WHITEHOUSE STATION, N.J. (AP) — Merck & Co. on Tuesday said a U.S. district court dismissed claims against the company in a second key case alleging the osteoporosis drug Fosamax causes painful jaw bone destruction. According to Merck, U.S. District Court Judge John F. Keenan granted Merck summary judgment in the case. The company said the ruling stated the plaintiff's physician was unqualified to render an opinion and the plaintiff failed to present sufficient evidence to support her contention that the drug caused her to sustain osteonecrosis of the jaw. Osteonecrosis involves a loss of blood to the bones, causing bone damage. As of Sept. 30, Merck faced 953 lawsuits by about 1,334 plaintiff groups who allege Fosamax caused the same jaw condition. Fosamax is approved to treat the thinning of bone tissue and loss of bone density. In September, a federal judge declared a mistrial in a separate case focusing on the same allegations. Jurors in that case could not reach a verdict. A third "bellwether", or key, case on Fosamax is scheduled to begin April 19, the company said.