Looks like there is a link to severe jaw problems with people taking not only Fosamax, but also Zometa and aredia. You can find several research articles
by searching in Google for "zometa side effects" or "aredia side effects" or "fosamax side effects"

From what I can tell it is pretty severe.

I an concerned that most people taking these drugs are
not aware of their severe jaw side effects.

I have done some research on not only Zometa, but
Aredia and Fosamax side effects. These types of
drugs(bisphosphonates) have been linked to losing jaw
bone.
This side effect is called by many names, "Bis-phossy
jaw",, "Dead Jaw", "Jaw Necrosis, Osteonecrosis of
the jaw"


Cases have been reported since 2000 and yet it took
the drug company in late
2004 to admit that there is a link. The FDA has taken
Novartis(Zometa and Aredia) to task about
the delay and the methods used to inform the public.
Novartis says they have 875 reported cases to them
about people losing their jaw. Researchers believe
that this 875 numbr represents
only about 1 to 10 % of the people who have this jaw
condition from taking these drugs.

Now the warning is to have all your dental work before
you take these drugs
or don't have dental work at all while on the
drugs,and even then it can be risky

Here are many links that I found.

http://www.usatoday.com/news/health/2005-03-13-jawbone-deaths_x.htm

http://www.cancerpage.com/news/article.asp?id=8122

http://online.wsj.com/public/resources/documents/SB110245057172293526.htm

http://sev.prnewswire.com/health-care-hospitals/20050506/CGTH06205052005-1.html

http://www.fda.gov/medwatch/SAFETY/2005/zometa_deardentite_5-5-05.pdf

http://www.fda.gov/medwatch/SAFETY/2004/ZometaHCP.pdf

http://www.fdaadvisorycommittee.com/FDC/AdvisoryCommittee/Committees/Oncologic+Drugs/030405_iressa/030405_ZometaR.htm

You can also go to ***** , ***, or Google and search
for "Zometa Side Effects"