With the exception of Internet seductions, "overall sexual abuse and sex crimes against children have declined about 50 percent since 1993," Finkelhor said. "I'm inclined to think [incidences of teacher abuse] haven't increased because the overall trend is down."
Experts are divided over what exactly has caused the increase in reports. Those who spoke to ABC News offered a variety of theories to explain the increased attention, which ranged from fallout over Catholic priest sex-abuse scandals to greater emphasis on educating abused students to come forward to increased media attention.
"What accounts for what we're seeing is a side effect of the clergy abuse scandal starting in 2001, when the whole idea that large institutions could be financially libel if they swept this kind of thing under the rug," Finkelhor said.
"There was a realization that schools needed to educate students better, take this problem more seriously, and bring cases to the authorities," he said.
The first recent case to capture the headlines and imaginations of the country involved Washington state teacher Mary Kay Letourneau. In 1997, Letourneau, who was then 33, was convicted of statutory rape after having an affair with her 13-year-old student Vili Fualaau. After serving two prison terms and having Fualaau's baby, the couple was married in 2005.
Nan Stein, a senior researcher at the Wellesley Centers for Women at Wellesley College, said she has developed a profile of a typical male teacher who preys on his students. Men, she said, typically teach subjects such as "drama, music and photography," classes that require "one-on-one time, where a surrogate mentor relationship" can develop.
No such profile exists for women, but Stein said female offenders seem to be young, in their 20s or early 30s and are often from rural areas.
Experts said that many of the same traits that lead men to become child molesters also lead women to abuse children. These factors can include sexual abuse, traumatic relationships and nonsexual problems in their personal lives, such as bereavement or debt.
"Female teachers are in a position of trust. When they have that emotional baggage, they act out just as male teachers have," said clinical psychologist Jeff Gardere. "Male victims are now reporting these cases more than they have in the past."
Additional reporting by Elizabeth Stuart