by: Linda Bren
"Heavy metal bands" may conjure up images of rock music today, but many baby boomers remember them as the clunky and conspicuous devices they wore in their mouths as children to straighten their teeth.
Today's braces are a lot different from the metal-mouth look of a generation ago. "They're more aesthetic and more efficient," says Donald Joondeph, D.D.S., an associate professor of orthodontics at the University of Washington in Seattle. And they're more comfortable to wear and better at repositioning teeth, he adds.
Braces used to be put on only after all the permanent teeth came in. Today, a multitude of dental devices, or orthodontic appliances, are being used at an early age to simplify later treatment, provide a better outcome, and, in some cases, avoid braces altogether. Adults, who make up one-fifth of orthodontic patients, also are opting for straighter teeth as more choices in orthodontic appliances become available.
About 4.5 million people in the United States are wearing braces or other appliances to achieve a beautiful smile and healthy teeth, according to the American Association of Orthodontists (AAO). These appliances are regulated by the Food and Drug Administration to assure their safety and effectiveness.
Not just for looks
Braces are more than the means to a stunning smile--they can improve dental health and function, says Susan Runner, D.D.S., chief of the Dental Devices Branch in the FDA's Center for Devices and Radiological Health. "They can be used to move teeth that are overcrowding," Runner says. Crowded or crooked teeth are harder to brush and floss, and improper cleaning can lead to tooth decay and other dental problems.
"Braces can correct severe bite problems that would hamper eating and give a greater risk of gum disease and tooth and bone loss," says Runner. Bite problems may occur when the upper and lower jaw don't come together properly. Uncorrected bite problems can cause teeth to wear down, make for difficult chewing, and put stress on the jawbone, producing pain.
Causes of crooked teeth
Most people do not have naturally straight teeth; in fact, the AAO estimates that up to 75 percent of people could benefit from orthodontic care.
Heredity and environmental factors are the two causes of crooked teeth and bite problems, says Terry Pracht, D.D.S., president of the AAO and an orthodontist in Westerville, Ohio. Crowding of teeth, too much space between teeth, and upper teeth that don't match lower teeth when biting down are usually inherited. But jaw-jolting accidents, as well as habits such as tongue thrusting and thumb sucking, can cause crooked teeth.
Tongue thrusting is the abnormal tendency to push the tongue onto the back of the front teeth during swallowing, causing the teeth to protrude over time.
Thumb sucking is normal in young children and isn't an orthodontic problem unless it persists when the permanent teeth come in, says Pracht. "If a child is still thumb sucking at about age 7 when the upper front teeth start to erupt, it can not only affect the teeth, but the shape of the jawbone," he says.
Then and now
Braces work by putting pressure against the teeth, moving them gradually over time. Most of the pressure is applied by a metal wire, called an archwire, that runs on the outside of the teeth. "Rubber" bands, actually made from surgical latex, put additional pressure on the teeth that the archwire alone cannot do.
Earlier types of braces had an archwire connected to large metal bands that were individually wrapped and cemented around each tooth. "The metal bands were uncomfortable," says Pracht, adding that it used to hurt to have braces put on and adjusted. "There was a lot of pushing and shoving."
Today, the archwire is attached to tiny brackets made of metal or ceramic. The brackets are bonded with a glue-type agent to the front of the teeth. Some of the bonding agents continuously release fluoride to help protect the enamel of the teeth underneath the brackets. Metal bands may still be used on the back teeth, but they are smaller and lighter than bands used previously.
The archwire requires periodic adjustment or replacement by the orthodontist to apply continuous pressure. Today's archwires are active over longer periods of time, meaning patients don't have to visit the orthodontist as often to get their braces adjusted. "It used to be every three to four weeks; now it's every six to eight weeks," says Pracht. And archwires are much gentler. "There is some sensitivity when eating for only a day or two after an adjustment."
Archwires now are made from a heat-activated, nickel-titanium mixture originally developed by NASA to activate solar panels of spacecraft in orbit. At room temperature, the wires are very flexible, allowing them to be attached to the teeth more easily. When they warm to mouth temperature, they apply gradual and constant pressure on the teeth.
Today's braces come with more options to make them less obvious--or, if a person chooses--more obvious, with an element of fun and fashion. Most of Pracht's adult patients opt for clear or tooth-colored brackets. "They are not apparent from a distance and not very noticeable up close," he says. Some people choose gold braces. "One company markets them as jewelry for the mouth," says Pracht.
Colors are especially popular with children and teens, who will often choose the colors of their school, a favorite sports team, or holiday colors, such as pink and red for Valentine's Day and orange and black for Halloween. The colors are mainly on the elastic ties that attach the archwire to the brackets, and they can be changed when the archwire is adjusted. Archwires and rubber bands also come in a variety of hues.
For complete invisibility, braces can be fitted onto the inside of the teeth. These "lingual braces" have limitations, says Joondeph. "They can be tougher on a patient. They affect speech more and may irritate the tongue." Treatment times may also be longer than with standard braces, he says, adding that patients should talk with their orthodontists to find out if lingual braces or other options are appropriate for them.
Innovations in materials and designs have brought braces a long way since the "tin-grin" look of the past, but one thing that hasn't changed significantly is the length of time they are worn. "It's important to move the teeth gradually," says Runner. "If you move the teeth too fast, it can result in severe loosening of the teeth or tooth loss."
Braces, on average, are left on between 20 and 24 months, says Joondeph.
To keep teeth straight after braces are removed, people must wear retainers. These appliances hold the teeth in their corrected position until the bones grow around the teeth to stabilize them. Since teeth tend to shift as a person ages, wearing retainers periodically may be a life-long requirement.
Retainers can be all plastic, or plastic with some metal wire. They are either fixed permanently in the mouth or are removable. Like braces, retainers come in different colors and designs. They can be roof-of-the-mouth pink or personalized with such items as sports team logos, pictures of pets, or a person's or orthodontist's phone number in case of loss.
The FDA's role
Braces, retainers, and other orthodontic appliances are classified as medical devices, which are regulated by the FDA. "Any innovative orthodontic devices or materials require FDA review before being allowed on the market," says Runner. In this way, the FDA can assure that any new devices or materials, including bonding agents and color dyes, are safe and effective.
Some older orthodontic appliances are exempt from review because they were already on the market in 1976, the year medical device regulations went into effect. "But medical device manufacturers are still required to register with the FDA and are subject to inspections," says Runner.
As with all medical devices, braces are not risk-free. The FDA has received reports of adverse events ranging from teeth broken during bracket removal to allergic reactions involving archwire and bracket materials.
"If you're going to have an allergic reaction, it will usually be to the nickel in the wires," says Pracht. Orthodontists can fit patients with titanium wires and brackets that don't contain nickel, he says.
And as for the risk of locking braces when kissing, Pracht says it only happens in the movies. "In my 33 years of practice, I've never seen it."
A Commitment
Having braces or any other orthodontic appliance requires more frequent brushing, flossing, and general care. "Orthodontics is a serious treatment commitment," says Janie Fuller, D.D.S., M.P.H., a regulatory review officer in the FDA's Office of Surveillance and Biometrics.
"If you have poor oral hygiene, you are trading one problem for another," adds Joondeph. "Your bite may be better and your teeth straighter, but there will be significant decay."
People with braces must avoid "hard, sticky, or gooey foods," says Joondeph, such as jawbreakers, peanuts, ice cubes, caramel, and taffy. These foods can break brackets, bend wires, or get caught in the braces, causing cavities.
Fuller advises parents to clean the teeth of young children. "Children shouldn't be expected to have the dexterity to clean their teeth properly until at least 8 or 9 years old, and parents need to help even without braces," she says.
And older children must want the braces and be willing to make the commitment to their care. "The work you have to do to take care of your mouth is too hard if you don't really want braces," says Fuller. "It's not just something that you have done to you--it takes a partnership with your orthodontist for it to work."
Joondeph uses a "combination of education and prodding" with children who are reluctant to get braces. "One option is to try to convince the child it's in their best interest in the long-term. We can also try to come up with a treatment plan that would expedite treatment." There's always the option of treatment later as an adult, but by then the jaw has stopped growing and some bite problems can be corrected only with surgery, he says.
Another straightening option
An alternative to braces, Invisalign, was cleared by the FDA to straighten crooked teeth in people who have all of their second molars, permanent teeth that usually come in by the late teens. Invisalign uses a series of clear removable aligners instead of wires and brackets. An orthodontist takes impressions of the teeth and sends these models to the maker of Invisalign, Align Technology Inc., of Santa Clara, Calif. The company uses a computer-generated simulation of the desired movement of the teeth to custom-make the aligners for each patient. Each aligner is worn for about two weeks.
The aligners are removable for eating, brushing, and flossing, so unlike people who wear braces, Invisalign-wearers aren't restricted from eating hard or chewy foods. But they still must visit their orthodontist every six weeks during treatment to ensure proper progress.
The total treatment time with Invisalign averages between nine and 15 months and the average number of aligners worn during treatment is between 18 and 30, according to Align Technology. For some people, a combination of braces and Invisalign is successful, requiring less time in traditional braces.
"Invisalign is intended to have the same function as braces in terms of gradual tooth movement," says Runner. But the device is not for everybody. "It depends on the extent of the orthodontic problem, and it is not intended for younger children," she says.
"They have a place in the spectrum of orthodontic treatments for mild to moderate cases," Joondeph adds. "But they can't give us the sophisticated tooth movement and control of braces."
Appliances for children
Other orthodontic appliances besides braces are available to help correct a broad range of tooth and jaw problems in growing children--from closing up a gap to widening the jaw to make room for new teeth to grow in properly. Some of these "functional orthodontics" are fixed in place; others are removable for brushing, eating, and sleeping.
Some children require headgear to guide the development of an improperly growing upper jaw. To move the jaw, wires must connect the upper teeth to another fixed point. Since no other teeth are strong enough to serve as a fixed point, headgear is used to anchor the upper teeth to a point outside the mouth: the head or neck. Elastic is wrapped around the top of the head or the back of the neck and connects an archwire to the upper teeth.
"Make sure the orthodontist demonstrates how to place the device and how to remove it," cautions Fuller. In one case reported to the FDA, a child was blinded in one eye and injured in the other when removing headgear improperly, causing the metal prongs from the mouthpiece to snap back into the child's face in a slingshot-like fashion.
"Never leave the office with headgear--or any other removable appliance--until you have demonstrated to the staff that you know how to remove the device safely and put it back in safely to avoid injury and to optimize treatment," says Fuller.
In some cases, a dental implant can replace the need for headgear. The implant contains a screw or pin that is inserted into the jawbone, allowing a post to protrude. The post serves as a point of stabilization to which a tooth-moving appliance is attached.
Functional orthodontics are ineffective after about age 16 for women and after age 18 for men. At these ages, the permanent teeth are in place and the jaw is set, so only braces or jaw surgery can produce straight teeth or a normal bite.
Early is better, but it's never too late
Although healthy teeth can be moved at almost any age, the AAO recommends that children get an orthodontic exam by age 7. Many will not need treatment then, but periodic checkups can help the orthodontist detect and evaluate problems early and determine the best time to treat them.
"This is the time you can see permanent teeth erupt and you can determine the size of the teeth, the room available, and the relationship of the teeth to the jaws," says Joondeph.
In some cases, early treatment can guide jaw growth and permanent teeth into better position, avoid the need to extract teeth, and reduce abnormal swallowing or speech problems. Waiting until all the permanent teeth have come in or until facial growth is complete may make correction of some problems more difficult, as Wendy Kelly of Issaquah, Wash., will tell you.
Kelly, who didn't get braces as a child, had crowded teeth and an overbite. At 31, she was getting headaches and having problems chewing, she says. "I was only able to chew in the front of my mouth because my back teeth didn't meet when I bit down."
Joondeph, Kelly's orthodontist, informed her that braces alone wouldn't fix the problem. She also needed oral surgery to reposition the jaws so that her teeth would fit together properly. After wearing braces for 10 months, Kelly had surgery under general anesthesia, spent a night in the hospital, and continued wearing braces for several more months.
"In the old days, it was a hopeless situation," says Pracht. But today, this type of surgery, called orthognathic surgery, can improve both function and appearance for people with severe skeletal problems such as a "*** Tracy" jaw that juts out. "It's done from inside the mouth," he says. "Nobody cuts on the face." In the early days of this surgery, the jaw was wired together for months. "Now we use little titanium screws," says Pracht, one on either side of the jaw.
"The end result is so fantastic," says Kelly, adding that her headaches are gone, she can chew without pain, and she can eat foods, such as steak, that she avoided before. But she admits that the recovery was rough. "I had a ton of pain," she says. "I was very swollen, and my jaw movement was so limited I couldn't really eat for awhile." She lost 15 pounds while recovering.
Kelly wanted to save her two girls from a similar painful experience, she says. The girls accompanied her to orthodontic appointments and got to know the staff so "they didn't have any fear" when they got their own braces at ages 7 and 9. The staff "had a very gentle way," she says, advising other parents to choose an orthodontist who talks to the child directly and explains the treatment thoroughly.
Joondeph, who treats all ages, says he has put braces on people in their 70s and 80s, as long as their gums and bones supporting the teeth are healthy. "They're the kind of people who are very vital and active," he says. "Typically, they've always wanted to have it done and for some reason they did not."
