Spread of Infection

Question 1

What is the difference between an infection and inflammation?

Answer 1

Infection = colonisation and invasion by a micro-organism.

Inflammation = the bodies response to the micro-organism

Question 2

What are the two ways in which an infection can spread to facial tissues?

Answer 2

1) Lymphatic

2) Tissue spaces

Question 3

What are the 3 factors that increase someone’s risk of infection spread?

Answer 3

1) Host susceptibility
2) Favourable environment
3) Micro-organism

Question 4

Name 6 things that can compromise the immune system increasing infection spread risk

Answer 4

• HIV/AIDS
• Chemotherapy
• Sickle cell anemia
• Transplant drugs
• Chronic renal failure
• Poorly controlled diabetes

Question 5

What is the difference between a periapical and periodontal abscess?

Answer 5

Periapical - collection of pus at root apex

Periodontal - collection of pus in the periodontal pocket

Question 6

What route does an infection take?

Answer 6

The path of least resistance.

It starts by spreading to surrounding damaged tissue.
The spread then continues and draining occurs through bone and into oral cavity.
Pus filled swellings then occur as fascial spread happens.

Question 7

What is the difference between an abscess and cellulitis?

Answer 7

Abscesses are localised and pus filled.

Cellulitis is a diffuse swelling due to fluid exudate leading to a hard abscess. It is a bacterial infection of the skin leading to hot and red skin presentation.

Question 8

What determines the pattern of the infection spread in the mouth?

Answer 8

• Position of the tooth apex relative to buccal/lingual cortical plate
• Position of tooth apex relative to muscle attachments
• Thickness of cortical plate

Question 9

What spaces do we have in the maxilla for spread of infection?

Answer 9

• Canine fossa
• Sub-periosteal plate
• Infratemporal fossa
• Buccal
• Subtemporalis

Question 10

What spaces do we have in the mandible for infection spread?

Answer 10

• Buccal
• Submasseteric space
• Parapharyngeal space
• Pterygomandibular space
• Submandibular space
• Sublingual space

Question 11

LOWER MANDIBULAR TOOTH INFECTION!

What are the 4 routes of infection spread?

Answer 11

1) Spread medial to buccinator - seen as buccal abscess
2) Spread to the cheek (under the buccinator muscle)
3) Sublingual gland (infection above the mylohyoid muscle)
4) Submandibular gland (infection below the mylohyoid muscle)

Question 12

UPPER MAXILLA INFECTION:

What are the 3 routes of infection spread?

Answer 12

1) Buccal abscess - spread through buccal cortical plate
2) Swelling to cheek and eye - spread above buccinator muscle
3) Maxillary antrum spread leading to chronic sinusitis

Question 13

What are the routes of infection for a lower wisdom tooth?

Answer 13

1 - Above masseter muscle causing cheek swelling

2 - Between masseter muscle and the mandible

3 - Between the mandible and the medial pterygoid muscle

4 - Parapharyngeal infection (between the pterygoids)

Question 14

If an upper tooth is infected and spread occurs to the cheek and under the eye, what serious problem can occur?

Answer 14

Cavernous sinus thrombosis.

This leads to bulging of the eyes, headaches, paralysis.

This needs an emergency admission , patient needs IV antibiotics and surgical drainage.

Question 15

Where does a swelling commonly present when there are mandibular incisor infections?

Answer 15

Sub-mental (swelling under the chin).

Question 16

What are local and systemic signs of infection?

Answer 16

Local:

• Swelling
• Tender to percussion
• Red and hot area
• Trismus
• Halitosis

Systemic:

• Fever
• Swelling of lymph nodes
• Body rash
• Difficulty breathing and swallowing

Question 17

What investigations do we need to do to localise the infection? (what tooth is infected)

Answer 17

• History
• Size, shape, mobility, colour
• Percussion
• Vitality testing
• Radiography
• Full blood tests

Question 18

What type of radiograph do we use to look for periapical lucencies?

Answer 18

Periapical radiographs

Question 19

What tests do we so in severe cases?

Answer 19

MRI and CBCT scans.

Question 20

What 3 factors determine the management of an infection?

Answer 20

• Source of infection
• Local spread extent
• Systemic spread extent

Question 21

What are some complications of infection?

Answer 21

1) Airway impingement
2) Intracranial spread
3) Osteomyelitis of jaws
4) Scarring
5) Sepsis
6) Endocarditis

Question 22

What is Ludwing’s angina?

What do we do?

Answer 22

• Bilateral spread submandibular, sublingual and submental
• Affects the airway and patient cant breathe
• Mainly cause by infected third molars
• Patient presents unable to talk, breathe and will be dribbling

Medical emergency! Tracheotomy needed sometimes, IV antibiotics, source of infection removed, surgical drainage.

Question 23

What is peritonsillar abscess?

Answer 23

Extreme tonsillitis! leads to abscess

Area needs to be drained, IV antibiotics given.

Question 24

What are the 3 main steps to managing any abscess?

Answer 24

1) Removal of source of infection
2) Drain pus
3) Supportive therapy - antibiotics, analgesics

Question 25

If a patient has an infection that wont go away, what do we suspect they may have?

Answer 25

Diabetes

Question 26

When do we refer a patient to oral and maxillofacial surgery?

Answer 26

1 - Life threatening signs such as dehydration and cellulitis

2 - If patient is an IN patient

3 - If patient fails to respond to any treatment given

Question 27

What are the 1st, 2nd and 3rd antibiotic choice?

Answer 27

1 - Amoxicillin (500mg 3 X a day for 5 days)

2 - Metronidazole (400mg, 3 X a ay for 5 days)

3 - Clarithromycin 250mg 2 X a day
OR
Azithromycin 500mg once a day for 2-3 days

Question 28

If an infection spreads systemically, where does it tend to go?

Answer 28

• Investing layer of deep cervical fascia
• Prevertebral fascia
• Pretracheal fascia
• Carotid sheath