Bone pathology II - OSTEORADIONECROSIS AND MRONJ

Question 1

What is the effect of osteoradionecrosis?

Answer 1

• Radiotherapy of oral malignancies causes the proliferation of
  the intima of the blood vessels (endarteritis obliterans).
• This affects vascularity of the bone.
• Inferior dental artery with its branches may become
  thrombosed.

you will have necrotic/non-vital bone

if you have RCT or extraction = highly susceptible to infections

Question 2

What is ORN?

Answer 2

a serious complication of radiation therapy in cancer treatment where radiated bone becomes necrotic and exposed.

ORN occurs most commonly in the mouth during the treatment of head and neck cancer, and can arise over 5 years after radiation.

Question 3

What is endarteritis obliterans?

Answer 3

radiotherapy of oral malignancies cause endarteritis obliterans

proliferation of
the intima of the blood vessels
- compromise blood supply to jaw, specifically mandible

Question 4

if infection occurs, does it spread quickly or slowly in osteoradionecrosis?

Answer 4

• Quick spread of infection, osteomyelitis, painful bone
  necrosis, sloughing of soft tissues.

Question 5

if pt has head/neck cancer, what should the dentist do before they undergo radiotherapy?

Answer 5

any infected/suspicious teeth are extracted to prevent osteoradionecrosis

Question 6

what disease is shown?

Answer 6

osteoradionecrosis

Question 7

why take bisphosphonates?

Answer 7

osteoporosis

Paget’s disease of bone

Question 8

effect of bisphosphonates on bone?

Answer 8

related osteonecrosis of the jaw (BRONJ), now termed medication- related osteonecrosis of the jaw
(MRONJ).

Question 9

how are bisphosphonates taken to cause MRONJ?

Answer 9

more than 8 weeks

Question 10

medications causing MRONJ?

Answer 10

BISPHOSPHONATES

MONOCLONAL ANTIBODY THERAPY - bevacizumab

Question 11

why do bisphosphonates cause osteonecrosis?

Answer 11

• The drug inhibits osteoclast action and thus interferes with
  normal bone turnover.

In the jaws, this appears to render the bone more susceptible to infection and loss of vitality, particularly when the integrity of the mucosa is compromised.

Question 12

symptoms of MRONJ caused by bisphosphonates?

Answer 12

localized pain, loosening of teeth, and swelling
of the gingival or adjacent mucosa, with infection and
inflammation.

Question 13

what factors effect risk of MRONJ?

Answer 13

correlates with the dose, the duration of therapy, and the number of intravenous administrations given.

Question 14

What are 2/3 of MRONJ cases associated with?

Answer 14

previous dental procedure, such as extraction or implant
placement.

Question 15

how many stages f MRONJ are there?

Answer 15

3

Question 16

stage 1 MRONJ?

Answer 16

lesions commence with exposed bone

Question 17

Stage 2 MRONJ

Answer 17

followed by the development of areas of mucosal or
bone inflammation with pain.

Question 18

Stage 3 MRONJ?

Answer 18

ultimately, there may be extensive bone exposure,
pathological fracture, and severe pain with florid necrosis, infection, and inflammation in both mucosa and bone.

Question 19

disease shown?

Answer 19

MRONJ

necrotic bone exposed

Question 20

tx for MRONJ?

Answer 20

• Preventive measures for patients on bisphosphonates
  include good oral hygiene, regular dental check- ups, and
  self- examination.
• Treatment of MRONJ can be challenging and measures
  may include daily irrigation, antibiotic therapy, surgical
  removal of necrotic bone, and covering of affected areas to
  prevent trauma.