Phosy Jaw

[ethandron]

I take alendronic acid for osteoporosis. I understand that I have to be careful/ watchful for jaw problems because of this. I have spoken to my very nice dentist about it but in spite of his explaining it to me, I still don't really understand why jaw problems occur. He mentioned that girls who worked in match factories in the olden days were prone to Phosy jaw, which is similar to the alendronic acid problem.
Could one of you very knowledgeable scientific people please explain it, in laymans terms, to me? Thank you.

[ABerrant]

http://en.wikipedia.org/wiki/Osteonecrosis_of_the_Jaw

[ethandron]

Ive read lots of literature about it but I still don't understand why it just affects the jaw, which is why I'm asking for an answer in laymans terms.

[kawakiri]

May help a little:

http://www.druginjurylaw.com/FosamaxCausesONJ.html

http://www.mayoclinic.org/diseases-conditions/osteoporosis/expert-answers/fosamax/faq-20058121

[LazyGun]

It affects the jaw specifically because of the high rate of bone turnover in the jaw when compared to other bones in the body, ethandron. Bone deposition and breakdown is a delicately balanced mechanism within the body, relying on the activity of osteoblasts which help to form bone, and osteoclasts, which help to resorb bone.

The phosphorus that lead to phossy jaw being called that, and the bisphosphonates such as alendronic acid is preferentially laid down in bone with a high turnover rate; In turn they affect the mechanism of bone formation/ resorption, which in turn leads to lesions and other rather nasty outcomes.

So this is why something that you might think should be systemic can have a very localised effect within the body.

[society]

Thank you LazyG. I too wanted a simple explanation.

[237SJ]

http://www.osteoporosistreatment.co.uk/osteonecrosis-of-the-jaw/

It`s more likely if you take bisphosphonate infusions though.

[Peter Pedant]

have we had this:
http://en.wikipedia.org/wiki/Bisphosphonate-associated_osteonecrosis_of_the_jaw

yes - sorry - and they say they dont know in the article

but then suggest the jaw is a high-turnover bone and that alendronate specifically hits one of steps...

simple but not particularly informative

[ethandron]

Thank you lazygun, that's the most understandable explanation I've had. I was very hopeful you'd read my question :)