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After studying this chapter, the student will be able to do the following:
1. List the different oral appliances used in dentistry.
2. Describe the reasons for the use of oral appliances.
3. Name the different thermoplastic materials used in the fabrication of oral appliances, and discuss the properties of these materials.
4. Explain the steps involved in fabricating an oral appliance.
5. Describe the proper maintenance of oral appliances.
6. Prepare a script or dialogue that may be used for patient education regarding oral appliances.
fluoride custom trays
obstructive sleep apnea
Oral appliances are made from a variety of materials: thermoplastic polymers, thermoset polymers, wires, bands, and other prefabricated parts. Thermoplastic materials have an advantage over other types of materials in that they are easily used to construct an oral appliance. They simply are heated and molded into the desired shape. Thermoplastic materials are increasingly used in the dental office to serve a variety of needs.
As dental hygienists, it is our responsibility to inform the patient of the need for an oral appliance, the care that is required to maintain it, and any possible side effects. Oral appliances currently available to patients include athletic mouthguards, whitening trays, fluoride custom trays, orthodontic appliances, nightguards, periodontal stints, space maintainers, and appliances for the treatment of obstructive sleep apnea (OSA) and snoring as well as nonnutritive (thumb) sucking. These appliances, along with their purposes, are listed in Table 18.1. Two different oral appliances are illustrated in Figures 18.1 and 18.2.
TABLE 18.1. The Purpose of Oral Appliances
FIGURE 18.1. Athletic mouthguard. (Courtesy of Great Lakes Orthodontics, Ltd.)
FIGURE 18.2. Klearway appliance for the treatment of snoring and obstructive sleep apnea. (Courtesy of Great Lakes Orthodontics, Ltd.)
Some oral appliances, such as athletic mouthguards and custom fluoride trays, are relatively easy to make in the laboratory area of a typical dental practice. This chapter discusses several types of oral appliances and provides a summary of the fabrication procedure for fluoride trays and mouthguards.
I. Types of Oral Appliances
A. Athletic Mouthguards
An athletic mouthguard is a removable oral appliance that protects the teeth and surrounding tissues during contact sports (see Figs. 1.12, 18.1, and 18.3). The athletic mouthguard, which is sometimes referred to as a mouth protector, provides protection against injuries to the teeth and supporting structures by absorbing energy. The force of the blow is spread over many teeth, and contact between maxillary and mandibular teeth is prevented. The mouthguard is dually capable of realigning and repositioning the jaws so that the condyles of the mandible do not contact the soft tissues of the joints, thus avoiding injury to these areas. Mouthguards are used to prevent orofacial trauma during contact sports and other recreational activities.
FIGURE 18.3. Athletic mouthguard. (Courtesy of Dental Arts Lab, Inc.)
Research has shown a significant decrease in injuries when a mouthguard is used. Injuries that can be decreased by wearing an athletic mouthguard include tooth avulsion, fractured teeth, gingival and/or mucosal injuries, jaw fractures, neck injuries, and concussions.
Mouthguards have been used since the 1950s. Many athletic associations, including the National Collegiate Athletic Association (NCAA), mandate their use. Interestingly, most professional sports do not require the use of mouthguards, but most professional athletes wear them voluntarily. The use of mouthguards by these professionals is an excellent example of a health promotional activity.
3. Wide Application
Mouthguards are recommended for a variety of contact sports and recreational activities. These are listed in Table 18.2.
TABLE 18.2. American Dental Association Recommended Activities for Use of Athletic Mouthguards
4. Encouraging the Use of Mouthguards
Many patients are unaware of the necessity for wearing an athletic mouthguard when playing contact sports or enjoying recreational activities. Dental hygienists are responsible for educating patients on the importance of the athletic mouthguard and the need to use it in all situations. Research suggests that the earlier a child starts wearing a mouthguard during amateur sports, the higher the compliance rate will be when he or she plays in more organized, competitive sports. In fact, younger, inexperienced children are more likely than older athletes to sustain orofacial injuries. Therefore, the importance of wearing a mouthguard is greater for these young participants.
Three types of athletic mouthguards exist.
a. The stock mouthguard is available in different sizes. It is not custom-made, nor is it preferred (because of poor fit and excess bulk).
b. A mouth-formed guard, which is generally referred to as a “boil-and-bite” style, can be heated in water and then placed in the mouth. The athlete bites into the guard, and an inexact fit is produced. This type of mouthguard can become distorted and does not accommodate an individual athlete’s unique oral features.
c. The most effective mouthguard is the custom-made mouthguard. This type of mouthguard is custom-fabricated and fits precisely over the individual athlete’s dentition. Because it is more comfortable and better fitting, compliance is increased; therefore, the custom-made mouthguard is better at reducing injuries. This type of mouthguard does need to be replaced, however, when changes occur to the athlete’s dentition. See Table 18.3 for information on ideal mouthguard properties.
TABLE 18.3. Ideal Mouthguard Properties
Adapted from American Dental Association. Using mouthguards to reduce the incidence and severity of sports-related oral injuries. J Am Dent Assoc. 2006;137(12):1712–1720.
B. Fluoride Custom Trays
Fluoride custom trays are ideal for patients who have a high prevalence of dental caries or high caries risk (see Fig. 18.4). These trays are custom-made to fit the particular individual’s dentition so that all tooth surfaces are covered with fluoride gel. Furthermore, these trays can be fabricated in the dental office by using the method described later in this chapter.
FIGURE 18.4. A fluoride custom tray. (Courtesy of Dental Arts Lab, Inc.)
1. Qualifying Conditions
Use of fluoride custom trays is indicated for the following oral conditions:
- A high incidence or risk of dental caries, including rampant enamel or root caries
- Radiation therapy
2. Compatible Gels
Types of fluoride gels that may be placed in the custom-made tray include
- Acidulated phosphate fluoride (0.5%)
- Sodium fluoride (1.1%)
- Stannous fluoride (0.4%)
3. Increasing Awareness
Dental hygienists should educate patients about the causes of dental caries and the role that fluoride plays in prevention of demineralization and the remineralization of teeth.
4. Other Uses
Although not thoroughly studied, these trays have been used for the treatment of dentin hypersensitivity by using desensitizing agents instead of fluoride. Remineralization is the process of restoring mineral ions to the tooth structure. There are calcium phosphate, arginine, and potassium nitrate products available that advertise that they may aid in the remineralization process when placed in a custom tray. These are used for caries prevention and dentinal hypersensitivity.
C. Orthodontic Appliances (Tooth Positioners)
Orthodontic appliances may be used to correct overbites, overjets, spacing problems, and slight malocclusions. Several types of thermoplastic orthodontic appliances are used. During the final stages of orthodontic treatment, tooth positioners are used to attain the final, precise position of the teeth. In cases involving only minor movements of the dentition, an oral appliance such as the Invisalign system (Align Technologies, Inc., Santa Clara, CA) can be used (Fig. 18.5).
FIGURE 18.5. Invisalign appliance. A. Appliance in storage case. B. Appliance in place. C. Lateral view.