INDIANAPOLIS - Nine students have been dismissed from the Indiana University School of Dentistry after a faculty council determined they cheated by improperly using passwords to open computer images before an examination.

The school also suspended 16 students from the second-year class for periods ranging from three to 24 months because of their involvement and 21 students received letters of reprimand for not reporting the cheating, dental school Dean Lawrence Goldblatt said Monday.

The cheating happened in February, but took about two months to review because of the number of students involved, Goldblatt said.

The actions were considered serious violations of the school's professional conduct code, he said.

"We view trustworthiness as a very important part of professionalism," Goldblatt said

Those involved participated in the "unauthorized acquisition, sharing and use of passwords to enter electronically locked image files meant only for examinations," Goldblatt said in a memo about the disciplinary actions.

The dean said some of the students, who were to graduate in 2009, discovered the computer password to open the photos they were expected to identify in an exam.

"They opened the files and then they shared that with some of their classmates," he said.

The dental school's faculty council voted on Friday to approve the disciplinary action against the students, who have five working days from their official notification to appeal the decision.

IU's dental school, the only one in the state, admits about 100 students a year into the four-year doctor of dental surgery program.