BON
Meaning of BON: An abbreviation from older drug references for jaw bone that dies and stays exposed during treatment with bone strengthening medicines.
Definition of BON
BON is an abbreviation for bisphosphonate associated osteonecrosis, the death of a patch of jaw bone in someone treated with a bisphosphonate. The dead bone is left exposed inside the mouth and fails to heal over, usually after a tooth extraction or another injury to the gum. The broader name now in use is medication related osteonecrosis of the jaw.
Which medicines are involved?
| Medicine group | What it is given for | How it acts on bone |
|---|---|---|
| Bisphosphonates | Osteoporosis, bone damage from cancer, high blood calcium | Suppress the cells that dissolve bone, and stay bound in the skeleton for years |
| Denosumab | A similar range of bone conditions | Blocks the signal those bone dissolving cells depend on, with the effect fading after the drug stops |
| Antiangiogenic cancer drugs | Several solid tumors | Limit the growth of new blood vessel networks that healing tissue needs |
Risk tracks the strength and duration of exposure rather than the drug name alone. It is low with the oral doses used for osteoporosis and considerably higher with the repeated intravenous doses given to control bone disease in cancer. Because the description no longer fits only one drug class, bisphosphonate associated osteonecrosis has largely given way to the wider term.
Why the jaw and not other bones?
Three things single it out. Jaw bone remodels faster than most of the skeleton, so it accumulates more of a drug that binds to bone during remodeling. It is covered by a thin, easily broken layer of gum rather than by muscle and fat. And the teeth themselves form a permanent channel between a mouth full of bacteria and the bone beneath. An extraction leaves a socket of raw bone that must heal in a contaminated space, which is why most cases begin with a dental procedure carried out during treatment.
How is it told apart from other causes of exposed bone?
Radiation to the head and neck damages jaw bone in a similar way, and that history is specifically excluded before the medication related label is applied. Ordinary dental infection, a fragment of dead bone after an extraction in someone taking nothing, and cancer invading the jaw all have to be separated from it. The working description is bone that stays exposed for more than about two months in someone taking or recently taking one of these medicines, with no history of radiation to the jaws.
Also known as
Used in a sentence
The oral surgeon evaluated the area of exposed jaw bone in a patient being treated with a bisphosphonate.
Good to know
Most cases follow an invasive dental procedure performed during treatment, which is why dental assessment before these medications are started has become routine practice.