OD18

Question 1

How far below the inferior border of the mandible should an incision be to prevent damage of inferior alveolar nerve?

Answer 1

2cm

Question 2

3 methods of spreading in oro-facial infections?

Answer 2

• Venous
Pterygoid plexus – likes up to central aspect of vein – as it has no valves things can go straight up and go into the brain
Angular veins @ medial canthus of eye – also has no valves – bugs can track up to the brain
• Lymphatics
First drain into superficial lymph nodes ringing mandible:
Submental
From floor of mouth, tip of tongue, lower lip and chin
Submandibular
From face, cheeks, upper lips and anterior two thirds of tongue
Then these drain to deep cervical lymph nodes along the course of the internal jugular v.
• Tissue (or fascial) planes
Well defined sheet of connective tissue surrounding organs and other structures
Major fascia that determine routes of infection in head and neck:
Prevertebral
Pretracheal
Deep cervical fascia
Carotid fascia
Superficial or subcutaneous fascia

Question 3

Functions of fascia?

Answer 3

Varied for different types of fascia

• Support of structures - muscle & parotid gland
• Provide pathways for neurovascular structures to pass
• Circulatory function -¬‐ promote venous drainage through maintaining the shape of structures
• Facilitate movement between structures by acting as a rigid surface for sliding e.g. pleura
• Mechanical protection to structures

Question 4

What is the most palatal root in the mouth?

Answer 4

Lateral incisor root

Question 5

What are the different types of abscesses possible with root morphology of lower molars?

Answer 5

• Lower molar root perforates below mylohyoid – GOES BELOW INTO SUBMENTAL – E/O SWELLING
• If perforates above mylohyoid – goes into FOM – I/O SWELLING

Question 6

Consequence of pus in the sub-masseteric space?

Answer 6

Trismus

Question 7

All fascia in the neck lead where?

Answer 7

Mediastinum

Question 8

What muscles govern the spread of infection IO or EO?

Answer 8

• Governed on buccal side by buccinator

* Governed on lingual side by mylohyoid

Question 9

Severe consequences of spread of infection?

Answer 9

• Airway obstruction
Ludwig’s angina – CELLULITIS – spreading of infection through tissue planes
Submental/mandibular/lingual – tracks down to epiglottis causing narrowing of glottis – AIRWAY COMPROMISED
• Intracranial spread
• Mediastinal infection
• Necrotising fasciitis
• Sepsis

Question 10

Signs of an airway obstruction?

Answer 10

o SOB (dyspnoea)
stridor- little space between focal cords(weezing)
o Drooling/ inability to swallow own saliva
o Difficulty swallowing (not due to pain)
o Decreased SaO2
o Hot potato voice (common in quinsy = PERITONSILLAR ABSCESS)

Question 11

Describe Ludwig’s angina?

Answer 11

Bilateral submandibular and sublingual cellulitis,

Spread down through lateral pharynx space to larynx

Oedema at glottis

Question 12

Treatment of Ludwig’s angina?

Answer 12

Bilateral through and through drains

Question 13

Worrying signs of intracranial spread?

Answer 13

Eye closing/ swelling in infra-orbital ridge
Altered conscious level
Decreased eye movement
Urgent referral needed

Question 14

2 intracranial infections complications?

Answer 14

Cavernous sinus thrombosis

Brain abscess

Question 15

What are 3 things inside the cavernous sinus?

Answer 15

• III
• IV
• V1, V2 and ganglion
• VI
• Internal carotid artery

Question 16

Signs of cavernous sinus thrombosis?

Answer 16

• Ophthalmoplegia - paralysis of the muscles within or surrounding the eye
• Proptosis – protrusion of eye
• Ptosis – drooping of lower eyelid
• High mortality

Question 17

Signs of mediastinum infection?

Answer 17

Pleuritic retrosternal chest pain radiating to neck or between shoulder blades

Spreading erythema down to sternal notch

Crepitus (abnormal popping/cracking sound) chest or neck

Hamman sign (crunching sound on in time with heart beat)

Radiographs – CT normally definitive:

Question 18

Describe the Glasgow Coma Scale.

Answer 18

A scale to measure consciousness.

Composed of 3 elements- eye-4, verbal-5 and motor-6..

Out of 15. 15= completely responsive 3= completely unresponsive.

Question 19

What are the eye tests for the GCS?

Answer 19

No opening of the eye- 1 point
Eye opening in response to pain stimulus- 2 points
Eye opening to speech- 3 points
Eyes opening spontaneously- 4 points

Question 20

What are verbal tests for the GCS?

Answer 20

No verbal response- 1 point
Incomprehensible sounds eg, moaning- 2 points
Speaks words but no sentences- 3 points
Confusion. The person responds to questions coherently but there is some disorientation and confusion- 4 points
Oriented. Person responds coherently and appropriately to questions- 5 points

Question 21

What are the motor tests for the GCS?

Answer 21

No motor response. Think spinal cord injury- 1 point
Abnormal Extension in response to pain- 2 points
Abnormal Flexion in response to pain- 3 points
Withdraws from pain- 4 points
Withdraws from touch- 5 points
Can obey commands- 6 points.