Hold your tongue: studies suggest oral appliances are still valuable to sleep therapy.
A systematic review of oral appliance that appeared in Sleep focused on randomized, controlled studies comparing mandibular repositioning appliances--just one type of oral appliance--to continuous positive airway pressure, placebo, other appliances and surgery for sleep apnea, as well as large case series with comprehensive long-term follow-up. The authors concluded that oral appliances provided successful treatment in more than half of the patients studied.
In fact, existing compliance data shows that at 30 months, 56 percent to 68 percent of patients continue to use oral appliances. Recent studies have focused on the effect of device design and patient compliance, different modalities for assessing the upper airway to predict treatment outcomes, and the evaluation of long-term adverse effects.
How do oral appliances work?
Oral appliances are worn in the mouth not unlike an orthodontic appliance or sports mouth guard. Patients wear them during sleep to prevent the tongue and soft tissues in the back of the throat from collapsing so that the airway stays open during sleep. These devices support air intake and help provide normal sleep for OSA patients.
Oral appliances can be used alone or in conjunction with other types of therapy, including CPAP. Determining the proper combination of therapy can only occur when a patient consults with his or her dentist and sleep physician.
Specially trained dentists who treat sleep-disordered breathing have more than 80 types of dental devices available for treating snoring and OSA. While this may seem like an overabundance of choices, most of the devices fall into one of two categories: mandibular positioners or tongue retaining devices. It's important to note the oral appliances are not available over the counter in the U.S. They must be prescribed and fitted by a dentist or physician.
Of the available oral appliances on the market, mandibular repositioning appliances are the most common. These devices reposition the lower jaw (mandible) and keep it in a protruded position during sleep. This position helps open the airway by pulling the tongue forward. Typically, mandibular positioners consist of two thin shells that cover a patient's upper and lower teeth, and a device that pulls the mandible as far forward as necessary to open the airway.
The elastic mandibular advancement appliance, or EMA[R], received FDA approval for the noninvasive treatment of snoring and sleep apnea in 1997. The device uses elastic force to advance the lower jaw. This is achieved through the use of interchangeable elastic straps that advance the mandibular at varying degrees. The flexibility of the straps provides lateral movement and comfort for the temporomandibular joint (TMJ).
To make an EMA device, hand plastic trays are pressure formed to models of a patient's teeth and utilize the undercut areas of the teeth for retention. This ensures the patient's teeth won't move during use. The degree of mandibular movement is determined by different length straps, and their elastic pull can be adjusted to suit each patient's musculature.
A clasp-retained mandibular positioner (CRMP) uses multiple clasps to lock the lower jaw into the appliance. This prevents the mandible from retruding. CRMPs are one-piece appliances, so dentists can control the vertical dimension by changing their height. Typically, these appliances have larger airways cut into the acrylic design than other mandibular devices.
Mandibular inclined repositioning (MIR) appliances keep the airway open by holding the lower jaw in a downward position using an incline flange. The flange is
Make plans to attended the 10th Anniversary Focus Conference May 13-15,2010 Disney's Coronado Springs Resort in Orlando, Florida made from thermoplastic material that softens at body temperature keeping it comfortable for the patient. The body of the appliance is made out of hard acrylic. MIRs have a breathing hole in the anterior portion in order to make breathing easy throughout the night.
A Herbst appliance has proven effective in treating chronic snoring and mild-to-moderate OSA patients. It was used for many years for TMJ therapy prior to being modified for OSA treatment. Unlike some other mandibular positioners, this device allows patients to move their jaw horizontally and vertically without disengaging the device. The advantage of the Herbst appliance is that it provides quick and accurate mandibular protrusive adjustability.
Oral positive airway pressure
Some patients are unable to use CPAP due to discomfort with the nasal mask. Others are claustrophobic, get headaches from the headgear or suffer from recurring sinusitis with CPAP. For these individuals, oral positive airway pressure, or OPAP, can be used as an alternative to nasal CPAP (or bi-level) while combining the benefits of a mandibular positioner.
OPAP can be used for mild to severe cases of sleep apnea once a patient's medical doctor or dentist deigns it suitable. The dental sleep specialist's exam will include panorex, cephalometrics and sonography of TMJ. Once the OPAP is custom made to a patient's dental impressions, a CPAP titration with polysomnography is recommended to ensure the best possible therapy.
According to the FDA, OPAP delivers oral air pressure capable of producing a reduction in a patient's apnea/hypopnea index in OSA, and it is as efficacious as nasal mask delivery. OPAP may be a therapeutic alternative to nasal CPAP and may be capable of treating mild OSA by itself.
Tongue retaining devices
Although they have been well-studied and shown to be effective, very few tongue retaining appliances are available to patients. Tongue retainers work by holding a patient's tongue in a forward position with a suction bulb. This positioning prevents the tongue from collapsing during sleep and obstructing the airway.
While the current evidence suggests oral appliances have a similar impact on health outcomes as CPAP, further research is required to address a number of unresolved issues. These include device design, titration procedures, prediction of treatment outcome and the clinical effectiveness of oral appliances for modifying the adverse health consequences of OSA.
Tongue retainers are usually constructed from flexible polyvinyl materials that are adapted to the contours of a patient's teeth and dental arches. The patient's tongue stays in a forward position due to the negative pressure created by a vacuum blub in the front of the device. These appliances are available in four tongue extensions with or without airway tubes for patients with compromised airway patency.
With tongue retainers, the lower jaw is not held firmly in place by the device, and patients have freedom of movement during use. This makes tongue retainers a good choice for patients with dentures, periodontal disease or TMJ dysfunction.
Slightly different from standard tongue retaining devices is a tongue stabilizing device that is FDA-approved for snoring treatment. They are made from soft, medical silicone and are non-adjustable. They work by holding a patient's tongue forward to keep the airway open. Unlike other tongue retaining devices, these do not attach to a patient's teeth and do not require special fitting by a dental professional.
Stephanie Richardson is a freelance medical writer in Philadelphia.
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|Title Annotation:||FOCUS ON SLEEP|
|Publication:||FOCUS: Journal for Respiratory Care & Sleep Medicine|
|Date:||Sep 1, 2009|
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