My Blog
By Koh Orthodontics
March 15, 2018
Category: Dental Procedures
Tags: orthodontics   retainers  

Moving your teeth to a more functional and attractive alignment is a big undertaking. You can invest months — even years — and a lot of expense to correct a bad bite. But all that effort could be for nothing if your teeth return to their original positions.

The very aspect of dental physiology that makes orthodontics possible can work against you in reverse. Your teeth are not actually rigidly fixed in the bone: they're held in place by an elastic gum tissue known as the periodontal ligament. The ligament lies between the tooth and the bone and attaches to both with tiny fibers.

While this mechanism holds the teeth firmly in place, it also allows the teeth to move in response to changes in the mouth. As we age, for example, and the teeth wear, the ligament allows movement of the teeth to accommodate for the loss of tooth surface that might have been created by the wear.

When we employ braces we're changing the mouth environment by applying pressure to the teeth in a certain direction. The teeth move in response to this pressure. But when the pressure is no longer there after removing the braces or other orthodontic devices, the ligament mechanism may then respond with a kind of “muscle memory” to pull the teeth back to where they were before.

To prevent this, we need to help the teeth maintain their new position, at least until they've become firmly set. We do this with an oral appliance known as a retainer. Just as its name implies it helps the teeth “retain” their new position.

We require most patients to initially wear their retainer around the clock. After a while we can scale back to just a few hours a day, usually at nighttime. Younger patients may only need to wear a retainer for eighteen months or so. Adults, though, may need to wear one for much longer or in some cases permanently to maintain their new bite.

Although having to wear a retainer can be tedious at times, it's a crucial part of your orthodontic treatment. By wearing one you'll have a better chance of permanently keeping your new smile.

If you would like more information on caring for your teeth after braces, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “The Importance of Orthodontic Retainers.”

By Koh Orthodontics
February 28, 2018
Category: Oral Health

Some people are lucky — they never seem to have a mishap, dental or otherwise. But for the rest of us, accidents just happen sometimes. Take actor Jamie Foxx, for example. A few years ago, he actually had a dentist intentionally chip one of his teeth so he could portray a homeless man more realistically. But recently, he got a chipped tooth in the more conventional way… well, conventional in Hollywood, anyway. It happened while he was shooting the movie Sleepless with co-star Michelle Monaghan.

“Yeah, we were doing a scene and somehow the action cue got thrown off or I wasn't looking,” he told an interviewer. “But boom! She comes down the pike. And I could tell because all this right here [my teeth] are fake. So as soon as that hit, I could taste the little chalkiness, but we kept rolling.” Ouch! So what's the best way to repair a chipped tooth? The answer it: it all depends…

For natural teeth that have only a small chip or minor crack, cosmetic bonding is a quick and relatively easy solution. In this procedure, a tooth-colored composite resin, made of a plastic matrix with inorganic glass fillers, is applied directly to the tooth's surface and then hardened or “cured” by a special light. Bonding offers a good color match, but isn't recommended if a large portion of the tooth structure is missing. It's also less permanent than other types of restoration, but may last up to 10 years.

When more of the tooth is missing, a crown or dental veneer may be a better answer. Veneers are super strong, wafer-thin coverings that are placed over the entire front surface of the tooth. They are made in a lab from a model of your teeth, and applied in a separate procedure that may involve removal of some natural tooth material. They can cover moderate chips or cracks, and even correct problems with tooth color or spacing.

A crown is the next step up: It's a replacement for the entire visible portion of the tooth, and may be needed when there's extensive damage. Like veneers, crowns (or caps) are made from models of your bite, and require more than one office visit to place; sometimes a root canal may also be needed to save the natural tooth. However, crowns are strong, natural looking, and can last many years.

But what about teeth like Jamie's, which have already been restored? That's a little more complicated than repairing a natural tooth. If the chip is small, it may be possible to smooth it off with standard dental tools. Sometimes, bonding material can be applied, but it may not bond as well with a restoration as it will with a natural tooth; plus, the repaired restoration may not last as long as it should. That's why, in many cases, we will advise that the entire restoration be replaced — it's often the most predictable and long-lasting solution.

Oh, and one more piece of advice: Get a custom-made mouthguard — and use it! This relatively inexpensive device, made in our office from a model of your own teeth, can save you from a serious mishap… whether you're doing Hollywood action scenes, playing sports or just riding a bike. It's the best way to protect your smile from whatever's coming at it!

If you have questions about repairing chipped teeth, please contact us or schedule an appointment for a consultation. You can also learn more by reading the Dear Doctor magazine articles “Artistic Repair of Chipped Teeth With Composite Resin” and “Porcelain Veneers.”


A poor bite (malocclusion) could be more than simply teeth out of alignment. There could be complex causes for the malocclusion, possibly involving the facial bone structure.

An example of this is the development of a cross-bite due to problems with the upper jaw and palate (the roof of the mouth), jointly called the maxilla. The maxilla is in fact formed by two bones fused together in the center of the palate in what's called the midline suture. The suture doesn't completely fuse until after puberty.

Sometimes a maxilla's development doesn't follow a normal track. The upper jaw doesn't widen as it should, which leads to the cross-bite where the upper back teeth abnormally bite inside the lower teeth. The upper front teeth continue to bite normally in front of the lower front teeth. This also can have profound influence on breathing, causing sleep apnea.

We can correct this by using an orthodontic appliance called a palatal expander before the midline suture fuses. The expander gradually widens the upper jaw to its normal width and thus eliminates the cross-bite.

Positioned at the roof of the mouth, the expander has metal arms that extend from a central hinge to exert pressure on the inside of the upper teeth. The patient or a caregiver uses a small key to turn a mechanism that extends the arms toward the teeth a tiny amount each day. This gradually widens the jaw, while at the same time stimulating bone growth at the midline suture. Eventually the gap fills with bone to solidify the new width as the suture fuses.

It's important to undertake this treatment before fusion. If you wait until after puberty, you will need to separate the bones first to attempt it. The overall impact and cost is much less if you act promptly in the early years.

Palatal expansion may not be the right treatment in every case, so we'll need to perform a thorough orthodontic exam first. If, however, we do determine it can help, using an expander can improve function, correct future breathing problems and make possible a more attractive future smile.

If you would like more information on orthodontic treatment options, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “Palatal Expanders: Orthodontics is more than just Moving Teeth.”

By Koh Orthodontics
January 29, 2018
Category: Oral Health
Tags: oral hygiene  

Question: What oral health issue do teenagers who wear orthodontic retainers and older folks who wear dentures have in common?

Answer: Both need to pay particular attention to cleaning their oral appliances.

The same goes for anyone who wears a nightguard to control tooth grinding, a mouthguard to protect teeth while playing sports, or a clear aligner for orthodontic treatment. Yet many people aren’t sure how to properly clean their appliances — so here are a few handy tips:


  • Use toothpaste on your appliance — the ingredients in toothpaste, which are designed to polish the hard enamel of your teeth, are too abrasive for the soft plastic of oral appliances, and will cause scratches.
  • Boil your appliance, or use bleach to clean it — both will end up breaking down and destroying the appliance. Don’t even use very hot water, as it can deform the plastic and make the appliance useless.
  • Leave your appliance out on the nightstand, or anywhere else — pets and small children have been known to find (and destroy) oral appliances left lying around. Instead, store it properly in its special case.


  • Use liquid dish detergent or hand soap to clean your appliance. A little mild soap plus warm water will do a great cleaning job. While you’re at it, get a brush just for the appliance — because, while it’s fine for plastic, you don’t want to brush your teeth with soap!
  • Put a towel in the sink basin when you clean your appliance. Soapy appliances (especially dentures) can be slippery, and can be damaged by dropping — and that’s an expensive mishap.
  • Consider investing in an ultrasonic cleaner. These inexpensive countertop devices are an excellent way to get the tiny ridges and crevices of your appliance really clean.

Whether you rely on dentures for everyday use, or just need to wear a retainer for a period of time, your oral appliance serves an important function. It may also represent a significant investment. That’s why it’s worthwhile to spend a few minutes each day giving these important items the care they need.

If you have questions about oral appliance care, please contact us or schedule an appointment.


There are many new and exciting ways now to transform an unattractive smile into one you'll be confident to display. But not all “smile makeover” techniques are new — one in particular has been around for generations: using braces to correct crooked teeth.

Braces have improved the smiles (and also dental health) for millions of people. But as commonplace this orthodontic treatment is, it wouldn't work at all if a natural mechanism for moving teeth didn't already exist. Braces “partner” with this mechanism to move teeth to better positions.

The jawbone doesn't actually hold teeth in place — that's the job of an elastic gum tissue between the teeth and bone called the periodontal ligament. Tiny fibers extending from the ligament attach to the teeth on one side and to the bone on the other. In addition to securing them, the dynamic, moldable nature of the ligament allows teeth to move incrementally in response to forces applied against them.

To us, the teeth feel quite stationary (if they don't, that's a problem!). That's because there's sufficient length of the tooth roots that are surrounded by bone, periodontal ligament and gum tissue. But when pressure is applied against the teeth, the periodontal ligament forms both osteoblasts (bone-forming cells) and osteoclasts (bone-resorbing cells) causing the bone to remodel. This allows the teeth to move to a new position.

Braces take advantage of this in a controlled manner. The orthodontist bonds brackets to the outside face of the teeth through which they pass a thin metal wire. They attach the ends of the wire to the brackets (braces), usually on the back teeth. By using the tension placed in the wire, the orthodontist can control the gradual movement of teeth to achieve proper function and aesthetics. The orthodontist continues to monitor the treatment progress, while making periodic adjustments to the tension.

It takes time, but through this marvelous interplay between nature and dental science you'll gain a more healthy and beautiful smile.

If you would like more information on improving your smile with orthodontics, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “Moving Teeth with Orthodontics.”

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