Absolutely there can be an element of denial contributing to the problem. As much as they might feign disinterest or even ignore you while you're talking, research has shown that children like to hear stories from their parents' childhood, reminisces that tell them their parents went through the same physical changes, emotional turmoil and upheavals of puberty that they are experiencing. Dr. Gillooly spoke with young women who told her that they appreciated hearing stories of their mother's experiences. Although the girls might not have been interested at the time or even told their mothers they weren't listening, the information stuck with them. The goal is to build good habits and convince teens that they are taking care of their bodies for themselves, not because of peer pressure and not because parents are forced to nag them.
Teens are very egocentric.
You want them to view good hygiene as being good to themselves. Sometimes I have to say, 'Come here. Talk to me,' so I can get a whiff of her breath. Hopefully, by now, your child has established good brushing habits. But the hormonal changes of adolescence can change the way teeth and gums react to plaque, putting preteens at greater risk of periodontal disease.