Bad breath and discoloured, rotten teeth will do you no favours in the classroom. Most children will do anything to avoid getting close to a mouthful of decay, but a mere mention of the dentist puts many teachers' teeth on edge and has them gnawing at their fists.
Cartoon images of swollen cheeks wrapped in ripped sheets flash into their minds, while memories of going under the gas or hearing the buzz of the drill are enough to halt any good intentions of visiting the surgery. Instead they drag themselves into dental surgeries only when mild toothache becomes a raging pain. By then it is often too late for anything other than extreme interventionist treatment.
Less than half the population regularly visits the dentist, despite more than 50 years of oral health education - and many of the no-shows are teachers. "Some have a fear of the dentist, some are afraid of the cost and, for others, there simply isn't a nearby NHS practice," says dentist Philip Martin, who practises in south London.
In a British Dental Association survey last year, one person in four admitted to anxiety about dental treatment and one in five claimed not to trust dentists. Reasons varied: 10 per cent had had a bad experience in recent years, 24 per cent said is was due to a bad experience as a child, 26 per cent feared pain or discomfort, 20 per cent hated the sound of the drill and 19 per cent disliked injections. Five per cent blamed the expense.
Jill Scheuer, a design and technology teacher at Elliott secondary school in Putney, London, didn't go to her dentist for seven years. "I was always put off by the cost. And there is the difficulty of getting there. You have to go during the holidays."
But for some teachers, the idea of regularly visiting the dentist, simply for a check-up, is inconceivable. One of Dr Martin's patients is a teacher who needs an intravenous sedative for even the lightest of treatments. She has been going to him for almost 10 years, after he was recommended as a specialist for people with dental-phobia. "She simply didn't go - it had been years since she'd had a check-up," he says.
She's not alone in the level of care she needs for a simple filling. Greg Davies, now a dental surgeon with the private health provider Bupa, used to work in the conscious sedative department at London's Guy's Hospital, which treated people with dental-phobia. He was part of a programme to ease troubled patients back into isiting a normal dentist. "People's fear must be taken into account. We, as dentists, are moving into their personal zone - the 16 inches around their body. We are also fiddling around their airways, while they are in a recumbent and vulnerable position."
Guy's treats these patients with great care, giving them sedatives and gradually building their confidence so they can move on to treatment without a general anaesthetic. However, treatments are less invasive these days and dental equipment has changed dramatically over the past decade or so. Drills are smaller and faster, needles have shrunk, and health education has improved oral hygiene. The introduction of fluoride toothpaste and the move, since the Forties, towards brushing teeth twice a day have altered the landscape of many mouths. The days of whole sets of teeth being removed because of gum disease are gone.
Yet children and young people are still developing a fear of the dentist. This is because the fear can be created without any particularly bad experience - more often than not it is learned from others.
"Teachers can make unfortunate comments to children who are seeing a dentist for the first time during a routine school oral check. They says things like: 'This won't hurt a bit' or 'There's no need to be frightened'," says Katrina Matthews, the oral health promotion manager for the Parkside Health Trust in north-west London. "This immediately puts ideas in the children's heads that the dentist is someone to fear."
Greg Davies agrees. "There is a fear learned from parents and teachers. They have to be careful what they say."
But some teachers are helping overcome these anxieties. Oral health promoters - such as Ms Matthews - are being backed by teachers in the classroom. Her project members cover more than 70 schools, where they run puppet shows and role-play sessions, and check children's teeth. She gets help from some teachers who talk about oral care and even show children how to brush their teeth properly by brushing their own in front of the class.
She reckons this positive attitude is doing much to alleviate or banish many children's learned fears of the dentist. This is just as well, because access to sedation in dental surgeries is becoming less common following the Poswillo report in the early Nineties. This recommended such treatment be limited to specialist centres where a qualified anaesthetist must be present, as well as the dental surgeon.
It is much simpler to encourage children to have a positive attitude if teachers can hide any fear they may have about dental treatment. So if you find yourself about to make negative comments about the dentist, bite your tongue.