Montgomery’s school board gave the go-ahead Tuesday to an update of lessons on sexual orientation, clearing the way for a plan to introduce the topic a year earlier in middle school and put an end to tightly scripted methods of teaching.

The Montgomery County Board of Education voted unanimously to begin a 30-day period of public comment on the proposal and scheduled a final vote for June 17. If approved, students could see changes this fall.

Board members praised the proposal Tuesday, pointing to the need for a more authentic teaching style on an important issue. They faced no visible backlash from social conservatives or other critics, despite the issue’s contentious history in the county.

“I think this is very important,” said Patricia O’Neill (Bethesda-Chevy Chase), the board’s vice president. who asked for the curriculum review in May and said she expected “a lot of comments” in coming weeks, though probably not the thousands that poured in during similar discussions in the past. Montgomery previously has faced legal challenges and other difficulties related to its sex-ed program, adopting in 2007 a practice of scripted lessons with required phrasings for teaching sexual orientation and for a condom demonstration.

Board member Shirley Brandman (At Large) said scrapping the script would make instruction more genuine and engaging.

Brandman and others quoted survey results showing that 11.2 percent of Maryland high-schoolers reported harassment based on perceived sexual orientation in 2011. Over six years, the level of reported harassment ranged from 9 to 13 percent.

David S. Fishback, advocacy chair for the Metro DC chapter of the Parents, Families and Friends of Lesbians and Gays (PFLAG), commended the board at Tuesday’s meeting, citing a longtime concern that the scripted format “got in the way of good teaching.”

“Teachers would now be able to explain, without first being asked a question, that our mainstream medical and mental-health professional organizations have long understood that being gay is not an illness,” he said. “And teachers would be able to explain the grave concerns those same mainstream groups have about so-called reparative therapies.”

Health courses in Montgomery’s secondary schools cover topics including drug abuse, gang violence, dating abuse, bullying, stress management and use of social media. The curriculum is being reconfigured so that fewer topics are covered per school year but each would be covered in greater depth. Students take nine weeks of health in grades 6, 7 and 8 in Montgomery, and they have one 18-week semester of health in high school.

Under the new plan, the topic of sexual orientation would first be taught in seventh grade, rather than in eighth grade, as it is now. The idea, school officials said, is to provide instruction during the same years when students might encounter harassment.

“Bullying and cyberbullying is such a huge issue at the middle-school level,” said Cara D. Grant, supervisor of physical education and health in the district’s Office of Curriculum and Instructional Programs, citing statistics on harassment related to perceived sexual orientation.

Montgomery parents are asked to give permission for students to participate in sex-education classes, officials said. About 97 percent of them do, they said.