Types Of Appliances
Curious about your appliance? Check out the information below for a full description (many have pictures as well).
The Bite Plane is a removable or fixed device to prop open the bite. It is usually used when the front teeth overlap too much (deep overbite) which can cause impingement on the gum tissue or the teeth to wear down. It also props open the upper teeth to keep lower braces from being bitten off and the wires to work more freely.
The removable Bite Plane fits in the roof of the mouth and has a flat plane just behind the upper front teeth. The lower front teeth contact this plane which keeps the front teeth apart. This also keeps the back teeth apart which makes chewing a little difficult until the back teeth grow down into contact (6 months to one year). It is worn all the time even for eating unless the doctor gives different instructions.
Besides the removable type, there are two fixed Bite Planes. A piece of plastic can be bonded to the back of the upper front teeth or two metal brackets called “turbos” can be bonded to each of the two large front teeth.
Bite Planes can be used on back teeth as well to prop open the bite in the back and let the front teeth grow down or be freer to move in the proper direction.
The bonded retainer is a bar or wire that is shaped to fit the inside of the front teeth after they have been straightened. It is not visible because it is bonded or permanently attached to the inside or tongue side of the upper or lower front teeth. It can fit behind two to six front teeth and can be bonded to just the two end teeth or all six front teeth.
It is most often used on the lower front teeth when braces have been removed because these small teeth are very prone to getting crooked again up to age 30. The bonded retainer can be left on with no decay problems or gum irritation until the age of 30 or even for life.
These fixed wires are also used to keep spaces closed that removable retainers cannot on nighttime wear program. Many adolescents and even adults either refuse to wear removable retainers or lose or damage them so consistent wear is a problem. The bonded retainer is fixed and eliminates cooperation although they are more difficult to clean around. The doctor can remove these any time the patient desires and will educate the patient as to what may happen in the future without a retainer.
Braces – Full Appliances
The term “braces” usually refers to a fixed appliance consisting of a bonded bracket on every tooth and bonded tubes or bands (ring) cemented to the molar teeth. An “archwire” is inserted into the back tubes and attached to each bracket with a plastic ring or a metal tie. The wire force causes the bracket to pull the tooth into a straight position. Once the wire has lined up all the brackets and straightened the teeth, rubber bands can be added to the wires or brackets to pull the teeth in each jaw toward each other for a better fit. Also, headgears, springs and other devices can be added to close space, or move jaws and teeth backward or forward.
Braces or brackets are either silver colored (stainless steel), gold plated or ceramic (clear). The clear is less noticeable, the gold is more dressy and the standard is the silver which make treatment a little quicker because they are easier to work with. The plastic ties or ligatures that hold the wire in the bracket can be different colors as well. School colors and holiday “decorations” are the most popular.
The bonded orthodontic appliance can be attached to the teeth for as short as six months or as long as 36 months. When the teeth are straight and the bite is right, all the brackets are removed, the teeth cleaned and retainers are placed to keep the teeth straight.
On the (next) (second) appointment (after brace removal) we would like to “equilibrate” your teeth. This is a funny word meaning to “balance your bite.”
It takes about four months after removal of braces for the teeth to “settle” into the best bite possible. At that time, the doctor will check the bite with some marking paper to see if any teeth are contacting in the wrong place or too heavily. If they are, he will “smooth off” (or shave) those areas with an air rotor. It is does not hurt since very little of the enamel on the biting surface of the tooth is removed.
When the bite is fitting evenly all around, the doctor will “manicure” the front teeth to remove any chips or rough edges and improve the smile and appearance.
The appointment takes twenty to thirty minutes and the equilibrated bites will provide less pressure to the jaw joint, less wear on the teeth and longer lasting straightness.
If you choose not to have this procedure done, you will still have a satisfactory bite and a nice smile. We offer this as an extra service to make a very good result an excellent and more stable one.
The face mask is also called a reverse-pull headgear. It is a removable device that uses the face; or more specifically the forehead and chin, as an anchor to move upper teeth and the upper jaw forward. It is used on young, growing patients where the upper jaw is not growing fast enough so the upper teeth bite inside the lower instead of outside the lower (cross-bite).
The face mask has a large metal bar that attaches to a pad for the forehead and a chin cup. Hooks are also attached to this bar at the mouth level so rubber bands can be attached to upper braces. These elastic bands exert a pulling force of the upper jaw and teeth to move them forward. In most cases, the rubberbands are hooked onto an upper jaw-widening device because the upper jaw moves forward better when it is being widened.
In order to be effective, the facemask must be worn 14 or more hours each day. If worn more than that, there is a much better chance of correcting the jaw problem. The period of wear is from 6 – 12 months. Even with good wear or apparent correction, some patients grow poorly again and may even need jaw surgery as a young adult.
Many young patients have oral habits that can be harmful to the bite or alignment of teeth. The two most common are a thumb or finger habit and a tongue-thrusting habit. If a thumb is constantly in the mouth and sucked on with some force, the upper front teeth will be raised, spaced, and flared. The lower teeth will be tipped back and crowded and the back teeth will become narrow on top causing a crossbite. If the tongue is thrust forward or just postured forward against the front teeth, both the upper and lower teeth can be spaced and flared and pushed apart so no bite exists in the front of the mouth (openbite).
The habit appliances are usually fixed or cemented on the upper first permanent molars. Bands on these molars have wires soldered to them that run across the roof of the mouth near the back of the upper front teeth. The thumb appliance has a wire screen that prevents the thumb or finger from resting on the roof of the mouth where it can create suction and feel good. If the “pleasure” of the habit is gone, it can be easily stopped. The tongue appliance has “spurs” that will poke the tongue when it comes forward and this directs the tip of the tongue up to the roof of the mouth where it is supposed to be in resting and swallowing. The tongue may be sore the first day but after that, the patient avoids the spurs and keeps the tongue in the ideal place.
Habit appliances need no adjustments and have no active force on the teeth. In many cases, the teeth will start to get straighter on their own since the tongue or thumb is no longer involved. Braces are still needed at some point to totally recover from the harmful effects of the habit. The habit appliances are left in place for six months to make sure the habit is gone and then removed with no retainer.
Hawley Retainer and RA
The Hawley retainer is a removable device with a plastic plate in the roof or floor of the mouth and a wire, which rests against the outside of the six front teeth. It can be made for the upper or lower jaw and has clasps on the side, which help hold it in place.
When used as a retainer, it is passive with no force on the front wire or behind the teeth. It is merely a holding device to prevent the teeth from heading back to their original position. When braces are removed, the retainer is placed as soon as possible and worn all the time for six weeks or longer. Then it can be worn 8 – 12 hours for the next two years. In many patients the retainer must be worn one or several nights a week for life to prevent movement.
The RA or Removable Appliance is an active appliance. It is made to move a few front teeth that need to go forward or backward or twist a slight amount. The RA usually has little springs that push against the teeth to move the four front teeth forward while the outside wire can exert a force backward against these same teeth. Because the RA is active, it must be worn all the time for four to eight months to move the teeth. Once the teeth are straight, it can be worn at night as a retainer.
The Headgear is a removable device that uses the head or neck as an anchor to move teeth or bones back toward the neck or back of the head. It has an inner bow of metal that slides into tubes on the upper molar bands and an outer bow of heavier metal that comes outside the mouth alongside the cheeks. An adjustable strap with elastic or spring force is then attached to the outer bow to pull on the upper teeth and jaw. The doctor can use a strap from the top of the head (highpull headgear) or one from the neck (cervical headgear) depending on the direction and type of force desired.
The headgear is used to move the upper jaw back or anchor it in place while the lower jaw grows forward to catch up in patients where the front teeth stick out too far. With less elastic force on the headgear, teeth instead of bones can be moved back to provide a better fit or room for crowding in the upper jaw.
In order to be effective, the Headgear must be worn 12-14 hours each day. If worn more than that it will get the job done quicker and if less, nothing will change. The Headgear is usually worn a minimum of one year. It should not be worn during sports or active play because someone grabbing it could cause injury to the teeth or face.
The Lip Bumper consists of a large wire with a plastic shield in front. The two back ends insert into large tubes on the outside of bands or rings cemented to the lower first molars. Stops on the wire keep the plastic shield two millimeters in front of the lower teeth and gums so the shield “bumps” against the lower lip. This wire is tied to the back bands so it is only removable by the doctor or staff.
The Lip Bumper is used to gain space for crowded lower teeth. It does this by holding the strong lip muscle away from the front teeth so the tongue can push these small teeth forward. The lip “bumping” against the shield puts a backward force against the molars, pushing them backward. The metal wire or bar holds the cheek away from the side teeth, allowing them to be widened or moved laterally toward the cheeks.
At each six to eight week appointment, the Lip Bumper is removed and advanced forward to maintain lip pressure and space for front tooth movement. The appliance normally stays in place for six months and then is removed and braces are placed to align the teeth. A lower holding arch (LHA) can also be placed to maintain the space gain if the permanent teeth are not erupted enough for braces.
Lower Holding Arch (LHA)
The Lower Holding Arch is a wire that contacts the inside of the lower front teeth at the gum-line and is attached to two bands on the lower first molar teeth. This wire can be fixed (permanent) and soldered to the molar bands or removable and fit into tubes or sheaths on the inside of the bands. The removable LHA is held in the tubes by friction and can only be removed by the doctor or staff.
The LHA is used to “hold” the space or arch length between the front and back lower teeth. The baby second molars are usually two millimeters bigger than the premolars that replace them. Thus, up to four millimeters of space can be “held” when these baby molars are lost if a LHA is in place. Without this arch, the molars drift forward and valuable space is lost to straighten crowded front teeth.
The LHA is also used to preserve space when baby teeth are prematurely lost due to decay. It can be used to widen, narrow, rotate or tip the molars as well. In many cases, the LHA is used as an anchor to keep molars and front teeth or incisors front moving when force is applied through rubberbands or functional appliances.
Missing permanent teeth is a genetically inherited condition, which occurs in many members of the same family. The most common missing teeth are the upper lateral incisors; the small front teeth next to the large central incisors. One or both of these may be missing or one or both may be “peg-shaped” or very undersized.
Since these teeth are in a very visible area of the smile and face, the decision on what to do about them is important. In some cases where teeth are crowded, the cuspids can be moved forward with orthodontics to replace the laterals and thus no replacement teeth are needed. These bigger cuspids have to be shaped and sometimes capped to look like they belong. In most cases, it is better for the bite and the appearance to move the cuspids back into an ideal fit and place “prosthetic” or plastic replacement teeth in the spaces. These plastic teeth can be attached to the braces, then be a part of the retainer after braces are removed. When the patient reaches adulthood, they can be permanently replaced with an implant or a fixed bridge. Space is also left around undersized laterals so they can be capped, veneered, or built-up to a normal size and appearance.
Other teeth that are commonly missing are second bicuspids and wisdom teeth. Many times, baby molars can be left in to replace the missing bicuspid or in cases of crowding they can be removed and the spaces entirely closed. Bridges or implants may be necessary if the baby molar is not a sound replacement. Missing wisdom teeth are, of course, a blessing.
The temporary replacement teeth that are used on the braces and retainers are not made to stay on if these teeth are under constant pressure from tongue force, nail-biting or biting food with the front teeth. Patients with replacement teeth must be very gentle with these teeth or they will easily break off of the braces or retainers.
Missing teeth can be a real challenge but the combination of orthodontics and restorative dentistry can result in a beautiful, long lasting smile with the cooperation and patience of the patient and family.
All athletes playing contact sports should wear a mouthguard. In people without braces, they protect the teeth from getting broken or knocked out and provide a cushion for blows to the head and neck. For people with braces, the teeth are already somewhat protected since they are wired together and covered with metal or ceramic. However, mouthguards are needed with braces to prevent the brackets and wires from penetrating the cheeks and lips and badly cutting up the soft tissue of the mouth.
Mouthguards for non-brace athletes are tight-fitting on the upper jaw only. They can be heat-formed by the athletes or custom made by the dentist. These types will not work for the athlete with braces because heat-formed plastic will get stuck in the brackets and wires and can prevent the braces from working properly. Also, as the braces move the teeth, the mouthguard will no longer fit and will have to be remade or remolded.
Mouthguards for athletes with braces must be loose fitting to allow tooth movement and cover the brackets on both the upper and lower jaws to prevent soft tissue damage. We have several different types of these mouth protectors and will proved you with one for no charge if you tell us what sport you need it for. When your braces have been removed and you are in retention, just remove your retainer for sports and use the heat-formed or custom-made model.
Mouthguards are important in orthodontics but for different reasons and we will help you protect your teeth and soft tissue from injury while you are in braces.
The Nance is a fixed appliance, which uses bands (rings) cemented to the upper permanent bicuspids or molars. Attached to these bands (soldered) is a wire, which extends up into the roof of the mouth. A plastic button the size of a quarter covers the end of the wire and fits snugly against the hard palate or front part of the roof of the mouth.
This device is passive and does not move or straighten teeth. The plastic button against the palate serves as an anchor to keep the banded molars or bicuspids from moving forward. It is used to hold front teeth from moving when pushing molars or posterior teeth back. It is also used after molars have been pushed back to stabilize these teeth while the front teeth are pulled back. The Nance button is kept in during the early stages of treatment and then removed near the end of treatment when final spaces are being closed and the molars need to be adjusted to perfect the bite.
T-Rex or Pendex
The T-Rex is a fixed upper appliance designed to both widen the upper back teeth and move the upper molars back. It is used when the upper jaw is narrow and when the molars need to be moved back for a better bite with the lower and to create space for crowding or blocked-out teeth.
It is made with a plastic piece that fits in the roof of the mouth and houses a widening screw. Metal arms extend to the four bicuspid teeth or baby molars where they are bonded or cemented. Two molar bands are also attached and are cemented on the upper first molar teeth so that the appliance is firmly fixed to six teeth. Special wire springs are also placed into tubes on the molars to exert a controlled backward push to these teeth.
The T-Rex expansion screw is turned once a day with a special key (parent or patient) to get the desired width first. This takes from 2-8 weeks depending on the widening needed. Then the special springs are activated to move the molars back and it takes about 4-6 months for these teeth to reach the optimum position. When this appliance is removed, the molars are retained in their new position by a Nance holding arch which uses a wire and a plastic button in the roof of the mouth.
The only difference between the T-Rex and Pendex is that the T-Rex expands first and then moves molars back. The Pendex moves the molars back from the day it is placed and some widening is done during backward movement. It is used when little or no widening is needed. Both appliances use a fixed (Nance) retainer to hold the molars back and then regular braces are placed to straighten the upper teeth.
Pre-orthodontic Guidance Program
At the initial exam, it was determined that your child may need orthodontic treatment in the future. In most cases, there is an optimum time to start treatment and this can only be established by regular six-month observation visits.
At each appointment, the doctor will check:
- Amount and direction of jaw and facial growth
- Looseness or loss of baby teeth
- Poorly or slowly erupting permanent teeth
- Amount of crowding in the developing jaws
- Changes in the bite and in oral habits
At each 6-12 month visit, the doctor may advise any of the following:
- Radiographs (X-rays) to determine dental development
- Referral to your family dentist or oral surgeon for baby tooth removal
- Passive holding arches to maintain space and tooth position or eliminate thumb or tongue habits
- Limited active appliances for expansion or guidance of erupting teeth
There is no charge for the 6-12 month pre-orthodontic evaluation appointments. It is so important that these visits are kept that we have no fee unless an x-ray or limited appliance is suggested. We would like to see all children by age 7 and follow them in regular pre-orthodontic visits to ensure preventative measures that will minimize the scope of later treatment. Thank you for the trust and confidence you have placed in our ability to create the best face, smile and bite possible.
Quad Helix (QH)
The Quad Helix is an appliance that widens the upper jaw. This widening or expansion is usually done when the upper jaw is so narrow that it causes a bad bite (cross-bite). The upper jaw can also be widened to get room for crowded or blocked out teeth and to improve the smile by increasing the amount of teeth shown.
The QH is made from a single piece of steel wire that is soldered to two upper molar bands. The wire is bent to fit in the roof of the mouth and has four (Quad) loops (helices) that give a continuous and gentle pressure outward against the upper back and side teeth. The Quad Helix is “cemented” to the upper molars and is not removable. It stays in place from four to six months and can be adjusted in the mouth every six weeks to maintain the expansion. The upper teeth are usually over-expanded and then allowed to settle with no retainer once it is removed.
The Sagittal is a removable appliance that fits over the upper back teeth and the roof of the mouth. It is mostly plastic but has some wires that clamp on the teeth to hold it in and it can have wire springs to move the front teeth forward. Plastic also covers the side or back teeth so the patient bites and chews on plastic which leaves the bite propped open so teeth can move more easily.
Two small expansion screws are imbedded in the plastic that opens in a “Sagittal” direction or front to back. As these screws are turned, the appliance gets longer instead of wider to move the front teeth forward or the back teeth backward. The doctor can adjust the position of the screws and the biting force on the plastic pads to create the desired forward or backward movement.
The Sagittal is worn all the time, including meals, for about 6 – 12 months. It is removed for brushing and active sports and the patient turns the screws two times each week. When the teeth are in the right position, the appliance can be worn at night for a retainer until ready for braces or more comprehensive treatment.
When teeth are crowded and there is not enough space or bone in which to straighten them, all or part of one or more teeth must be removed to create that space. This can be done by extracting one or more teeth or by “slenderizing”. Slenderizing removes just a slight amount of enamel on each side of the tooth, which makes it more slender and creates one half to one extra millimeter of space.
Slenderizing causes no pain in the tooth since only the outer enamel is sanded. It does not make the tooth sensitive or more prone to decay. Usually, just the four front teeth are slenderized and this can pick up two to three extra millimeters of space. In some cases, the back teeth are also slenderized resulting in a space gain of four to five millimeters.
The front four teeth are slenderized with a hand instrument that looks like a small emery board. A motorized device can vibrate the same sandpaper strip between front teeth and a diamond disk on an air-driven handpiece is occasionally used. The back teeth are slenderized with a rotating bur in a high-speed handpiece.
Besides creating enough space to straighten teeth without extraction, slenderizing can help to maintain tooth alignment. The flatter sides of the teeth tend to fit more exactly with adjacent teeth, keeping them from twisting or moving as easily. Close to half of our patients have benefited from this routine procedure.
A Splint is a removable overlay or cover that fits over all of the upper or lower teeth. It is usually made on the upper teeth because it is easier to keep in and adjust. It is held in by friction on the teeth but can have small metal clasps that also hug the teeth. The Splint can be adjusted by the doctor by adding plastic or grinding plastic away and this will change the surface quickly to provide the most optimum bite for the teeth and facial muscles.
The hard plastic Splint serves a number of functions. It is often used on people who “grind” their teeth (usually at night) to protect the tooth enamel from wearing or chipping. The plastic may wear down but it can be added back. Another use is to relieve stress on strong muscles that close the jaw. People who “clench” these muscles too much will often have facial pain or headaches. The doctor can design the splint to reduce the clenching pressure on back teeth and thus reduce muscle fatigue and pain. The ability of the splint to relax facial muscles will let the jaw drop back into the socket and let the doctor more easily record the true relationship between upper and lower jaws. Also, the splint can be used as a retainer to hold all teeth in the ideal position.
Depending on the reason for the splint, it can be worn all the time except for eating or just at night. Some wear them as short as three months and some wear them at night forever.
The Spring Retainer is a special purpose custom made removable appliance. It is very effective in aligning slightly to moderately crowded front teeth. It may be used in either the upper or lower arch. It is used after slenderizing of the irregular teeth.
An impression is made of the crowded teeth. In the laboratory the teeth are cut from the plaster model, reshaped and aligned in wax on the model. The appliance is constructed over the perfectly aligned teeth. In the mouth the teeth are reduced in width and the appliance is worn 100% of the time. The teeth are aligned rapidly but may require additional reshaping.
When the teeth are properly aligned the appliance may be used as a retainer by wearing it part-time. We usually suggest a fixed wire retainer attached to the inside of the lower front teeth to assure long term stability.
The Haas is an appliance that widens the upper jaw. This widening or expansion is usually done when the upper jaw is so narrow that it causes a bad bite (cross-bite). The upper jaw can also be widened to get room for crowded or blocked out teeth and to improve the smile by increasing the amount of teeth shown.
The Haas appliance is a fixed appliance (not removable) with a plastic center piece that fits into the roof of the mouth and houses an expansion screw. It is supported by bands or metal rings that are cemented onto four teeth; two molars and two bicuspids. The expansion crew is turned once a day (1/4-mm) or twice a day (1/2-mm) for more rapid expansion. A key is provided for the parent or patient to activate the screw. As the screw is turned, the wires and bands put an outward pressure on the teeth and the palatal plastic exerts force on the bone in the roof of the mouth to get maximum pressure on the upper jaw bone.
It will take three to eight weeks to get the 7-8 millimeters of width desired. As the jaw gets wider, the upper front teeth space more but this goes back after widening or can be closed with a few brackets. The Haas is left on for two to three months after the widening period and then removed and a removable plastic retainer is made to hold the new width.
The Herbst appliance is a fixed, functional appliance that brings the lower jaw forward to correct a jaw problem where the upper front teeth and jaw stick out, and the lower teeth and jaw are receded back. It is called a “functional” appliance because it makes the patient function, or talk, swallow and eat in a new jaw position. If the patient functions in this new position for one year, the change becomes permanent. The upper jaw and teeth are pulled back and the lower jaw and teeth are pulled forward to create a better bite and a better facial balance and appearance.
Many times the upper jaw must be widened for the lower jaw to be moved forward. This can be done with an expansion screw on the Herbst or with a separate Hyrax appliance before placing the Herbst.
The Herbst is fixed to the teeth by crowns (caps) or bands (rings) that are cemented to the first molar teeth. The lower bands have arms extending forward to the bicuspid teeth and these arms can be supported by rests bonded to the bicuspids. A tube is attached to the upper band and a piston that fits inside the tube is attached to the lower arm at the bicuspid region on both sides. These sliding pistons allow jaw opening and closing but keep the jaw forward all the time in the new and desired position.
Braces can be used on the front teeth with the Herbst to straighten and better position these teeth. A lower holding arch (LHA) is often used in the lower for support and a transpalatal arch (TPA) is sometimes used in the palate to support the upper.
The Herbst is checked every 8 – 10 weeks and can be advanced or moved forward more by adding two or three millimeter “shims” to the pistons. It stays in place for one year to make sure the correction is permanent and then is removed and full braces are placed to continue and finish the straightening process.
The Hyrax is an appliance that widens the upper jaw. This widening or expansion is usually done when the upper jaw is so narrow that it causes a bad bite (cross-bite). The upper jaw can also be widened to get room for crowded or blocked out teeth and to improve the smile by increasing the amount of teeth shown.
The appliance has a screw-type mechanism that is suspended 1/4 of an inch from the roof of the mouth and wires that attach it to the upper back and side teeth. The Hyrax can either be banded or be attached to the upper molars by cemented bands or bonded with plastic pads that fit over the upper molars and are bonded to the surfaces of the back teeth. The Bonded Hyrax is used more with younger people (baby molars) and the Banded Hyrax is usually used when all teeth are permanent.
Both appliances have a small hole in the screw, which is turned once a day with a special key we provide. It can be done by either the patient or parent. The Hyrax opens 1/4 millimeter per turn and it takes six weeks of daily turning to get the 7-8 millimeters of width desired. As the jaw gets wider, the upper front teeth space more but this goes back after widening or can be closed with a few brackets. After the six-week activation period, the Hyrax is stabilized with plastic and left for two to three months. Then it is removed and a removable plastic retainer is made to hold the new width.
The Resting Phase
CONGRATULATIONS! You have successfully completed Phase I of your orthodontic treatment and are halfway to an ideal bite and smile. You probably have noticed many positive changes in this first phase but the entire process cannot be finished until ALL of your permanent teeth including second (12-year) molars are in the best position possible.
While waiting for the rest of your growth and your adult teeth to come in, you will need to wear a fixed or removable retainer to hold the changes that have been made. This period of retention is called the RESTING PHASE since no active tooth or jaw movement is taking place. The holding appliances will be worn full time for three to six months and then at night only until Phase II is ready to begin. Since no active movement is occurring, you will only need to be seen every three months to check the holding device and tooth exchange. The retainers and all visits during the resting phase were covered by the Phase I fee so there is no additional expense until Phase II starts. The RESTING PHASE may last as little as six months or as long as four years.
When all the adult teeth are in or on their way, the orthodontist will consult with the family on the scope of Phase II treatment to achieve the final optimum bite, smile and facial features. New diagnostic records will be taken and the time in braces and the Phase II fee will be discussed. Then the “rest” is over and it’s back to active treatment for a year or more to finish what you started. After doing such a great job in Phase I, the RESTING PHASE and Phase II will be the downhill part of the journey.
The tongue is a powerful muscle, which can cause teeth to space and flare if held in the wrong position. It can also cause an open-bite where only a few of the back teeth contact in full closure and the front ones remain apart with no bite at all. In order to successfully get the spaces closed, upright the teeth, and get full contact, the tongue must be “trained” to rest in a position that will not influence the teeth.
The ideal positions for the tongue are up and back. The tip should rest in the very top of the roof of the mouth and not down low in the bottom jaw or against the front teeth. “Training” people with tongue-caused bite problems to properly position their tongue is difficult. Speech therapy can help but requires much patient compliance and dedication.
The best way for the orthodontist to control the tongue is with Tongue “Spurs” or a tongue “Crib”. The spurs are sharp projectiles (metal wire) which stick down from a removable plastic retainer or a bar in the roof of the mouth that is fixed to cemented molar bands. These metal prongs poke the tongue unless it is held up and behind the spurs. The tongue may be sore for a day or two but quickly learns the new posture to avoid getting poked and soreness beyond a few days is rare. The crib is a metal screen or shield, which is also attached to an expansion appliance or fixed bands to contain or “jail” the tongue. It is fairly easy to tolerate but does not work quite as well as the spurs because there is no “avoidance of pain” stimulus.
The tongue control appliances can also be used to discourage thumb or finger sucking. The appliance is usually left in place for six months to make sure the bad habit is terminated and the new tongue posture is established.
If baby teeth do not come out on time or there is a lack of space, the permanent replacement teeth can become “impacted.” This means that the tooth tips sideways in the jawbone which prevents it from even coming in on its own. Once a tooth is impacted, it either needs to be pulled, left up in the bone, or surgically exposed and brought down into place with orthodontic appliances.
The tooth most often impacted from age 12 – 18 is the cuspid tooth. Since this tooth is in the front of the mouth and extremely important in appearance and chewing, it is rarely left impacted or removed. The orthodontist has the baby cuspid removed, makes space for the impacted permanent cuspid and sends the patient to the surgeon to have the tooth uncovered or “exposed”.
The upper cuspid is usually the tooth needing exposure. If the cuspid is on the outside toward the lip, the surgeon just makes an incision in the gum and raises it up like a window-shade to reveal the tooth. The orthodontist can then put a bracket on it and bring it down to the level of the other teeth. If the upper cuspid is on the inside toward the roof of the mouth, the surgeon has two options. If the tip of the cuspid lies just above the palatal tissue, the tooth can be uncovered and a bracket placed on it. If it is high or deep in the tissue, the surgeon will uncover it, place an attachment and then replace the tissue back over the tooth. A small chain or wire will be left coming down from the covered tooth for the orthodontist to pull on to move the tooth down through the gum.
Moving a tooth into position from the palate is a long and time consuming process. It can be done at any age but works better at earlier ages. At least five to ten percent of cuspids that are impacted will not move even after being exposed. This lack of movement is more common in the palate and in the adult patient. If the tooth does not move down or is “ankylosed”, then it must be extracted and an implant or bridge placed after orthodontics.
Transpalatal Arch (TPA)
The Transpalatal Arch is a wire that goes across (trans) the roof of the mouth (palate). It attaches onto bands or rings that are cemented onto the two upper first molar teeth. The TPA can be fixed or soldered to the bands or removable and slide into tubes or sheaths on the inside of the bands. The removable arch can be removed and adjusted by the doctor without having to take off and re-cement the bands.
The TPA can be used passively to anchor the molars where they are. The heavy wire locking them together prevents forward or tipping movement of these teeth. Also tongue pressure on the wire will keep them from extruding or moving downward. The orthodontist can make the TPA active as well. By making various bends in the wire before inserting the appliance, the molars can be widened, moved backward, or rotated. The crown of the molar can also be moved out toward the cheek or in toward the tongue (torque). The loop at the top of the TPA can even be used to teach proper tongue position in patients with a poor tongue posture.
The removable TPA is held in the bands with small plastic rubberbands. It is adjusted when necessary and is usually left in for at least one year. It is removed when spaces are closed and finishing wires are in place.
The Transverse or “Schwarz” appliance is a removable appliance designed to widen the upper jaw. It can also be used in the lower jaw to upright teeth and create a little more width. The upper widening is done to correct a narrow jaw which causes a bad bite (cross-bite) as well as to gain room for crowded teeth and improve the smile.
The Transverse is a plastic piece, which fits over the back teeth and the roof of the mouth. The only wires in the appliance are used to clamp the teeth and hold it in place. The plastic covers the back teeth to free up the bite so the teeth can move “transversely” or get wider without restriction. There are one or two metal screws embedded in the plastic near the roof of the mouth that create the force to move both teeth and bone to a wider position.
The Transverse is worn all the time, including meals for about 6-12 months. It is removed for brushing and active sports and the patient turns the screws two times each week. When the desired width has been reached, the appliance can be worn at night for a retainer until ready for braces or more comprehensive treatment.
Many times, braces are placed when back baby teeth are still present or when the front teeth need to be moved before the side teeth. The Utility Arch attaches to braces on the four front teeth and then is stepped away from the teeth to lie near the gum until it is stepped back up to fit in the molar band. The step bend in the rectangular or square steel wire keeps it away from the chewing forces and gives it more flexibility to move the teeth it attaches to.
The wire is called a “Utility” arch because it can perform so many different movements. It is usually used to move front teeth up or down to open or close the bite. It can also move front teeth forward or backward and tip back teeth as well. Often, the Utility is used to anchor the front and back teeth where they are while the side permanent teeth erupt. They also can support rubber bands to pull the front and back teeth in different directions.
These arches are most often placed in the lower but work well in both jaws. They are used early in treatment and after their work is done in 6 – 12 months, side braces are added to complete the full appliance and finish the straightening and treatment.
The Wilson Appliance
The Wilson appliance is a system of braces, wires and rubber bands used to push the upper molars back into a better bite with the lower molars. It also creates more space in the upper jaw for eruption of crowded or blocked out teeth.
Two orthodontists named Wilson (father and son) designed the appliance. It consists of brackets on the four upper front teeth that hold the upper wire firmly so that springs at the end of the wire can push on molar bands to move the molars back. The force of the spring is aided by rubber bands which are worn from the upper wire to lower molar bands which are anchored by a lower inside wire or lower holding arch. Lower braces can be used with this system but are not always needed.
At each appointment, the spring is compressed by a simple adjustment of a loop. Because the spring force is so great and could push front teeth forward, three rubber bands are worn for the first five days on each side. Then two are worn for the next five and finally one on each side is worn for six weeks or until the next adjustment. It usually takes six months to move the molars back far enough – if the rubber bands are worn all the time.