Oral Appliances for Treatment of Obstructive Sleep Apnea
Oral Appliances for Treatment of Obstructive Sleep Apnea
Associate Professor Paraya Assanasen, M.D.
Department of Otorhinolaryngology
Faculty of Medicine Siriraj Hospital
The obstructive sleep apnea syndrome (OSAS) is a disorder characterized by abnormal breathing in sleep and sleep fragmentation. Epidemiological data suggest that OSAS is quite common, particularly in its milder forms. The use of a variety of prosthetic devices is one approach for treatment of patients with OSAS and the nasopharynx (retro-nasal area) and the posterior tongue (retro-lingual area) are the two anatomic areas of concern. Insertion of a nasopharyngeal airway has been used to prevent upper airway occlusion at the level of the soft palate. The American Sleep Disorders Association recommends that oral appliances can be used in patients with primary snoring, mild OSAS, or in patients with moderate to severe OSAS who refuse or are intolerant of nasal continuous positive airway pressure (CPAP).
Common side effects of oral appliance therapy include excessive salivation, xerostomia, soft tissue irritations, transient discomfort of the teeth and temporomandibular joint (TMJ), and temporary minor occlusal changes. Uncommon yet more serious complications include permanent occlusal changes and significant TMJ discomfort.
Removable anterior repositioning splints have been used somewhat successfully to temporarily advance the mandible while passively bringing the tongue forward with it (Figure 1). The optimal amount of forward movement is between 50 and 75% of the patients maximum protrusive distance. An important design feature of these devices is that the appliance must maintain the mandible in the forward position while the patient is asleep. Mandibular anterior repositioning splint was used to determine whether surgical advancement of the mandible would have any lasting and positive effect on a patients obstructive sleep apnea.
A tongue-retaining device (TRD) (Figure 2) which pulls the tongue forward without moving the mandible forward has also been used successfully in some patients with mild to moderate OSAS. The TRD functions by placing the tongue into a cup or bubble positioned between the anterior teeth. Surface adhesion holds the tongue in place and the appliance requires that the patients jaw remains partially open. One disadvantage of the TRD is that the tongue is not always held forward because surface tension of the tongue in the bubble is lost after a time. The TRD and mandibular anterior repositioning splints both force nasal breathing, which can be difficult for patients with inadequate nasal airways.
Another commonly used and effective oral appliance is an anterior mandibular positioning device (Figure 3). It consists of two full-coverage clear acrylic components snapped onto the maxillary and mandibular teeth connected with two rod and tube attachments that allow vertical opening, protrusion, limited lateral movement, and no retrusive movement. It is used only at night and advances the mandible 5 to 7 mm or at least 75% of the patients maximum protrusive distance.
Another disadvantage of oral appliances is the need to wear them nightly. As with any device, compliance has been shown to be a problem with oral appliances. If oral appliance therapy is unsuccessful, further treatment options include mandibular advancement surgery to achieve the same forward tongue position on a permanent basis.
