Doc's weekly Derry News column "Wired" covering a variety of orthodontic treatment topics.
Biting Remarks top
Instead of opening wide, most orthodontists are likely to ask their patients to bite down so that they may observe the way in which their teeth fit together. A proper occlusion is essential if patients are to chew their food effectively. The orthodontist will want to see if the upper front teeth overlap the lowers and that the biting edges of the lower teeth lightly touch the inner surfaces of the uppers. The premolars and the molars should also meet evenly, with the chewing surfaces of the lower teeth slightly inside the uppers so that their outer cusps mesh with the central grooves of the uppers. Ideal bites also have the lower molars and premolars positioned slightly forward of the corresponding upper teeth. Having said all that, each bite is individual and must be evaluated as such.
A person’s bite (occlusion) changes throughout his or her life.
The Straight Facts top
When the facts about straight teeth are taken into account, it is surprising that more of us are not sporting braces. According to several studies published in professional publications, 50% of the population of this country is in need of orthodontic care. This need arises from improperly positioned teeth (malocclusion). Whether due to heredity or habit, the teeth do not fit together correctly when the jaws are closed. In cases where malocclusions are handed down from generation to generation, either the teeth are improperly positioned within one or both jaws, or the jaws may not be comparable in size. When malocclusions are acquired, such habits as thumb sucking and tongue thrusting may be the culprits. Regardless of the cause, the solution rests with orthodontic treatment.
Open and Shut Case top
While the condition known as a deep bite occurs when the lower jaw closes too deeply under the upper one to create a collapsed look to the vertical dimension of the bite, an “open bite” is just the opposite – the molars meet when the jaws close, but a gap remains between the upper and lower front teeth. The condition may be caused by over eruption of the rear molars, which prevents the front teeth from meeting fully, or may be a consequence of the bones of the jaw simply growing in different directions. More often, however, it is the result of habits such as thumb-sucking. Whatever the cause, it can create problems for the person with an open bite in terms of being able to bite into harder foods effectively. If the gap is very wide, open bite may even be a source of embarrassment, to the point where a person may be hesitant to speak up. Orthodontic treatment can provide a remedy.
Due to the rocking effect of the jaws during chewing, an open bite can lead to gum disease and a consequent loss of teeth if left uncorrected.
At Cross Purposes top
The malocclusion known as a “crossbite” results from a faulty vertical relationship between the lower and upper jaws. Normally, the arch of the lower jaw (mandible) is slightly smaller than that of the upper jaw, so that the lower front teeth close inside the upper front teeth and the upper side teeth close on the outer edge of the lower side teeth. With a crossbite, the lower teeth overlap the upper teeth, instead of a slight overlap coming from above. As a result, one side of the mouth can appear lopsided. However, many people with minor crossbites do not experience problems and may not even be aware that they have crossbites. Whether the problem is severe enough to carry the potential for joint degeneration or so minor that it is barely noticeable, it should be diagnosed and treated to bring the jaws into the proper relationship with each other and assure their continued health.
Double crossbite occurs when both sides of the lower jaw overlap the upper jaw.
Bite Your Lip? top
As improbable as it may seem, harmful lip habits can cause misalignments of the teeth and jaws that require orthodontic treatment. Persistent habits such as wetting, sucking, and biting the lips, as well as chin-lip movements, can create inward pressures that may tend to narrow the jaws and make less space available for the teeth. If the force associated with these habits is sufficiently strong, the teeth may even be forced inward. This action can be observed in the child who bites his or her lower lip. Holding the lip between the teeth with the jaws at rest can force the upper teeth forward and the lower teeth backward over a period of time. A similar effect is exerted by those with chin-lip habits that involve puckering the chin muscle in order to push the lower lip upward when closing the lips (usually when swallowing). Before treatment starts, these habits must be corrected in order to avoid future problems.
Coated wires known as lip and cheek bumpers may be used to hold the lips and cheeks away from the teeth, relieving the teeth and jaws from the pressure of the lip and cheek muscles.
Less Taxing Brackets top
In terms of aesthetics, perhaps the most important advancement in orthodontics of the past few years has been the introduction of brackets that bond directly to the teeth. In the past, orthodontists wrapped each tooth in a stainless steel band, with which other teeth served as points of attachment for the main wire that moved the teeth. Now, all that is needed to hold the arch wire in place are the tiny brackets affixed to the front of each tooth. As a result, the “tin grin” of the past has been replaced with far less metalwork. In fact, the amount of metal in the patient’s mouth can be reduced even further by choosing clear brackets that allow the natural color of the teeth to show through. With this choice, all that really shows in the patient’s mouth is the metallic arch wire, which gives more of an impression of a retainer than of the fixed appliances that we have come to know as “braces”.
Because today’s braces are less visible, they help reduce any feelings of self-consciousness that the wearer might feel.
Closing the Gap top
If patients wish to close the gap between their front teeth, the reason for the spacing must be determined before the best method of correction can be decided upon. In the majority of cases, the cause is developmental. As the teeth grow, there is simply more room that is needed to accommodate them. As a result, gaps appear. Another reason that gaps might appear in the upper front teeth relates to the muscle attachment (frenum) found between the upper lip and the upper dental arch in the area of the two front teeth. It sometimes happens that very large or fibrous attachments may contribute to splaying of the front teeth. Once these causes are addressed, corrected, or at least recognized, the orthodontist may then close the gap by utilizing the long-term procedure of orthodontically moving the teeth together with a retainer appliance.
Gaps between the front teeth may also appear as the result of habits, such as continually picking one’s teeth or sucking fingers or writing utensils.
In Cases of Cleft Lip and Palate top
When children are born with cleft lips and palates, the baby and permanent teeth closest to the cleft are most often either malformed, malpositioned, crowded, or missing. As a further complication, the upper jaw may be misshapen to make it more difficult to close the mouth properly. These problems of tooth position and how they fit together (occlusion) should be evaluated by the orthodontist as the child’s baby teeth begin to erupt, if not sooner. (Sometimes, orthodontic appliances are used to align the gums prior to surgical closure of the cleft lip.) This monitoring, which includes an assessment of the overall growth of the jaws and the rest of the face, usually continues until the permanent teeth and is then designed.
In the later childhood when there is a mixture of baby and permanent teeth, children with cleft lip and palate may require the use of an orthodontic appliance to widen the upper dental arch.
Adult Matters top
If you think that fixed orthodontic appliance (“braces”) are only intended for adolescents and younger children, you may be surprised to learn that more than 300,000 adults are fitted with braces each year. Most of these adult patients are women. The usual reason for seeking orthodontic treatment later in life in life is usually cosmetic, but orthodontic treatment may also be needed to prevent decay and gum disease caused by crowded teeth or tooth loss resulting from a bad bite (malocclusion). One advance in orthodontics that makes the idea of treatment more palatable to adults is the use of tiny brackets, made of stainless steel, tooth-colored ceramic, or clear plastic. These brackets require fewer adjustments than the old bulky bands than with their signature “train-track” look. There are also lingual braces, which are attached to the back of the teeth to render them virtually invisible.
Today’s braces also feature heat-activated nickel-titanium wires that are attached to the brackets on each tooth and run across the full span of the dental arch. This material allows the arch wire to exert continuous pressure without frequent replacement.
Steady Erosion top
Bulimia, an eating disorder involving episodes of binging followed by purging, can give rise to tooth enamel erosion and lead to a number of tooth spacing and bite disorders. For example, a bulimic may experience a closed bite (characterized by decreased vertical tooth dimension and an abnormal overbite in which the lower jaw protrudes) as a result of tooth enamel loss due to repeated purging of stomach acids. In such cases, it is not uncommon for incisors, for instance, to lose almost 1/3 to 1/2 of their original length. As a consequence, a closed bite results from excessive eruption of lower jaw incisors into the space created by eroded teeth. Fortunately, fixed orthodontic appliances can be effective in aligning teeth so that sufficient space is created so that they may receive porcelain veneer crowns to restore the damage.
The first step in treating teeth damaged by bulimia is treating the eating disorder itself.
An Ounce of Prevention top
The phrase “an ounce of prevention is worth a pound of cure” is most certainly appropriate to orthodontic treatment. Those children who schedule their first visit to the orthodontist by age seven for an examination benefit from an early determination of how and when a particular problem does not always lead to early treatment, some problems can be treated in an interceptive manner. If so, early intervention takes advantage of facial growth and tooth eruption to lessen the severity of the problem and frequently makes later completion treatment (if necessary) less time-consuming. By addressing bad bites (malocclusions) in a timely manner, patients are assured that they can circumvent the problems of tooth decay, bone destruction, tooth loss, gum disease, and joint problems that might otherwise attend untreated conditions.
If left uncorrected, malocclusions carry the potential to adversely affect a child’s speech, general health, and self-esteem.
Biting Comments top
The malocclusion known as an overbite deserves attention because it can potentially interfere with speaking, swallowing, and chewing certain foods. It is characterized by upper teeth that stick out over the lower teeth. People with overbites tend to compensate by sticking out their lower jaws, which can result in the additional problem of overstressing the jaw joint to cause pain, in some cases. To determine whether on overbite is in need of correction a person need only bite down and insert his or her index finger in the space between the backs of the upper teeth and the fronts of the lower teeth. If the finger fits this space, there is an overbite of about half an inch. This condition should be discussed with the orthodontist. As for underbites, which consist of lower teeth that stick out further than the uppers, they rarely lead to problems with the jaw joint. Improved appearance is usually the motivating force behind seeking correction.
Only about three percent of the population suffers from underbites.
Limited Orthodontic Treatment top
While most people associate orthodontic treatment with adolescents and “braces”, there are cases of patients who require restorative dental care benefiting from limited orthodontic treatment. For instance, in the case where extracted or missing teeth may cause other teeth to drift out of alignment, temporary use of limited orthodontic appliances can realign and redistribute the space around these teeth sufficiently to enable them to support a fixed bridge. As for people with under- or oversized teeth who have abnormal spacing between their teeth, limited orthodontics may redistribute the space and de-emphasize the size difference between neighboring teeth. In addition, misaligned teeth in the front of the mouth can be straightened with limited orthodontics in order that the teeth may properly accept porcelain veneers or crowns. In short, limited orthodontics may be used to facilitate restorations.
Limited orthodontic treatment may also be utilized to eliminate plaque pockets to improve oral health.
Instrumental Role top
While children who play musical instruments should be encouraged to play at every available opportunity, it should be noted that, as far as teeth are concerned, practice may make less than perfect. The reason is that woodwind and brass instruments have the potential to push teeth out of their proper positions to either cause, or worsen, orthodontic problems. Consider the fact that braces move teeth with 100 grams of pressure, while playing a musical instrument exerts 500 grams of pressure. Trumpets, trombones, and French horns have the tendency to push front teeth back, while clarinets and saxophones force front teeth out. To see if playing an instrument poses a problem, have the orthodontist evaluate your child’s instrument’s effect upon his or her teeth while he or she plays it. If a problem does exist, the orthodontist can prescribe a plastic splint to be placed over the front teeth as a preventative measure.
Parents should also monitor their children’s thumb- and finger-sucking habits for signs of tooth and bite problems.
Crooked Ways top
Many people assume that crooked teeth are inherited and can scarcely be avoided, and that is partially true. The primary causes of crooked teeth consist of tooth loss due to decay or infection, late shedding of baby teeth, loss of permanent teeth, bad habits, and injuries. When these noninherited factors are addressed with interceptive measures, it may be possible to either circumvent any future need for orthodontic treatment or significantly reduce its length. As for heredity’s role in the formation of crooked teeth, it usually involves a mismatch between teeth and jaw sizes. In the event that one parent has very large teeth and jaws and the other has small teeth and jaws, their children may have large teeth in small jaws (overcrowding) or small teeth in large jaws (open spaces). These factors may be addressed with preventative measures intended to help the teeth avoid improper paths and positions.
Another inherited problem that could lead to the need for orthodontic treatment (or in severe cases the need for orthognathic “jaw-correcting” surgery) occurs when either of the jaws protrudes in comparison with the other.
Causes and Effects top
The factors that contribute to tooth irregularities and poor bites (malocclusion) that require orthodontic treatment are varied. Crowded teeth, wide spacing, and incorrect relationship of the jaws are inherited malocclusions that do not lend themselves to prevention. On the other hand, thumb-sucking that persists after the permanent incisors have come in open up lasting spaces that may have been averted with preventative measures. Similarly preventable, the swallowing reflex known as tongue-thrusting (pressing the tongue against the front teeth while swallowing) is often the result of faulty nursing during pregnancy and is responsible for may cases of malocclusion. Sometimes, tongue-thrusting is induced by mouth-breathing caused by disorders that block the nasal passages. Whatever the cause of the tooth and bite irregularities, they can be treated and sometimes avoided altogether with early prevention techniques.
Sucking or chewing the lower lip may accompany thumb-sucking and tends to aggravate the outward flaring of the upper front teeth.
Finger and Nail-Biting Problems top
When either children or adults have the habit of biting their fingers or fingernails, attention often centers on the damage that they are doing to their fingers and nails. The orthodontist’s concern, however, is likely to center on the teeth and jaw joint. There is good reason for this concern because any habit that involves holding the teeth in an abnormal position for prolonged periods of time can lead to such jaw-joint problems as temporomandibular joint (TMJ) syndrome. To treat these problems, the orthodontist may likely rely on jaw-repositioning appliances made of acrylic (also called splint) that are used to influence the jaws to close in a more favorable position. If the finger- or nail-biting habit causes a gap between the front teeth, it can be closed with either fixed or removable appliances, depending on the severity of the problem.
A finger- or nail-biting problem cannot be successfully treated until the patient is broken of the habit. The orthodontist can help in the respect, as well.
Getting in Gear top
Orthodontists will often prescribe the use of orthodontic headgear when no structures within the mouth are strong enough to anchor corrective appliances. Headgear makes use of the neck or back of the head as anchorage, from which elastic straps extend forward to a wiry face bow that connects to bands on the molar teeth. This arrangement is particularly useful in cases where the molars require correction. These teeth, which usually serve as anchors themselves to shore up the pressure exerted by archwires on traditional “braces”, have sturdy roots which require considerable force to be moved. Headgear can exert the backward force needed to carry out the job. It may also be prescribed for those patients who wish to wear corrective equipment in the privacy of their own homes at night; however, today some feel it is fashionable to wear headgear during the day.
Headgear is but one of a number of removable appliance in a category that includes positioners, retainers, and bite plates.
Thumb Sucking and Related Problems top
Chances are that a child who persists in sucking his or her thumb beyond the age of five or six could end up needing braces. Permanent front teeth usually begin to emerge after age six. If the thumb-sucking habit is not broken by then, it can have profound and irreversible effects on the formation of the mouth and jawbone. The most common problems related to thumb-sucking include protruding and poorly spaced teeth, an open bite, and a narrow upper jaw. The degree to which these distortions manifest themselves depends a great deal upon how persistently and for how long a period the habit continues. Some children only suck their thumbs in private at home and at night, which is less likely to give rise to problems, while other children put their thumbs in their mouths all day and all night. If this habit is not broken in time, the orthodontist stands ready to deal with its effects.
The majority of children who suck their thumbs as toddlers give up the habit when they start school.