Walls of orbit

WALLS OF ORBIT

Q. 1

A teenager brought with blow out fracture of orbit. The fracture may involve mainly:

 A

Roof of the orbit

 B

Posterior wall of floor of orbit

 C

Medial wall of orbit

 D

Medial part of floor of orbit

Q. 1

A teenager brought with blow out fracture of orbit. The fracture may involve mainly:

 A

Roof of the orbit

 B

Posterior wall of floor of orbit

 C

Medial wall of orbit

 D

Medial part of floor of orbit

Ans. D

Explanation:

Blowout fractures mainly involve orbital floor and medial wall. When an external force is applied to the globe, intraorbital pressure increases to the point that one or more of the thin-walled bones of the orbit “blow-out” or fracture. The most common bone fractured is the maxillary bone which comprises the floor of the orbit. The orbital contents can be significantly displaced inferiorly after orbital blowout fracture.

Ref: Shirakbari A.A., Hall M. (2011). Chapter 23. Maxillofacial & Neck Trauma. In R.L. Humphries, C. Stone (Eds), CURRENT Diagnosis & Treatment Emergency Medicine, 7e.

Q. 2

Blow out fracture of the orbit, most commonly leads to fracture of:

 A

Posteromedial floor of orbit

 B

Medial wall of orbit

 C

Lateral wall of orbit

 D

Roof of orbit

Q. 2

Blow out fracture of the orbit, most commonly leads to fracture of:

 A

Posteromedial floor of orbit

 B

Medial wall of orbit

 C

Lateral wall of orbit

 D

Roof of orbit

Ans. A

Explanation:

“The most common site for a blowout fracture to occur is the posteromedial aspect of the orbital floor, medial to the infraorbital neurovascular bundle where the maxillary bone is very thin.” – The Internet Journal of Otorhinolaryngology

Blow out fracture: The usual mechanism is a blow to the eye, with the forces being transmitted by the soft tissues of the orbit downward to the thin floor of the orbit. The floor is usually the path of least resistance, and fractures downward into the maxillary sinus.
 
Clinical features:

Enophthalmos Recession of the eyeball within the orbit
Diplopia: Double vision Especially on upward gaze

Due to inferior rectus entrapment
Forced Duction test is positive confirming the presence of muscle restriction
Hypesthesia: Reduced sense of touch or sensation Due to injury of infraorbital nerve

Usually have numbness of the gingiva and of the skin of the midface

Investigation:

  • Radiograph (Waters view) may see a soft tissue mass on the superior margin of the maxillary sinus, representing the herniated periorbital tissues into the sinus.
  • Hanging drop or tear drop sign: hanging opacity of superior maxillary antrum.
  • Computed tomography is the gold standard. Coronals provide best view. Extraocular muscle rounding and herniation of fat into maxillary sinus can be clearly viewed.
Management:
  • Medical management for asymptomatic patients–IV antibiotics and short course of oral steriods.
  • Surgical management for symptomatic patients.
Ref: Parson’s Disease of the eye, 20th Edition, Page 468; Comprehensive opthalmology, By A.K Khurana, 4th Edition, Page 397

 


Q. 3

Medial wall of orbit formed by:

 A

Body of sphenoid

 B

Lesser wing of sphenoid

 C

Greater wing of sphenoid

 D

All

Q. 3

Medial wall of orbit formed by:

 A

Body of sphenoid

 B

Lesser wing of sphenoid

 C

Greater wing of sphenoid

 D

All

Ans. A

Explanation:

A i.e., Body of sphenoid 


Q. 4

Blow out fracture of orbit most commonly leads to fracture of:

 A

Lateral wall

 B

Roof of orbit

 C

Medial wall of orbit

 D

Posterior-medial wall of floor

Q. 4

Blow out fracture of orbit most commonly leads to fracture of:

 A

Lateral wall

 B

Roof of orbit

 C

Medial wall of orbit

 D

Posterior-medial wall of floor

Ans. D

Explanation:

D i.e. Posterior-medial wall of floor


Q. 5

“Blow out” fracture of orbit involve:

 A

Floor

 B

Medial wall

 C

Lateral wall

 D

a and b

Q. 5

“Blow out” fracture of orbit involve:

 A

Floor

 B

Medial wall

 C

Lateral wall

 D

a and b

Ans. D

Explanation:

A > B i.e. Floor > Medial wall

Blow out fracture most frequently involves the floor of orbit along the thin bone covering the infraorbital canal (i.e. posteromedial wall of floor)Q. Occasionaly the medial wallQ may also be fractured. After h/o trauma from relatively large often rounded object (e.g. tennis ball, first) patient presents with periorbital oedema and blood extravasation in & around orbit, emphysema of eyelid, parasthesia & anaesthesia of infraorbital nerve, I/L epistaxis, proptosis, enopthalmos, diplopia (with forced duction test) Q. Water’s (nose-chin) view show hanging drop or tear drop sign Q

Blow Out Fracture

Occur when a blunt (non penetrating) force applied to anterior periorbital region compresses the orbital contents & causes a sudden increase in intraorbital pressure. This force is transmitted outward to the weakest orbital segment along with bone fragment & orbital content (eg fat). Severe ocular injury is rare as this is a nature’s way of protecting globe. It generally occurs after trauma to orbit by a large round object eg cricket ball or human fist.

These are isolated comminuted fractures of orbital floor (most common) & medial wallQ. Although lamina papyracea is truly thinner than the orbital floor, it is actually buttressed by perpendicular elements of ethmoid sinus bony lattice and therefore fractures less often than orbital floor. Orbital emphysema is most common in medial wall fractures.

Clinical features

  • Periorbital oedema and blood extravasation in and around the orbit (such as subconjunctival ecchymosis)
  • Emphysema of eyelid (mostly with medial wall fractures and made worse by blowing of nose)
  • Parasthesia & anaesthesia in the distribution of infraorbital nerve (lower lid, cheek, side of nose, upper lip & upper teeth)
  • Ipsilateral epistaxis
  • Proptosis due to orbital oedema
  • Enopthalmos after about 10 days as the oedema decreases, the eyeball sinks backward & inferiorly. It is due to

– Enlargement or orbit

Escape (herniation) of orbital fat into maxillary sinus Q

– Backward traction due to entrapped inferior rectus

  • Diplopia Q in both up & down gaze (double diplopia)
  • The presence of muscle restriction Q can be confirmed by a ‘positive forced duction test’ Q
  • Restriction movements occur due to entrapment of inferior rectus & inferior obliqueQ
  • Severe ocular damage is rare as this is a nature’s way of protecting globe. 
Management
  • Water’s view show hanging drop or tear drop sign Q (hanging opacity of superior maxillary antrum)
  • Surgery (optimal time is after 10-14 days of injury) is indicated in

– Persistent diplopia

– Enopthalmos > 3 mm

– Fracture with large herniation of tissue into the antrum

– Incarceration of tissue in the fracture with resulting globe retraction and increased applanation tension on attempted upward gaze

* Pure blow out fractures are not associated with orbital rim involvement. Impure b.o.f. are associated with fractures of middle third of face.



Q. 6

A boy presents with diplopia and restriction of eye movements following blunt trauma to his eye. X-ray reveals blow out fracture of orbit. Which part of orbit is most likely damaged:

 A

Superior wall

 B

Inferior wall

 C

Lateral wall

 D

Medial wall

Q. 6

A boy presents with diplopia and restriction of eye movements following blunt trauma to his eye. X-ray reveals blow out fracture of orbit. Which part of orbit is most likely damaged:

 A

Superior wall

 B

Inferior wall

 C

Lateral wall

 D

Medial wall

Ans. B

Explanation:

B i.e. Inferior wall

Blow out fracture mainly involve orbital floor (inferior wall) & medial wall Q. It presents with hanging drop or tear drop sign Q.


Q. 7

True about blow out # orbit:

 A

Herniates into maxillary antrum

 B

Movements restricted

 C

Looking down is easy

 D

a and b

Q. 7

True about blow out # orbit:

 A

Herniates into maxillary antrum

 B

Movements restricted

 C

Looking down is easy

 D

a and b

Ans. D

Explanation:

A i.e. Herniates into maxillary antrum; B i.e. Movements restricted

  • There is herniation of fat into the maxillary antrum.
  • There is restriction of movements specially vertical, and adduction & abduction when MR is entraped.
  • Diplopia on looking up/down is a prominent sign.
  • Small cracks & fractures involving less than half of the orbital floor with little or no herniation & improving diplopia do not require treatment unless more than 2mm enopthalmos develop. Fractures involving half or more orbital floor with entrapment of orbital contents & persistent diplopia in the primary position should be repaired with in 2 weeks by using synthetic material such as silicon, teflon, or supramidQ.

Q. 8

Blow out # orbit is characterized by:

 A

Diplopia

 B

“Tear drop: sign

 C

Forced duction test

 D

All

Q. 8

Blow out # orbit is characterized by:

 A

Diplopia

 B

“Tear drop: sign

 C

Forced duction test

 D

All

Ans. D

Explanation:

A i.e. Diplopia; B i.e. Tear drop sign; C i.e. Forced duction test

Blow out fracture is fracture of orbital floor or medial wall Q. It presents with emphysema of lid, subconjunctival ecchymosis, diplopia & forced duction test Q (due to entrapment of muscle), epistaxis, proptosis, enopthalmos & parasthesia in distribution of inferior alveolar nerve. X ray shows tear drop or hanging drop sign Q


Q. 9

Bone that not forms medal wall of orbit:

 A

Greater wing of sphenoid

 B

Lesser wing of sphenoid

 C

Ethmoid bone

 D

a and b

Q. 9

Bone that not forms medal wall of orbit:

 A

Greater wing of sphenoid

 B

Lesser wing of sphenoid

 C

Ethmoid bone

 D

a and b

Ans. D

Explanation:

A, B i.e. Greater wing of sphenoid; Lesser wing of sphenoid


Q. 10

Most common cause of fracture of roof of orbit:

 A

Blow on back of head

 B

Blow on parietal bone

 C

Blow on the forehead

 D

Blow on the upper jaw

Q. 10

Most common cause of fracture of roof of orbit:

 A

Blow on back of head

 B

Blow on parietal bone

 C

Blow on the forehead

 D

Blow on the upper jaw

Ans. C

Explanation:

C. i.e Blow to forehead

Most common cause of fracture of roof of orbit is blow on forehead

Medial orbital wall is formed by frontal process of maxilla, lacrimal bone, ethmoid bone (orbital plate) and body of sphenoid bone (not lesser or greater plate) and body of sphenoid bone (not lesser or greater wing)Q.

Blow in Fracture

It is produced by blunt (blow) trauma usually against forehead (frontal bone), check (maxilla) or nose (nasal bone), with energy consequently transmitted towards the orbital roofQ, floor or medial wall respectively. The fracture fragments are characteristically displaced towards the orbital space & may cause globe (ocular) injury. Pure forms of blow in & blow out fractures involve the internal orbital skeleton, with the orbital rim remaining intact. Where as in not pure complex orbital fractures, the rim is also fractured.

Orbital Wall Anatomy

Roof (Vault)

– Frontal bone (orbital

plate)

 

– Lesser wing of sphenoid

Floor (Inferior

Orbital surface / process /

wall)

plates of

 

– Maxillary

 

– Zygomatic

 

– Palatine

Medial wall

Frontal process of

(lamina

maxillaQ

papyracea)

Lacrimal boneQ

 

– Ethmoid boneQ (orbital

plate)

 

Body of sphenoidQ

Lateral wall

– Zygomatic (frontal

process)

 

Greater wing of sphenoidQ



Q. 11

Le Forte II facial fracture implies –

 A

Fracture running through alveolar ridge

 B

Fracture running through midline of the palate and zygomatico maxillary suture

 C

Fracture running through zygomatic process of the maxilla, floor of orbit, root of nose on one side only

 D

Similar to C but on both sides

Q. 11

Le Forte II facial fracture implies –

 A

Fracture running through alveolar ridge

 B

Fracture running through midline of the palate and zygomatico maxillary suture

 C

Fracture running through zygomatic process of the maxilla, floor of orbit, root of nose on one side only

 D

Similar to C but on both sides

Ans. D

Explanation:

Ans. is ‘d’ i.e., Similar to C but on both sides 

Le Fort Classification of Mid-face #s

  • Le Fort I (transverse fracture)

the # line runs above & parallel to the palate and effectively separates the alveolus and palate from the facial skeleton above.

it crosses the lower part of the nasal septum, maxillary antra and the pterygoid plates.

  • Le Fort II fracture

it is pyramidal in shape and passes through the root of nose, lacrimal bone, floor of orbit, upper part of maxillary sinus and pterygoid plates. the orbital floor is always involved

  • Le Fort III fracture (craniofacial dysjunction) there is complete separation of facial bones from the cranial bones.

the # line runs high through the nasal bridge, septum and ethmoids, and through the bones of orbit to the frontozygomatic suture. The zygomatic

arch fractures and the facial skeleton is separated from the bones above at a high level through the lateral wall of maxillary sinus and the pterygoid plates.


Q. 12

A 20 year old man is hit on the eye with a ball. On examination there is restriction of lateral and upward gaze and diplopia. There is no obvious visible sign of injury to the eye ball, but there is some enophthalmos, the likely diagonosis is ‑

 A

Zygoma fracture

 B

Maxillary fracture

 C

Blow out fracture of the orbit

 D

Injury to lateral rectus

Q. 12

A 20 year old man is hit on the eye with a ball. On examination there is restriction of lateral and upward gaze and diplopia. There is no obvious visible sign of injury to the eye ball, but there is some enophthalmos, the likely diagonosis is ‑

 A

Zygoma fracture

 B

Maxillary fracture

 C

Blow out fracture of the orbit

 D

Injury to lateral rectus

Ans. C

Explanation:

Ans. ‘c’ Blow out fracture of the orbit 


Q. 13

Tear drop sign is seen in:

 A

Fracture of floor of orbit

 B

Fracture of lateral wall of nose

 C

Le Fort’s fracture

 D

Fracture on zygomatic arch

Q. 13

Tear drop sign is seen in:

 A

Fracture of floor of orbit

 B

Fracture of lateral wall of nose

 C

Le Fort’s fracture

 D

Fracture on zygomatic arch

Ans. A

Explanation:

 

“Tear Drop” sign is a radiological sign seen in blow out fracture of orbit.

It signifies entrapment and herniation of orbital content through a defect in floor of orbit into maxillary antrum.


Q. 14

Thinnest wall of the orbit is:

 A

Medial wall

 B

Floor

 C

Roof

 D

Lateral wall

Q. 14

Thinnest wall of the orbit is:

 A

Medial wall

 B

Floor

 C

Roof

 D

Lateral wall

Ans. A

Explanation:

Ans. Medial wall


Q. 15

Thickest wall of the orbit is:

 A

Medial wall

 B

Lateral wall

 C

Roof

 D

Floor

Q. 15

Thickest wall of the orbit is:

 A

Medial wall

 B

Lateral wall

 C

Roof

 D

Floor

Ans. B

Explanation:

Ans. Lateral wall


Q. 16

Unilateral lacrimal gland destruction may be caused by:

 A

Inferior orbital fissure fracture

 B

Fracture of roof of orbit

 C

Fracture of lateral wall

 D

Fracture of sphenoid

Q. 16

Unilateral lacrimal gland destruction may be caused by:

 A

Inferior orbital fissure fracture

 B

Fracture of roof of orbit

 C

Fracture of lateral wall

 D

Fracture of sphenoid

Ans. B

Explanation:

Ans. Fracture of roof of orbit


Q. 17

The walls of the orbit which are removed in the two wall decompression for proptosis of thyroid ophthalmopathy include part of:

 A

Orbital floor and medial wall

 B

Orbital floor and lateral wall

 C

Orbital roof and medial wall

 D

Medial and lateral walls

Q. 17

The walls of the orbit which are removed in the two wall decompression for proptosis of thyroid ophthalmopathy include part of:

 A

Orbital floor and medial wall

 B

Orbital floor and lateral wall

 C

Orbital roof and medial wall

 D

Medial and lateral walls

Ans. A

Explanation:

Ans. Orbital floor and medial wall


Q. 18

Blow-out fracture of orbit is characterized by all except:

 A

Diplopia

 B

‘Tear drop” sign

 C

Positive forced duction test

 D

Exophthalmos

Q. 18

Blow-out fracture of orbit is characterized by all except:

 A

Diplopia

 B

‘Tear drop” sign

 C

Positive forced duction test

 D

Exophthalmos

Ans. D

Explanation:

Ans. Exophthalmos


Q. 19

Blow out fracture of the orbit, most commonly leads to fracture of:

 A

Posteromedial floor of orbit

 B

Medial wall of orbit

 C

Lateral wall of orbit

 D

Roof of orbit

Q. 19

Blow out fracture of the orbit, most commonly leads to fracture of:

 A

Posteromedial floor of orbit

 B

Medial wall of orbit

 C

Lateral wall of orbit

 D

Roof of orbit

Ans. A

Explanation:

Ans. Posteromedial floor of orbit


Q. 20

Orbital blow-out fracture involves:         

AIIMS 09; FMGE 10; MP 10; JIPMER 11; Bihar 11; PGI 11

 A

Lateral wall and floor of orbit

 B

Medial wall and floor or orbit

 C

Lateral wall and roof or orbit

 D

Medial wall and roof or orbit

Q. 20

Orbital blow-out fracture involves:         

AIIMS 09; FMGE 10; MP 10; JIPMER 11; Bihar 11; PGI 11

 A

Lateral wall and floor of orbit

 B

Medial wall and floor or orbit

 C

Lateral wall and roof or orbit

 D

Medial wall and roof or orbit

Ans. B

Explanation:

Ans. Medial wall and floor or orbit


Q. 21

Lamina papyracea is between ‑

 A

Optic nerve and orbit

 B

Maxillary sinus and orbit

 C

Ethmoid sinus and orbit

 D

Cranial cavity and orbit

Q. 21

Lamina papyracea is between ‑

 A

Optic nerve and orbit

 B

Maxillary sinus and orbit

 C

Ethmoid sinus and orbit

 D

Cranial cavity and orbit

Ans. C

Explanation:

The thinnest portion of medial wall of orbit is the lamina papyracea which separates ethmoid sinuses from orbit. o Infection from ethmoidal sinus can easily breach this paper thin bone and affect the orbital contents.


Q. 22

Haller cells are seen in‑

 A

Roof of nose

 B

Orbital floor

 C

Lateral nasal wall

 D

Maxillary sinus

Q. 22

Haller cells are seen in‑

 A

Roof of nose

 B

Orbital floor

 C

Lateral nasal wall

 D

Maxillary sinus

Ans. B

Explanation:

The Onodi and Haller cells are ethmoidal air cells.

Some air cells may invade the orbital floor. These are known as the Haller’ cells.

The Onodi cell is usually regarded as the most posterior ethmoid cell that pneumatizes lateral and superior to the sphenoid sinus and is intimately associated with the optic nerve.


Q. 23

Enophthalmos caused by fracture of ‑

 A

Floor of orbit

 B

Medial wall of orbit

 C

Lateral wall of orbit

 D

Roof of orbit

Q. 23

Enophthalmos caused by fracture of ‑

 A

Floor of orbit

 B

Medial wall of orbit

 C

Lateral wall of orbit

 D

Roof of orbit

Ans. A

Explanation:

Ans. is ‘a’ i.e., Floor of orbit

Post traumatic enophthalmos is caused by blow out fracture through the floor of orbit.

ENOPHTHALMOS

  • It is the inward displacement of the eyeball. About 50 percent cases of mild enophthalmos are misdiagnosed as having ipsilateral ptosis or contralateral proptosis.

Common causes are :‑

  1. Congenital. Microphthalmos and maxillary hypoplasia.
  2. Traumatic, Blow out fractures of floor of the orbit.
  3. Post-inflammatory. Cicatrization of extraocular muscles as in the pseudotumour syndromes.
  4. Paralytic enophthalmos. It is seen in Horner’s syndrome (due to paralysis of cervical sympathetics).
  5. Atrophy of orbital contents. Senile atrophy of orbital fat, atrophy due to irradiation of malignant tumour, following cicatrizing metastatic carcinoma and due to scleroderma.

Q. 24

Lines of Sebileau pass through

 A

Floor of orbit and maxillary antrum

 B

Floor of nasal cavity and maxillary antrum

 C

Floor of orbit and nasal cavity

 D

Floor of orbit and roof of mouth

Q. 24

Lines of Sebileau pass through

 A

Floor of orbit and maxillary antrum

 B

Floor of nasal cavity and maxillary antrum

 C

Floor of orbit and nasal cavity

 D

Floor of orbit and roof of mouth

Ans. A

Explanation:

 

Ledermann’s classification of maxillary carcinoma uses two horizontal lines – one passing through the floor of orbits and the other through the floor of the maxillary antra dividing the area into superstructure, mesostructure and infrastructure.



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