Orofacial infections - head and neck infections: tissue space and bone

What are the main causes of dental infection? (3)

1. dental caries

2. pericoronitis

3. periodontal disease

Where do acute suppurative infections around the jaw originate from? (3)

1. the teeth

2. from skin sepsis

3. from salivary gland sepsis

What can a peri-apical infection lead to? (3)

1. dentoalveolar abscess

2. involvement of the local tissue spaces (cellulitis)

3. suppurative lymphadenitis (infection of lymphs so they become raised)

What is a dentoalveolar abscess?

Where is the exit of pus dictated by?

What determines what tissue spaces into which the pus will enter?

It is suppuration at the apex of a tooth

The direction of the exit of pus is determined by the relationship of the apex to the cortical plate and the thickness of the cortical plate.

The tissue spaces invaded will be dictated by the muscle and fascial attachments associated with the area.

Through what 3 mediums can the infection spread?

1. direct local spread

2. lymphatics

3. veins

What 3 factors influence the spread of infection?

1. host factors and their susceptibility to infection

2. micro-organism factors (how virulent the bacterium is)

3. local tissue structures and arrangements

What are tissue spaces?

They are potential spaces between tissues which ONLY exist in the presence of pathology

What two areas can pus exit into from an alveolar abscess from an upper central incisor?

1. as there is a thin labial cortical plate the pus can exit into the labial sulcus

2. if the incisor is long rooted it can enter the nasal cavity

What area does the pus exit into from an alveolar abscess from an upper lateral incisor?

As the apices of the lateral incisors have a steep inclination into the palate infections will tend to cause a palatal swelling

What two areas can pus exit into from an alveolar abscess from an upper canine?

1. It can enter into the labial sulcus

2. It can travel infraorbitally up towards the eye

What area can pus exit into from an alveolar abscess from an maxillary posterior tooth? why is this the case (2)

The abscess usually tends to form in the buccal sulcus because there is a thin buccal cortical plate and a high attachment of the buccinator muscle.

What 2 areas can pus exit into from an alveolar abscess from an mandibular incisor?

1. As there is a thin labial cortical plate it can present labially

2. As the mentalis is attached above the apices the swelling can present in the submental space around the chin point.

What dictates the spread of infection lingually for mandibualr posterior teeth?

The relationship of the apices of teeth to the attachment to the mylohyoid (mylohyoid line)

If the tooth apices is above the mylohyoid line where will the swelling present?

The sublingual space .

Which teeth have their apex above the mylohyoid line?

Anterior teeth. 6's can be sometimes above the line and sometimes below the line.

If the tooth apices is below the mylohyoid where will the swelling present?

The submandibular space

Which teeth have their apex below the mylohyoid line?

The molars.

Describe the spread of infection originating from pericoronitis of the 8? (2 possibilities)

1. spreads along fascial planes either into the buccal sulcus or deeper past the buccinator into the cheek

2. More seriously it can spread into the pterygoid space or the lateral pharyngeal space at which point there is nothing stopping it from spreading into the media stinum

What are the fascial systems of the neck? (4)

1. deep cervical fascia - wraps around the sternomastoid and is anterior to the infra hyoid muscle

2. carotid sheath- contains the carotid artery and the vagus nerve

3. pre vertebral fascia

4. pretracheal fascia

How can we manage a dental abscess infection which leads to blockage of the airways (3)

1. removal of the source of infection

2. drain the swelling

3. antibiotics

What is Ludwigs angina and why is it dangerous?

It is an infection involving the sublingual and submandibular spaces bilaterally.

This causes the floor of the mouth to swell so it raises causing the airway to be blocked.

What is acute cellulitis? How does it present?

When does suppuration present? Which microorganisms are responsible?

It is a bacterial skin infection which presents as a swelling of tissues usually around the jaw, no suppuration, redness or pain.

You get suppuration when the body responds with its immune system.

It is a mixed infection (both aerobic and anaerobic) containing mainly oral anaerobes.

What is necrotising fasciitis? What are its key features? (4)

It is the infection of the fascia which results in necrosis and is a v dangerous condition.

1. Rapid progression/ spread

2. pain out of proportion with presentation

3. systemic toxicity

4. dark mottled skin

What is osteomyelitis? What are the 2 main predisposing factors? What are the signs? (6)

How is it treated? (4)

It is infection of the bone through bone marrow spaces (typically long bones)

Predisposed by decreased vascularity of bone (radiation, trauma etc) and systemic factors (diabetes and immunocompromised)

1. Severe deep seated pain

2. swelling

3. non-healing necrotic bone including sequestra

4. non specific symptoms

5. trismus

6. paraesthesia if the mandible is affected

It is treated by removing the source of infection, antibiotics, analgesics and by sequestromy

What is a cavernous sinus thrombosis?

How is it related to dental infections?

What are the signs and symptoms? (6)

It is a blood clot formed within the cavernous sinus which can restrict the jugular blood return and place pressure on the optic nerve.

It can be caused by dental infections from the canine teeth which can spread through the facial nerve to the sinus (danger triangle)

1. palpebral oedema

2. proptosis

3. cyanosis

4. fixed dilated pupil (due to reduced blood supply)

5. limited eye movement

6. deteriorating sight

What is erysipelas?

How does it present? (3)

What causes it?

It is an acute streptococcal infection of the deep dermis with lymphatic spread.

1. swelling

2. rash

3. tenderness

It is caused by streptococcus pyogenes which releases an endotoxin responsible for the classic rash

What is actinomycosis?

How does it present? (3)

What type of bacterium causes it?

When should you suspect it?

A chronic suppurative infection.

1. soft tissue swelling usually around the angle of the mandible

2. there can be multiple external draining sinuses

3. trismus

It is caused by a gram positive anaerobe known as actinomyces Israeliiyou should suspect acintomycosis when there is a persistent extra oral sinus which remains once the dental cause (infected tooth) is removed.

How can we manage actinomyocosis? (3)

1. drain the abscess surgically

2. remove the local cause

3. give a prolongedd cause of antibiotics- usually penicillin

What is cancrum oris?

What are the three risk factors and how does it present? (2)

It is a fast acting gangrene infection which affects the soft tissues and bone.

It affects the malnourished, immunocompromised and people with poor OH

1. necrotising gingivitis

2. ulcers which progress to produce a gangrenous slough