2. Plan
 Definition
 Etiology
 Classification
 Pathogenesis
 Symptoms

3. Definition
The word “osteomyelitis” originates from
the ancient Greek words:
 osteon (bone)
 muelinos (marrow)
Meaning inflammation of medullary
portion of the bone caused by infection.

4. This disease is now rare due to the value of
antibiotics and early treatment but the
importance of predisposing factors such as:
 Poor nutrition
 Untreated dental diseases
 Impaired immunity
 Exposure to radiation…

5. It is quite rare but seen particularly in
those patients whose defense
against infection is compromised
because of local or systemic factors.

7. Etiology
There are many various causes of osteomyelitis:
 Acute periapical infection
 Pericoronitis
 Acute periodontal lesions (postsurgical)
 Trauma-fractures and extraction of teeth
 Acute infection of the maxillary sinus
 Infection from skin(boils-skin abcess)
 Middle ear infections
 Haematogenic origin
 Vascular Insufficiency

10. Osteomyelitis of the jaws induced by
hematogenous spread has become rare
since the introduction of antibiotics;
however, in regions of limited medical
access these forms may still be noted.

11. Classifications

16. Pathogenesis

17. Pathogenesis
For osteomyelitis to occur exudate must
spread through the cancellous spaces of the
bone producing thrombosis of the nutrient
vessels with ischemia, infarction, and
sequester formation.

18.  Until old age the main blood supply to the
mandible is the inferior alveolar artery with
its centrifugal distribution anastamosing
with the peripheral vessels which enter
through Volkmann's canal.
 Parts of the ramus and coronoid processes
are supplied by additional small nutrient
arteries but are dependent to a substantial
extent upon small vessels entering the
cortex from muscle attachments.

21.  In most incidences periapical and periodontal infections
are localized by a protective pyogenic membrane or soft
tissue abscess wall which serves as a certain barrier.
 This condition represents a carefully balanced equilibrium
between microorganisms and host resistance preventing
further spreading of the infection. If the causative
bacteria are sufficient in number and virulence, this
barrier can be destroyed. Furthermore, permanent or
temporary reduction of host resistance factors for various
reasons mentioned previously facilitate deep bone
invasion by microorganisms.

22.  Bacterial invasion induces a cascade of inflammatory host
responses causing hyperemia, increased capillary permeability,
and local inflammation.
 Proteolytic enzymes are released during this immunological
reaction creating tissue necrosis, which further progresses as
destruction of bacteria and vascular thrombosis ensue.
 Accumulation of pus inside the medullary cavity, consisting of
necrotic tissue and dead bacteria within white blood cells,
increases intramedullary pressure. This leads to vascular
collapse, venous stasis, thrombosis, and hence local ischemia.
Pus travels through the haversian and nutrient canals and
accumulates beneath the periosteum, elevating it from the
cortical bone and thereby further reducing the vascular supply

23. Chronification of bone infection
 The chronification of the disease reflects the
inability of the host to eradicate the pathogen
due to lack of treatment or inadequate
treatment, resulting in failure to reestablish the
carefully balanced equilibrium between host
factors and pathogens found in a healthy oral
environment.
 After the acute inflammatory process occurs
and local blood supply is compromised,
necrosis of the endosteal bone takes place.
The bone fragments die and become
sequestra.

26. Chronic osteomyelitis at the molar region
and region of first premolar of the left side of
the mandible

27.  Osteomyelitis is a rare problem in the
maxilla because it has predominantly
cancellous alveolar bone with a thin
cortex and a rich plexiform blood supply.

28. Diagnosis
 Clinical Picture
 X-ray
 Complete blood count
 Erythrocyte sedimentation rate
 Needle aspiration or bone biopsy
 Radionuclide bone scans
 CAT scans
 MRI
 Ultrasound
 C-reactive Protein

29. Signs and Symptoms

30. Symptoms of Acute
Osteomyelitis Severe pain
 Tenderness in the affected area
 Swelling in the affected area
 Regional lymphadenopathy(lymph nodes enlarged & tender)
 If the infection involves the mandibular canal near premolar
region, a paresthesia of the lip is common.
 Problem opening jaw (trismus)
 An important symptom is a developing numbness over the
chin as a result of mental nerve involvement.
 Percussion is painful over involved teeth
 Some teeth involved can become loose and mobile
 Puss discharges
 A fetid oral odor caused by anaerobic pyogenic
bacteria often is present.
 Fever (sub-febrile) and weakness

31. On Radiographs:
 Can be seen on x-ray only after 1-3 weeks
 The typical feature is a rarefying of the bone. This may
extend through a large area of bone, involving the
inferior dental canal and lower cortex of the mandible.
 decreased density of trabeculae
 multiple small radiolucent areas become
apparent
 sequestra - irregular calcified areas separate from remaining
bone.

32. Chronic Osteomyelitis
Clinical features
 Clinical course lasting over a month.
 Painful exacerbations and swelling are
always present, although this is likely to be
less severe than in the acute form.
 Preservation of mental and labial sensation
 One or more soft tissue sinuses are
typically present, draining pus. The affected
bone may become enlarged owing to
periosteal reaction.

35. A- Patient with a clinically extensive secondary chronic
osteomyelitis of the frontal region with multiple fistula and abscess
formations. The patient was treated with i.v. bisphosphonates for
metastatic breast cancer.
B- CT scan corresponding to a: The bone and periosteal reaction is
not as strong as would have been expected from the clinical picture
and compared with cases of secondary osteomyelitis of the
mandible with no underlying bone pathology.

37. To Be
Continued…….