2. * Topics of discussion:
* Definition
* Etiology
* types
* Microbiology of OI
* Nature of progression and spread
* Facial spaces and its involvement
* Complications of OI
* Management of OI
* Summery
* references
3. An odontogenic infection is an infection that originates
within a tooth or in the closely surrounding tissues.
The term is derived from odonto- (from ancient Greek odous
- "tooth") and -genic (from Greek genos - "birth")
An infection which arises from the teeth, and spread
beyond the teeth to the alveolar process and deeper tissues
of oral cavity, face, head and neck and have a characteristic
flora.
4. Simple odontogenic infection; which is limited
to alveolar process and vestibuler space
It could be treated with simple
endodontic surgical procedure (Rct) or
extraction
Complex odontogenic infection; which spread
beyond vestibular space and couldn't be treated
with simple procedure like Rct and Extraction
simple
complex
5. Odontogenic infections have two major origins:
(1) periapical: as a result of pulpal necrosis and subsequent
bacterial invasion into the periapical tissue.
(2) Periodontal: as a result of a deep periodontal pocket
that
allows inoculation of bacteria into the underlying soft
tissues.
Of these two, the periapical origin is the most common in
odontogenic infections.
6. Poly microbial infection(including indigenous bacteria also)
* Anaerobic only 50 %
* Mixed anaerobic and aerobic 44%
* Aerobic only 6%
Anaerobic bacteria : it is found in odontogenic infections are predominant.
Anaerobic gram-positive cocci: these are found in about 65% of
cases. These cocci are anaerobic Streptococcus and
Peptostreptococcus.
Anaerobic gram-negative rods: these are cultured in about three
quarters of the infections. The Prevotella and Porphyromonas spp.
are found in about 75% of these, and Fusobacterium organisms are
present in more than 50%.
7. Microbiology of OI
Aerobic bacteria: In odontogenic infections predominant species
(found in about 65% of cases) are the Streptococcus milleri
group, which consists of three members of the S. viridans group
of bacteria:
Facultative bacteria: These which can grow in the presence or the
absence of oxygen, may initiate the process of spreading into
deeper tissue , which includes:
S. anginosus, S. intermedius, and S. constellatus.
Miscellaneous bacteria contribute 5% or less of the
aerobic species found in these infections. Rarely found bacteria
include staphylococci, group D Streptococcus organisms, other
streptococci, Neisseria spp., Corynebacterium spp., and
Haemophilus spp.
8. Microbiology of OI
After initial inoculation into deeper tissues, the facultative S.
milleri group organisms can synthesize hyaluronidase, which allows
the infecting organisms to spread through connective tissues,
initiating the cellulitis stage of infection.
Metabolic byproducts from the streptococci create a favorable
environment for the
growth of anaerobes.
The release of essential nutrients, lowered
pH in the tissues, and consumption of local oxygen supplies. The
anaerobic bacteria are then able to grow, and as the local
oxidation–reduction potential is lowered further, the anaerobic
bacteria predominate and cause liquefaction necrosis of tissues by
their synthesis of collagenases.
9. Microbiology of OI
As collagen is broken down and invading white blood cells necrose
and lyse, microabscesses form and may coalesce into a clinically
recognizable abscess.
In the abscess stage, anaerobic bacteria
predominate and may eventually become the only organisms found
in culture.
Early infections appearing initially as a cellulitis may be
characterized as predominantly aerobic streptococcal infections,
and late, chronic abscesses may be characterized as anaerobic
infections.
10.
11. *Odontogenic infections have two major origins:
(1) periapical: as a result of pulpal necrosis and subsequent
bacterial invasion into the periapical tissue.
(2) Periodontal: as a result of a deep periodontal pocket that
allows inoculation of bacteria into the underlying soft tissues.
Of these two, the periapical origin is the most common in
odontogenic infections.
12. Caries cause necrosis of pulp, allows a pathway for bacteria to
enter the periapical tissues. Once this tissue has become
inoculated with bacteria and an active infection is established,
the infection spreads equally in all directions, but preferentially
along the lines of least resistance. The infection spreads through
the cancellous bone until it encounters a cortical plate. If this
cortical plate is thin, the infection erodes through the bone and
enters the surrounding soft tissues. Treatment of the necrotic
pulp by standard endodontic therapy or extraction of the tooth
should resolve the infection. Antibiotics alone may arrest, but do
not cure, the infection because the infection is likely to recur
when antibiotic therapy has ended without treatment of the
underlying dental cause.
13. *
* The location of the infection arising from a specific tooth is
determined by the following two major factors:
* (1) the thickness of the bone overlying the apex of the tooth and
*(2) the relationship of the site of perforation of bone to muscle
attachments of the maxilla and mandible.
15. *Definition:
The potential spaces between the various
layers of fascia normally filled with loose connective
tissue and bounded by anatomical barriers, usually
bone, muscle or facial layers.(Moore -1975)
It exist between the fasciae and underlying organs
and other tissues.
In health, these spaces do not exist; they are only
created by pathology, e.g. the spread of pus or
cellulitis in an infection.
58. *
*If odontogenic infection isnot treated on time it leads to
life threatni ng complications like;
Ludwig's angina
Cavernous sinus thrombosis
Danger space infection
59. * First described in 1836 by Wilhelm Friedreich
Von Ludwig
*The word angina derived from the latin word
“angere” means suffocation or chocking
sensation
*“Ludwig” comes from the person to whom the
credit goes for its description
60. *DEFINITION:
*Ludwig’s angina is a massive, firm, brawny cellulitis or
induration and acute, toxic stage , involving
simultaneously , the submandibular, sublingual &
submental spaces bilaterally.
*Ludwig's angina is a type of severe cellulitis rather
than abcess formation, involving the floor of the mouth
leads to
dysphagia(leads to drooling of saliva)
dyspnea (compromising the air way/oedema )
dysphonia
61.
62. *
*Cavernous sinus thrombosis (CST) is the formation of a
blood clot within the cavernous sinus,
When maxillary odontogenic infections erode into the
infraorbital vein in the infraorbital space or the inferior
ophthalmic vein via . the sinuses, they can follow the
common ophthalmic vein through the superior orbital
fissure and extend directly into the cavernous sinus.
Intravascular inflammation caused by the invading bacteria
stimulates
the clott- ing pathways, resulting in a septic cavernous
sinus thrombosis
67. *The carotid siphon of the internal carotid
artery,
* Cranial nerves III, IV, V (branches V1 and V2)
and VI all pass through this blood filled space.
68.
69. *
*Infecton of the deep neck spaces RPS, PVS leads to
danger space infection.
106. *
*Odontogenic infection is tooth borne infection
*Initiated by pulpal or periodontal infections.
*It is polymicrobial infection – Aerobic, Anaerobic gram +
cocci (Streptococci, Peptostrep,pepto), gram + rods
(Eubac, Lacto), and gram - rods (Porphromonas or
Prevotella, Fusobacterium)
*It spreads through different fascial spaces(potential sites
for spread of infection _absent normally)
*Diagnosed through pt; Hx , Examination,
investigations(radiographs) and microbes are confirmed
though culture and sensitivity
107. *
*Principles of Management of Odontogenic
Infections
*• Determine severity.
* • Evaluate host defenses.
*• Determine the setting of care.
* • Treat surgically.
* • Support medically.
*• Choose and prescribe appropriate antibiotic(s).
*• Administer antibiotic appropriately.
* • Re-evaluate frequently.
108. *
*Ludwig's angina, cavernous sinus thrombosis &
danger space infections are the most complicated
infections may caused by odontogenic infections
*Infection is more speedily progressing in
immunocompromised patient.
109. *Treat OI in early stages as possible _during 1st
simple odontogenic infection stage.
*Antibiotic is not necessary to be given in each and
every odontogenic infections but in special
conditions
*Dose and duration of antibiotics are necessary for
its effectiveness
*Culture and sensitivity should be done in special
conditions like not responding infections.
*Ludwig's angina and cavernous sinus thrombosis like
condition should be vigorously treated bcz it may
leads to death.
110. *
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