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ORTHODONTIC TREATMENT TOPICS:
ORTHODONTIC CROSSBITES AND PALATAL CONSTRICTION, TYPICAL TREATMENT
THUMB OR FINGER SUCKING HABITS AND ORTHODONTIC TREATMENT
ORTHODONTIC RETAINERS FOR HOLDING THAT GREAT SMILE
CROSSBITES AND PALATAL CONSTRICTION
Crossbites are a reverse position of one or more teeth. A crossbite can be due to either the teeth themselves being reversed in position, or more commonly, the upper jaw and palate are constricted to the extent that the upper teeth do not match the lower teeth on one or both sides. Think of normal as the upper teeth being like a jelly jar top fitting out and over the jar. The upper teeth should be to the outside of the lower teeth on both sides of the mouth.
This is what we call a dental crossbite. The width of the palate is normal, but the teeth in the front of the mouth are reversed. The right photo shows the teeth before full closure and the left photo after full closure. Note the bone and tissue or gum loss around the bottom incisor which is being forced out of the arch. This type of damage usually calls for tissue grafts.
What causes the palatal constriction and crossbite? Usually genetics, but sometimes unusual eruption of the teeth themselves. A constricted palate, which causes the teeth to be in crossbite is usually genetic in nature, and can be traced to one side of the family. Another cause can be thumb sucking which functionally constricts the palate and deforms the upper jaw. In either case, the result is the same and it is never self-correcting.
Signs of a genetic type problem: the bone of the lower jaw is wider than the upper. The upper jaw has a "pinched", narrow look. Note the upper teeth in the back cross over to the inside on one side, but not the other. With this "unilateral" type of crossbite, the midline of the upper and lower teeth do not match. Sometimes the back teeth are reversed on both sides and this is due to an extremely narrow upper jaw.
Generally, correction of an upper jaw problem should be started as soon as the upper first molar is fully erupted. This usually occurs at age eight. If the molar is not fully erupted, then the correction appliance is too difficult to fit and maintain. The other reason to delay treatment is due to very immature or fearful children. In severely constricted cases, treatment as early as age five may be necessary and can be successfully completed in the same time frame as later treatment, however a second phase of treatment may be necessary.
In either type of crossbite, it is essential to start treatment before growth is completed. Consequences of not treating the problem are severe: one side of the jaw will grow longer than the other, the nasal airway will be too narrow, and the jaw joints will not function properly. If the growth period (up to age 16) is missed, then surgery may be required to correct the problem.
Positive results which occur from correcting the constricted palate are: widening of the cheek bones, opening up of the airway and nasal passages to improve breathing, better muscle control during chewing, more space to align the teeth and avoid crowding, allows normal growth of the lower jaw, normal development of the jaw joints.
The palatal crossbite is corrected with a fixed (cemented) appliance, and usually requires about six months to get the correction. There are three variations in the devices which are used to make the correction. We use two types of fixed rapid palatal expander which actively moves the upper jaw apart (without any discomfort and in as little as two weeks) These devices are used for more severe bone constrictions. A longer acting fixed quad-helix appliance is used when long term expansion of just teeth is needed. The doctor will decide which appliance is best suited for your particular problem.
THUMB OR FINGER SUCKING HABITS
As an orthodontist, I see the results of long term thumb or finger sucking on a daily basis. Many of the kids who present for their first exam will indicate on their history sheets that they sucked their thumb for a number of years.
So, what's normal? Many kids will automatically quit sucking habits around age five, up to that point not much damage is done. After about age seven, I start to see problems with the upper teeth being brought forward, and the early stages of permanent damage in the form of distorted bone growth. It is not normal for a well adjusted, healthy nine year old, or older child to have a regular sucking habit.
Why do babies do it? Obviously it feels good! The sucking instinct is one of the baby's natural reflexes that allows the baby to obtain nourishment. It is a normal infant activity that seems to make the baby feel happy and secure. Some babies seem to need to suck a lot more than others. There are apparently hereditary factors influencing the need to suck. Stress is another factor that seems to increase the need. If there is disruption in the family, as in divorce, many times the stress of that situation will precipitate a sucking habit even in older children. This is not to say that sucking a finger or thumb indicates the child is under excess stress, but that stress may simply cause the child to suck more than if there were not a stressful environment.
These photos illustrate the damage a long-term thumb habit can cause. As can be seen in the photo on the right, the upper teeth are moved out and the arch is warped. The bottom teeth are tipped backward. It's a mess....but fixable as you can see we are trying to do with a Phase One treatment for this child.
Why worry about it? Thumb or finger sucking habits can and do cause tooth misalignment or jaw deformation. The degree of disruption depends on several factors: like how hard the child sucks, how often, and to what age. The problems produced by these habits are:
Protrusive upper front teeth. This can be a simple tooth position problem, where the upper incisor teeth were simply tipped outward. Occasionally the formation of the upper jaw can be effected, and upper jaw and teeth will warp out and away from the rest of the face.
Tipped back lower incisors. Commonly found with thumb sucking: the pressure of the thumb forces the lower incisors backward toward the tongue. This exaggerates the protrusion of the upper incisors -- making the face even more distorted.
Distortion of nasal growth. In a long term or severe situation, the nose will appear to be tipped up. When viewing the child from the front, you can see right up the nose since it is tipped up at a severe angle by the constant pressure of the thumb on the under side of the nose. These distortions of the upper jaw and nasal complex are very difficult to reverse without long term orthodontic intervention.
Open bite. The upper and lower front teeth do no overlap when the back teeth are together. The shape of the opening between the upper and lower front teeth may match the shape of the child's finger or thumb. This obviously interferes with the child's ability to bite into food, and will cause problems with digestion.
Cross bite. The formation of the upper jaw is too narrow for the lower jaw. This distortion seems to be due to the flexing of the cheek muscles during sucking. Severe bite problems occur from these prolonged forces, and must be treated before completion of growth.
What are the variables to consider? Every child will not express the habit the same way. I once observed a very content seven year old happily switching between the thumb on her right hand and two fingers on the opposite hand while watching a movie. The duration and intensity on either hand was short, but the frequency was constant. Her front teeth stuck straight out!
Duration: Before age five, there are usually no jaw deformation problems, although you may notice the front teeth getting out of line. As an orthodontist, I usually do not worry too much about these early habits. After age six or seven, the shape of the jaw may be affected, so some action should be considered.
Intensity: Some children suck harder than others and may in turn cause more damage. In general, the harder they suck, the more damage.
Frequency: If it is less than one hour each day, and the thumb or finger falls out at night, the habit is not much of a problem. However, if the child sucks all night beyond age five, some action may be needed.
When to worry and what to do. If the child is over five, and wants to quit, but says they cannot help themselves, then some emotional support is needed. In my office, I first ask the child if they want to stop. If they respond in a positive manner, I gently get them to agree to a method of helping themselves. They are given control over the problem and offered a reward if they stop for two weeks. The technique works better coming from a respected authority figure than a parent. A deal must be struck between the child and the parent if they do end the habit. I like the parent to offer a special meal out at the child's favorite restaurant if they stop for two weeks. I find this psychological approach works 99% of the time when the child says they want to stop. The trick is to gain the confidence of the child and let them make the decision to stop. Anything mechanical to stop the habit will just frustrate them and other, less socially acceptable habits may be substituted.
How to stop. Our method to break the habit is to use about six inches of white, fabric type, bandage adhesive tape on the offending finger or thumb. The child is given the tape and allowed to cut it each day, and apply it in a ragged manner. Wrap the end of the finger, not the joint. Make it messy. You don't want a smooth surface. If there is still a problem after the third day, you might try a sock taped on by the child. They have to agree and want to do it. We also use a two week calendar on which the child can place a star for each successful day they have left the tape in place and not sucked their finger or thumb.
A final word! Never try to force or shame a child to stop a sucking habit. It is easy to appreciate how comforting the habit can be to a child. It can be a big help during those early dependent years. If they fail on the first try, wait a couple of months and try again. The idea is to let them finish with the habit before any damage is done.
LAST, BUT NOT LEAST...RETAINERS
As you look through this site and view the pictures of our patients, you may notice there are no wire retainers showing to ruin their smiles and slur their speech. The reason: we don't use them! So, what do we use? For the upper teeth, we use a clear retainer which is vacuum formed over the "perfect" teeth. This retainer is clear, is worn only at night, and can also be used with tooth whitener liquids. We ask our patients to wear their retainer full-time the first week and then twelve hours at night for the first year.
Placing a removable, "clear" upper retainer which is only worn at night.
The retainer for the lower teeth is really simple: there is a small diameter wire bonded between the lower cuspids. It is called a "bonded lower retainer" or a "bonded 3 to 3" in orthodontese. This is a retainer which will hold the lower six front teeth in perfect position as long as the retainer remains in place. We tell our patients that it is "forever", or as long as you want to be perfect. In reality, the wire in unseen and unnoticed after the first day. You have to floss around the "bonded retainer" to keep it clean, but you would floss anyway...right?
Lower bonded retainer, cuspid to cuspid.
The theory on lower permanent retainers is prevention of a naturally occurring process which tends to crowd the lower front teeth as we age. In the late teens, the lower jaw will normally grow forward a little at the end of growth which crowds the bottom teeth against the back side of the upper teeth. As long as the bonded retainer is in the lower, the teeth stay straight.
Remember: You may only get one chance to do your orthodontics the right way."
