Common Lesions showing Multilocular Radiolucency

A good dentist should have keen knowledge and expertise to make an accurate diagnosis based on the radiographical image of various conditions. It is often said that "The eyes do not see what the brain doesn't know." That is absolutely correct. We must have a good knowledge about the condition, its clinical presentations and radiological appearance in our mind to make an accurate diagnosis.

Common lesions which show multilocular radiolucency are:

• Ameloblastoma
• Odontogenic keratocyst
• Odontogenic Myxoma
• Central Giant Cell Granuloma
• Central Hemangioma
• Aneurysmal bone cyst
• Cherubism

1. Ameloblastoma
- Soap bubble or honeycombed appearance
- Most common in 3rd molar- ramus area
- Notching is seen in advancing end of tumor
- Root resorption and displacement of adjacent teeth is seen
- Rarely causes perforation

2. Odontogenic Keratocyst
- Soap bubble appearance
- No expansion of cortical plates, because the lesion grows anteroposteriorly

3. Odontogenic myxoma
- Exclusively seen in Jaws, only in tooth-bearing portions
- angular or tennis racket or honeycomb appearance
- May be found in association with an impacted tooth

4. Central giant cell granuloma
- It is a reactive process, but not a neoplasm
- Soap bubble or honeycomb appearance
- a characteristic feature is that the septa are perpendicular to the periphery of the lesion and notching is seen corresponding to outline where septa arise.

5. Central hemangioma
- soap bubble appearance
- Swelling of Jaws, gingival bleeding through sulcus is seen
- " Pumping action " is a characteristic clinical feature. If tooth in the region of the tumor is pushed into the tumor, it will be rebound back to the original.

6. Aneurysmal bone cyst
- history of trauma, the cyst is reactive process  secondary to trauma
- honeycomb or soap bubble appearance
- frank blood on aspiration
- pseudocyst
- multinucleated giant cells are seen histologically

7. Cherubism
- seen at 2-6 years of age with a familial history
- When maxilla is involved, the skin over it is stretched with pulling of skin below eyes. The sclera is visible giving "angelic look" or "eyes towards heaven".
- Multiple unerupted teeth are seen which appear to be floating in cyst-like spaces.

MCQs in Anatomy - Basic General Anatomy : Skeletal System / Osteology

 Click HERE to view all our MCQ Topics.
# Bregma is the name given to the junction of the :
A. Coronal and sagittal sutures
B. Frontal bone with the nasal bone
C. Lambdoid and sagittal sutures
D. Two parietal bones

# 'Pterion' is :
A. is a point of articulation of four skull bones
B. is a point where 'bregma' and 'lambda' meet
C. it is the region of the anterolateral fontannele merge
D. lies deep to the zygomatic arch



# Lateral part of middle cranial fossa and posterior cranial fossa are divided by :
A. Petrous temporal bone
B. Crista galli
C. Transverse groove
D. Sphenoid bone

# The maxilla articulates with all of the following bones, except one. Identify the exception.
A. Frontal
B. Zygomatic
C. Palatine
D. Temporal

# Highest point on skull :
A. Pterion
B. Pogonion
C. Lambda
D. Vertex

# Which of the following structures is not present on the internal surface of the mandible ?
A. Genial Tubercle
B. Mylohyoid ridge
C. Lingula
D. Mental foramen

# Among all the following foramens in the base of the skull, which is the most posteriorly present?
A. Foramen spinosum
B. Foramen rotundum
C. Foramen lacerum
D. Foramen ovale

# Mental foramen is located :
A. Between roots of premolars
B. Between roots of molars
C. Near canine
D. Between incisors

# The palatine bone furnishes the link between :
A. Maxilla and the sphenoid bone
B. Sphenoid and the ethmoid bone
C. Sphenoid and the vomer
D. None of the above

# Lingula gives attachment to :
A. Upper medial incisor
B. Sphenomandibular ligament
C. Temporomandibular ligament
D. All

# Number of bones in adult skull are :
A. 18
B. 20
C. 22
D. 40

# The point where the parieto mastoid, occipito mastoid, and the lambdoid sutures meet is :
A. Pterion
B. Obelion
C. Asterion
D. Bregma

# Which of the following is the unpaired bone of facial skeleton ?
A. Nasal
B. Lacrimal
C. Inferior nasal conchae
D. Vomer

# Foramen magnum transmits all except : (Two answers correct )
A. Vertebral artery
B. Spinal branch 10th nerve
C. Spinal cord
D. Vertebral venous plexus

# Structure passing through foramen spinosum is :
A. Accessory meningeal artery
B. Middle meningeal artery
C. Mandibular nerve
D. Maxillary nerve

# Foramen caecum is seen in:
A. Ethmoid bone
B. Tongue
C. Sphenoid
D. A and B
# Bone better described as 'bat with extended wings' is :
A. Ethmoid
B. Sphenoid
C. Nasal
D. Mandible

# All of the following features of skull of a newborn are true except :
A. Diploe not formed
B. Styloid process has not fused with rest of the temporal bone
C. Anterior fontanelle open
D. Mastoid process is of adult size

# Suprameatal triangle externally represents :
A. Transverse sinus
B. Promontory of middle ear
C. Internal acoustic meatus
D. Mastoid antrum

# Anterior limit of infratemporal fossa is :
A. Lateral pterygoid plate
B. Maxillary posterior wall
C. Pterygomaxillary fissure
D. Mastoid process

# Which of the following muscles originates from the zygomatic process off the maxilla ?
A. Middle temporal
B. Lateral pterygoid
C. Superficial layer of masseter
D. Posterior portion of the buccinator

# Muscle, which pulls the disk of TMJ downward :
A. Lateral pterygoid
B. Medial pterygoid
C. Digastric
D. Mylohyoid

# Foramen transversarium transmits :
A. Inferior jugular vein
B. Inferior petrosal sinus
C. Sigmoid sinus
D. Vertebral artery

# Structures passing through foramen ovale :
A. Emissary vein
B. Mandibular nerve
C. Trigeminal nerve
D. A and B

# Which of the following is present in the posterior cranial fossa in a five year old child ?
A. Foramen rotundum
B. Foramen lacerum
C. Jugular foramen
D. Foramen spinosum

# Which structure passes through infra orbital fissures ?
A. Superior ophthalmic vein
B. Ophthalmic artery
C. Trochlear nerve
D. Zygomatic nerve

# Which of the following does not pass through superior orbital fissure ?
A. Occulomotor nerve
B. Optic nerve
C. Ophthalmic division of the trigeminal
D. Trochlear nerve

# Which vertebra has the most prominent spine ?
A. C2
B. C7
C. T10
D. L2

# Accessory meningeal artery enters cranial cavity through :
A. Foramen lacerum
B. Foramen rotundum
C. Foramen spinosum
D. Foramen ovale

# Mental spine provide attachment to :
A. Genioglossus
B. Anterior and posterior bellies of digastric
C. Mylohyoid
D. Superior constrictor of pharynx

# Following foramina are found in greater wing of sphenoid except :
A. Foramen rotundum
B. Canaliculus innominatus
C. Foramen spinosum
D. Optic canal

# The first costochondral joint is a :
A. Fibrous joint
B. Synovial joint
C. Fimosis
D. Synarthrosis

# The typical cervical differs from thoracic vertebra in that it:
A. has a triangular body
B. has a foramen transversarium
C. Superior articular facet directed backwards and upwards
D. has a large vertebral body

# The joint between the atlas and axis :
A.is Synovial
B. is closely related to the first cervical nerves
C. allows rotation of the head
D. is supported by the alar ligaments

# Joint between two bony surfaces linked by cartilage in the plane of body is called :
A. Syndesmosis
B. Symphysis
C. Synchondrosis
D. Suture

# Which out of the following bones ossify first ?
A. Mandible
B. Nasal bone
C. Vomer
D. Occipital

# The type of suture represented by sagittal suture of the cranial vault is :
A. Serrate
B. Denticulate
C. Squamous
D. Plane

# Which of the following is the weakest part of the orbit ?
A. Medial wall
B. Lateral wall
C. Floor of the orbit
D. Roof of the orbit

# The hyoid bone lies in the midline at the front of the neck at the level of the :
A. Third cervical vertebra
B. Fourth cervical vertebra
C. Fifth cervical vertebra
D. Seventh cervical vertebra

# The orbital opening is somewhat:
A. Quadrangular
B. Oval
C. Oblong
D. Circular

# Mandibular fossa is a part of :
A. Mandible bone
B. Maxilla bone
C. Sphenoid bone
D. Temporal bone
# Which of the following is located medial to the third molar at the junction of the maxilla and the horizontal plate of the palatine bone ?
A. Posterior nasal spine
B. Mylohyoid line
C. Pterygoid hamulus
D. Greater palatine foramen

# All of the following canals open on the posterior wall of the pterygopalatine fossa EXCEPT :
A. Greater palatine canal
B. Foramen rotundum
C. Pterygoid canal
D. Palatovaginal canal

# All of the following are pneumatic bones except :
A. Mastoid
B. Mandible
C. Maxilla
D. Ethmoid

# What is the number of bones a neonate has in the skeleton ?
A. 270
B. 250
C. 230
D. 206

# Deepest layer of deep cervical fascia is :
A. Prevertebral
B. Carotid sheath
C. Pretracheal
D. Temporal

# Not a part of Ethmoid bone is:
A. Inferior turbinate
B. Agar nasi cells
C. Uncinate process
D. Crista galli

# A dome shaped skull is known as :
A. Brachy-cephaly
B. Oxy-cephaly
C. Scapho-cephaly
D. Rhombo-encephaly

# The suture between the two halves of the frontal bone is :
A. Metopic
B. Symphysis
C. Mendosal
D. Coronal

Composites in Dentistry

Composite is a compound of two or more different constituents with properties that are superior to those of the individual constituent.

COMPOSITION:
a) Resin Matrix
The matrix consists of Bis-phenol Glycidylmethacrylate (Bis-GMA) and Triethylene Glycol Dimethacrylate (TEGDMA). TEGDMA is used as a viscosity controller.

b) Fillers - silica
Addition of fillers increases the strength, hardness, abrasion resistance and decreases the polymerization shrinkage and water sorption.

c) Coupling agent
Organosilane, zirconates or titanates. They bond the filler particles to the resin matrix.

d) Inhibitor - Hydroquinone
Prevents premature polymerization

e) Opacifiers and coloring agents
Titanium dioxide and aluminum oxide are the opacifiers.
The coupling agent between filler particle and the resin is VINYL SILANE.

TYPES:
CHEMICALLY ACTIVATED COMPOSITES:
# Supplied in two pastes

• Basic Paste - Contains the initiator benzoyl peroxide
• Accelerator Paste - Contains tertiary amine as activator (N-dimethyl-p-toluidine)

# It is manipulated by mixing the proper proportions on a mixing pad with an agate spatula as metal spatula discolors the material.

# Cavity should be slightly overfilled.
# Shrinkage occurs towards the centre of the material.
LIGHT ACTIVATED COMPOSITES
# Consists of a single paste
Initiator - Camphoroquinone
Activator - diethyl-amino-ethyl-methacrylate or diketone

- They interact when exposed to light at wavelength of 400-500 nm i.e. blue region of the visible light spectrum.

- Ultraviolet light curing is not indicated because of its limited depth of penetration through tooth structure. It also poses a potential health hazard.

- The source of light is a tungsten halogen bulb.

- The tip should be kept as close as possible to the restoration and should be cured in increments.

- Each increment should not be greater than 2 mm and the exposure time should be 40-60 seconds.

- Darker shades require longer exposure time.

- Light emitted may cause retinal damage and can be prevented by using protective eyeglasses.

- Shrinkage occurs towards the light source.

- Cavity preparation for composites is beveled except when margins are in cementum.

Glass Ionomer Cement (GIC) - Composition, Properties, Composition and Modifications

- Glass Ionomer Cement is also known as Polyalkenoate cement / Man-made dentin / Dentin Substitute / Aluminosilicate Polyacrylic cement (ASPA)
COMPOSITION :

Powder / Liquid	Contents
Powder / Ion Leachable Glass	Silica           -          35 - 50 % Alumina      -           20 - 30 % NaF             -           3 - 6 % AlF3            -           1.5 - 2.5 % Aluminium Phosphate  -    4 - 12 % Traces of Barium, Strontium for radioopacity
Liquid	Polyacrylic acid        -        45 % Itaconic acid + Maleic Acid + Tricarballylic acid    - 5 % (Decreases Viscosity) Tartaric acid (Increases working time) Water   - 50 %

CLASSIFICATION:

Type I GIC - Luting cement

Type II GIC - Restorative Cement

Type III GIC - Liner

Type IV GIC - Fissure Sealant

Type V GIC - Orthodontic Cement

Type VI GIC - Core Build Up Cement

Type VIII and Type IX - Posterior packable GIC for atraumatic restorations

Among the first three types, the highest cumulative release of fluoride after 30 days is from glass ionomer liner.

- GIC was introduced as a potential replacement for silicate cement. It has been evolved as a hybrid from the silicate and polycarboxylate cement.

Light Polymerization:

The powder contains initiators for light curing and liquid component is modified with hydroxyethyl methacrylate (HEMA).

The polymerization starts when exposed to light and subsequently followed by acid base reactions. This is called dual cure GIC.

PROPERTIES:

GIC has low fracture toughness and wear resistance.

It is very sensitive to moisture, especially during initial setting reaction. During this period, absorption of water leads to weak cement and over drying will lead to cracks in the cement. Therefore, the surface of cement should be protected by coating with varnish or cocoa butter during setting. 

It bonds chemically to the tooth structure.

- The bond of enamel is always higher than that of dentin.

- It is relatively biocompatible, the pulpal reaction is greater than ZOE but less than Zinc Phosphate Cement.

- Due to continuous fluoride release, it has some anticariogenic property.

 

- Powder: Liquid ratio is 3:1 by weight. Mixing should be done by agate or plastic spatula.

- 10 % polyacrylic acid should be used for conditioning the cavity surface before insertion of the cement.

- Final finishing is done 24 hours after the insertion.

MODIFICATIONS OF GIC:

a) Miracle Mix or Silver Cement

Silver-Tin alloy powder is added to GIC Powder. None of the properties were improved and it gave a gray or blackish color to the cement. It is also called as silver alloy mix.

b) Glass Cermet or Cermet

Glass and metal ( Silver-tin-titanium) powders were sintered at high temperature and made to react with liquid. It improved the fracture toughness and wear resistance and at the same time maintained the esthetics.

c) Resin modified GIC

BisGMA, TEGDMA, are added to powder and HEMA to the liquid. With exposure of light polymerization is initiated along the methacrylate groups. After that the liquid reacts with the glass particles through acid base reaction. It improved the wear resistance and decreased the sensitivity to

water attack. 

d) Compomer (Polyacid modified composite resins)

It is a combination of composite and GIC. Glass particles are partially silanated (for bonding with the matrix) and are added as fillers in the composite resin. There is no water in the reaction. The properties were inferior to composites but superior to resin modified GIC.

e) Bilayered or Sandwich restoration

In this technique, GIC is used as a liner under composite restorations. It increases the retention form as GIC bonds both the tooth and composite and the fluoride content reduces secondary caries.

f) Tunneling restorations

Joining the occlusal lesion with the proximal lesion by means of a prepared tunnel under the involved marginal ridge. The marginal ridge remains intact. GIC is used as the restorative material in this technique.

g) Atraumatic restoration (ART)

Involves removal of affected tooth structure with hand instruments, followed up by restoring with GIC material (GC Fuji VIII).

h) High viscosity GIC

Used for atraumatic restorative treatment. They contain small particle sizes and a high P/L ratio, yielding greater compressive strength and excellent packability. Also used for core buildups, primary tooth fillings and intermediate restoration.

i) Calcium aluminate GIC

It is a hybrid product of calcium aluminate and  GIC. The GIC components are responsible for early properties (i.e. setting time, viscosity, and strength). The calcium aluminate contributes to basic pH, biocompatibility and reduction in microleakage. Also called as hydraulic cement.