Sitting quietly for more than four decades could make anyone lose his head - even Brigham Young.

A 9-foot plaster mold of Brigham Young, commissioned in 1945, is missing its detachable head, said Brent Harker, Brigham Young University spokesman. The head was seen last year sitting in the colossal statue's lap in BYU's motion picture studios, but it has been lost, misplaced or stolen since then, according to officials at the BYU Museum of Art, which is responsible for storing such valuables."It's not worth anything really because there's no market for it," said Harker, discounting art theft as motive.

Perhaps the best explanation for the head's disappearance is that it simply toppled over and broke on the floor, Harker said, noting that the plaster mold would be quite fragile.

The plaster mold had been in the studio because of lack of space in the Harris Fine Arts Center, where artwork was stored before completion of the new Museum of Art. The head was discovered missing during preparations to move the statue to the museum's storage units, which Harker described as "state of the art."

The head is probably 2 feet tall, maybe 3 feet with its beard, and was sculpted by Mahonri Young, a grandson of Brigham Young. The mold was one of several used to complete a marble statue of Brigham Young in the U.S. Capitol in Washington, D.C. Mahonri Young also did a statue of his grandfather for the "This Is The Place" monument in Salt Lake City.

Mahonri Young's artwork and paintings account for a large portion of BYU's 14,000-piece art collection. Some of the paintings will be on exhibit in the Museum of Art this fall, Harker said.

The plaster head is the latest of numerous pieces of art to turn up missing at BYU. In 1987, Virgie Day, now associate director of the new museum, undertook a vast cataloging and recording of BYU's art collection, Harker said. Her organizing revealed that as many as 1,300 pieces of art, worth between $4 million and $6 million, had disappeared from BYU.

"That loss was part of the reason for a new facility," Harker said.

BYU launched a major investigation at that time, resulting in charges being filed against a former BYU art curator and a New York City art dealer.