TLDR
- Osteoradionecrosis (ORN) is delayed bone death in a previously irradiated field, most often the mandible after head and neck radiation.
- The Marx Protocol is the classic hyperbaric oxygen (HBOT) framework used around dental surgery and for staged treatment of mandibular ORN.
- Common prophylactic structure for high-risk extractions in irradiated bone: 20 HBOT sessions before surgery and 10 after.
- Established ORN often uses ~30 preoperative sessions, surgery/debridement as indicated, then ~10 postoperative sessions, with total courses frequently in the 30-60 range under specialist guidance.
- Typical treatment pressures discussed in clinical protocols are about 2.0-2.5 ATA, often 90 minutes of oxygen breathing (sometimes longer at 2.0 ATA).
- OxygenWell delivers medical-grade HBOT up to 2.4 ATA in grounded monoplace chambers in Sherman Oaks and Calabasas, and our billing team helps with pre-authorization for qualifying, covered cases.
What is osteoradionecrosis of the jaw?
Osteoradionecrosis is avascular, aseptic necrosis of bone inside a previously irradiated field. After high-dose radiation, bone and soft tissue can lose microvascular supply. The tissue becomes hypoxic, hypocellular, and hypovascular. Small insults, especially dental extractions or implant surgery in the mandible, can open a wound that fails to heal and progresses to exposed bone, pain, infection risk, fistula, or fracture.
Clinically, ORN of the mandible is often staged with systems derived from work by Robert E. Marx, DDS. Staging guides whether minor debridement is enough or whether more extensive surgery and reconstruction are required. A practical clinical summary of Marx staging and HBOT adjuncts is maintained for hyperbaric clinicians on WoundReference’s mandibular ORN protocol.
Delayed radiation injury of bone and soft tissue is also a UHMS-recognized indication category. See the UHMS overview of delayed radiation injury (soft tissue and bony necrosis).
What is the Marx Protocol?
The Marx Protocol is not a single “one size” visit. It is a peri-surgical and staged HBOT regimen designed to restore oxygen-dependent healing capacity in irradiated jaw tissues before and after oral surgery, and to support debridement or reconstruction when ORN is already present.
In plain terms, HBOT raises the amount of oxygen dissolved in plasma under pressure. Over a series of sessions, better tissue oxygenation supports angiogenesis and wound biology in irradiated fields that no longer heal well on their own.
OxygenWell already covers broader radiation-injury context in our guide to HBOT before, during, and after radiation therapy. This article focuses on the jaw-specific Marx pathway patients and referring dentists/oral surgeons ask about most.
Prophylaxis before dental work in irradiated bone: 20 before, 10 after
When a patient needs extractions or other invasive dental procedures in a heavily irradiated mandible, many hyperbaric programs still reference the classic Marx prophylactic pattern:
- 20 HBOT sessions before the planned oral surgery
- 10 HBOT sessions after surgery
That 20 + 10 structure is widely taught as the peri-operative Marx prophylaxis regimen for high-risk patients. OxygenWell summarizes the same 20/10 framing in our radiation-therapy HBOT guide (oxygenwell.com radiation therapy article).
Who is typically “high risk”? Patients with substantial head and neck radiation dose to the jaws (historically discussed around and above ~6,000 cGy in clinical teaching), planned surgery in the irradiated field, and limited soft-tissue reserve. Exact risk thresholds belong with the treating radiation oncologist and oral/maxillofacial surgeon. HBOT is an adjunct, not a substitute for surgical judgment.
Why the pre-op block matters Irradiated bone does not bounce back after a single oxygen exposure. A multi-week preoperative series is intended to improve the local wound environment before the extraction or implant so the surgical site has a better chance to close.
Established mandibular ORN: 30 before surgery, 10 after (and longer courses)
For existing mandibular ORN, clinical hyperbaric protocols based on UHMS committee recommendations commonly describe:
- About 30 daily HBOT sessions at roughly 2.0-2.5 ATA with ~90 minutes of oxygen breathing (air breaks as protocol requires)
- Then surgical debridement or resection as stage requires
- Then about 10 postoperative HBOT sessions
- Overall treatment thresholds often cited in the 30-60 session range, with peer review for longer courses
WoundReference’s mandibular ORN HBOT protocol walks through Marx Stage I–III and III-R pathways in that 30 + surgery + 10 pattern, and notes that when radiation injuries are treated at 2.0 ATA, some clinicians extend oxygen time toward 120 minutes, while 2.4 ATA is frequently discussed as a preferred pressure based on Marx’s experimental work and clinical experience.
Marx stages in brief (clinical orientation)
Stage (Marx framework) | Practical picture | Typical HBOT + surgery pattern
Stage I | Exposed bone; may respond to HBOT ± minor debridement | Series of HBOT; escalate if little improvement after ~30 treatments
Stage II | Needs more radical debridement while trying to keep mandibular continuity | ~30 HBOT → debridement → ~10 postoperative HBOT
Stage III | Advanced disease (e.g., pathologic fracture, orocutaneous fistula, resorption to inferior border) | ~30 preoperative HBOT → resection as indicated → ~10 postoperative HBOT; reconstruction pathways (III-R) as planned
Staging and operative decisions stay with oral/maxillofacial surgery. Hyperbaric medicine supports tissue readiness and postoperative healing.
Does HBOT help prevent ORN? What modern trials add
Classic Marx-era practice made prophylactic HBOT standard in many centers for high-risk extractions. Modern research continues to test prevention questions carefully.
The HOPON trial (Hyperbaric Oxygen for the Prevention of Osteoradionecrosis) is a randomized protocol studying HBOT around dental surgery in irradiated patients, including treatment arms using 2.0 ATA with controlled session timing (HOPON protocol on PMC; Springer trial protocol). Results and local standards evolve; patients should decide with their surgeon and hyperbaric team rather than from internet summaries alone.
Broader late radiation tissue injury evidence, including bone and soft tissue endpoints, is synthesized in Cochrane-linked reviews such as HBOT for late radiation tissue injury (PMC).
What a Marx-style course feels like at OxygenWell
Chambers and pressure OxygenWell uses grounded monoplace chambers with 100% medical-grade oxygen delivered by non-rebreather mask, at pressures up to 2.4 ATA. That matches the pressure range used in many radiation-injury protocols.
Schedule Prophylactic 20/10 and therapeutic 30/10 patterns usually mean daily or near-daily visits for several weeks. We are open 7 days with extended hours in Sherman Oaks (Galleria) and Calabasas, which helps working patients finish a Marx course without multi-month gaps.
Team coordination Successful Marx care is a triangle: oral/maxillofacial surgeon or dentist, radiation oncology history, and hyperbaric team. We coordinate timing so preoperative sessions finish before the planned extraction or reconstruction date whenever possible.
Related reading on our site
Insurance, Medicare, and pre-authorization
Delayed radiation injury (including osteoradionecrosis pathways used with dental surgery in irradiated jaws) is among the on-label conditions many payers evaluate for HBOT coverage when documentation is complete. Coverage still depends on plan rules, diagnosis coding, operative plans, and medical necessity notes.
OxygenWell accepts Medicare and many PPO plans for qualifying FDA-cleared / UHMS-recognized indications. Our billing partners gather physician notes and pursue pre-authorization before you start a long course whenever the case is insurance-eligible. Details and condition lists live on our insurance page.
Cash-pay pathways remain available when a case is off-label, not authorized, or when patients prefer not to use insurance.
Who should ask about the Marx Protocol?
Consider a hyperbaric consult if any of these apply:
- History of head and neck radiation, especially to the jaws
- Planned extraction, implant, or jaw surgery in the irradiated field
- Exposed bone, non-healing socket, fistula, or suspected ORN after radiation
- Prior ORN treatment with incomplete healing
- Surgeon or dentist specifically requested Marx-protocol HBOT
Bring radiation summary doses/fields when available, current imaging, and the surgical plan. That shortens authorization and staging time.
FAQs
Is the Marx Protocol only for the jaw?
Marx’s best-known staging and 20/10-30/10 patterns center on mandibular osteoradionecrosis and irradiated dental surgery. Other delayed radiation injuries (soft tissue radionecrosis, cystitis, proctitis) use related HBOT principles with condition-specific protocols.
How long is each session?
Many radiation-injury tables use about 90 minutes of oxygen time at pressure, sometimes longer at 2.0 ATA. Total door-to-door time is longer because of compression and decompression.
Can I do Marx Protocol sessions at a soft-sided “wellness” chamber?
Marx-style radiation protocols are built around medical-grade pressures in the ~2.0-2.5 ATA range with 100% oxygen. Mild, low-pressure wellness enclosures do not deliver that physiology. Ask any center what ATA, oxygen source, and safety standards they actually use.
Does HBOT replace surgery for ORN?
No. HBOT supports tissue biology. Advanced stages still need appropriate debridement, resection, or reconstruction directed by oral/maxillofacial surgery.
Next step
If you or your patient need dental surgery after head and neck radiation, or already have exposed bone in an irradiated jaw, early hyperbaric planning is easier than late salvage.
Call OxygenWell at (818) 661-0939 or request a visit through oxygenwell.com/contact. Locations: Sherman Oaks and Calabasas, open 7 days.
Bring your radiation history and surgeon’s plan. We will map whether a 20/10 prophylaxis course, a 30/10 therapeutic course, or another radiation-injury pathway fits, and start insurance review when the case qualifies.
