when tetanus status is unknown or uncertain, what should be done?
  1. Ignore
  2. Refer the patient for tetanus immunization
  3. Prescribe antibiotics
  4. Use topical antifungals
সঠিক উত্তর:
Refer the patient for tetanus immunization
উত্তর
সঠিক উত্তর:
Refer the patient for tetanus immunization
ব্যাখ্যা
Post-Exposure Prophylaxis (PEP) of Tetenus
Depends on the wound and immunization status:

Clean minor wounds:
If ≥3 doses and last dose <10 years → no vaccine needed.
If incomplete or unknown → give TT or Td.

All other wounds (e.g., contaminated):
If ≥3 doses and last dose <5 years → no vaccine needed.
If incomplete or unknown → TT + tetanus immune globulin (TIG).

Special Notes:
Pregnant women should receive Tdap during each pregnancy (27–36 weeks).
Immunity wanes, boosters are essential for lifelong protection.
৫৩.
What is the “Rule of Nines” estimate for head and neck burn area in adults?
  1. 9%
  2. 18%
  3. 27%
  4. 36%
সঠিক উত্তর:
9%
উত্তর
সঠিক উত্তর:
9%
ব্যাখ্যা
Rule of Nines – Burn Surface Area Estimation
The Rule of Nines is a quick method to estimate the total body surface area (TBSA) affected by burns, crucial for fluid resuscitation and management.

Adult Body Surface Area Distribution:
Head and Neck: 9%
Each Arm (entire): 9% (4.5% front + 4.5% back)
Each Leg (entire): 18% (9% front + 9% back)
Anterior Trunk (chest and abdomen): 18%
Posterior Trunk (back and buttocks): 18%
Perineum and Genitalia: 1%

Notes:
Applies best to adults; children have different proportions (head is proportionally larger).
Used for quick estimation in emergencies.
TBSA helps determine fluid requirements (e.g., Parkland formula).
৫৪.
The fracture of the tooth-bearing segment of the mandible with communication to the oral cavity is called:
  1. Simple fracture
  2. Compound fracture
  3. Comminuted fracture
  4. Green stick fracture
সঠিক উত্তর:
Compound fracture
উত্তর
সঠিক উত্তর:
Compound fracture
ব্যাখ্যা
Dentofacial Fracture Classification

1. By Skin/Mucosal Involvement:

Simple (Closed) Fracture:
No communication between fracture site and external environment (skin or oral mucosa intact)

Compound (Open) Fracture:
Fracture communicates with external environment via skin or mucosa breach

2. By Anatomic Location:

Maxillary Fractures:
Le Fort I, II, III
Alveolar fractures
Palatal fractures

Zygomatic Complex Fractures:
Zygomatic arch, orbital rim involvement
Nasal Bone Fractures

Orbital Fractures:
Floor, medial wall, rim

Mandibular Fractures:
Condylar, coronoid, ramus, angle, body, symphysis, alveolar

Other Facial Fractures:
Nasoorbitoethmoidal (NOE), frontal, panfacial

3. By Fracture Pattern:

Transverse, oblique, comminuted, greenstick (in children), segmental
৫৫.
Which midface fracture pattern is pyramid-shaped, involving the inferior orbital rim and maxilla?
  1. Le fort I
  2. Le fort II
  3. Le fort III
  4. Zygomatic arch
সঠিক উত্তর:
Le fort II
উত্তর
সঠিক উত্তর:
Le fort II
ব্যাখ্যা
Le Fort II Fracture 
Le Fort II is a pyramidal midface fracture that involves the central midfacial skeleton, separating the maxilla from the base of the skull along a pyramid-shaped path.

Fracture Line Pathway:
Starts at the nasal bridge
Extends through the medial orbital wall
Passes through the inferior orbital rim and floor
Continues through the anterior wall of the maxillary sinus
Crosses the zygomaticomaxillary suture
Extends through the pterygoid plates posteriorly

Key Structures Involved:
Nasal bones
Medial and inferior orbital walls
Maxillary sinuses
Infraorbital rim and foramen (may involve infraorbital nerve)
Pterygoid plates

Clinical Features:
Facial swelling and midface mobility
Dish-face” deformity (flattened midface profile)
Periorbital edema & ecchymosis (black eyes)
Epistaxis (nosebleed)
Infraorbital nerve paresthesia (numbness of cheek, upper lip)
Malocclusion
Mobility of nasal bridge and maxilla as a unit
CSF rhinorrhea (if skull base involved)

Diagnosis:
Clinical examination (check midface mobility)
CT scan with facial bone window (best for defining fracture extent)
Water’s view X-ray (may show maxillary involvement)
৫৬.
In suspected facial fractures, the best imaging modality is:
  1. Panoramic radiograph
  2. Ultrasound
  3. CT scan
  4. MRI
সঠিক উত্তর:
CT scan
উত্তর
সঠিক উত্তর:
CT scan
ব্যাখ্যা
Imaging Best 

IOPA -Tooth root, alveolar High resolution, limited field
OPG -Mandible overview Screening tool
CT / CBCT -Complex facial fractures Gold standard
Water’s View -Orbit, sinus walls Quick but less sensitive
MRI -Soft tissues, nerves Not for primary bone imaging
৫৭.
Persistent red or white mucosal patches in the oral cavity that resist healing for over 2 weeks should be considered:
  1. Pseudomembranous lesions
  2. Potentially malignant disorders
  3. Traumatic ulcers
  4. Herpetic gingivostomatitis
সঠিক উত্তর:
Potentially malignant disorders
উত্তর
সঠিক উত্তর:
Potentially malignant disorders
ব্যাখ্যা
Premalignant Lesions 
Oral lesions with potential to transform into squamous cell carcinoma.
1. Leukoplakia
White patch; cannot be rubbed off
Homogeneous (low risk), Non-homogeneous (high risk)
Malignant transformation: 5–18%

2. Erythroplakia
Red, velvety patch
High-risk lesion
Transformation: ~50–70%

3. Oral Submucous Fibrosis (OSMF)
Due to areca nut chewing
Features: Burning, blanching, trismus
Risk: 7–13%

4. Actinic Cheilitis
Sun-induced lip lesion (mostly lower lip)
Crusting, ulceration
Risk of lip cancer

5. Oral Lichen Planus (Erosive type)
Bilateral, white striae (Wickham’s striae)
Erosive form has higher risk
Risk: ~1–2%

6. Discoid Lupus Erythematosus (DLE)
White/red ulcerative patches
Rare malignant transformation

High-Risk Sites:
Floor of mouth, tongue (lateral/ventral), soft palate

Management:
Biopsy, eliminate risk factors, surgical excision if needed, long-term follow-up
৫৮.
A "driven‑snow" radiographic appearance in the posterior mandible with amyloid-like deposits suggests which tumor?
  1. Adenomatoid odontogenic tumor
  2. Central giant cell granuloma
  3. Calcifying epithelial odontogenic tumor (Pindborg tumor)
  4. Ameloblastoma
সঠিক উত্তর:
Calcifying epithelial odontogenic tumor (Pindborg tumor)
উত্তর
সঠিক উত্তর:
Calcifying epithelial odontogenic tumor (Pindborg tumor)
ব্যাখ্যা
Pindborg Tumor (CEOT)
Full Name:
Pindborg Tumor = Calcifying Epithelial Odontogenic Tumor (CEOT)

Key Features:
Common Site:
Posterior mandible (most frequent)
Associated with impacted teeth, especially mandibular molars
Age & Gender:
Adults (30–50 years)
No strong gender predilection

Clinical Features:
Slow-growing, painless swelling
May cause bone expansion
Can be locally aggressive

Radiographic Features:
Unilocular or multilocular radiolucency
May show radiopaque flecks ("driven snow" appearance)
Often associated with impacted tooth

Histopathology:
Sheets of polyhedral epithelial cells with prominent intercellular bridges
Amyloid-like material (eosinophilic)
Liesegang ring calcifications (concentric rings) – diagnostic hallmark
Congo red stain: amyloid shows apple-green birefringence under polarized light
৫৯.
Which benign jaw lesion is multilocular, shows giant cells histologically, and often affects the anterior mandible in patients under 30?
  1. Ameloblastoma
  2. Central giant cell granuloma
  3. Odontogenic keratocyst
  4. Adenomatoid odontogenic tumor
সঠিক উত্তর:
Central giant cell granuloma
উত্তর
সঠিক উত্তর:
Central giant cell granuloma
ব্যাখ্যা
Central Giant Cell Granuloma (CGCG)
A benign intraosseous lesion of the jaws composed of fibroblasts and multinucleated giant cells. Can be aggressive or non-aggressive in nature.

Etiology:
Unknown; possibly reactive or neoplastic
May be associated with hyperparathyroidism → must rule out brown tumor

Age & Gender:
Most common in <30 years, especially in children & young adults
Female > Male

Location:
Anterior mandible most common
Often crosses midline

Clinical Features:
Slow-growing, painless swelling
May cause facial asymmetry
Aggressive form may cause:Pain
Cortical perforation
Tooth displacement or root resorption

Radiographic Features:
Unilocular or multilocular radiolucency
Well-defined or ill-defined borders
Can expand or perforate cortex
May displace teeth

Histopathology:
Multinucleated giant cells in a background of spindle-shaped fibroblasts
Hemorrhage and areas of hemosiderin
Similar to brown tumor, aneurysmal bone cyst, cherubism – needs differential diagnosis

Treatment:
Curettage for non-aggressive lesions
Surgical resection for aggressive lesions
Intralesional corticosteroids
calcitonin, or interferon-α may be used in selected cases

Rule out hyperparathyroidism with serum calcium, PTH tests
৬০.
Multiple OKCs in a young patient may indicate which syndrome?
  1. Gardner syndrome
  2. Gorlin‑Goltz syndrome
  3. Goldenhar syndrome
  4. Maroteaux‑Lamy syndrome
সঠিক উত্তর:
Gorlin‑Goltz syndrome
উত্তর
সঠিক উত্তর:
Gorlin‑Goltz syndrome
ব্যাখ্যা
Gorlin-Goltz Syndrome (Nevoid Basal Cell Carcinoma Syndrome – NBCCS) 

An autosomal dominant genetic disorder characterized by multiple basal cell carcinomas, jaw cysts, and various skeletal and developmental anomalies.

Key Clinical Features:
1. Odontogenic Keratocysts (OKCs):
Multiple, recurrent cysts of the jaws
Often the first presenting sign (appear in teens/early 20s)
Common in posterior mandible
Histologically identical to sporadic OKCs but more aggressive
2. Basal Cell Carcinomas (BCCs):
Multiple lesions starting in adolescence
Occur even in sun-protected areas
3. Skeletal Anomalies:
Bifid ribs
Frontal bossing
Hypertelorism (wide-set eyes)
Spina bifida, kyphoscoliosis
4. Intracranial Calcifications:
Falx cerebri calcification (seen on skull X-rays or CT)
Often bilateral and early-onset
5. Other Findings:
Palmar or plantar pits
Medulloblastoma (especially in children)
Ovarian fibromas (in females)
Facial milia

Diagnostic Criteria:
Major Criteria:
Multiple BCCs or one before age 20
Histologically proven OKC
Bifid, fused, or markedly splayed ribs
Palmar/plantar pits (≥3)
Calcified falx cerebri
First-degree relative with NBCCS

Diagnosis:
2 major criteria or
1 major + 2 minor criteria
৬১.
Which term best describes the TMJ’s joint type?
  1. Ginglymoarthrodial joint
  2. Hinge joint only
  3. Gliding joint only
  4. Ball-and-socket joint
সঠিক উত্তর:
Ginglymoarthrodial joint
উত্তর
সঠিক উত্তর:
Ginglymoarthrodial joint
ব্যাখ্যা
The TMJ is a unique, bilateral synovial joint connecting the mandible to the temporal bone, allowing jaw movement for chewing, speaking, and yawning.

1. Articulating Structures:
Mandibular condyle (head of the condylar process)
Mandibular fossa (of temporal bone)
Articular eminence (anterior to fossa)


2. Articular Disc:
Fibrocartilaginous biconcave disc between condyle and temporal bone
Divides TMJ into upper and lower compartments:

Upper compartment: translational (gliding) movement
Lower compartment: rotational (hinge) movement

Attached medially and laterally to the capsule; posteriorly to retrodiscal tissue

3. Joint Capsule:
Fibrous capsule enclosing the joint
Lined internally by synovial membrane
৬২.
The primary sensory innervation of the TMJ is via which nerve?
  1. Mandibular branch (V₃)
  2. Facial nerve (VII)
  3. Hypoglossal nerve (XII)
  4. Glossopharyngeal nerve (IX)
সঠিক উত্তর:
Mandibular branch (V₃)
উত্তর
সঠিক উত্তর:
Mandibular branch (V₃)
ব্যাখ্যা
Innervation of TMJ
-Auriculotemporal nerve (branch of mandibular nerve, V3)
-Minor supply: masseteric and deep temporal nerves
৬৩.
In unilateral TMJ ankylosis:
  1. Multiple carious teeth are present
  2. Chin deviation toward the affected side
  3. Facial asymmetry with fullness on normal side
  4. Antegonial notch on the affected side
সঠিক উত্তর:
Chin deviation toward the affected side
উত্তর
সঠিক উত্তর:
Chin deviation toward the affected side
ব্যাখ্যা
Clinical Features – Unilateral TMJ Ankylosis:

1. Facial Asymmetry:
Chin deviates toward the affected side
Flattening of the affected side
Fullness or bulging of contralateral (normal) side
Midline shift toward ankylosed joint

2. Restricted Mouth Opening:
Markedly limited jaw opening
Deviation of jaw toward affected side on opening
Interincisal distance reduced

3. Occlusal Issues:
Posterior crossbite on affected side
Open bite on contralateral side (in growing children)

4. Functional Deficits:
Difficulty in mastication and speech
Pain usually absent (if bony ankylosis)
Clicking or crepitus not present (joint is immobile)

5. Growth Disturbance (if in children):
Hypoplasia of mandible on ankylosed side
Bird-face or micrognathia may develop over time
৬৪.
Disc displacement with reduction is most commonly associated with:
  1. No joint sound
  2. Crepitus
  3. Reciprocal click on opening and closing
  4. Fixed, painless limitation
সঠিক উত্তর:
Reciprocal click on opening and closing
উত্তর
সঠিক উত্তর:
Reciprocal click on opening and closing
ব্যাখ্যা
TMJ disc displacement refers to abnormal position of the articular disc relative to the mandibular condyle and articular eminence. It is a subtype of internal derangement of the TMJ.
Types:

1. Disc Displacement with Reduction (DDWR):
Disc is anteriorly displaced at rest
Clicks during opening and closing as disc reduces and displaces
Normal range of motion
Often painless or mild discomfort

2. Disc Displacement without Reduction (DDWOR):
Disc remains displaced during all jaw movements
No clicking, but restricted mouth opening (closed lock)
May cause pain, joint stiffness, and deviation of the jaw on opening

Chronic stage: mouth opening may improve, but joint remains non-functional


Clinical Features:
Clicking or popping sounds (DDWR)
Limited mouth opening (DDWOR)
Deviation of mandible toward affected side
Joint tenderness, preauricular pain
Muscle fatigue or spasm (esp. lateral pterygoid)
৬৫.
Ridge augmentation before implant placement is required when loss > :
  1. 0.5 mm
  2. 1 mm
  3. 2 mm
  4. 5 mm
সঠিক উত্তর:
2 mm
উত্তর
সঠিক উত্তর:
2 mm
ব্যাখ্যা
Ridge Augmentation for Implant Placement – Purpose

Purpose:
To rebuild deficient alveolar bone to provide a stable, adequate foundation for dental implant placement, ensuring long-term implant success.


Why It’s Essential for Implants:
Achieve Sufficient Bone Volume:
Implants require minimum bone width (~6 mm) and height (~10 mm) for primary stability and osseointegration.
Ridge defects from resorption, trauma, or infection can prevent ideal implant placement.
Ensure Implant Stability and Longevity:
Adequate bone prevents implant failure due to insufficient support or biomechanical overload.
Restore Proper Implant Position:
Allows correct 3D positioning of implant for optimal prosthetic function and esthetics.
Improve Esthetic Outcome:
Restores natural gingival contours and alveolar architecture, avoiding soft tissue recession or “black triangles.”
৬৬.
First‑line intervention for anaphylaxis during surgery:
  1. IV hydrocortisone
  2. Subcutaneous epinephrine
  3. IM epinephrine
  4. IV antihistamine
সঠিক উত্তর:
IM epinephrine
উত্তর
সঠিক উত্তর:
IM epinephrine
ব্যাখ্যা
Anaphylaxis Management – Quick Practical Guide

Definition:
Anaphylaxis is a severe, rapid-onset systemic hypersensitivity reaction that can be life-threatening.


Immediate Management Steps:
Stop exposure to allergen if identifiable.
Call for emergency help immediately.
Administer intramuscular adrenaline (epinephrine):

Dose: 0.3–0.5 mg IM (adult), 0.01 mg/kg IM (children, max 0.3 mg)
Site: Anterolateral thigh (vastus lateralis)
Repeat every 5–15 minutes if symptoms persist.
Positioning:

Lay patient flat with legs elevated (unless vomiting or respiratory distress).
Avoid standing or sudden changes in posture (risk of shock).
Airway and Breathing:

Provide high-flow oxygen (6–8 L/min) via mask.
Prepare for airway management (intubation if severe obstruction).
Circulation:

Establish IV access; start rapid infusion of isotonic crystalloids (normal saline).
Monitor blood pressure, pulse, oxygen saturation.
Adjunct Medications:

Antihistamines: Diphenhydramine IV or orally (for urticaria, itching; NOT life-saving).
Corticosteroids: Hydrocortisone IV to prevent biphasic reaction (delayed benefit).
Bronchodilators: Inhaled salbutamol for bronchospasm refractory to adrenaline.
Observation:

Monitor for at least 4–6 hours for biphasic reactions.

Post-Emergency Care:
Prescribe epinephrine auto-injector for self-use.
Refer to allergist for testing and long-term management.
Educate patient on allergen avoidance and emergency plan.
৬৭.
What is the most common site for oral lichen planus lesions?
  1. Buccal mucosa
  2. Tongue posterior
  3. Gingiva
  4. Hard palate
সঠিক উত্তর:
Buccal mucosa
উত্তর
সঠিক উত্তর:
Buccal mucosa
ব্যাখ্যা
Oral Lichen Planus – Common Locations
1. Buccal Mucosa: Most common site
Characteristic bilateral, symmetrical white striae (Wickham’s striae)
2. Tongue: Dorsal and lateral borders
May present as white patches, erosions, or atrophic areas
3. Gingiva: Especially mucosal-dental junction (desquamative gingivitis)
Erosive or atrophic types commonly affect gingiva causing redness and soreness
4. Labial Mucosa: Less common but can be involved
5. Floor of Mouth and Palate: Rarely involved compared to other sites

Summary:
Buccal mucosa > tongue > gingiva > labial mucosa > floor of mouth/palate
৬৮.
Assessment of airway difficulty is critical preoperatively because it predicts:
  1. Risk of allergic reactions
  2. Potential intubation challenges
  3. Choice of local anesthetic agent
  4. Post-op nausea risk
সঠিক উত্তর:
Potential intubation challenges
উত্তর
সঠিক উত্তর:
Potential intubation challenges
ব্যাখ্যা
Risks & Complications of GA
Respiratory depression
Cardiovascular instability
Allergic reactions
Postoperative nausea and vomiting (PONV)
৬৯.
Aphthous ulcers are commonly located on:
  1. Attached gingiva
  2. Non-keratinized mucosa
  3. Hard palate
  4. Dorsal tongue
সঠিক উত্তর:
Non-keratinized mucosa
উত্তর
সঠিক উত্তর:
Non-keratinized mucosa
ব্যাখ্যা
Apthous Ulcer – Concise Clinical Note

Definition:
Aphthous ulcers (also called canker sores) are common, recurrent, painful, small ulcers on non-keratinized oral mucosa.


Types:
Minor: Small (<1 cm), heal within 7-14 days without scarring
Major: Larger, deeper, longer healing (weeks), may scar
Herpetiform: Numerous tiny ulcers, may coalesce

Etiology / Predisposing Factors:
Stress, trauma
Nutritional deficiencies (B12, folate, iron)
Immunologic factors
Hormonal changes
Allergies
Genetic predisposition
Systemic diseases (e.g., Behçet’s, Crohn’s)

Clinical Features:
Round or oval ulcers with erythematous halo
Painful, interfere with eating and speaking
Usually on non-keratinized mucosa (buccal mucosa, ventral tongue, floor of mouth)

Diagnosis:
Clinical examination
Exclusion of other ulcerative diseases
Biopsy if atypical or persistent

Treatment:
Topical corticosteroids (e.g., triamcinolone acetonide)
Analgesics or topical anesthetics for pain relief
Avoidance of triggers
Nutritional supplementation if deficient
৭০.
Which is the most common extra-articular cause of TMJ pain?
  1. Myofascial pain dysfunction
  2. Internal derangement
  3. Osteoarthritis
  4. Rheumatoid arthritis
সঠিক উত্তর:
Myofascial pain dysfunction
উত্তর
সঠিক উত্তর:
Myofascial pain dysfunction
ব্যাখ্যা
Myofascial Pain Dysfunction Syndrome (MPDS)
A chronic musculoskeletal pain disorder involving trigger points in the masticatory muscles, causing localized or referred pain, restricted jaw movement, and functional limitations.

Key Features:
Pain:

Deep, aching, often referred to teeth, head, neck, or ear
Tender muscle knots (trigger points) on palpation
Muscle Dysfunction:

Limited mandibular movement
Muscle stiffness and spasm
Commonly Involved Muscles:

Masseter
Temporalis
Medial pterygoid
Occasionally trapezius or sternocleidomastoid
Associated Symptoms:

Headaches (tension-type)
Ear fullness or tinnitus
Difficulty chewing

Etiology & Risk Factors:
Muscle overload (bruxism, clenching)
Trauma or poor posture
Psychological stress
Malocclusion (controversial)

Diagnosis:
Clinical examination identifying trigger points
Reproduction of pain with pressure on muscles
Exclusion of dental pathology

Management:
Patient education and counseling
Physical therapy: massage, stretching, heat application
Pharmacologic: NSAIDs, muscle relaxants, low-dose tricyclic antidepressants
Occlusal splints (night guards) for parafunctional habits
Trigger point injections (lidocaine) in refractory cases
Stress management
৭১.
The most common site affected in mandibular osteomyelitis (by frequency):
  1. Condyle
  2. Ramus
  3. Angle
  4. Body
সঠিক উত্তর:
Body
উত্তর
সঠিক উত্তর:
Body
ব্যাখ্যা
Common Site of Mandibular Osteomyelitis

The mandible is more commonly affected than the maxilla due to its denser cortical bone and relatively poorer blood supply.

Most Common Site:

Body and angle of the mandible.Sometimes involves the ramus and condylar region. These areas have thick cortical bone and less collateral blood flow, making them prone to infection spread and sequestration.
৭২.
Which autoimmune disorder affects salivary and lacrimal glands, causing dry mouth/eyes and possible lymphoma risk?
  1. Mikulicz disease
  2. Sjögren’s syndrome
  3. Sialolithiasis
  4. Sialosis
সঠিক উত্তর:
Sjögren’s syndrome
উত্তর
সঠিক উত্তর:
Sjögren’s syndrome
ব্যাখ্যা
Sjögren’s Syndrome – Key Features

Definition:
A chronic autoimmune disorder primarily affecting exocrine glands, causing dryness of mouth (xerostomia) and dry eyes (keratoconjunctivitis sicca).


Clinical Features:
1. Sicca Symptoms:

Xerostomia: dry mouth, difficulty swallowing, altered taste, increased dental caries
Keratoconjunctivitis sicca: dry, gritty eyes, burning, redness, blurred vision
2. Glandular Involvement:

Enlargement of parotid glands (often bilateral, painless swelling)
Dryness of other mucous membranes (nose, throat, vagina)
3. Systemic Manifestations:

Fatigue, arthralgia, myalgia
Raynaud’s phenomenon
Lymphadenopathy
Vasculitis, neuropathy, renal tubular acidosis (less common)
4. Increased Risk of: Non-Hodgkin lymphoma (especially mucosa-associated lymphoid tissue lymphoma)
৭৩.
Most common benign salivary gland tumor is:
  1. Warthin’s tumor
  2. Mucoepidermoid carcinoma
  3. Pleomorphic adenoma
  4. Adenoid cystic carcinoma
সঠিক উত্তর:
Pleomorphic adenoma
উত্তর
সঠিক উত্তর:
Pleomorphic adenoma
ব্যাখ্যা
Salivary Gland Tumor Classification – Concise Overview

Salivary gland tumors are classified based on histopathology and site of origin (major vs. minor glands).


1. Benign Tumors:
Pleomorphic Adenoma (Mixed Tumor):
Most common benign tumor; composed of epithelial and myoepithelial cells with stromal (cartilage-like) areas.
Warthin Tumor (Papillary Cystadenoma Lymphomatosum):
Common in parotid; cystic with lymphoid stroma.
Canalicular Adenoma:
Typically minor salivary glands of upper lip.
Basal Cell Adenoma
Oncocytoma

2. Malignant Tumors:
Mucoepidermoid Carcinoma:
Most common malignant salivary tumor; mucous, epidermoid, and intermediate cells.
Adenoid Cystic Carcinoma:
Characterized by perineural invasion; slow but aggressive.
Acinic Cell Carcinoma
Polymorphous Low-Grade Adenocarcinoma:
Common in minor salivary glands, especially palate.
Carcinoma ex Pleomorphic Adenoma:
Malignant transformation of pleomorphic adenoma.
Others:

Salivary duct carcinoma
Mammary analogue secretory carcinoma (MASC)

3. Site-based Classification:
Major Salivary Glands:

Parotid (most common site for both benign and malignant)
Submandibular
Sublingual (rare tumors)
Minor Salivary Glands:

Palate (most common site for minor gland tumors)
Buccal mucosa, floor of mouth, tongue, lips
৭৪.
Ideal timing for primary cleft lip repair (“Rule of 10”)?
  1. 1–2 months
  2. 3–6 months
  3. 9–12 months
  4. 18–24 months
সঠিক উত্তর:
3–6 months
উত্তর
সঠিক উত্তর:
3–6 months
ব্যাখ্যা
Rule of 10 for Cleft Lip Repair – Key Criteria
The Rule of 10 is a classic guideline used to determine the optimal timing for primary cleft lip repair surgery.


The 10s to Meet Before Surgery:
Age: At least 10 weeks old
Weight: Minimum of 10 pounds (4.5 kg)
Hemoglobin: At least 10 g/dL
White Blood Cell Count: Normal (to ensure no infection)

Purpose:
Ensures the infant is medically stable, reduces surgical risks, and improves healing.
৭৫.
By what week of gestation does the primary palate normally fuse?
  1. 2–4 weeks
  2. 4–7 weeks
  3. 8–12 weeks
  4. 12–16 weeks
সঠিক উত্তর:
4–7 weeks
উত্তর
সঠিক উত্তর:
4–7 weeks
ব্যাখ্যা
Embryology of the Palate 

Development Timeline: Weeks 6 to 12 of intrauterine life


Components:
Primary Palate:
Derived from the intermaxillary segment (fused medial nasal prominences)
Forms the anterior 1/3 of the hard palate (premaxilla area)
Contains the incisors
Secondary Palate:
Formed by the palatal shelves (outgrowths of maxillary prominences)
These shelves grow vertically, then elevate horizontally above the tongue and fuse in the midline
Forms the posterior 2/3 of the hard palate and the soft palate
Fusion:
Fusion occurs between the primary palate and the secondary palate
Also involves fusion with the nasal septum

Clinical Correlation:
Failure of fusion results in cleft lip (primary palate defect) or cleft palate (secondary palate defect)
Timing and site of fusion failure determine the type of cleft
৭৬.
Standard initial treatment for Bell’s palsy within 72 hours is:
  1. Antiviral only
  2. Corticosteroids
  3. Surgery
  4. Physiotherapy alone
সঠিক উত্তর:
Corticosteroids
উত্তর
সঠিক উত্তর:
Corticosteroids
ব্যাখ্যা
Bell’s Palsy – Treatment Summary

Definition:
Idiopathic, acute unilateral facial nerve (CN VII) paralysis.


Management:
Corticosteroids:
Prednisolone 60 mg/day for 5 days, then taper over next 5 days
Most effective if started within 72 hours of onset
Antiviral Therapy: (controversial but often combined)
Acyclovir or Valacyclovir added in severe cases or if herpes simplex virus suspected
Eye Care:
Protect cornea due to incomplete eyelid closure
Artificial tears, lubricating ointments, eye patch at night
Physical Therapy:
Facial muscle exercises to prevent contractures
Massage and electrical stimulation (optional)
Analgesics:
For pain relief as needed

Prognosis:
Most recover completely within weeks to months
Early treatment improves outcomes
৭৭.
First-line medications for trigeminal neuralgia include all except:
  1. Carbamazepine
  2. Oxcarbazepine
  3. Gabapentin
  4. Morphine
সঠিক উত্তর:
Morphine
উত্তর
সঠিক উত্তর:
Morphine
ব্যাখ্যা
Trigeminal Neuralgia – Treatment Summary

Definition:
A chronic pain condition characterized by sudden, severe, electric shock-like pain along the distribution of the trigeminal nerve (CN V), typically unilateral.


First-Line Medical Treatment:
Carbamazepine (Gold standard)

Dose: Start with 100 mg twice daily, increase gradually
Monitor for liver function, blood counts
Side effects: dizziness, drowsiness, rare aplastic anemia
Oxcarbazepine

Fewer side effects, similar efficacy
Start with 150–300 mg twice daily
Other Alternatives (if not responding or intolerant):

Gabapentin
Pregabalin
Baclofen (muscle relaxant, may be combined)
Phenytoin, Lamotrigine (less commonly used)

Surgical Options (for refractory cases):
Microvascular Decompression (MVD):

Relieves pressure from vessels on nerve root
Most effective long-term result
Radiofrequency Rhizotomy:

Destroys part of the nerve selectively
Can cause some numbness
Gamma Knife Radiosurgery:

Focused radiation on nerve root
Glycerol injection or balloon compression

Minimally invasive, temporary relief

Supportive Measures:
Avoid trigger stimuli (cold air, chewing, touching face)
Psychological support (chronic pain impacts mental health)
৭৮.
Which is true about the hepatitis B vaccine for healthcare workers?
  1. Booster doses are required every year
  2. Vaccine is 40% effective
  3. Immunity develops in 1 week
  4. It is a 3-dose schedule at 0, 1, and 6 months
সঠিক উত্তর:
It is a 3-dose schedule at 0, 1, and 6 months
উত্তর
সঠিক উত্তর:
It is a 3-dose schedule at 0, 1, and 6 months
ব্যাখ্যা
Hepatitis B Vaccination – Clinical Summary

 Purpose:
To prevent Hepatitis B virus (HBV) infection, which can lead to chronic hepatitis, cirrhosis, and hepatocellular carcinoma.


Vaccine Type:
Recombinant subunit vaccine (HBsAg – Hepatitis B surface antigen)
Intramuscular (IM) injection, usually in deltoid (adults) or anterolateral thigh (infants)

Accelerated Schedule (e.g., healthcare workers, exposure):
0, 1, 2 months + booster at 12 months

Post-Vaccination Protection:
Anti-HBs titer ≥10 mIU/mL = protective
Check serologic response 1–2 months after 3rd dose, especially in healthcare workers

Non-responders:
Repeat the 3-dose series
If still negative → consider as non-responder and use HBIG if exposed

Special Groups Who Should Be Vaccinated:
Healthcare workers
Newborns of HBsAg-positive mothers
People with multiple sexual partners or IV drug use
Dialysis patients
Immunocompromised individuals
Travelers to endemic areas
৭৯.
Which PPE combination offers optimal protection during HIV-sensitive dental procedures?
  1. Sterile gloves + N95 mask
  2. Single gloves + surgical mask
  3. Double gloves + goggles + gown
  4. No PPE is required with proper hand hygiene
সঠিক উত্তর:
Double gloves + goggles + gown
উত্তর
সঠিক উত্তর:
Double gloves + goggles + gown
ব্যাখ্যা
Concise PPE Guidelines Against HIV

Purpose: Prevent contact with HIV-infected blood or body fluids.

Essential PPE:
Gloves:

Single or double gloves during invasive procedures
Mask:

Surgical mask for splash protection
N95 if aerosol-generating
Protective Eyewear/Face Shield:

Prevents fluid contact with eyes
Gown/Apron:

Fluid-resistant; protects clothing and skin
Head Cover (Cap):

In surgeries or high-risk zones

Other Key Points:

Follow universal precautions
Perform hand hygiene
In case of exposure, start PEP within 72 hours
৮০.
What is the primary advantage of CBCT over conventional CT in dentistry?
  1. Lower cost and radiation dose
  2. Superior soft-tissue contrast
  3. Unlimited field of view
  4. Real-time imaging
সঠিক উত্তর:
Lower cost and radiation dose
উত্তর
সঠিক উত্তর:
Lower cost and radiation dose
ব্যাখ্যা
CBCT Over CT – Why Choose Cone Beam?

CBCT (Cone Beam Computed Tomography) is preferred over conventional CT in dental and maxillofacial imaging for several key reasons:


Advantages of CBCT over CT:
1.High-Resolution Imaging: Superior spatial resolution for hard tissues (teeth, bone, TMJ, sinuses)

 2.Lower Radiation Dose: Up to 10× less radiation than conventional CT
Safer for repeated use in dental patients

3.Cost-Effective: Less expensive equipment and imaging cost

4.Office-Friendly: Smaller machines, often installed in dental clinics
Quicker scans (~20 seconds)

5.Ideal for Dental Use: Accurate 3D assessment of:Implant planning
Endodontics (root canal anatomy, resorption)
Orthodontics
TMJ evaluation
Impacted teeth
Pathology and fractures

Limitations vs CT:
Poor soft tissue contrast (not ideal for tumors, muscle, brain)
Limited field of view (unless large CBCT used)