Michelle Lalonde, Montreal Gazettemlalonde@montrealgazette.comMONTREAL, QUE.: February 26, 2015 -- Five- year-old Myriam Stewart has her teeth cleaned by dental hygienist Kayla Giacomodonato in Montreal Thursday February 26, 2015. (John Mahoney / MONTREAL GAZETTE)John Mahoney / Montreal GazetteA longitudinal study of the dental health of 1,286 Quebec children aged five months to eight years has confirmed some fairly obvious toothy truths — brushing twice a day helps, sugary snacks do not — but some of the findings are not exactly intuitive.For example, being very shy seems to be associated with dental caries or cavities, the study suggests. And giving a baby a bottle containing milk does not seem to be associated with cavities any more than giving a bottle filled with water or giving no bottle at all. Sugary drinks are, of course, another story.Having a young mother seems to be strongly linked to having at least one cavity by age eight, as does having a mother who did not go beyond high school with her formal education.The analysis, done by two researchers at Montreal’s public health department, uses data from the Quebec Longitudinal Study of Child Development (1998-2015), an in-depth study by the Institut de la statistique du Québec looking at factors that contribute to social adaptation and academic success. Multiple questions were posed to the children, their primary caregivers (usually mothers) and teachers every year or two throughout the 17-year duration of the study.The dental health study, which was published by the Institute on Wednesday, drilled down into the dental health issue for kids up to eight years old. It showed that 55 per cent of Quebec-born eight-year-olds had already had at least one cavity.Giving babies sugary drinks in their bottles during the daytime, at nap time or at night is clearly a bad idea for dental health, the data shows. Sixty-five per cent of those kids had at least one cavity by eight years old. But milk in the bottle, contrary to what many dentists recommend, might not be such a problem. The cavity rate for those who got milk in their bottles was 53.9 per cent, while 54.5 per cent of those who got no bottles or bottles filled with water had at least one cavity.The study also looked at certain psychosocial and behavioural traits and the researchers checked whether any of these were associated with good or poor dental health. Almost 50 per cent of the kids whose mothers described them as “easy going” had a cavity by age eight. About 65 per cent of those described as difficult had one cavity or more. The cavity rate for kids described as very hyperactive and inattentive was 62.4 per cent, compared to 50 per cent of those described as neither.More striking, almost 73 per cent of kids described as “very shy” had at least one cavity by age eight, while only 50 per cent of those described as “not shy” did.The authors note that theirs is not the first study to point out the shyness-cavities link. They theorize that the temperament of a child manifests itself early in life and can influence parent-child interaction.“We think that shyness in toddlers presents a challenge for parents and may favour the adoption of comforting practises, such as prolonged use of the bottle or other practices that contribute to the development of dental caries,” write Ginette Veilleux and Martin Généreux, primary authors of the study.Other studies have shown that very shy children resist being taken to the dentist.Two other factors strongly associated with poor dental health for kids were having a young or poorly educated mother. For children whose mothers were under 25 years old when they were five months old, the cavity rate was almost 70 per cent as opposed to 51 per cent for those whose mothers were 25 or over. For those whose mothers did not graduate from CEGEP, the cavity rate was 71.4 per cent compared to almost 59 per cent of those whose mothers had their CEGEP diploma and 45.8 for those who went on to university.Other factors associated with dental caries: eating sugary snacks more than once a day, being born third or later in birth order, having a mother who does not work outside the home, having a single mom, living in a low income household and living in a rural area, the data suggests.Dentist Taras Konanek, who practices with the Drummond Dental Group in downtown Montreal, was not at all surprised by most of the study’s findings. He said most cavities can be prevented by parents establishing a good dental hygiene regime, including brushing twice a day and flossing at night starting at age two. And he recommends parents brush and floss their children’s teeth, or supervise carefully, until age nine.“Here (at the clinic) we are very hard on our parents,” he said. “I always say to them that if your kid gets a cavity it’s your fault, because kids really can’t take care of their own teeth properly until age nine.”Parents need to demonstrate good dental hygiene to their children, by brushing and flossing daily themselves, he said. Brushing should take at least two full minutes, and every surface of the tooth should get at least 10 strokes to get the plaque off, he said. And since most cavities occur between teeth, flossing is as important as brushing, although both are key to good dental health.“I tell parents, ‘Don’t lose the battle when your kids are little. Some kids are more adamant then others about not wanting to brush, but don’t lose that battle, because if they don’t let you in at three, four and five years old to do a good job, it just gets harder and you will see caries, caries, caries. And they will hate going to the dentist,” said Konanek.