First of two articles.

Mandy is feeling pretty relieved right now. She just convinced her mom to cancel her dentist appointment -- for the second time. Mandy pretended to be sick, but she's not, really. Even though she's 9 years old, she's scared of the dentist.

Then the phone rang. It was the receptionist in Mandy's dentist's office calling. "We just had a cancellation for tomorrow," she told Mandy's mom. "You can bring your daughter in then if she's feeling better."

Once Mandy heard that she would be going to the dentist the next day, she got nervous again. Her heart started pounding, and she felt light-headed. "Mom, I can't go," Mandy said. "I'm too scared."

"Don't be silly, Mandy," her mom said. "You're acting like a baby. There's nothing to be anxious about."

Mandy's mom is wrong about one thing and right about another. These days, a dental appointment isn't anything to be frightened about. But Mandy's fear is not silly, and it's not babyish. It's real, and it's a fear she shares with many other people. Dental anxiety is not unusual. Dentists say that as many as 12 million people in the United States are so scared of having their teeth checked that they never go to the dentist at all.

For some adults, fear of the dentist is even more serious than Mandy's anxiety, and it has a fancy name: dental phobia. A phobia is a fear, but it's a special kind of fear. It can be powerful and paralyzing. Although the fear may be about something that seems harmless, people who feel it can't talk themselves out of feeling scared. They panic. The phobia makes their hearts race and their skin feel clammy.

Some people experience phobias about things that other people don't even give a second thought. Some people are phobic about flying in airplanes. Other people have phobias about cleanliness or riding steep escalators. Some people have an overwhelming fear of snakes. Others get terrified by crowds, or in large, open spaces like malls. People who suffer from phobias that interfere with their daily lives often seek help from psychologists or other experts in emotional problems. Luckily, phobias are treatable, and people do get over them.

Mandy's mom doesn't admit it out loud, but she has a phobia about going to the dentist. She takes Mandy, but she hasn't been examined herself for many years. According to experts in dental anxiety, Mandy's mom's fear adds to Mandy's. As you probably know from experience, fear is catching. "If mom is too scared to go, it must really be horrible," Mandy thinks.

Mandy has forgotten that her last dental appointment was easy. She had her teeth cleaned, had a fluoride treatment, and that was that. She didn't even have any cavities. Today, thanks to good eating habits and dental care, more than half the American children Mandy's age don't have any cavities at all.

The American Dental Association reports that children's tooth decay has been reduced by about one third in the last 10 years. Unlike her mom, who had many cavities as a child, Mandy is likely to get through life with only a few cavities. She may never get any at all, especially if she avoids eating a lot of sugary things, brushes and flosses her teeth every day and uses a tooth-hardening chemical called fluoride.

Mandy is going to a new dentist tomorrow, one she has never met before. Her new dentist may come as a surprise. His office is bright and cheerful. There are games and toys to play with in the waiting room. There's a VCR and tapes -- including tapes that show kids going to the dentist. And Mandy's new doctor is a specialist in pediatric dentistry. That means that he has studied the special needs and problems kids have and has learned special techniques for treating their problem. He spent two extra years in training, including taking classes in child psychology. He knows how kids feel, and he takes their feelings seriously.

Next week in this column, we'll go to the dentist with Mandy and find out just what an appointment with a pediatric dentist is like. Tips for Parents

The Maryland State Dental Association says that regular checkups are necessary because cavities are not the only problem children may develop. Regular checkups reinforce good dental habits and also provide early detection of such problems as gum disease and malocclusion -- bad fit of the jaws and teeth -- which are easier to treat when they are caught early.

Catherine O'Neill is a free-lance children's writer in Silver Spring.