Another common situation where a permanent tooth is not in its normal path of eruption is when the first molars (six year molars) are attempting to come in too far forward thus resorbing the roots of the baby tooth that is ahead of it. If this situation is allowed to continue, then it will cause the baby tooth to be lost prematurely. The offending permanent molar will then erupt too far forward, thus leaving no room for the bicuspid to erupt later. I have found that by pushing the molar back before the baby tooth is lost, then the baby tooth can be retained until its normal time to come out. The procedure is call distalization. I connect orthodontic bands on a couple of molar teeth and connect them to a spring. I then bond a hook on the chewing surface of the offending tooth and engage the spring. This pushes the tooth back into its normal position. I remove the spring and allow the tooth to erupt normally. The process takes from two to four months.
Ectopic eruption is where a permanent tooth is in an eruptive path that is out of line with the norm. The most common example is that of wisdom teeth. Since there is not very much room for them to come in normally, it is extremely common for the wisdom teeth to be directed in all sorts of directions. The usual corrective procedure for that is removal of the wisdom teeth. A common occurrence of ectopic eruption is when the permanent lower incisors erupt too far on the tongue side. It kind of looks like shark teeth with them in two little rows. I have had many a frantic patient rush their child into my office to show me that problem. I have found that if the baby teeth are extremely mobile, they can be allowed to come out naturally. However, if not, I recommend extracting the offending baby tooth or teeth. By doing that at the proper time, the tongue will push the permanent teeth forward into their natural place without the need for expensive orthodontic treatment.
An orthodontic evaluation during routine dental examination is very important for children. In many cases, early treatment of orthodontic problems can make subsequent phases much easier, less expensive, or may even eliminate the need for further treatment. Many parents think that one has to wait until all of the baby teeth come out and the permanent teeth are in before starting orthodontic treatment, however, many problems – such as lack of space or crossbites – can be corrected early while there are still baby teeth present. The results can be much more stable when done early. The muscle tone of the lips, cheeks, and tongue are still in a states of flux in a young child. The muscle tone usually doesn’t become set for life until all of the permanent teeth come in. That gives a little window of time that the size of the jaw can be changed and the result will be relatively stable, whereas, doing it later in will have a high rate of relapse.
When a nerve has been exposed on a baby tooth, that usually means that there was a sizable cavity. Since baby teeth are so small, large cavities can make it difficult to retain fillings for any length of time. Therefore, it is best to place crowns over those type of teeth. Since baby teeth will be coming out in a few years, it is best to not put an expensive porcelain crown on it. The recommended procedure is to place a crown made of stainless steel.
These crowns come pre-formed so they do not have to be custom made. They come in various sizes. The dentist will remove the outer layer of the tooth, then try on different sizes until one is found that fits. The stainless steel is thin enough that it can be modified with special pliers if needed to get a better fit. The crown is then cemented into place with the same cement used for adult crowns. Although this technique is not ideal for long term, it works well in the interim for baby teeth and keeps the costs down significantly.
When a cavity has extended into the nerve of a baby tooth and the nerve is still healthy, it is best to save the tooth. When a nerve is exposed in an adult tooth, normally a root canal would be performed. However, since a baby tooth will only be in a child’s mouth for a few years, there is no need to do an expensive treatment like a root canal. A procedure called a vital pulpotomy is recommended. In a pulpotomy, the top portion of the nerve is removed leaving only the remnants inside the roots behind. The remaining nerve stump is treated with a medication to stop the bleeding. The most commonly used medicament is formocresol, although ferric sulfate, calcium hydroxide, or mineral trioxide aggregate have also been tried with varying success. Formocresol will not only stop any bleeding, but also mummifies the tissue effectively sterilizing it and keeping the underlying nerve alive and vital. The area is then covered with a base such as zinc oxide and eugenol, calcium hydroxide, or glass ionomer.
In children, cavities tend to grow much quicker than they do in adults. This may be due to their immature immune systems not being able to keep the cavity producing germs at bay, the tendency toward a higher sugar content in their diet, and their lack of manual dexterity to properly clean their teeth. With the relatively rapid expansion of decay coupled with the small size of the baby teeth, it is not uncommon to see a cavity reach all of the way to the nerve. Once that happens, a decision has to be made on whether to restore the tooth or to extract it. If the tooth still has a healthy nerve, then it is usually best to save the tooth if it is restorable. Front teeth aren’t as important in maintaining space, so they can be removed without regret other than the cosmetic aspect. If the tooth does have to be extracted and it is a back baby tooth and it will still be more than a year before the permanent tooth is expected to erupt, then a space maintainer must be cemented in place to keep the permanent teeth from shifting.
Once a cavity has been cleaned out and the tooth prepared to accept the filling, now we have to decide what to fill it with. The two major choices are amalgam and composite. Amalgam is the material that has been used for over a century. It is an alloy of silver and mercury. Over the years, there has been a lot of negative media coverage on the use of mercury, however, once the silver and mercury are mixed together, the alloy becomes inert.
Since the material has been used since the 1800s and has been no population study that has shown any ill effects of using the mercury containing fillings, you need not worry if your dentist recommends using amalgam to fill your child’s teeth. In our office, we give the parent the choice of either the amalgam or tooth-colored filling material. The newer composite fillings have been shown to have a life span long enough to have the baby tooth come out naturally and are therefore a fine alternative.
Once a tooth is numb, the child should not experience any further discomfort. However, there are a lot of sights and sounds that can unnerve a child into thinking that what is happening is painful. Since a drill has to be used to clean out the decay and shape the inside of the tooth to hold a filling, the chatter of the drill’s bur, the water spray, and the high pitch sound can startle some children. At our office, we show the patient every step that we are about to take before we do it. For example, we take the high speed handpiece and hold their hand up to it and let them feel the water spray. We tell them that the water spray is going to clean out all the cavity bugs. With their fears allayed, most children will be still while the cavity is being drilled out. We tell them that the water spray will tickle their teeth, so the vibration of the drill is well tolerated. Taking the extra time to demonstrate what’s going to happen is well rewarded with a calm, cooperative child.
Filling cavities in baby teeth can be very important. Many people think that just because the baby teeth fall out eventually, you don’t need to be concerned about caring for them. Baby teeth are important to keep space open for the permanent teeth. If a baby tooth is lost too early, the teeth will crowd up making any subsequent orthodontics much more difficult. And if a cavity gets too deep, the tooth could abscess which can cause a lot of pain, not to mention the chance of serious infection. One of the worst parts of my job as a dentist is seeing a child writhing in pain with a toothache only to find out that this is their first trip to the dentist. It’s not too hard to imagine how much they will look forward their next trip to the dentist. It is also very hard to get profound numbness on an abscessed tooth which makes the experience that much worse. By pre-planning and catching things early, teeth can be filled painlessly on children.
When filling children’s teeth, I ALWAYS use local anesthetic on children. My practice includes a large segment of adult patients requiring sedation. The overwhelming reason for their extreme fear of the dentist is because their dentist didn’t use novocaine when they had their teeth filled as a kid. By numbing teeth ahead of time, a tooth can be drilled on without any pain whatsoever. Fear of the “shot” is a very common issue in children (not to mention many adults). We try to make that part of the visit as easy as possible for the patient. We start with a topical numbing gel that is placed on the gum at the injection site with a cotton swab. Once the gum is fully numb, the child is told that they will feel a little “pinch”. The anesthetic syringe is passed to the dentist out of sight of the patient. By quickly inserting the needle into the numbed gums and very slowly injecting the anesthetic solution, the child experiences little to no discomfort. It is such a heart-warming feeling to hear a child run out to the waiting room saying “Mommy, Mommy – I didn’t have to have a shot! He just pinched my gums.”