Actress Julia Roberts understands just how valuable her wide, dazzling smile is to her career. She once insured that smile for $30 million.

Not everyone would place such a high price tag on their facial expressions, but a smile can make a significant difference in anyone’s career advancement, just as Roberts’ did for her, says Dr. Jamie Reynolds, an orthodontist, national and international lecturer and author of “World Class Smiles Made in Detroit.”

“A smile works on both the physical and emotional level to transfer positive feelings between two people,” Reynolds says. ”A beautiful smile can communicate a sense of well-being to those who see it.”

Of course, not everyone has a brilliant smile they’re ready to show off to the world, and so they turn to whiteners, braces or other fixes to improve the look.

“I’ve had some patients who are self-conscious about their smile, and it has seriously affected them,” Reynolds says. “It made them feel timid or hesitant.”

And that’s not beneficial to career advancement.

Reynolds says a few ways that a winning smile is valuable in our efforts to land jobs or seek promotions include:

•    A smile helps your self-esteem. Feeling good about your smile is an important component of self-esteem. “Too many people cover up their smile or stop themselves from smiling because of embarrassment over their teeth,” Reynolds says. “That’s a shame. A beautiful, healthy smile gives you the confidence to smile proudly and be yourself without hiding.” Exuding confidence is crucial to career advancement, whether you’re going in for a job interview, or trying to impress the boss in hopes of getting a raise or landing a better position in the company.

•    A smile helps create a connection. Your smile puts others at ease. That can be advantageous during a job interview, which can be emotionally taxing as questions are asked and answered in a fashion that can seem like an interrogation if everyone doesn’t just relax. That smile can work wonders to ease the tension and create a connection with the person interviewing you.

•    A smile conveys the message you are competent and productive. When you smile, you appear more likeable and courteous, which probably isn’t a surprise, but you also appear more competent, according to a study from Penn State. “That smile can go a long way if you’re looking for a promotion,” Reynolds says. “It will help you come across as a hardworking employee because studies have shown that happy employees are the most productive.”

“Employers care about whether you have the skills to do the job that they are interviewing you for, but they’re also trying to gauge whether you’re someone who would work well with others in the organization,” Reynolds says. “A smile helps make you seem more personable and can give you an edge on your competition.”