Many teenagers are tempted to believe that oral sex is not sex. They believe that because oral sex cannot lead to pregnancy, it will also keep them safe from emotional risks and from STDs. Some teenagers are much more likely to engage in oral sex (and to have oral sex with a greater number of partners) than intercourse. Unfortunately, oral sex is just as risky as intercourse when it comes to STDs.
In particular, recent studies show that HPV (known to cause cervical cancer in women) is also a risk factor for throat cancer. Make sure that when you discuss sex and STDs with your teenager, you emphasize that any genital contact (even mouth to genital) increases the risk of contracting an STD.