How hygienists can provide support for the movement
by Ann-Marie C. DePalma, CDA, RDH, MEd, FAADH
As defined by Wilkins, orthodontics is the area of dentistry concerned with the diagnosis, supervision, guidance, and treatment of the growing and mature dentofacial structures – including conditions that require movement of the teeth – and the treatment of malrelationships and malformations of the craniofacial complex.
As dental hygienists, we are familiar with Dr. Edward Angle's classifications of occlusal relationships. Dr. Angle is considered the "father of modern orthodontics," who designed a classification system in the late 1890s to early 1900s based on the first molar as the key to occlusion. As a review, normal occlusion is considered when the mesiobuccal cusp of the maxillary first molar occludes with the buccal groove of the mandibular first molar. Deviations from this norm are considered malocclusions.
Class I malocculsion has normal molar relationships present, but other teeth may be crowded, rotated, or have excess spacing. In Class II malocclusion, the maxillary first molar is forward of the normal molar relationship so that the mesiobuccal cusp of the maxillary first molar is mesial to the buccal groove of the mandibular first molar. Class II malocclusions are further divided into Division 1 and Division 2. With Division 1, the maxillary incisors are protruding, while in Division 2 the maxillary central incisors retrude and the lateral incisors protrude. Class III malocclusions present with the mesiobuccal cusp of the maxillary first molar distal to the buccal groove of the mandibular first molar. Additionally, occlusal discrepancies including anterior or posterior open bites, increased overbite and overjet, crossbites, and diastemas may be present.
Hereditary, acquired, or habitual factors are also involved. Teeth that are in malocclusion are hard to clean and maintain and can lead to periodontal disease, caries, or tooth loss. Orthodontic problems can cause abnormal wear patterns, speech and chewing difficulties, and possible temporomandibular joint disturbances. The American Academy of Orthodontics recommends that every child receive an orthodontic evaluation by age seven. Early interventional treatments use the patient's growth and development and can make any corrective treatment faster and easier. Adults can also receive orthodontic treatment, and there are a variety of treatment options available. This article reviews the basics of orthodontic treatment and investigates current alternate modalities.
What causes tooth movement?
Orthodontic tooth movement is the result of pressure applied to the teeth by orthodontic appliances. The pressure is transmitted down the clinical crown to the root and periodontal ligament and alveolar bone. Slow, continuous forces work best, while excessive forces destroy the periodontium and may cause root resorption. Basic orthodontic concepts involve pressure exerted on the tooth in the direction of desired movement, which squeezes the periodontal ligament and results in compression. The bone surface contacting the ligament begins to resorb due to the activation of osteoclasts.
On the opposite side of the movement, the periodontal ligament is stretched and activation of osteoblasts occurs. The osteoblasts create new alveolar bone where the tooth was once located. Once active pressure and movement is stopped, the bone regenerates and fills in the area, allowing the tooth to become secure and the periodontal ligament to reattach normally. Orthodontic appliances are designed to create this movement and can be removable or fixed, placed buccally, lingually or both, and can be metal, ceramic, or plastic. The patient's clinical situation and needs, along with the orthodontist's preferences, determine type(s) of appliances.
Advancements in treatment
Over the past few decades, advancements in technology have contributed to a variety of new materials and techniques in orthodontic care. Many of the new materials make it easier for patients and professionals to maintain healthy gingiva and tooth structure during orthodontic treatment.
NASA has been instrumental in these developments, including the development of heat-activated nickel titanium alloy wires and plastics. At room temperature, NiTi (nickel titanium) wires are very flexible. As they warm to body temperature, they become active and move teeth to the shape of the wire. These wires maintain their shape for extended periods of time.
One new technology system involves the self-ligating bracket. Several companies, including Ormco (Damon System), Dentsply GAC (In-Ovation), 3M Unitek (Smartclips), and Ortho Organizers (Carriere System) use these self-ligating attachments. Self-ligating braces and brackets use a permanently installed moveable component that entraps the archwire. Self-ligators are often referred to as "speed braces." Self-ligating bands and brackets eliminate the need for plastic ties or wire ligatures to hold the archwire in place. Traditional ligatures tend to become bioflim traps, thus complicating treatment. Manufacturers of self-ligating bands and brackets claim that there is less friction between the arch wire and bracket, they require less frequent office visits, and they are easier to clean and more comfortable for patients than traditional bands and brackets.
Manufacturers produce both metal and ceramic (clear) models depending on the patient's needs and clinician's preferences. Treatment time, outcome, and patient satisfaction have been rated higher than traditional brackets and bands through various product manufacturers.
Another innovation in orthodontics is the use of removable aligners, including Invisalign (Align Technologies), ClearCorrect (ClearCorrect, Inc.), Triple Play (Ortho Organizers, Inc.), and Simpli5 (AOA Orthodontic Laboratory). In preparing these aligners, each manufacturer has proprietary software that provides patient-specific case planning. The results of the data obtained via impressions, photographs, and other information determines how many aligners (trays) are made on a case specific basis (each manufacturer may require different orthodontic records to be sent).
Movement occurs through the series of trays designed to cover each arch completely. Each aligner, which resembles a whitening tray, is worn approximately 20 to 22 hours per day for two to three week intervals before the next set of aligners is inserted. However, patient compliance is an important factor; in order for proper alignment to occur, the patient must be willing to wear the trays for the designated time, removing only at meals. Total treatment time varies from six months to two years and depends on the experience of the dentist in achieving the desired results.
Aligner design depends heavily on the practitioner's clinical judgment and experience. Determining the need for any interproximal reduction (IPR) or attachments (composite materials attached to specific teeth to increase aligner retention and movement) is also included in the overall treatment plan. The aligners are constructed of a thermoplastic resin material and do not contain bisphenol A. Depending on the brand used, manufacturers claim high success rates and the ability to orthodontically correct a variety of problems. However, some patients and situations may not be ideal candidates for aligner treatment. The most common candidate for aligner treatment is an adult with orthodontic relapse or minor discrepancies who is concerned about esthetics. Additionally, Align Technology has a line specifically for teenagers called Invisalign Teen that targets 13- to 19-year-olds.
Clear braces (ceramic or plastic) are another alternative to traditional metal ones. These can be traditional brackets and bands or the self-ligating orthodontic appliances. Clear elastic ligature ties used for traditional bands/brackets allow for a less conspicuous appearance. However, clear braces have been reported to have a higher rate of friction and can be more brittle than metal counterparts, although this has only been reported in literature. This brittleness can make removing the appliances difficult.
In a process used by OraMetrix's SureSmile, computerized robotic arms bend archwires into desired shapes based on 3-D imaging. Using a specially designed OralScanner, the orthodontist records digital models of patients to visualize treatment results and map tooth movement to achieve final results. The orthodontist chooses the bands/brackets and archwire, and the robotic arms create the shape of the wire as needed in the treatment process. The company claims that the treatment time is less than traditional orthodontics and that the patient experiences fewer adjustments and less discomfort. However, the OralScanner is a cone beam computed tomography (CBCT) unit, and although CBCT is optimum in certain circumstances, there is concern about the amount of radiation patients are exposed to.
Several new areas of orthodontic appliances are currently being investigated. For less difficult cases involving only the six maxillary or mandibular anterior teeth, a spring aligner may be an option. These aligners resemble traditional orthodontic retainers but contain high tensile strength alloy wires that provide force through springs. "Smart brackets" contain a microchip capable of measuring forces applied to the bracket/tooth interface. The goal of smart brackets is to reduce the duration of orthodontic therapies while setting the appropriate forces within nonharmful ranges. At this time, smart brackets are investigative only.
TADs (temporary anchorage devices) are titanium-alloy mini-screws (also known as microimplants) that serve as anchors for moving specific teeth in the most predictable manner possible. TADs have been in use in orthodontics since 1983. Oral surgeons and orthopedists used them prior to that. TADs allow orthodontists to move teeth without moving adjacent teeth and without cumbersome appliances such as headgear. Patient compliance is minimal since the TAD is anchored into the bone, and movement devices (chains or appliances) are orthodontically attached. Insertion and removal of TADs are often painless, and are done with only a topical gel applied in the orthodontist's office.
From a hygiene perspective, there are a variety of home care and professional products available to maintain the orthodontic patient. For the patient, there are manual orthodontic toothbrushes designed with a "V" cut design that allows the brush to fit over the orthodontic bracket and wires. Power brushes, including the Sonicare Flexcare and Flexcare for Kids, Oral-B Triumph, and Arm & Hammer Spinbrush, offer patients an alternative to manual brushing and have been found to remove biofilm better than manual brushing in a variety of situations.
The use of oral irrigators, such as the WaterPik Water Flosser, adds another dimension to the orthodontic patient's home care routine. Interdental cleaners, including Superfloss, Oral-B Hummingbird, and WaterPik Power Flosser, are also great alternatives. The Platypus Flosser fits under the arch wire due to its innovative design by a hygienist to help her orthodontic patients. Other adjuncts include Oral-B Floss Picks, Sunstar/Butler Floss Threaders, Eez-Thru Flossers, Thornton 3-in-1 Floss, and GUM Soft-Picks. A variety of interproximal brushes, end-tuft brushes, and sulca brushes all help orthodontic patients maintain a biofilm-free mouth.
Dental professionals can offer patients remineralization products, including MI Paste (GC America), Clinpro 5000 (3M ESPE), NovaMin, and SensiStat, to treat areas of decalcification that may occur during orthodontic treatment. Retainer Brite can be used to clean retainers or other removable hard acrylic appliances. Premier's 2pro Total Access prophy angles are a patented dual action cup and tip that can help gain easier access around orthodontic appliances. The prophy cup can be removed to reveal a tip that can fit easily under wires.
Treatment can be costly
Orthodontic treatment in any form may present cost issues for patients. Patients may or may not have insurance coverage. Many insurers cover children up to age 19, whereas only select insurers/employers cover adult orthodontics. Plans also have a lifetime orthodontic maximum ranging from $1,000 to $2,500. Depending on the type(s) of appliances and the severity of the case, orthodontic charges can range from $1,000 to $8,000. Patients often experience sticker shock when it comes to discussing the finances. However, dental professionals can work with outside credit agencies such as CareCredit or Chase Financial. Many offices offer in-house financing with no interest for several months. Hygienists should be familiar with the office policy regarding payment options.
Hygienists play a critical role in the orthodontic process by providing support, encouragement, and education. Orthodontics has changed considerably in the last few decades. New and easier treatments that make moving teeth and creating a healthy, happy smile for a lifetime for many children and adults are available or coming soon.
Disclosure: The author did not receive any compensation for products discussed in this article.
Ann-Marie C. DePalma, RDH, MEd, FAADH, is a fellow of the American Academy of Dental Hygiene and a member of ADHA and other professional associations. Ann-Marie presents continuing-education programs for hygienists and dental team members and has written numerous articles on a variety of topics. She can be reached at [email protected].