odontogenic infections

Question 1

Factors contributing to immunity of host against intra oral infections

Answer 1

1. Humoral: circulating immunoglobulins, promote phagocytosis by macrophages. Inflammatory mediators
2. Cellular: phagocytes, lymphocytes
3. Local: abundant vascular supply, mechanical cleansing by salivary flow, igA, high epithelial turnover

Question 2

Progression of odontogenic infection

Answer 2

1. inoculation
2. cellulitis – 5 cardinal signs of inflammation . diffuse redness and soft at early stage, hard after 24 h
3. abscess
4. resolution

Question 3

When is aggressive/prompt treatment of odontogenic infection required

Answer 3

• 24 hour painful swelling ie rapid
• pain on swallowing
• severe trismus (0-5mm opening)
• pediatric patient
• dyspsnea

Question 4

pain durning swallowing indicates that odontogenic infection has

Answer 4

gone backwards to involve epiglottis and pharyngeal mucosa

Question 5

Severe trismus indicates that odontogenic infection has

Answer 5

involved the muscles of mastication (masticator space), which can progress to involve the lateral pharyngeal space –> retropharyngeal space –> danger space –> go down to mediastinum and cause mediastinitis

Question 6

Factors affecting path of spread of odontogenic infection

Answer 6

Thinness of bone
Location of apex
Insertion of muscle

Question 7

If apex of lower molar is above insertion of mylohyoid, infection spreads to

Answer 7

sublingual space

Question 8

If apex of lower molar is below insertion of mylohyoid, infection spreads to

Answer 8

submandibular space

Question 9

Odontogenic infection of central incisor can spread to

Answer 9

Canine space –> infraorbital space –> angular vein –> cavernous sinus thrombosis

Orbital space has two compartments. Preseptal is superficial. Once it goes past orbital septum, must treat aggressively as highway to cavernous sinus

Question 10

What is ludwig’s angina

Answer 10

odontogenic infection spreads backwards to involve submandibular space –> r/l submental –> contralateral submandibular space –> r/l sublingual space ie bilateral involvement of submand and sublingual space

Tongue is pushed upwards and backwards which obstructs breathing and causes asphyxiation. Hence accessory muscles of inspiration are engaged

When FOM palpated, hard, cannot be depressed

Question 11

Palatal abscess likely to originate from which teeth

Answer 11

Palatal root of upper molar

Upper lateral incisor

Question 12

What happens when there is odontogenic infection buccal space involvement

Answer 12

Reduced mouth opening of 15-25mm due to guarding. Mouth opening improve when LA given (not true trismus)

Question 13

Masseteric space infection typically originate from

Answer 13

lower molars

Question 14

What kind of radiograph do you take to investigate odontogenic infection

Answer 14

CT scan

Question 15

Treatment for odontogenic infection

Answer 15

1. Identify cause
2. Determine severity eg trismus time of onset, vital signs (>38.5º and elevated heart rate, fever, malaise indicate systemic involvement), is tissue fluctuant/indurated, distortion of tissue architecture eg soft palate deviation indicate involvement of lateral pterygoid space

Question 16

Complications of odontogenic infections

Answer 16

• Meningitis
• Encephalitis
• Base of skull
• Spread to cavernous sinus after spreading past orbital septum
• Air way embarrassment
• Septic thrombosis

Question 17

Principles in treatment of odontogenic infection

Answer 17

1. Setting of treatment (do you refer to OMS)
2. Protect airway
3. Remove cause
4. Establish drainage
5. Antibiotic therapy
6. Suppportive care

Question 18

When to refer to OMS for treatment of odontogenic infection

Answer 18

Moderate infection with some buccal space involvement and patient not immunocompromised –> either GP/OMS

Moderate infection with immunocompromised eg diabetes patient –> OMS

Severe eg difficulty breathing, >38.5ºC, severe trismus –> OMS

Question 19

How to protect air way in patient with odontogenic infection as GP

Answer 19

Ambubag, posture of patient

Question 20

LA infiltration may not be effective in patient with odontogenic infection due to increased acidity of environment. What should you do?

Answer 20

Give block

Sodium bicarbonate buffer

Question 21

How to give LA to patient suffering from trismus

Answer 21

Mouth prop with conventional IDN block

Closed mouth akinosi technique

Question 22

In patient with odontogenic infection, trismus is most often caused by

Answer 22

Guarding

Spasm of masticatory muscles

Question 23

How long does it take for Ab to show effect

Answer 23

48 hours

Question 24

Drain options for incision and drainage

Answer 24

Rubber dam, fingers of glove, penrose drain

Suture drain to surrounding mucosa to anchor it

Question 25

Instructions for giving antibiotics for patient with odontogenic infection

Answer 25

Effecs only after 48 hours
Give for at least one week
Choose bacteriocidal antibiotic
Adequate tissue concentration achieved in 24-48h
Empirical antibiotics likely enough for simple cases

Question 26

Drug of choice for odontogenic infection

Answer 26

Penicillin (first line)
Clindamycin (first line after penicillin)
Erythromycin (bacteriostatic, second line after penicillin)

Question 27

principles of odontogenic infection management

Answer 27

Secure airway, early and aggressive drainage of all anatomic spaces affected by cellulitis or abscess

Question 28

natural history of infection

Answer 28

First stage is inoculation, where bacteria begins to spread beyond local confines. Patient may experience mild to moderate pain. Edema begins to occur, wth interstitial fluidbuikd up from neighbouring infection/inflammation

Second stage is cellulitis ie spread of bacteria into a space along with interstitial fluid formation. Inflammation (5 cardinal signs) is underway, and begins to overwhelm the host defense. Patient experiences more severe and generalised pain.

Third stage is abscess formation. Maturation of inflammatory response is achieved and there is focal accumulation of purulent discharge. Severe focal pain

Lastly, resolution

Question 29

pain on swallowing indicates involvement of

Answer 29

epiglottis and pharyngeal mucosa

Question 30

source of buccal space swelling

Answer 30

upper molars, premolars
lower premolars

Question 31

where can buccal space abscess spread to

Answer 31

infratemporal space
infraorbital space
pterygomandibular space

Question 32

clinical signs of ludwigs angina

Answer 32

fluctuant swelling may be present, firm induration of skin at the submental and submandibular region extraorally, elevation of FOM and tongue

patient can present with airway distress (use of accessory muscles for inspiration), trismus, dysphagia, dysphonia