Bloomfield Hills, MI (Michigan) Orthodontist Roy D. McAnnally, MS, PHD, DMD

Shortcuts: Choices - Fixed or Removable Appliances | Anatomy of an Appliance
Appliance Guidelines | Space Management - General Considerations
Space Maintenance Appliances | Habit Appliances | Regaining Lost Space | Closing Space
Adults and Cosmetic Dentistry | Arch Development | Suture Expanding Appliances
Sagittal (Front to Back) Development with Removable Appliances
Functional Orthodontics | Finishing and Maintaining | Minor Anterior Alignment/Realignments
Retention

Choices - Fixed or Removable Appliances

Many tooth movements can be treated with either fixed or removable appliances. In cases where either appliance will accomplish the same results, the following check list is provided to help decide which approach may be best for you.

Fixed: (1) Bodily movements of teeth are needed; (2) Anterior bands, brackets, and wires are acceptable to you; (3) Teeth to be banded have fully exposed clinical crowns; (4) Oral hygiene is excellent minimizing the possibility of decay; and (5) Cooperative removable appliance wear is doubtful.

Removable: (1) Bodily movements of the teeth are not required as removable appliances mainly provide a tipping action; (2) Esthetics is important. You need an inconspicuous appliance; (3) Teeth are present and sufficiently erupted for anchorage of the appliance; (4) You require an appliance that does not interfere with proper oral hygiene; (5) You are cooperative and responsible, i.e. you will wear an appliance as prescribed and will guard against loss or breakage; and (6) There are economic considerations. Removable appliances require less chair time.

Anatomy of an Appliance

Adams Clasp

The Adams clasp can be used on both molars and bicuspids. It is retained by engaging the mesial and distal undercuts of these teeth. Therefore, it is essential that the mesial and distal undercuts are fully exposed. The clasp also must be placed where it will not create a bite interference. A bite interference can cause a functional shift of the lower jaw.

“C” Clasps are most commonly used where other clasps would create significant bite interferences. Eliminating bite interferences is important for two reasons. In children, bite interferences may cause an abnormal jaw shift. In adults, biting on clasp interferences is uncomfortable and may lead to poor appliance wear. To make this clasp more retentive, it can be used in conjunction with a bonded composite buccal attachment. An undercut on the attachment allows the clasp to snap into position.

Ball Clasp

Ball clasps are typically used in conjunction with other clasps to provide auxiliary retention. They are usually placed tightly into the interproximal embrasure between two back teeth. This is usually sufficient to gain the retention needed. Ball clasps can also be adjusted mesially or distally to engage the undercut of either tooth. This is particularly useful during when primary teeth are lost or exfoliated in the late mixed dentition. When one primary molar is lost, a simple adjustment will allow you to regain the retention needed to continue treatment.

Rapid Palatal Expansion Screws

Rapid Palatal Expansion (RPE) screws were designed for rapid expansion and separation of the midpalatal suture. To be effective, they must be used in a fixed and retentive banded or bonded appliance. These screws are available in a variety of sizes and in configurations that offer a wide range of lateral expansion. Although designed for rapid palatal expansion, these screws are frequently used to apply gentle forces to induce slow development.

Sagittal Screw

This expansion screw has a “U” shaped guide pin. It is used primarily to gain sagittal or anterior/posterior arch length. It is available in a variety of sizes.

Retraction Screw

This screw is placed between two sections of acrylic in the “open” position. When activated, it draws the two sections of acrylic together to close or reduce interproximal spaces. It can be used for reducing modest flaring of front teeth.

Anterior Bite Planes – Flat and Inclined

An anterior bite plane can be flat and neutral or inclined and active. An anterior bite plane is created by thickening the lingual acrylic behind the upper front teeth. An anterior bite plane can (1) open the vertical dimension by allowing the posterior teeth to erupt; (2) provide the occlusal clearance needed to correct a lingually-locked crossbite; (3) reduce occlusal forces on the front teeth in severe closed bites; and (4) provide occlusal clearance for the proper placement of brackets on the lower front teeth.

An acrylic anterior inclined bite plane is used to actively guide then maintain the mandible in a forward postural position. It is used when a minor skeletal correction is needed or as part of a support phase during Class II treatment.

Posterior Occlusal Bite Planes

Posterior bite planes are used to minimize vertical growth of posterior teeth, actively intrude posterior teeth, and aid crossbite correction. While jumping an anterior crossbite, posterior coverage will prevent the eruption of the posterior segments and development of an anterior open bite. During the correction of a posterior crossbite, occlusal coverage will allow one arch to be developed without exerting a reciprocal affect and dragging the opposing arch along with it. With modifications an anchorage unit can be set up to aid unilateral crossbite correction.

Lingual Arches

A lingual arch is a stainless steel wire that fits closely behind the lower front teeth. It is held in place by bands on the molars, bicuspids, or cuspids. Lingual arch wires can be attached to the bands in several ways. For simple space maintaining devices, the arch wire can be soldered directly to the bands. If the arch wire has adjustment loops, or soldered lingual lap springs, the arch wire can be attached to the molar bands with either horizontal or vertical lingual sheaths. This allows easy wire removal and replacement when adjustments are necessary.

Arch Wire Stops

Mesial or distal stops can be added to an archwire to prevent undesirable drift of teeth into an adjacent space that must be held for another tooth or teeth.

Brackets

Brackets are small mechanical attachment devices. Traditional designs include a rectangular slot, tie wings, and sometimes a hook to hold an arch wire, elastics, or other orthodontic auxiliaries. Brackets are welded to bands or directly bonded to teeth. The brace or archwire is then attached to the brackets. Brackets are available in stainless steel, ceramic, or plastic.

Appliance Guidelines

Imaginative Designs

Removable appliances come in a wide variety of designs. Each appliance is custom made. The various wires and mechanical screws can be configured in ways seemingly limited only by the imagination of the designer. However, several important guidelines must be observed to maintain optimum appliance effectiveness.

Maintain Anchorage

Although we can build a large number of adjustments into a removable appliance, adjustments should be implemented in a logical sequence. Activate too many simultaneous adjustments and the appliance will not stay in place.

Use Light, Steady Force

Remember, when moving teeth, the harder you push, the slower they move. Light, continuous force will give you the optimum tooth movement.

Adjust Wires with Care

Wire breakage is one of the most common problems with removable appliances. When making appliance adjustments, care must be taken not to stress or nick finger springs, arch wires, or clasps.

Space Management - General Considerations

Most orthodontic problems begin between the ages of 7 and 11 during the early transition from the primary to the permanent dentition. During this period the masticatory apparatus, including the dental arches and occlusion, are undergoing rapid development. Unfortunately, many patients do not see the orthodontic specialist early and miss the opportunity to take advantage of the benefits of early treatment.

The general dentist cares for the dental needs of the vast majority of growing children. Youngsters must be screened early by a practitioner that recognizes the early onset of dentofacial orthopedic and orthodontic problems, understands the benefits of preventive and interceptive care, and is either able to actively intervene or provide a timely referral to a qualified specialist. The patient relies on the general dentist for dental care and direction, and for referral to an orthodontic specialist when needed.

Leeway Space

The sum of the mesio-distal widths of the primary cuspid and first and second primary molars is generally larger that that of the permanent cuspid and premolars by about 1.0 mm per quadrant in the maxilla and about 2.0 mm per quadrant in the mandible. This difference is called the leeway space. This leeway or extra space is a fundamental factor that allows for a normal exchange of primary for permanent teeth. Once the second primary molar is lost, the leeway space is lost very quickly, usually within a month. The leeway space, therefore, offers a narrow window of opportunity that must be seized for advantage.

Space Management in the Child

A normal eruption sequence of the permanent teeth must take place in both the maxilla and the mandible. In the mandible, the most frequent eruption sequence is the cuspid, first bicuspid, and second bicuspid. In the maxilla, the sequence is the first bicuspid, second bicuspid and cuspid, or first bicuspid, cuspid and second bicuspid.

Preservation of the leeway space affords an opportunity for a net space gain that can be used to align crowded front teeth. This is how it works! When the second primary molar is lost, the eruptive force of the permanent second molar pushes the permanent first molar forward into the leeway space. The leeway space is lost over a period of about 30 days as the permanent molars move forward. The back teeth are now closer to the front. There is less space available to straighten crowded front teeth. In fact, the arch circumference of the permanent dentition measured from right first molar to left first molar becomes shorter than that of the primary dental arch. Prevention of leeway space loss is a primary means to gain space in crowded developing dentitions. For this reason, we like to brace the teeth just BEFORE the second primary molars are lost. Timing is critical.

Unfortunately, a smooth transition through these stages is often disrupted by the premature loss of teeth. Tooth decay, trauma from a fall, or some other accidental injury are just some of the common reasons teeth are lost early. When this occurs, early space management is the key to preventing a serious malocclusion in the permanent dentition. In the posterior quadrants, the early loss of primary teeth often results in a reduction of arch length. This change can directly affect the normal eruption of the adult teeth. If space loss has not already occurred, rapid intervention with a space maintaining appliance is of utmost importance. Otherwise, more difficult space regaining procedures must be undertaken or teeth may need to be extracted. In the anterior region space maintenance is important to maintain normal speech, function, and esthetics.

Adult Space Management

Proper space management is important for adults in a variety of situations. An interim space maintenance appliance is often needed during restorative dental procedures. Temporary space maintainers may be needed in patients who, because of an accident, rampant caries, or hereditary partial anodontia, are missing either anterior or posterior teeth. Space maintenance may prevent tooth drift and aid bite correction. Temporary replacement teeth can be incorporated in a space maintainer to replace visible missing teeth until permanent restorations can be fabricated. A space maintainer may stabilize teeth and promote healing after extractions or a traumatic injury. Space maintainers can be designed to maintain function while accomplishing minor tooth movement.

Space Maintenance Appliances

Lingual Arch

This simple retainer prevents both mesial and lingual tipping of the molars while maintaining the arch length.

The Nance

The Nance appliance is designed to prevent arch length loss by maintaining the position of the maxillary molars. An acrylic pad is placed against the palate behind the upper front teeth to prevent the molars from drifting forward. The Nance can be used during full banding and bracketing to provide anchorage. This appliance must be monitored carefully since inflammation of the palate may occur under the acrylic pad.

Essix Retainer

The Essix retainer is a popular and esthetic retainer. It is fabricated by thermoforming a thin sheet of clear Essix C+ acrylic material over the entire arch. This material is tough, stain and abrasive resistant, and has light reflecting properties that approach natural teeth in appearance.

Habit Appliances

A variety of habit appliances are available to correct abnormal swallowing patterns, clenching, grinding of teeth, and extended digit-sucking habits (see Closing Spaces).

Regaining Lost Space

Abnormal Eruption Sequences

Children

When dental development occurs normally at every stage and these stages occur in the proper sequence, there is a good chance a normal healthy permanent dentition and occlusion will be established. Unfortunately, many factors can adversely affect the eruption sequence and normal occlusal development. Some of the more common problems are described below.

Early Extraction or Loss of the Second Primary Molar – Because of the high prevalence of caries found in second primary molars, it is not unusual to lose this tooth prematurely. Normally the eruption of the first permanent molar is guided by the distal surface of the second primary molar. When premature loss of the second primary molar occurs and the primary molar space is not maintained, the first molar moves forward before the second bicuspid can erupt.

Early Loss of a Primary Cuspid – Normally the location and arrangement of the permanent incisors are guided by the mesial surface of the primary canine. When the primary canine is prematurely lost, arch length can be reduced by both mesial drift of the posterior teeth and distal drifting of the incisors. The midline can also shift right or left and cause the development of arch asymmetry.

An Abnormal Eruption Sequence – Normally the greater mesio-distal width of the primary molars provides adequate space for the easy eruption of the bicuspids and cuspids.

(1) If the arch length shortens due to an unfavorable eruption sequence, there may not be enough space for the erupting cuspids and the cuspids will either remain impacted or erupt into abnormal positions. Commonly, the crowded cuspid is forced to erupt labially with a decided mesial inclination. Less commonly, the crowded cuspid may erupt into the palate. If the cuspid remains impacted, surgical exposure and orthodontic traction may need to be applied.

(2) If the adult second molar erupts prior to the second bicuspid, the second molars exert a strong mesial driving force that will move the first molar forward over the unerupted second bicuspid. The first molar then blocks the normal eruption of the second bicuspid.

Adults

Once all adult teeth have erupted, regaining lost space becomes much more difficult. You are reduced to two fundamental choices. The requirement for space can be reduced by extraction or slenderization of teeth or the space available for the teeth can be increased by arch expansion. The first molar that has drifted forward due to premature loss of a primary second molar is much harder to move back once the second molar has erupted. Then, to regain the space for an impacted or blocked out bicuspid, you will have to move both first and second molars posteriorly. This is a very difficult and challenging movement.

In an adult, our treatment goal, with a few exceptions, is to create room for normal alignment of all the teeth. Exceptions include very crowded or protrusive dentitions where judicious expansion will produce a better result.

Creation of room for the teeth is usually accomplished through a combination of techniques including molar distalization, correction of rotated molars, lateral arch development, proclination of anterior teeth, and air rotor slenderization. Basic appliance designs used are presented below.

TB SAG-2000™

The TB SAG-2000™ is a patented appliance design of Dr. Michael Williams, the inventor of the new Series 2000™ appliances. This is a tooth borne sagittal design for Class II Division 2 correction. This appliance will distalize maxillary molars and simultaneously put pressure on central incisors for forward movement, excellent for Class III skeletal cases.

MAX-2000™

The MAX-2000™ is a patented appliance design of Dr. Michael Williams. It is a spring loaded palatal expander. The MAX-2000™ utilizes a continuous, low force, nickel titanium open coil spring rod-in-tube mechanism to gain upper arch width.

DMAX-2000™

The DMAX-2000™ is a patented appliance design of Dr. Michael Williams. It is a distalizing maxillary expander. It utilizes either a midpalatal nickel titanium open boil sprint rod-in-tube mechanism or a standard jackscrew for transverse expansion. Sagittal rod-in-tube mechanisms on the lingual of upper teeth are simultaneously used to distalize the upper molars.

The Labial Lip Bumper – A Muscle Anchorage Appliance

This appliance utilizes a labial lip bumper that inserts through buccal tubes on the molar bands. This appliance alters the equilibrium of forces acting upon the incisors and molars. Lip pressure places a distal force on molars that moves them posteriorly. The shielding affect of the lip bumper removes the force of the lip against the incisors. The now unopposed forces of the tongue move the incisors forward. Thus space is gained by a combination of molar distalization and incisor proclination. The position of the lip bumper is adjusted by opening or closing the loops that are soldered to the labial wire.

Closing Space

Children and Adults

Tongue thrusting, tooth size discrepancies, periodontal disease, and posterior bite collapse are just a few of the factors that can cause excessive space. We must identify the cause of the problem then select an appliance that will close the space and keep it closed.

The most common result of a tongue thrust is the creation of an anterior open bite with flared front teeth. Although the etiology of a tongue thrust is often debated, the need to address the problem early is not. If a thrusting pattern remains past the age of 4 or 5, there is increasing likelihood that the pattern will remain. An appliance that is used to close excess space caused by a tongue thrust should also address cause of the thrusting problem. If this is not done, tongue forces will cause the problem to reoccur.

Nocturnal grinding or bruxism can cause excessive, even pathologic wear to the teeth, flaring of front teeth, morning tension headaches, and temporomandibular joint or myofascial paid disorders. Nocturnal grinding or bruxism may be the result of centric bite interferences and the absence of normal cuspal guidance during excursive movements of the jaw. Front teeth tend to wear excessively in deep bites. Posterior teeth tend to wear excessively in open bites. Flared incisors can be retracted. It may be necessary to first correct the posterior vertical dimension. Retroclined incisors may need to be proclined and the maxillary arch expanded to free a posteriorly-locked mandible. These movements are usually accomplished through a combination of dentofacial orthopedics, orthodontics, and, when necessary, restorative work.

Periodontal disease can also cause anterior flaring and spacing. After initial periodontal therapy, an anterior retraction appliance can be used to correct the flaring and close excessive anterior space. If the periodontal support for the front teeth is weak, the teeth may need to be splinted together to increase their stability after retraction and space closure.

Spaces caused by tooth size discrepancies are managed either by prosthetically widening teeth that are too narrow or slenderizing the opposing normal teeth. If teeth are too wide, slenderization is the best choice. There are benefits and disadvantages to all approaches. Widening narrow teeth may improve esthetics but require prosthetic bonding, veneers or crowns, shade management, and ongoing maintenance and repair. Slenderization eliminates prosthetic involvement and generally doesn’t increase decay or sensitivity of the teeth but abnormal tooth widths may compromise the esthetic outcome.
The outcomes, regardless of choice, are inevitable compromises.

The sum of the widths of normal upper teeth bears a constant mathematical ratio to the sum of the widths of normal lower teeth. This constant is known as the Bolton ratio. A simple analogy may help explain the significance of the Bolton ratio. If upper teeth are the widths of round tooth picks and lower teeth are the widths of popsicle blades the teeth will not fit together well or look their best. Teeth must be normally proportioned relative to each other to bite together normally without spaces or crowding.

The key to successful management of tooth size discrepancies is to weigh the benefits and disadvantages of alternative treatments and select the best plan for the patient. Caution must be exercised when using any form of retraction mechanics to close excess space. Over retraction of front teeth and impingement upon the intraoral tongue space must be avoided.

MSC-2000™ – Mandibular Space Closer

The MSC-2000™ is a patented appliance design of Dr. Michael Williams. It is excellent for bodily advancing molars where second bicuspids have been removed. The unique rod-in-tube and nickel titanium coil spring produces light, continuous force for space closure without crown tipping. The self-adjusting springs require no adjustments once the appliance is cemented in place.

Adults and Cosmetic Dentistry

Today, more than ever, cosmetic dentistry is becoming an active claim, if not integral part, of most active general dental practices. A cosmetic dentist befitting of the claim should recognize the limitations of prosthetics or general dentistry alone and acknowledge when orthodontic therapy is needed to create a superior esthetic result. Orthodontics in conjunction with prosthetic care can be used in many ways to enhance a patient’s appearance. A small amount of tooth movement may allow your dentist to use a less invasive procedure and minimize the reduction or loss of natural tooth structure. Orthodontic procedures may allow you to avoid unnecessary veneers, or allow the placement of a veneer instead of a crown for a better esthetic result.

Arch Development

Arch development is a collective term that describes a variety of appliances used to gain arch width, depth, and perimeter. These appliances range from the simple Schwarz appliance to the high-speed rapid palatal expanders. They may utilize orthodontic movement, orthopedic movement, or a combination of both, and may be either fixed or removable.

With proper design, expansion appliances can be used to move teeth either unilaterally or bilaterally, transversely or sagitally, and even vertically. They can be used to relieve anterior and posterior crowding, expand collapsed dental arches, and advance retroclined front teeth.

There are many indications for arch development. In children, the overwhelming majority of lateral expansion appliances are used to treat crossbites, medial collapse of both arches, crowded front teeth, excessive overjet, or a combination of these conditions.

In adults, arch development appliances are mainly used to correct crowding in the anterior region, upright lingually tipped posterior segments to correct their positions over the basal bone, distalize molars that have drifted forward, and advance retroclined front teeth. In conjunction with braces or Invisalign, narrow arch forms can be corrected, teeth aligned, and the occlusal plane leveled.

Arch development is a prerequisite for the correction of many skeletal imbalances. An underdeveloped maxilla and narrow maxillary dental arch are main causes of a skeletal Class II relationship. It is rare to find a Class II malocclusion where the teeth are well aligned, the arches are ideally shaped, and only a jaw-to-jaw alignment with a functional appliance is needed.

Even though the direction and the amount of force applied are controlled by these appliances, proper case selection is still essential. This is particularly true in a growing child. For example, in cases with a shallow overbite and a clockwise mandibular growth pattern, arch expansion may exacerbate the problems, cause a further increase in the lower facial height, and create a significant anterior open bite. Patients with long lower anterior facial heights and anterior open bite tendencies need to be monitored carefully. If the bite begins to open further, treatment may need to be altered or abandoned. Whether you use a removable or fixed approach, a successful and stable result will depend on the patient’s morphogenic pattern, muscle function, and growth and development.

Upper Schwarz Appliance

A narrow maxilla is one of the most common orthopedic problems seen in a developing child. Left untreated, a narrow maxilla can lead to severe crowding and both anterior and posterior crossbites. Narrow maxillas also inhibit the normal forward development of the mandible. The correlation between narrow maxillas and skeletal Class II malocclusions is very high.

The removable Schwarz appliance is used to widen a narrow arch. A transverse expansion screw near the center of the appliance is turned one-quarter turn once or twice a week. This slow expansion applies a lateral acrylic force against the palatal tissue and the teeth. This force tends to tip the side teeth toward the cheek. Slow expansion largely avoids this adverse tipping tendency, and normal tooth inclinations and occlusal function are maintained. These appliances can be made in different colors, designs, and with decals to motivate patients.

Upper Adult Expansion

Although arch development is more common when treating developing children, arch expansion appliances can successfully treat adults. They are particularly effective when the back teeth are tipped lingually, the dental arch is narrow, and the front teeth are crowded.

Schwarz with Posterior Bite Plane – The Schwarz Plate

Bilateral posterior crossbites are usually the result of an underdeveloped maxilla. Some of the reasons the maxilla fails to develop normally include abnormal tongue posture, abnormal swallowing patterns, chronic colds and allergies, nasal polyps, a deviated nasal septum, enlarged turbinates, or other nasal airway obstructions that impair nasal air flow and prevent normal nose breathing.

When a patient presents with a bilateral crossbite, a Schwarz appliance with posterior occlusal coverage can be used. The occlusal coverage opens the vertical dimension and is typically finished flat to allow for the quick resolution of the crossbite without a reciprocal affect on the opposing dentition. By covering the occlusal surface with acrylic, lateral tipping of the dentition is kept to a minimum.

Turning the expansion screw one-quarter turn a week will exert a slow constant pressure on the teeth and bone. Arch development will move the posterior segments buccally to correct the crossbite. In the process, a high palatal vault will drop. The increase in width of the palate and drop of the palatal vault improve nasal airway patency. Once the crossbite is corrected, the occlusal coverage can be removed to allow normal occlusal function.

It may be beneficial to retain the occlusal coverage. Occlusal coverage helps level the Curve of Spee and Curve of Wilson. Occlusal coverage frees the mandible for autonomous advancement in Class II skeletal patterns. Occlusal coverage slows vertical dentoalveolar growth and intrudes posterior teeth in patients with excessive lower anterior facial height. These movements aid autorotation of the mandible upward and forward. Upward and forward mandibular movement reduces overjet and aids correction of Class II dental patterns.

Maxillary occlusal coverage also minimizes the development of maxillary palatal plunger cusps. Plunger cusps can produce occlusal interferences in lateral excursive movements and tend to open the bite. Plunger cusps are the result of excessive buccal crown tip.

Recognition and treatment of a posterior crossbite early in a child’s development is essential. As a general rule of thumb, “All crossbites should be corrected as soon as they are detected.” When left untreated, crossbites can lead to numerous serious medical complications including Class II skeletal deformity, TMJ dysfunction, and airway obstruction.

Lower Schwarz Appliance – Mixed Dentition

An underdeveloped maxilla is said to be the major cause of a narrow, crowded mandibular dental arch. The constricted maxillary dental arch is thought to pinch the enclosed lower arch. The outcome has been referred to as “bidental arch collapse” in the orthodontic literature. Expansion of both arches is necessary to restore normal arch forms and space for the teeth. A lower Schwarz appliance can upright lingually tipped lower back teeth and aid resolution of lower anterior crowding.

I believe the direct causes of arch collapse are fundamentally attributable to respiratory adaptations and dysfunction of the soft tissue matrix, the cheeks, lips, and tongue.

I often initiate maxillary arch expansion 2 to 4 months before beginning lower expansion therapy. Why? First, the upper arch encloses the lower arch. It makes mechanical sense to jump start the upper expansion. Second, patients find it easier to get used to one appliance before adding a second. We have no objection to wearing upper and lower appliances at the same time. It simply is logical and easier on the patient to “jump start” the upper expansion before adding the lower.

Lower Bowbeer

The lower Bowbeer appliance is a popular modification of the Schwarz design. It is most commonly used when treating adults who have both a narrow arch and lingually tipped back teeth. Since it is designed without clasps, it is often used in conjunction with full arch bracketing in order to expedite the treatment. One must remain aware that arch bracketing and dental alignment can lead to loss of appliance fit.

The design is extremely esthetic and its small size makes it less likely to affect the patient’s speech. For all of these reasons, this appliance is often preferred over other designs. This modification was developed by Dr. Grant Bowbeer, an Ann Arbor orthodontist.

MSX-2000™

The MSX-2000™ is a patented appliance designed by Dr. Michael Williams. It is a totally spring activated mandibular appliance requiring only recall observation visits. The MSX-2000™ employs sagittal nickel titanium open coil rod-in-tube mechanisms bilaterally. A midline jackscrew can be substituted for the transverse nickel titanium open coil rod-in-tube mechanism.

Suture Expanding Appliances

When a crossbite is due to a deficiency of the maxillary apical base, the use of a rapid suture expansion appliance can be very effective. Rapid palatal expansion is also commonly used to increase arch perimeter, level the curve of Wilson, broaden the smile, and increase airway patency.

Unlike slow expansion at a rate of 1 turn per week, rapid expansion is obtained by turning the expansion screw 1 to 2 turns per day. This rapid expansion rate generates an orthopedic force adequate to separate the midpalatal suture.

Indeed, research shows that the whole circummaxillary sutural system is affected. The actual expansion correction will generally occur within a two to three week period. The appliance is then worn for at least another three to five months to allow time for osseous fill at the midpalatal suture. The biggest errors practitioners make with this appliance are too short a period of post expansion stabilization and failure to obtain a commensurate expansion of the opposing lower arch. If the opposing lower arch is not managed correctly, the reciprocal influence of the narrow lower arch will force a relapse of the recently expanded upper arch.

The best time to use this technique to accomplish orthopedic change is during the mixed dentition and early permanent dentition. After that time, fewer skeletal and more dental adaptations will be observed.

Haas Suture Expanding Appliance

In a patient with a severe maxillary constriction in the early permanent dentition or with moderate maxillary constriction in late adolescence, the Haas appliance is often the appliance of choice.

This suture expanding appliance utilizes acrylic to support the transverse expansion screw and add extra stability to the appliance. The acrylic closely contacts the palatal mucosa. Haas believed that more bodily movement and less tipping occurred with the presence of the palatal coverage. I concur. The palatal coverage delivers forces against the soft and hard palatal tissues and the alveolar bone that supports the roots of teeth, as well as directly to the teeth. This provides greater alveolar and palatal anchorage and minimizes the dental tipping that occurs when teeth alone are used for anchorage.

Hyrax Expander

The rapid palate expansion Hyrax design can be used successfully in patients with mild to moderate transverse constriction in the late mixed or early permanent dentitions. Evidence suggests that the midpalatal sutures may be patent or at least separable until 22 to 24 years of age. This Hyrax appliance eliminates the palatal acrylic and uses an all-stainless metal framework. While much easier than the Haas to keep clean, the Hyrax produces greater dentoalveolar bending and adaptation and less sutural skeletal expansion. The Hyrax appliance should be activated rapidly to minimize orthodontic tooth movement and obtain the desired midpalatal orthopedic expansion.

Direct Bonded Suture Expansion

This design uses composite direct bonded occlusal pads for retention instead of bands on the 1st bicuspids and 6-year molars. The occlusal pads unlock the bite and facilitate crossbite correction. The occlusal pads cover the cusp tips. Cusp tip coverage minimizes buccal crown tipping. The occlusal pads and rigid framework result in movement that is mainly orthopedic in nature.

This is an excellent design, especially for patients in the early mixed dentition or early adult dentition. This design is not recommended for patients in the late mixed dentition as loose or exfoliating teeth will not provide suitable support for the direct bonded occlusal pads, and the anchorage of the appliance will be compromised. In the early adult dentition, teeth in the midarch must be available to support the direct bonded occlusal pads.

In my opinion, the hygiene under and proximal to the direct bonded pads often results in excessive inflammation. I am not a great fan of this appliance although it is commonly used elsewhere.

Sagittal (Front to Back) Development with Removable Appliances

Class II Division 2 Sagittal Appliance

The fundamental characteristics of the Class II Division 2 malocclusion are a collapsed maxillary arch and a posteriorly-locked mandible. The premaxilla and maxillary central incisors are retroclined, the maxillary lateral incisors are labially tipped and overlap the adjacent central incisors, the maxilla is constricted, and the mandible is posteriorly displaced. The posteriorly displaced mandible is locked in a retrognathic position by the collapsed maxilla and anterior deep bite.

The primary objectives of a minimum anchorage sagittal appliance are premaxilla development and advancement of palatally-inclined maxillary central incisors. The primary objective of a maximum anchorage sagittal appliance is distalization of the posterior segments.

A minimum or maximum anchorage 3-way sagittal appliance can add maxillary arch width to the sagittal objectives described above. Expansion can be accomplished by the activation of expansion screws or the use of active coil springs.

Premaxillary Development Sagittal

This minimum anchorage sagittal appliance is designed to move the premaxillary segment labially to regain lost cuspid space and correct an anterior crossbite.

Upper Sagittal to Distalize Molars

The Upper Sagittal to Distalize Molars is designed primarily to treat skeletal Class I dental Class 2 cases and skeletal Class II dental Class 2 cases. Adequate anterior and midarch anchorage is the key to successfully moving molars distally.

Upper Sagittal to Distalize Posterior Segments

When primary molars are lost prematurely, first bicuspids often erupt too far forward in the arch and preempt the space intended for the cuspids. When this occurs, first and second bicuspids and the first molars need to be moved distally to regain the cuspid space. This distalization of the posterior segments is difficult after the permanent second molars erupt. Early treatment avoids his difficulty.

Second Molar Exchange

Second molar exchange may be indicated. When third molars, the wisdom teeth, are well positioned and expected to have favorable root development, the second molars can be extracted. This will allow the third molars to erupt into the second molar positions. With the second molars removed, the arch length is regained predominantly by distalization of the first molar and bicuspids. This course of treatment results in a full complement of teeth, albeit 1st and 3rd molars rather than 1st and 2nd molars, and eliminates the probable later difficult extraction of impacted wisdom teeth. The general rule of thumb is, “Extract the 2nd molars in the lower arch before the age of 15 and extract the 2nd molars in the upper arch before the age of 20 and the 3rd molars will predictably erupt, sometimes 3 to 5 years earlier and with better root formation.” If the 3rd molars need tidying up when they erupt, so be it. This, in my opinion, is a reasonable risk to assume if it helps maintain a 28 tooth occlusion and an attractive profile with normal facial convexity.

With the second molars in place, movement of both the front teeth and back teeth will occur. Care must be excercised to avoid excessive dental proclination and too much facial convexity.

Three Screw Sagittal

It is not unusual to see cuspids blocked out of the arch. To properly select an appliance to treat blocked out cuspids, the underlying cause should be addressed. The primary molars are often lost early. The primary molars normally serve to maintain space for the eruption of the bicuspids and cuspids. When primary molars are lost early, the permanent first molars drift forward into the areas intended for bicuspid eruption. Bicuspids will either become impacted or erupt forward in the space intended for cuspid eruption.

The arch also may be too narrow because of a finger sucking habit or mouth breathing pattern. Habit or nasal-respiratory management may be indicated. To make room for the cuspids, both arch length and width may need to be regained. Arch width is obtained by transverse expansion. Arch length is regained by distalizing the posterior segments. Distalization of posterior teeth simply returns the back teeth to positions where they belong.

As a general rule, the midline screw is activated first. Engaging this screw will give the additional arch width desired and create enough lateral force to set up the anchorage needed to move the posterior segments distally. Once the second molars have erupted, distalization of the posterior segments becomes very difficult. This argues in favor of early treatment.

Three-Way Sagittal

This unique device features independently expanding sections in three housings for transverse as well as sagittal arch development. When an equal amount of sagittal movement is desired, turn the two sagittal sections at the same time. By turning one of the sagittal sections you can obtain unilateral sagittal movement.

Modified Lateral and AP Arnold Appliance

This appliance shares many features with the patented Series 2000 appliances designed by Dr. Michael Williams, a Gulfport, Mississippi orthodontist. The use of compressed open coil nickel titanium (NiTi) springs allows arch development to be accomplished in patients who simply will not wear a removable appliance. The Modified Arnold can produce both lateral and AP development. The introduction of NiTi coil springs add a new dimension to this design by providing lighter, very effective continuous forces over a greater range of motion. The appliances are self-limiting since expansion stops when the compressed coil spring is fully expanded.

Swing Lock Expander

Many patients present with a V-shaped, omega, or bell-shaped upper arch form as a result of an abnormal digit sucking habit or nasal airway obstruction during development. When the arch width is narrow in the anterior but normal in the posterior, an expansion appliance that expands equally in the front and back is not appropriate. The Swing Lock Expander uses an expansion screw in conjunction with a posterior pivot hinge. This appliance, unlike other transverse expansion appliances, expands the anterior without significantly disturbing the posterior arch width and bite relationship.

Functional Orthodontics

The three major components of the stomatognathic system are the teeth, the bone, and the musculature. A balanced stomatognathic system exists when there is normal expression of a person’s hereditary pattern, without the influence of unfavorable internal or external forces.

Abnormal forces cause malocclusion. Most involve more than the positions of the teeth. Often there are underlying orthopedic or skeletal discrepancies and muscular dysfunctions. Attention must be given to correction of both dental and skeletal abnormalities.

Functional appliances control and direct orthopedic and muscular forces to prevent or correct a malocclusion. They are designed to influence the growth and development of the facial skeleton in the vertical, horizontal, and transverse dimensions.

Functional appliances work hand-in-hand with nature. The uniqueness of functional appliances is their mode of force application. They do not act on teeth like the springs, screws, elastics, and arch wires of conventional appliances. Instead, they transmit, eliminate or guide natural forces. Functional appliances control the muscle activity and natural forces of the tongue, lips, cheeks, and tooth eruption. The magnitude and direction of maxillary and mandibular growth is subject to such control.

Although functional appliances often exert an orthodontic affect on the dentoalveolar structures, it is not their primary function. Improperly shaped, short, narrow, or crowded arches should first be prepared using other arch preparation appliances better suited for dentoalveolar correction.

When treating children, functional therapy allows the normal hereditary pattern an opportunity for full expression. Functional therapy must start early to give the hereditary pattern and growth their greatest opportunity for expression. The best time to accomplish Class II corrections is between 7 and 11. At these ages, the patient is usually mature enough to follow the doctor’s instructions, and there is still ample potential for the expression of normal, favorable growth.

Diagnosis is the key to successful functional orthopedic care. An abnormal jaw-to-jaw relationship can be due to multiple factors. A skeletal Class II relationship may be characterized by a maxilla that is too protrusive, a mandible that is too retrusive, or both in varying degrees. We need to know which components of the stomatognathic complex are errant and to what extent. This knowledge is the key to choosing the best appliances and techniques for resolution of complex problems.

Functional therapy can also be used when treating adult patients. Although the sequence of treatment and the types of appliances may be different when treating an adult, the basic concepts remain the same: Always respect the health of the Temporomandibular Joint. Create a harmonious balance between the bones, teeth, and muscles. Treatment direction will totally depend upon the diagnosis of the patient’s existing skeletal, dental and muscular relationship. All three components must be addressed to achieve a stable result.

The Bionator

The Bionator is a myofunctional appliance that repositions the mandible in a forward and, if necessary, centered position. Its main use is to correct a Skeletal Class II pattern with a retruded mandible. The goal is a healthy, fully functional Skeletal Class I pattern. The Bionator can be used to treat a variety of conditions. It can increase vertical dimension and eliminate deep overbites. Another variant can close openbites. It can be used to treat TMJ dysfunction when the mandible is posteriorly-locked. It can widen moderately narrow maxillary and mandibular arches, correct excessive overjet, correct improper upper and lower lip relationships, and eliminate tongue thrusting and sucking habits. Naysayers who contend these appliances don’t work have been dwindling in numbers over the last thirty-five years.

Bionators are intended for the treatment of reasonably uncrowded dental arches that are misaligned sagitally, transversely, and vertically. Although the appliance can successfully treat arches with minor crowding, moderate or major crowding and other dental irregularities are best addressed by other appliance either preferably before but sometimes after Bionator wear.

Although the Twin Block has replaced the Bionator as the mainstay appliance for Class II corrections in many practices, the Bionator retains a significant advantage. The Bionator, unlike the Twin Block, does not depend on posterior teeth for retention and can be worn throughout the mixed dentition. This is important because skeletal corrections are always easier to obtain during periods of exuberant growth in the mixed dentition. Additionally, patients are often most compliant in the mixed dentition. If you wait for teeth to erupt to be used for Twin Block anchorage, you miss the patient’s greatest growth period and age of greatest compliance.

A Bionator can be a great night time retainer. This has contributed to the continued popularity of Bionators in adult therapy. Whether the patient has been treated for TMD or a skeletal dysplasia, the Bionator will hold the mandible forward throughout sleep, retain an orthopedic correction, and prevent the patient from clenching.

Bionator I to Open

The Bionator I is designed to open a closed bite in Class I and Class II malocclusions and to correct Class II skeletal relationships. The lower front teeth are covered with an acrylic incisal bite cap. The bite cap holds the bite open posteriorly, prevents anterior teeth from over erupting, and serves as a bite plane for the opposing maxillary incisors. The posterior lingual acrylic shields are carefully ground-in to permit controlled eruption of the molars and bicuspids until the over closed bite is corrected. Opening an optional midline expansion screw aids posterior eruption by relieving tight interproximal contacts. The expansion screw also allows for a limited amount of arch development if needed.

An extended Balter’s labial bow acts as a buccal shield to keep the cheek musculature away from the buccal surfaces of posterior teeth. Minimizing cheek forces against the posterior teeth encourages arch expansion and vertical eruption.

A common cause of anterior deep bite is the tongue resting between the back teeth. This is prevented by the lingual acrylic shields. Blocking the tongue and cheek from interposition between the back teeth is the key to the bite opening affect of the Bionator I.

Bionator II to Close

The Bionator II is designed to correct Class I and Class II anterior open bite malocclusions. The posterior teeth are covered with acrylic to prevent their eruption. Acrylic is kept away from the incisors to permit lingual and palatal tipping and vertical eruption. Both movements aid open bite closure. An optional midline expansion screw can be used for arch development if needed. Adding a Balter’s type labial bow that extends into the cheek areas will also enhance lateral arch development by relieving the force of cheeks against the teeth. The lower incisors can be capped with acrylic, if needed, to prevent their eruption.

Orthopedic Corrector

The Orthopedic Corrector is similar to a Bionator with the addition of twin sagittal expansion screws. The additional screws allow incremental mandibular advancements. This circumvents the need for the construction of new appliance in severely retruded skeletal Class II or TMJ advancement cases each time the mandible is advanced further. After the third or fourth month of wear, when the patient’s muscles have adjusted to their new postural positions, the sagittal screws can be activated in unison to move the anterior incisal cap and the mandible forward. This can be repeated after another 3 or 4 months of wear.

The Orthopedic Corrector I is used to increase the vertical in deep overbite cases. The Orthopedic Corrector II is used to close open bites.

Bio-Finisher

Functional treatment can be slow because natural forces are not always enough to stimulate a rapid onset of measurable changes. Patients may experience “burnout” due to long treatment times. Dr. Jack Lynn developed the Bio-Finishing appliances to help overcome this problem. These very active appliances allow the doctor to control the time of treatment with much more accuracy and confidence than with many of the other functional appliances.

The nighttime Bio-Finisher is basically a Bionator with the addition of two buccal rakes placed into the body of the appliance at the plane of ideal occlusion. Small hooks are placed on the rake in line with the vertical axis of each of the opposing posterior teeth. One-eight inch elastics are then placed from the hooks to the opposing bracketed teeth in order to extrude the attached teeth at a faster rate than is possible with the standard Bionator. This appliance offers excellent control of the direction and amount of posterior eruption. It is designed to be worn only at night. Frankly, with the vertical elastics hooked up, it’s a little too demanding to wear during the day.

A daytime appliance is used in conjunction with the nighttime Bio-Finisher. The daytime appliance is worn full time during waking hours including while eating. The normal design of this appliance includes lingual ball clasps for retention and an anterior bite plane to encourage passive posterior vertical eruption. Bilateral lingual tongue cribs are used to prevent the tongue from resting laterally between the posterior teeth.

Twin Block Appliance

Approximately 70% of all malocclusions are Skeletal Class II relationships. The majority have a constricted maxilla that is in a normal in sagittal position relative to the cranial base, a retrognathic mandible, a normal or short lower face height, a large overjet and a deep overbite.

Although a wide variety of appliances have been successfully used to correct this type of problem and achieve a proper functional occlusion, most of them share one major disadvantage. The upper and lower components are joined together making it difficult for the patient to speak and function normally. The end result is poor patient compliance. The Twin Block is designed to overcome these objections.

The Twin Block appliance has been described as “the most comfortable and the most esthetic of all the functional appliances.” Unlike the other bulky one-piece functional appliances, the Twin Block has separate unattached upper and lower components. While this design holds the mandible forward like the other functional appliances, the mandible is free to move normally in both anterior and lateral excursions. It can be worn 24 hours a day, even while eating. This allows you to take advantage of all the functional forces applied to the dentition during mastication. This advantage leads to faster results and shorter treatment plans.

Although its main use is to correct Class II Division I and Class II Division 2 cases, the appliance is versatile enough to also treat Class I open bites, Class I closed bites, Class III lateral arch constrictions, and anterior/posterior arch length discrepancies. The Twin block can also be used effectively in TMJ therapy.

Herbst Appliance

The Herbst is a two-piece fixed appliance used in the treatment of skeletal Class II malocclusions. In this design, the mandible is held forward with telescoping sliding tubes attached buccal to the upper six year molars and the lower first bicuspids. The Herbst is often recommended for patients who will not wear removable functional appliances as directed.

Cantilevered Herbst Appliance

This appliance is excellent for correction of skeletal Class II malocclusions, especially if patient compliance is an issue. The effectiveness of this appliance, as with all Herbst designs, is enhanced if the transverse deficiencies are addressed first.

Many of the Herbst appliances in use today include additions to the basic design. Expansion screws can be added to widen the arches. Brackets and arch wires can be worn to simultaneously align the teeth. These and other modifications extend the treatment effects of the Herbst beyond Class II correction. A combination of dental and skeletal changes insures a rapid and predictable Class II correction.

MARA

The MARA or Mandibular Anterior Repositioning Appliance is attached to stainless steel crowns on the first molars. Crowns are preferred over bands to help withstand the tremendous leverage forces generated by the appliance. The MARA was developed to overcome the complaints that patients expressed when wearing a Herbst appliance, particularly the bulk in the lower bicuspid area. In addition to the normal rectangular arch wire tube, the upper first molar has a large .062 square tube, which accepts an adjustable .060 square “elbow” that hangs vertically.

The lower first molar has the normal rectangular tube as well as a .059 round wire “arm” projecting buccally from the mesial. The lower arm will hit the upper elbow and prevent the teeth from occluding unless the lower arm and lower jaw are held forward in front of the elbow. Typically, the lower crowns or bands are stabilized by either a lingual arch or lower braces to prevent the resting pressure of the elbows from rotating the lower molars mesio-lingually. The elbows are held in place with both elastics and ligature wire.

Most skeletal Class II cases have normally positioned maxillas, retrognathic mandibles, and constricted maxillary arches. To help develop the narrow maxillary arch, a Hyrax screw is soldered to the lingual of the crowns. If the maxillary arch is normal in width, a transpalatal arch is used to anchor the molars and help distribute the forces generated by the appliance. Occlusal rests are placed on the first bicuspids. The rests can be bonded with composite for additional retention.

The Frankel appliances are composed of a system of oral shields that lie in the vestibule of the mouth, free of direct contact with the dentoalveolar areas. The action of the appliance, as described by Dr. Ralph Frankel, is to favorably influence arch development by changing the force distribution of the surrounding soft tissues. Lateral development of the arches is encouraged by the buccal shields in two ways. The inward force of the cheeks is blocked by the buccal shields. This allows the tongue to exert an unopposed outward molding effect on the dentition. Continuous stretching of the connective tissue fibers in the vestibular fold by the vestibular extensions of the shields stimulates bone formation.

There are basically four Frankel appliances variations. The FR I is designed to treat Class I and Class II Division 1 malocclusions. The FR II treats the Class II Division 2 malocclusions. The FR III is for the treatment of Class III problems, and the FR IV is used to treat open bites and bimaxillary protrusions.

Because of the importance of growth to the success of the Frankel technique, best results are obtained before the permanent bicuspids and cuspids erupt into position. Young patients usually tolerate the Frankel appliance very well. This allows treatment to be started at a very early and productive age.

Excellent impression technique and accurate bite registrations are crucial to the proper construction of the Frankel appliance. Impressions of the soft tissues are as important as impressions of the teeth. Impressions of the soft tissues must extend deep into the vestibules. The impression technique is challenging.

The Frankel appliance is worn full time except when eating. Inexperienced clinicians commonly recommend wearing the Frankel appliance one or two hours a day for the first two weeks then gradually increasing the wear to fulltime. Efforts to start the treatment slowly to allow the soft tissues time to adjust to the appliance are self defeating. Our considerable experience has established, with rare exception, that gradual start-up protocols are a formula for failure. Once the patient is conditioned to part time appliance wear, the patient will seldom muster the resolve to wear an appliance fulltime.

During treatment, adjustments and repairs usually are necessary. Most repairs are due to distortions introduced into the Frankel appliance when it is outside the safe haven of the mouth. These, of course, are avoidable. Productive adjustments include the adjustment of wires and shields, and the repositioning of the anterior lip pads after desired movements have occurred.

Frankel patients must be carefully selected. Success depends on a positive, cooperative attitude toward appliance wear. The Frankel appliance must be introduced to the patient and managed by the doctor in a manner that insures complete cooperation and compliance.

In the late 1970s and 1980s we had one of the largest Frankel appliance practices in the United States. This is a wonderful functional appliance and few found fault with the outcomes, but its fabrication and wear were attended by many difficulties. It was very difficult to obtain accurate tissue impressions for its fabrication. The appliance inflated the cheeks during wear. Patients often complained that they “looked like chipmunks.” Its complex and somewhat fragile wire and acrylic construction resulted in frequent appliance distortion, impingement on the soft tissues, and noncompliant wear. Disheartened patients frequently dropped out of treatment. Throughout the United States Frankel appliance therapy began to decline. First Bionator variants, and later Herbst, MARA, and other designs replaced the Frankel in the orthodontist’s arsenal.

Face Mask Therapy – Reverse Head Gear

This utility appliance is used in conjunction with a facemask as described by Dr. Henri Petit. Face mask therapy can provide effective treatment for midface insufficiency, mandibular prognathism, maxillary hypoplasia, clefts, and tongue problems.

The appliance consists of occlusal onlays to free the bite and hooks buccal to the cuspids for the attachment of the elastics to the facemask. Protraction forces move the maxillary complex forward en masse.

Finishing and Maintaining

As the end of orthodontic therapy approaches, a little fine tuning is usually needed to settle -in the occlusion or align a tooth that still has a slight residual rotation. The major tooth movements often appear to occur early in treatment when teeth are leveled and aligned. The finishing movements seem small in comparison. As treatment winds down, there is often the perception of diminishing return. This is particularly true in patients who have undergone extensive orthodontic therapy and are simply burned out. Yet the success of the treatment often rests in the fine details. Numerous appliances have been designed that will allow us to fine tune treatment through a combination of minor orthodontic corrections and the use of normal functional forces. Once tooth movement is completed, the final step in most orthodontic procedures is some method of retention until the soft tissue and bony changes have stabilized and are able to support the teeth in their new location.

An effective retainer should meet certain objectives. It should securely retain the teeth in their new positions and prevent their tendency toward relapse. It should permit as much functional activity as possible to allow the teeth to respond in a normal physiological manner. Finally, retainers should be comfortable to maintain and inconspicuous.

The best retention appliance and protocol will depend on patient. Some of the factors that are considered include: (1) The type of orthodontic treatment performed, (2) length of retention expected, (3) age, (4) ability to maintain good hygiene, (5) periodontal condition, and (6) future restorative needs.

A removable upper retainer and a simple bonded lower retainer would clearly be an inappropriate choice for a patient who can’t or will not use a floss threader to maintain the oral hygiene of the lower front teeth. Lower fixed retainers are also ongoing maintenance problems. A bonded lower retainer may detach from one or more teeth. Detachment may go unnoticed until the teeth have shifted. For most patients a removable appliance is a better selection.

Choosing the right appliance after aligning the upper front teeth and placing veneers is another example where the selection of the best method of retention matters. Here, the metal labial used in a traditional Hawley acrylic and wire retainer could cause damage to the facial surface of the veneers. A better selection would be a thermoplastic vacuum-formed retainer. This appliance will retain your orthodontic corrections by night, protect the veneers against abnormal forces, and control the damage to teeth that can occur from bruxing at night.

When final retainers are not worn as prescribed and retention protocols are not followed, recurrent crowding, spacing, rotation of teeth or other undesired movements of teeth may occur. The most common relapse is recurrent lower incisor crowding. When this happens, patients generally prefer the simplest realignment possible. If the relapse is minor, we probably can realign the teeth simply and at low cost. In-house Essix realigners, Dynaflex E-Z Align, and AOA Red-White and Blue and RW II appliances offer alternatives for treating mild recurrent crowding. More extensive relapse usually requires retreatment with appliances, braces, or Invisalign. Extensive and even moderate relapse is avoidable if our post-treatment retention protocols are followed. Minor shifting of teeth as the bite settles-in is a natural occurrence after treatment and should be of no great concern.

Minor Anterior Alignment/Realignments

EZ-Align

EZ-Align is a Dynaflex appliance for the treatment of mildly crowded Class I malocclusions. It is suitable for treating minor relapse following active orthodontic treatment. EZ-Align uses crystal clear invisible retainers to straighten and align the anterior region in the upper and lower arch. There are no wires, no clasps, and no visibility.

Red, White, and Blue and RW II Systems

If all you need is a little cosmetic improvement for a great smile and you would prefer not to have braces, the nearly invisible Red, White, and Blue or RW II no-braces system may be the treatment for you. A series of active aligners are custom-made for you. One, two, or three light-weight aligners are made depending on your alignment. Subtle corrections are incorporated in each appliance to direct your front teeth to desirable positions.

Retention

The “Invisible” Essix Retainer

This is a popular, nearly invisible retainer. It is fabricated from a thin sheet of Essix Type C+ clear acrylic that is vacuum-formed to the occlusal and incisal surfaces of the entire arch. The completed appliance typically extends over the buccal and labial surfaces, and can be finished just short of the gingival margins on the labial and buccal surfaces. On the upper appliance, the palate is horseshoe shaped for patient comfort.

Type C+ Essix material is made of a clear acrylic that is tough, and stain and abrasive resistant. Essix C+ light-reflecting properties give the teeth a normal appearance when the retainer is worn. The material also resists tearing and bruxism. It is thermo labile and should not be subjected to high heat.

Invisible Essix retainers can also be fabricated out of Type A Essix material. Type A is the material we use when auxiliary attachments must be bonded to the retainer. The light-reflecting properties make the teeth appear somewhat more brilliant than C+ material.

E-Z Bond Lingual Retainer (Direct Bonded Lingual Retainer, U/L)

The E-Z Bond Retainer is a multi-strand, dead-soft wire that is carefully contoured and bonded with composite to the lingual of the six front teeth. Overbite and overjet must afford clearance for the maxillary E-Z Bond.