7. Oral and Maxillofacial Infections

Question 1

What is an odontogenic infection

Answer 1

One in which the source of infection is from the teeth Access through necrotic pulp or deep pocket Polymicrobial in nature (avg of 5 bacteria)

Question 2

What type of bacteria typically cause odontogenic infections?

Answer 2

Aerobic gram + cocci Anaerobic gram + cocci Anaerobic gram - rods

Question 3

Progression of odontogenic infection

Answer 3

Initial inoculation Aerobic bacteria (more virulent) start infection Cellulitis (diffuse) type of infection Local reduction-oxidation potential is lowered Anaerobic bacteria begin to grow Abscess type of infection Anaerobic bacteria become exclusive

Question 4

Describe initial inoculation phase

Answer 4

duration: 0-3 days small and diffuse, not localized mild, minimal/no loss of function edema aerobic bacteria tx: remove source of infection, systemic AB

Question 5

Describe cellulitis phase

Answer 5

acute, 3-7 days large, severe and generalized diffuse borders hard, indurated & tender serosanguinous (serum and blood) aerobic and anaerobic bacteria thick & red skin severe loss of function tx: treat and remove source; incision & drainage (I&D); systemic AB

Question 6

Describe abscess phase

Answer 6

chronic, >5 days moderate & localized small, well circumscribed fluctuant, tender pus moderate-severe anaerobic bact shiny & peripherally red moderate loss of function tx: remove infection source, I&D, with or w/o systemic AB

Question 7

4 steps of diagnostic workup

Answer 7

1. Pt assessment: history & physical exam 2. Imaging 3. Lab Studies 4. Aspiration

Question 8

What do we look for in the physical exam of the head and neck?

Answer 8

Swelling, abscess, vital signs, fistula, trismus, cause of infection, airway evalutation

Question 9

What do we look for in radiographs?

Answer 9

Bone changes (not seen in acute) Collection of pus demarcated by radioopaque halo Extent of spread of infection Airway constriction

Question 10

What do we check in lab studies?

Answer 10

CBC WBC with differential (high in infection)

Question 11

How is aspiration done?

Answer 11

Use 18 gauge needle Expel air Recap Needle Send specimen for gram stain and culture

Question 12

What factors influence the spread of infection?

Answer 12

Host factors: -local factors (anatomical) -systemic factors (status of host defenses) Bacterial factors: -bacterial virulence -bacterial drug resistance

Question 13

How do compromised host defenses affect infection?

Answer 13

More frequent infections Infections progress rapidly

Question 14

Principles of therapy of odontogenic infection

Answer 14

1. Determine severity of infection from the Dx workup 2. Evaluate state of patient’s host defense mechanisms 3. Treat infection surgically 4. Support patient medically 5. Choose & prescribe appropriate Abx 6. Administer Abx properly 7. Evaluate patient frequently

Question 15

What would be indications for hospital administration?

Answer 15

temp >101F dehydration toxic appearance difficulty breathing or swallowing rapidly spreading infection fascial invovlement spread of infection to secondary spaces trismus threat to airway or vital structures compromised host defenses need for general anesthesia

Question 16

How do we treat infections?

Answer 16

Surgically: 1. Remove cause of infection 2. Provide drainage of pus 3. Do not wait for unequivocal accumulation of pus 4. Remove foreign body 5. If potentially life-threatening, intubate/secure airway early on

Question 17

Principles of I & D

Answer 17

-aspirate before incision -place incision in healthy skin/musosa -place incision in aesthetically acceptable area (near natural crease) -use blunt dissection to avoid damage to vessels -advance closed hemostat, spread beaks, and remove completely before reinserting -secure drains with sutures & irrigate -monitor drain output

Question 18

What instructions/medical support should you give the pt?

Answer 18

-encourage perioral fluid intake -support nutrition by high calorie nutrition supplement -prescribe analgesics for pain -rest -careful instructions

Question 19

What determines need for AB?

Answer 19

1. seriousness of infection 2. whether adequate surgical tx can be achieved 3. state of pt’s host defenses

Question 20

Indications for AB use

Answer 20

Rapid progressive swelling Diffuse swelling Compromised host defenses irrespective of type of infection Involvement of fascial spaces Osteomyelitis

Question 21

What is AB of choice?

Answer 21

Penicillin If allergic, use clindamycin or clarithromycin

Question 22

Factors to consider when choosing AB

Answer 22

Use narrow-spectrum, bacteriocidal AB Keep in mind cost for patient (penicillin is cheap) Low incidence of toxicity and side-effects

Question 23

What is a primary space?

Answer 23

One that is in direct contact with alveolar structure (these are the first to get infected) E.g. canine, buccal, infratemporal, submental, submandibular

Question 24

What is a secondary space?

Answer 24

Spaces that can’t be involved until infection of a primary space E.g. masseteric, pterygomandibular, prevertebral

Question 25

What is the most common source of infection in the infratemporal space?

Answer 25

3rd molars

Question 26

What is an uncommon, but potentially lethal extension of odontogenic infection?

Answer 26

Cavernous Sinus Thrombosis

Question 27

What are symptoms of cavernous sinus thrombosis?

Answer 27

Headache, fever, malaise (precede ocular findings) Proptosis, orbital swelling, and pain

Question 28

Tx of Cavernous Sinus Thrombosis

Answer 28

AB, corticosteroids, and heparin

Question 29

Which primary spaces are drained extra-orally?

Answer 29

Submandibular and submental