Asia
Hyperbaric
Centre
Who Is
This For?
This supportive protocol is for people who received radiation therapy to the head and neck — often years ago — and now face its most serious late complication: osteoradionecrosis (ORN). The breakdown of irradiated bone, most commonly in the lower jaw.
It serves two groups:
Group 1 — Prevention (before dental or oral surgery): You need a tooth extraction, dental implant, or other procedure involving a jaw that received radiation. Surgical trauma to irradiated bone is the single most common trigger for ORN. The strongest evidence in this field supports preparing the tissue before that trauma occurs [3].
Group 2 — Established ORN (adjunctive support): You have been diagnosed with ORN — exposed bone, a non-healing socket, persistent pain, or discharge in an irradiated area — and your maxillofacial surgeon or oncologist has recommended hyperbaric oxygen as part of your care plan, alongside surgical management.
Clients in either group typically have:
A history of radiation therapy to the head and neck (commonly 50 Gy or higher to the affected jaw).
A planned dental or oral surgical procedure in the irradiated field, or an existing diagnosis of ORN confirmed by their specialist.
A doctor's referral, which is required before any protocol begins at our centre.
With osteoradionecrosis, timing changes outcomes. The Undersea and Hyperbaric Medical Society (UHMS) recognises delayed radiation injury — including bony necrosis — as an established indication for hyperbaric oxygen [1]. The published evidence is clearest when sessions begin before the damage is done.
You should consider introducing hyperbaric oxygen into your care plan if:
Your dentist or oral surgeon has advised that a tooth in an irradiated jaw must be removed, and they want the tissue prepared first. This is the scenario the classic Marx Protocol was built for: 20 sessions before surgery, 10 sessions immediately after [3].
You already have early-stage ORN — a socket that has not healed months after extraction, persistent exposure of bone, or recurring infection — and your specialist is planning conservative management or sequestrectomy.
You are facing major reconstructive surgery for advanced ORN, and your surgical team uses hyperbaric oxygen to optimise the tissue bed before and after reconstruction [1] [2].
You are planning dental implants in irradiated bone, where compromised circulation makes failure — and the triggering of ORN — significantly more likely.
When to Consider HBOT
Rebuilding the Blood Supply Bone Needs to Live
Bone is living tissue. It repairs itself constantly — but only while it has blood supply, cells, and oxygen. Radiation quietly removes all three. Years after therapy ends, the microscopic vessels inside irradiated bone continue to narrow and scar (obliterative endarteritis). The tissue is left hypovascular, hypocellular, and hypoxic — the "three H's" first described by Dr. Robert Marx, whose research defined this condition [2].
In that state, bone cannot meet even its basic repair needs. A routine dental extraction — trivial in healthy bone — becomes a wound the tissue physically cannot close. The bone breaks down. Infection moves into tissue with no defences.
Breathing harder cannot fix this. Neither can pure oxygen at normal pressure. The red blood cells that carry oxygen can no longer reach the tissue through the damaged vessels.
Inside the chamber, we change the physics. At 2.0 to 2.5 ATA, 99.5% medical-grade oxygen dissolves directly into the blood plasma, bypassing red blood cells entirely [1]. This hyper-oxygenated plasma diffuses into irradiated bone and soft tissue that normal circulation has abandoned.
Over repeated sessions, three documented effects follow. New capillary networks grow into the starved tissue (angiogenesis). The bone's surviving repair cells regain the oxygen they need to function. And your own stem cells are mobilised to the injury site [1] [2] [8].
The goal is not to mask the problem. It is to rebuild the circulation the bone needs to heal — and to keep it healed.
The Science & Clinical Evidence
We do not make promises. The research does that — and in this field, it also sets honest limits. Here is what the evidence shows, including where it is strongest.
The landmark study is a randomized prospective trial by Marx and colleagues, published in the Journal of the American Dental Association [3]. Patients who needed teeth removed from heavily irradiated jaws were assigned either prophylactic hyperbaric oxygen (20 sessions before and 10 sessions after extraction) or antibiotics alone. The difference was decisive:
5.4% — the incidence of osteoradionecrosis when extractions in irradiated jaws were prepared with hyperbaric oxygen, versus 29.9% with antibiotic coverage alone (P = .005). — Marx et al., Journal of the American Dental Association, 1985 [3]
A Cochrane systematic review of hyperbaric oxygen for late radiation tissue injury [4] — updated in 2023 — further found that across randomized trials in irradiated head and neck tissue, hyperbaric oxygen significantly increased the likelihood of complete mucosal coverage (complete healing of the tissue over the bone) and significantly reduced the risk of surgical wound breakdown.
3 randomized trials — showing significantly improved odds of complete mucosal coverage in irradiated head and neck tissue with hyperbaric oxygen. — Lin, Bennett et al., Cochrane Database of Systematic Reviews, 2023 [4]
The largest prospective outcome series in this field — 411 clients treated for chronic radiation tissue injury — reported positive responses across the overwhelming majority of cases, including osteoradionecrosis of the jaw [7].
411 clients — the largest prospective series of hyperbaric oxygen for chronic radiation injury, with positive outcomes reported across the great majority of cases. — Hampson et al., Cancer, 2012 [7]
Where we are honest with you: one multicentre randomized trial (Annane et al., 2004) did not find benefit from hyperbaric oxygen used alone for advanced, established ORN, and the trial was stopped early [5]. The specialist community has debated its design since — but we take the message seriously, because it matches what the rest of the evidence says: for established ORN, hyperbaric oxygen works with surgical care, not instead of it. That is why our protocols are coordinated with your maxillofacial surgeon or oncologist, and why we will tell you plainly if your situation is not one where hyperbaric oxygen is likely to help.
Our protocols follow the standards set by the UHMS [1] and the session structures used in the clinical trials above. The numbers are not arbitrary — they are the parameters that produced the published outcomes.
Oxygen Purity: 99.5% Medical-Grade Oxygen — pharmaceutical-grade purity certified under the Pharmacy and Poisons Ordinance (Cap. 138) [9].
Chamber Pressure: 2.0 to 2.5 ATA (Atmospheres Absolute) — the clinical pressure required to dissolve oxygen into plasma and drive it into irradiated bone [1].
Session Duration: 90 minutes at depth — the standard window for cellular activation and angiogenic stimulation.
Frequency: Once daily, 5 days per week — continuous, rhythmic stimulation for micro-vascular regrowth.
Prevention (Marx Protocol): 20 sessions before dental or oral surgery, 10 sessions immediately after [3].
Established ORN: Typically 30 to 40 sessions as an adjunct to your surgeon's plan; advanced cases may require up to 60, structured around surgery [1] [2].
The Protocol
What To Expect
We understand that entering a hyperbaric chamber can feel unfamiliar. Our team is here to guide you through every step of the process, ensuring you feel comfortable, safe, and supported.
Step 1 — The Briefing & Preparation: Before your first session, our technician will walk you through the safety protocols. You will change into 100% cotton clothing (provided) to eliminate static risk. No electronics, watches, or oil-based cosmetics are allowed inside the chamber.
Step 2 — Pressurisation: As the chamber pressurises over 10-15 minutes, you will feel a sensation in your ears similar to descending in an airplane. Our technician will coach you on simple techniques to clear your ears. Once at depth (2.0-2.4 ATA), you will breathe 99.5% pure oxygen through a comfortable hood or mask. You can read, rest, or watch a screen during the 90-minute session.
Step 3 — Depressurisation & Next Steps: The chamber will slowly depressurise over 10-15 minutes. Once open, you can return to your normal daily activities immediately. Our technician will examine your wound site and coordinate with your primary wound care team to track your progress.
FAQ
How many sessions before I notice a difference?
For prevention, the benefit is measured by what does *not* happen — the tissue healing cleanly after surgery rather than breaking down. For established ORN, most protocols run 30 to 40 sessions. Improvements such as reduced pain or a healthier wound bed are typically assessed within each 20-session block, together with your specialist. Bone recovery is slow biology. The full course is what makes it durable.
Is hyperbaric oxygen a replacement for surgery for osteoradionecrosis?
No — and we will always be direct about this. The evidence shows hyperbaric oxygen is most powerful as *prevention* before dental surgery in irradiated jaws, and as an *adjunct* to surgical care for established ORN \[1] \[3] \[5]. Advanced cases still require surgical management. Our role is to give that care the best possible tissue to work with.
Can hyperbaric oxygen cause my cancer to come back?
This is one of the most common and important questions we hear. The published evidence — including systematic reviews specifically examining this concern — has found no indication that hyperbaric oxygen stimulates tumour growth or recurrence [1] [10]. The protocol supports the recovery of normal, healthy tissue damaged by radiation. Nothing more.
Feldmeier J, et al. Delayed Radiation Injury (Soft Tissue and Bony Necrosis). UHMS Hyperbaric Oxygen Therapy Indications, 15th Edition. Undersea and Hyperbaric Medical Society. UHMS Official Indications
Marx RE. Osteoradionecrosis: a new concept of its pathophysiology. J Oral Maxillofac Surg. 1983;41(5):283-288. PubMed 6572729
Marx RE, Johnson RP, Kline SN. Prevention of osteoradionecrosis: a randomized prospective clinical trial of hyperbaric oxygen versus penicillin. J Am Dent Assoc. 1985;111(1):49-54. PubMed 3897335
Lin ZC, Bennett MH, Hawkins GC, et al. Hyperbaric oxygen therapy for late radiation tissue injury. Cochrane Database of Systematic Reviews. 2023;8(8):CD005005. Cochrane Library
Annane D, Depondt J, Aubert P, et al. Hyperbaric oxygen therapy for radionecrosis of the jaw: a randomized, placebo-controlled, double-blind trial from the ORN96 study group. J Clin Oncol. 2004;22(24):4893-4900. PubMed 15520052
Shaw RJ, Butterworth CJ, Silcocks P, et al. HOPON (Hyperbaric Oxygen for the Prevention of Osteoradionecrosis): a randomized controlled trial. Int J Radiat Oncol Biol Phys. 2019;104(3):530-539. PubMed 30776463
Hampson NB, Holm JR, Wreford-Brown CE, Feldmeier J. Prospective assessment of outcomes in 411 patients treated with hyperbaric oxygen for chronic radiation tissue injury. Cancer. 2012;118(15):3860-3868. PubMed 22139829
Thom SR, et al. Stem cell mobilization by hyperbaric oxygen in humans is mediated by nitric oxide. Am J Physiol Heart Circ Physiol. 2006;290(4):H1378-H1386. PubMed 16199259
Hong Kong e-Legislation. Pharmacy and Poisons Ordinance (Cap. 138). Cap. 138 on e-Legislation
Feldmeier J, et al. Does hyperbaric oxygen enhance tumor growth or recurrence? A systematic review. Undersea Hyperb Med. 2003;30(1):1-24. PubMed 12841604
