Sylvère Maes died on December 5, 1966 at the age of 57.
Nicolaes Maes died in 1693.
Robert Maes died on May 6, 1971.
Waldemar Maes died on June 12, 1951.
Virginia Orr Maes died in 1986.
Camillus Paul Maes died in 1915.
Lilliane Maes died on November 2, 1967, in Denmark.
Romain Maes died on February 22, 1983 at the age of 69.
Jef Maes died on June 30, 1996, in Antwerpen, Flanders, Belgium.
Everard Crijnsz. van der Maes died in 1647.
Gust Maes died on June 11, 1979, in Sint-Agatha-Berchem, Belgium.
Keis Maes died on February 24, 2010, in Los Angeles, California, USA of cancer.
Maes Hughes is alive in Full Metal Alchemist: Brotherhood because Brotherhood is a remake of the series, not a sequel, so everybody who died in the original series will most likely be alive but die in this series. I hope that answered your question!