If you waited until your children started school to take them to the dentist, you waited too long. Good dental care starts in infancy, even before the first tooth emerges. By school age, children should be well on their way to a lifetime of healthy teeth and gums.

Few of us are naturally inclined to have a healthy mouth. Good oral health depends on proactive measures: frequent daily cleaning; the control of destructive habits like lip biting and thumb sucking; consumption of adequate fluoride; application of topical fluoride and a dental sealant; a wholesome diet with a minimal consumption of sweets and refined starches, especially between meals; and periodic care by a dentist knowledgeable about the special oral needs of children.

The earlier in life your children get on the right dental track, the greater their chances of joining the cavity-free generation and keeping their own teeth for life. Parents cannot afford to be cavalier about baby teeth. Decay and early loss can damage permanent teeth even before they erupt, and even a toothless baby should receive regular dental care.

Developing Good Habits

Having spent much of my childhood and far too many adult hours in a dentist's office getting cavities filled and crowns and bridges installed, I was determined that my sons would enjoy a better fate. They were off to a good start given that our city water was now fluoridated, a benefit missed by nearly everyone my age who did not live in an area where the water supply was naturally fluoridated.

In addition to giving them unfiltered tap water, I gave them juices and powdered milk reconstituted with city water.

It also helped that I had read an article by a pediatric dentist admonishing parents to clean their babies' gums daily with gauze and to take their toddlers to the dentist for the first time at or before the age of 2.

Now, however, pediatric dentists suggest an even earlier first visit. By 2, some poor oral habits and neglect can be all too well established, and harder to reverse than if the right steps had been taken earlier -- say, between the ages of 6 months and 1 year.

These are the things that a dentist should do during an infant's first visit, according to the American Academy of Pediatric Dentistry:

Examine the baby's mouth for oral and facial development and any sign of potential problems; assess the need for supplemental fluoride; check on potentially damaging habits like pacifier use, thumb sucking, lip biting and tongue thrusting; question the parents about nursing or bottle-feeding the baby before sleep; teach the parents how and when to clean the baby's mouth and teeth; and provide information on eating habits and foods that can foster dental health.

Babies who fall asleep with bottle or breast milk, formula, sugar water or fruit juice in their mouths risk developing nursing-bottle syndrome -- serious decay of the front teeth that results from an attack of bacterial acid that thrives on sugars and erodes dental enamel.

If a baby is given a ''pacifying'' bottle before a nap or at bedtime, it should contain only water. And before the baby goes down for a nap or for the night, the gums and teeth should be cleaned. You can use gauze or a soft cloth, or one of the new infant tooth cleaners and toothpastes now available in many pharmacies.

A Mouth-Healthy Diet

A well-balanced diet that is good for a child's general health and lasting well-being is also good for the mouth. This diet essentially follows the government's food pyramid. It emphasizes whole grains, vegetables and fruits, dairy products and low-fat animal protein foods -- meat, poultry and fish.

Too frequent snacking on sweets and refined starches, including pretzels, crackers, sweetened dry cereal and dried fruit sticks, cannot only kill a child's appetite for more wholesome foods, it can promote tooth decay. Try to limit snacks to three or four a day and to emphasize healthful snacks like fresh fruit or fruit canned in water, vegetable sticks, whole-grain bread or crackers, peanut butter and calcium-rich foods like yogurt and milk.

Even chocolate milk gets a thumbs-up from dentists, who would rather see a child drink flavored milk than none at all. Milk builds strong bone, and it is bone that holds teeth in the mouth.

Fruit juices should be diluted with water. But children should not be given soda, which is nothing but colored, flavored sugar water that fosters tooth decay. Set a good example: A recent study showed that children are much more likely to drink soda if their parents do. If it's not in the house, they will have much less opportunity to drink it.

Of course, nearly every parent knows how picky and fickle a child's eating habits can be. Wholesome foods that a child is unwilling to eat in their natural state can often be disguised in smoothies, pasta sauces, soups, pancakes, breads, muffins and so on. Be patient; don't push foods and don't use desserts and treats as bribes. Eventually, taste buds mature and dietary choices tend to expand.

Remember the Fluoride

Fluoride is the primary secret to a decay-free mouth. If the drinking water is not adequately fluoridated or if the baby is exclusively breast-fed or given ready-made infant formula, a fluoride supplement may be recommended. A supplement may also be recommended for families that rely on bottled water or home-filtered water that lacks fluoride.

The dentist can also apply topical fluoride to the teeth of a toddler or to the permanent teeth, as well as dental sealant to the chewing surface of permanent molars. For older children, there are toothpastes and mouth rinses containing fluoride.

Brushing the teeth daily is a habit best started early and never stopped. Toddlers should have their mouths cleaned at least twice a day -- after breakfast and before bed. If possible, brush or at least rinse the child's mouth after sweets are consumed.

Parents should do the brushing for at least the first four or five years. Pediatric dentists recommend using only a pea-sized amount of a toothpaste made especially for children. Toddlers should be cautioned to spit out the toothpaste, not swallow it.

By age 5 or 6, children should be able to brush their own teeth, with parental supervision. By school age, daily flossing should be added to the regime. And every child should visit the dentist at least once a year for a professional cleaning, occasional fluoride treatments and a check for teeth-damaging habits.

Children who play sports may need guidance about the use of proper mouth guards. And those with orthodontic problems may need intervention to assure proper positioning of the permanent teeth, which can prevent the need for periodontal treatments years later.

Drawing (Drawing by Toni Zules)