MRONJ Flashcards
Fleischer 2015
Is MRONJ Avascular? Is osteomyelitis involved?
Dr. F says that vasculature is still present and should not be called avascular necrosis.
Yes osteomyelitis usually detected
What is MRONJ?
Medication related osteonecrosis of the jaw
Patient had history of antiresorptives or antiangiogenics
No history of radiation of mets to jaw
Exposed bone of fistula >8 weeks
What are other clnical and radiographic signs of MRONJ?
Pain/paresthesia
Osteosclerosis
PDL widening
What scan is useful in identifying MRONJ “hotspots”?
PET CT - used to guide diagnosis and surgery
1 mm cuts of mandible and maxilla
what are 3 theoretical etiologies of MRONG?
- infection/biofilm
- altered bone remodeling
- altered host immune system
Altered bone remodeling/ Over Suppression Hypothesis? What is it?
What doesn’t work with this theory?
The hypothesis contends that jaw bones undergoes a higher remodeling/bone turnover rate compared to other bones. So antireportives are preferential to the jaws = increased MRONJ risk.
This theory doesn’t work because bone turnover in the jaws was found to be no different than bone turnover elsewhere in the body
What are biofilms? How are they involved in MRONJ?
they produce and polymeric polysaccharide “shield” making them resistant to host defenses. The cell colonies have increased antibiotic resistance. Also host has altered immune response leading to increased pathologic bacteria.
Are bisphosphonates worth it?
YES!!!
They maintain normal bone health in osteoporosis (preventing fractures and pain) and in metastatic bone cancers.
they also treat hypercalcemia possibly improving survival in patients.
Benefits»> Risks
Can MRONJ occur without antiresorptives?
yes as ONJ but usually on other chemotherapeutics that affect immune response
VEGF inhibitors, steroids,
Does poor oral health (perio and caries) correlate with MRONJ?
No, oral health is not correlated.
there is some association with periodontal disease
How long after starting chemo therapy does MRONJ occur?
IV group within 1-2 years… not as clear with oral antiresorptives
Triggers for MRONJ?
Extraction and spontaneous (infected tooth without surgery) are about equal risk
What is denosumab?
Monoclonal antibody against RANKL (activates osteoclast) - may suppress immune response
Subcutaneous administration
Half life = 1 month - not retained in bone
Prolia = Osteoporosis Xgeva = Metastasis
Does fleischer use “drug holiday”? Avoiding extractions?
No and No - no data to support. He is film believer that infection causes MRONJ - requires removal of source and debridement as needed.
Is CTX a useful correlate/diagnostic lab for risk of MRONJ?
What is CTX?
No it is not associated.
CTX is a normal byproduct of collagen after osteoclast metabolizes it. So the idea was increased BP = decreased osteoclasts and the effect can be measure via CTX an osteoclast byproduct. But it is unfounded and not to be used with the current science.
Is biopsy recommended?
Is hematopathology testing (flow cytometry) recommended?
Yes - 5% incidence of metastatic disease.
Sometimes!
- flow cytometry analyzes quantity and characterics of cells and can find malignant plasma cells indicative of multiple myeloma.
- Immunohistochemistry can detect abnormal proteins like lambda protein excess secreted by multiple myeloma plasma cells.
Cytologists requires viable bone that surrounds the necrotic bone in particulate fashion - not block. Submit if fresh saline and send to lab asap.
what is treatment for MRONJ?
What are the 5 goals of treatment?
Start conservatively - rinse and antibiotics with toothbrush daily debridement.
If no improvement or worsening symptoms consider debridement
- Remove infection nidus.
- Remove necrotic bone.
- Remove of manage hypovascular bone.
- Promote healing
- Improve function
What are the 4 stages of MRONJ?
Stage 0 = asymptomatic pain/symptoms - no bone
Stage 1= exposed bone > 8 weeks - asymptomatic
Stage 2 = Bone exposure and pain
Stage 3 = necrotic bone with pathologic fx or fistula (extraoral)
Can cone beam be sued in the management of MRONJ?
Can be used to evaluate PDL widening, sequestration and sclerosis
How are MMPs involved? (matrix metalloproteinase)
Chronic infection and inflammation (TMJ!) can increase MMP production which break down wounds and prevent healing.
How is Doxycycline used to MRONJ?
Doxy is deposited in bone and reduces inflammatory destruction by reducing MMPs, collagenase and super oxide radicals.
It can aid in the MRONJ to delineate itself facilitating debridement/resection as the antibiotic won’t go to the dead or dying/hypovascular bone (dependent on osteoblasts and vasculature)
Osteosclerosis a complication of MRONJ?
More likely a reaction to infection - body reacts by increasing density and decreasing vascularity of bone.
Decreasing vascularity allows bacteria to seed in bone = increased risk of infection long term.
Makes identifying healthy bone very difficult in surgery.
LONG TERM FOLLOW UP NEEDED IN PATIENTS WITH SCLEROSIS
Is HBO a useful adjunctive treatment to MRONJ?
YES! HBO - stimulates angiogenesis and oxygenates sclerotic areas
- good for severe cases, sclerosis, 1 cm of inferior border is unaffected, smokers.
- 5-10 dives preop; 20-25 dives postop= likes more postop so it can stimulate healthy tissue.
- contraindicated on patients with near pathologic fx, patients unable to tolerate HBO, or end of life pts
- contraindicated on patients on Doxil, Cis-platinum, and bleomycin - must cessate drugs prior
- get through insurance by submitting biopsy to rule out osteomyelitis - if they can’t rule it out then insurance will pay for dives
Does HBO affect cancers?
HBO has no impact on tumor growth as per current evidence
Avelox? What is it? When is it used?
Oral abx for acute exacerbations and symptomatic infections - not primary therapy
4th generation fluoroquinolone
very broad spectrum and good against odontogenic pathogens
good bone penetration
Rx- 400mg qd
Risks = elevates INR - check with cardiologist a few days after
What is Ertapenam used for in MRONJ?
Invanz/ertapenam = for patients with significant sclerosis who aren’t candidates for segmental resection.
- beta lactamase inhibitor and very broad spectrum > unasyn
- requires ID consult and picc line
Is PRP useful for MRONJ?
Yes it is useful to promote soft tissue healing - but platelets may be compromised by chemotherapy making it less likely to be effective.
Likes to make splint with PRP as biologic dressing! and can’t hurt prognosis.
Does Implant surgery increase risk of MRONJ?
Read with care - oral and IV BP use is not an absolute contraindication for dental implant placement
What is AAOMS’s position on surgeries on patients taking antiresorptives?
Oral bp’s < 4 years = ok to do surgery
Oral bp’s > 4 years or with steroids = drug holiday of 2-3 months pre and post op.
IV bp’s should avoid surgery
Fleischer implant protocol?
No drug holiday
If extraction heals with patient is probably OK for implant. Staged process. Extract - heal - graft - heal- implant - heal.
Cancer patients - only if it will improve oral function.
Avoid sclerotic areas - increase infection risk!
BMP is contraindicated in active cancer.
