Bacterial orofacial infections - their causes, spread and control

Question 1

Range of bacterial infections (11)

Answer 1

Dental caries
Chronic & aggressive periodontitis 
Dentoalveolar abscess
Periodontal abscess
Acute streptococcal gingivostomatitis
ANUG & Noma
Tuberculosis
STDs – syphilis, gonorrhoea
Actinomycosis
Acute bacterial sialadenitis
Osteomyelitis

Question 2

Classical signs of acute inflammation are diagnostic (5)

Answer 2

Swelling
 Redness
 Pain or tenderness
 Heat
 Loss of function
-may also be systemic signs such as pyrexia or malaise as well as regional lymphadenopathy

Question 3

Abscess formation (4)

Answer 3

Pus-filled pathoogical cavity
Can form as part of inflammatory response to acute infection
Acute exacerbations of chronic inflammation can also occur, followed by periods of quiescence
Every abscess should be drained

Question 4

How can abscess formation be determined clinically (3)

Answer 4

‘Fluctuance’ to gentle palpation
Pressure exerted by 1 finger should be detected by another finger as ‘bounce’
If no fluctuance then cellulitis is present, which does not need drainage

Question 5

Radiographs in diagnosis of an acute dentoalveolar abscess (3)

Answer 5

Radiographs do not typically show any change in periapical tissues
Because it take ~10 days for sufficient bone loss to occur to be detectable on an intra-oral film
Earliest sign is widening of perio ligament space

Question 6

Clinical presentation of apical abscess - where will the abscess be (2)

Answer 6

Pus from an acute dentoalveolar abscess takes the track of least resistance through cancellous bone and points on nearest epithelial surface
Usually on buccal aspect of maxillary or mandibular alveolus, where overlying bone is thinnest, but can be palatally/ lingually

Question 7

General measures: principles of acute infection (3)

Answer 7

Admission if unwell
-IV abx + surgical drainage
Analgesia
-NSAIDS (pain relief and anti-pyrexial)
Control of infection
-abx given blindly as it not practical to await results of culture and sensitivity testing

Question 8

Local measures: principles of acute infection (4)

Answer 8

Removal of the cause
Drainage Prevention of spread
Restoration of function

Question 9

Abx used for dental abscesses (3)

Answer 9

Typically amoxicillin and metronidazole are used in combination, and changes made only in the face of microbiological results.

Question 10

Local measures: removing the cause (2)

Answer 10

Most important principal
E.g. extraction of non-vital or hopelessly mobile teeth, removal of sequestrae (dead bone), foreign bodies or salivary calculi

Question 11

Local measures: drainage (3)

Answer 11

Pus should always be drained and a surgical incision leaves less scarring than spontaneous drainage, particularly through skin
Abx not substitute

Question 12

Drainage of IO abscesses (8)

Answer 12

Adequate anaesthesia – need to have sufficient anaesthesia to allow a painless incision. Use 2% lignocaine with adrenaline injected into the overlying mucosa, not into the abscess cavity.
Horizontal incision parallel to the occlusal surface of the teeth 1 – 2cm in length.
Take into account local anatomy eg mental nerve
Use a no. 11 blade held backwards with an upward sweep
Open the abscess cavity with artery forceps (Hilton’s method).
Hot salt water mouthwashes afterwards will encourage any remaining pus to drain.
Incising an abscess cavity to drain it is almost always sufficient for intra-oral abscesses. However, when pus has to pass through several tissue planes in order to escape, for example in deep neck abscesses, a drain can be inserted into the abscess cavity which is exteriorized into the mouth or onto the skin surface (sometimes both: through-and-through).

Question 13

Local measures: prevention of spread (2)

Answer 13

This is achieved by drainage, use of antimicrobials and rest. Rest is difficult in the orofacial region, but trismus when present achieves this naturally.

Question 14

Local measures: restoration of function (2)

Answer 14

Review the patient after the acute phase to ensure that things have settled and function has been restored. Sometimes trismus can persist and need treatment eg. Therabite.

Question 15

Microbial aetiology of dentoalveolar abscesses (7)

Answer 15

Black-pigmented anaerobes
 Fusobacterium
 Anaerobic cocci (Peptostreptococcus, Parvimonas)
Streptococcus
non-pigmented anaerobes
Eubacterium
spirochaetes

Question 16

Symptoms of periodontal abscess (4)

Answer 16

Pain
Swelling - small localised to diffuse
Lymphadenopathy and fever may be present
Facial or neck cellulitis rare

Question 17

Periodontal abcess - Tooth usually vital (3)

Answer 17

pre-existing periodontal pockets that become occluded (foreign body)
Trauma to the periodontium
Secondary infection of lateral periodontal cyst

Question 18

Periodontal abscess - radiography (1)

Answer 18

Radiolucency on lateral aspect of root

Question 19

Diabetic patients - periodontal abscesses (2)

Answer 19

Multiple seen in poorly controlled diabetes

Question 20

Microbial aetiology of periodontal abscesses (2)

Answer 20

Same as chronic perio + candida

Question 21

Treatment of periodontal abscesses (2)

Answer 21

Drain and debride

Question 22

Sptreptococcal gingivostomatitis (2)

Answer 22

Rare in non-compromised hosts
-most frequently follows tonsillitis
Severe inflammation of the gingivae with marked pain
Caused by S.pyogenes
-complications - fasciitis, tissue destruction, rheumatic heart disease, nephritis etc.
Differentiate from drug and viral causes

Question 23

Treatment of streptococcal gingivostomatitis (1)

Answer 23

Requires prompt treatment with penicillin

Question 24

Acute ulcerative gingivitis (3)

Answer 24

Poor oral hygiene, smoking, stress
Ulceration + destruction of interdental papilla - invasion of tissue
Halitosis, bad taste, malaise, lymphadenopathy

Question 25

Cancrum oris or Noma (5)

Answer 25

Usually preceded by ANUG and recent debilitating illness Infection -viral (e.g. measles) -bacterial infection (e.g. Tuberculosis, scarlet fever) -parasitic infection (e.g.malaria) Immune-suppressive drugs/disease Malnutrition F. necrophorum, P. intermedia, T. vincentii, T.denticola, T.forsythia, a-streptococci

Question 26

Tuberculosis (3)

Answer 26

Increasing incidence in UK particularly among immigrants Rare in oral cavity -usually 2º to pulmonary TB -cough or cervical lymphadenopathy Can result in delayed healing after tooth extraction - 2˚ osteomyelitis

Question 27

Tuberculosis investigation (3)

Answer 27

Biopsy- ZN Culture – LJ 4-6 wks (Serology), PCR, reactive T cells

Question 28

Tuberculosis - histology (2)

Answer 28

Epithelioid granulomas | Giant cells and caseation

Question 29

Syphilis - primary lesion (4)

Answer 29

Chancre on lip or tongue. Ulcer, local oedema, painless Smear shows spirochaetes Lymphadenopathy

Question 30

Secondary syphilis (4)

Answer 30

~6 weeks after healing Snail track ulcers Lymphadenopathy Skin rash

Question 31

Tertiary syphilis (3)

Answer 31

Now rarely seen in western world Gumma on palate, tongue or tonsil -firm, necrotic centre surrounded by inflamed tissue, Leukoplakia on dorsum of tongue and increased incidence of oral cancer

Question 32

Congenital syphilis (2)

Answer 32

Hutchinson’s incisors | Mulberry molars

Question 33

Gonorrhoea (4)

Answer 33

Pharynx and any part of oral mucosa can be affected Pain and lymphadenopathy Variable appearance -Ulceration -Oedema -Pseudomembranes Direct examination of a smear and/or culture necessary to diagnose Neisseria gonorrhoeae

Question 34

Actinomycosis caused by (3)

Answer 34

Actinomyces israelii, A.oris, A.naeslundii

Question 35

Treatment for actinomycosis (2)

Answer 35

Surgical drainage & debridement | Antibiotics 6-8 weeks

Question 36

Acute bacterial sialadenitis features (3)

Answer 36

Ascending infection – mainly parotid, Usually failure of secretion -Sjögren’s syndrome, gland pathology, sialolithiasis, drugs Unilateral, firm, red swelling, extreme pain, trismus, possibly febrile, milking duct releases pus

Question 37

Sampling for acute bacterial sialadenitis (4)

Answer 37

``` Difficult Microbial causes -oral streptococci -oral anaerobes -staphylococcus aureus ```

Question 38

Tx for acute bacterial sialadenitis (2)

Answer 38

Amoxicillin, flucloxacillin

Question 39

Exploration of acute bacterial sialadenitis (2)

Answer 39

sialography AFTER resolution, possibly surgical exploration

Question 40

Angular cheilitis causes (3)

Answer 40

Haematological deficiency – Fe, vitamin B2,3,6,12 Candida sp., Staph. aureus, (Strep. pyogenes) – alone or mixed Treat with miconazole, nystatin or fusidic acid, depending on cause

Question 41

Spread of infection - anatomy (3)

Answer 41

The spread of dentoalveolar infections is governed by the site of origin and the surrounding tissue planes that are limited by fascial layers and muscle insertions. The position of the apices of the originating tooth relative to muscles and fascia will influence the clinical presentation

Question 42

Fascial planes and tissue spaces

Answer 42

The neck is surrounded by multiple layers of fascia, of which the deep cervical fascia is the most important. These fascial layers continue superiorly and split around various structures to form tissue spaces. Fascial planes and tissue spaces are an anatomical framework for understanding how infection can spread.

Question 43

3 different parts to deep cervical fascia (3)

Answer 43

Investing layer Visceral layer Prevertebral fascia

Question 44

Spread in the mandible - antomy

Answer 44

How infection spreads from a mandibular tooth depends on the relation of the tooth to the insertion of 2 muscles: buccinator and mylohyoid. Buccinator attaches to the lateral (buccal) cortex of the mandible, adjacent to the molar teeth, and mylohyoid attaches to the mylohyoid ridge, which is on the medial (lingual) cortex. Abscesses that track laterally, above buccinator point in the mouth. Those below buccinator point onto the facial skin. Abscesses that track medially above mylohyoid point in the sublingual space. Those below mylohyoid point into the submandibular space Infection from lower 2nd and 3rd molars can also track posteriorly into either the masticator space or the parapharyngeal/retropharyngeal spaces. A sub-masseteric abscess causes profound trismus, and the patient will not be able to open their mouth Spread into the parapharyngeal and/or retropharyngeal spaces is dangerous due to possible airway compromise and tracking of pus into the chest via the retropharyngeal space.

Question 45

Spread in the maxilla

Answer 45

Most maxillary dental abscesses track buccally, as the bone is thinnest here, to point in the mouth, but abscesses arising from upper lateral incisors and palatal roots of 1st molars can point palatally. The relationship between the tooth apices and the levator anguli oris and buccinator muscles determines whether the abscess points in the oral cavity or on the skin of the cheek. The apex of the upper canine tooth can occasionally be situated above the origin of levator anguli oris, and infection can therefore present at the medial canthus of the eye, deep to levator labii superioris.

Question 46

Presentation of deep neck space infection (5)

Answer 46

These are rare, but most are dental in origin, typically from mandibular 2nd/3rd molars as their apices are often below the mylohyoid muscle. ``` Presenting features include: Fever Pain Sore throat Difficult or painful swallowing (dysphagia, odynophagia) Trismus ```

Question 47

Management of deep neck space infection (3)

Answer 47

The same principals of management of intra-oral abscesses apply, namely general and local measures, but broadly speaking the mainstays are: Airway management Intravenous antibiotics Surgical drainage

Question 48

Complications of orofacial infections - cavernous sinus thrombosis

Answer 48

``` The cavernous sinus is a venous sinus that surrounds the pituitary gland. It receives blood from the orbits, skull vault and cerberal hemispheres. At the medial canthus of the eye there is communication between the facial and opthalmic veins. Infection from an upper anterior tooth can, very rarely, drain into the cavernous sinus, causing venous thrombosis. The presenting symptoms are: Opthalmoplegia (no eye movements) Ptosis (drooping upper lid) Proptosis (bulging eye) Chemosis (red eye) ```

Question 49

When are antibiotics indicated (5)

Answer 49

``` When systemic symptoms present -fever, malaise, nausea etc. Spreading infections Chronic infection despite drainage -e.g. actinomycosis Immuno- or medically compromised Conditions difficult to resolve without or that speed up recovery -osteomyelitis, ANUG, sialadenitis LOCAL MEASURES FIRST - ABX USUALLY NOT FIRST LINE TX ```

Question 50

How to use anti-microbials (3)

Answer 50

Must be aimed at the organism(s) present Dose must achieve 4-8 times MIC in blood -keep up-to-date with BNF Must be present long enough to penetrate adequately to the site - but not too long

Question 51

Selection of agent (3)

Answer 51

Broad spectrum agents -associated with rise in C. difficile disease -care when prescribing to elderly and GI disease (including proton pump inhibitors and reflux disease) Empirical use -main drugs are amoxicillin, pen V, metronidazole and erythromycin -clindamycin, co-amoxiclav, clarithromycin no advantage Do not prescribe for -pulpitis -prevention of dry socket -in difficult extractions in immunocompromised

Question 52

Reasons why antibiotics fail (4)

Answer 52

``` Agent does not reach the site -inadequate drainage -poor blood supply -presence of a foreign body -inadequate duration Impaired defences -immunocompromised (bacteriostatic agent used) Inappropriate agent - resistance -inherent; acquired (mutation, plasmids) Poor patient compliance ```