COMPREHENSIVE ORAL APPLIANCE TREATMENT

SUMMARY

Obstructive sleep apnea (OSA) is caused by choking on the tongue base and soft palate when they drop back into the throat during sleep. Many dentists treat OSA with mandibular advancement appliances. They can pull the lower jawbone (mandible) forward to create space behind it for the airway passage, and they are well tolerated; but they are only effective in about half of the patients treated, because the mandible is only loosely attached to the tongue and not at all attached to the soft palate. To solve this problem, Dr. Summer has devised an improved mandibular advancement appliance and mechanisms that can be added to ineffective mandibular advancement appliances or denture base plates to also control the positions of the tongue and soft palate, creating a comprehensive oral appliance treatment approach. The High Push Herbst K243752 and the soft palate elevator K222127 have already been FDA cleared, and the tongue holding device is in its final clinical trial. A detailed description of the new mechanisms and a protocol for their use in comprehensive oral appliance treatment of OSA can be found in the file entitled, MULTILEVEL ORAL APPLIANCE TREATMENT under the FOR DOCTORS tab.  A description of their use in denture patients is found in a separate file under this tab.

BACKGROUND

OSA affects millions of people, but current treatment for it is problematic. Minor surgeries can be helpful but rarely curative. CPAP is usually effective if the pressure is high enough, but compliance is poor, because many people find it difficult to tolerate; and it is very likely to limit the glymphatic circulation process that clears waste products from the cranium during sleep. Oral appliances currently treat the problem by advancing the mandible, which increases the space available in front of the tongue; but it cannot draw the tongue forward into that space, because the mandible is only attached to the tongue by muscles, which naturally lose their tonus during sleep. As a result, even extreme mandibular advancement cannot prevent the tongue from falling back into the throat to block the airway, it just has further to fall, and mandibular advancement only cures about half of the people treated, as seen in hundreds of studies.  

Now new mechanical devices can be added to ineffective mandibular advancement appliances to make them more effective by also holding the tongue to prevent it from dropping back into the throat, elevating the middle of the soft palate to draw its distal end away from the obstruction, and gradually prying the tongue base off the pharyngeal wall. To prevent unnecessary treatment, these modalities can be added one at a time to an oral appliance or denture base plates until the problem is solved, as described below:

STAGE ONE 

MANDIBULAR ADVANCEMENT - The first stage of multilevel oral appliance treatment for patients with healthy natural teeth, includes using an adjustable mandibular advancement appliance to gradually move your mandible further forward until you find the most advanced position that you can comfortably tolerate. A variety of oral appliances are currently available from many dentists for this "titration" process. The appliances often cause bite changes, which should be treated by bite adjustment, as explained in CLINICAL CONSIDERATIONS in the file entitled MULTI-LEVEL ORAL APPLIANCE TREATMENT OF SLEEP APNEA under the FOR DOCTORS tab.

Telescopic (Herbst) appliances have the longest history of successful treatment of sleep apnea and the best control over mandibular position, but the hardware they employ was designed more than a century ago for bite jumping in children, and it is unnecessarily bulky and restrictive for adults, leading to discomfort and breakage. Our high-push Herbst appliance has a lower profile for comfort, free lateral movement to prevent binding and breakage, an upward vector of force on the mandible to prevent mouth breathing, and unlimited adjustability without tools by just rotating the tubing assembly on the threaded connector. 

STAGE TWO

A SOFT PALATE ELEVATOR - If the apnea persists, we add a soft palate elevator to "tent" the soft palate. The effect is like removing a gasket from the narrow gap between the tongue base and the pharyngeal wall. 

 

The soft palate elevator employs a silicone rubber bulb on the end of a thin flexible arm to elevate the middle of the soft palate, where there are few gag reflexes, in order to draw its distal end, which is full of gag reflexes, upward and forward away from the obstruction. The soft palate is a thin flap of muscles that lose their tonus during sleep, leaving the uvula just hanging in the airway and moving back and forth due to airway flow. In this relaxed state, a light force is able to keep its center elevated about 1/4” all night without causing any discomfort. Most patients don't even know it's there.    

 

STAGE THREE – The next stage of multi-level oral appliance treatment is to "pin" the tongue against the mandible between specialized upper and lower tongue gripping plates that each contain thousands of forward slanted plastic pin points, (AKA tongue velcro), to prevent it from dropping back into the pharynx. The points are packed so closely together that they feel like fuzz. Their grip is so effective that a lightweight spring pushing one tongue gripping plate toward the other provides enough compressive force to hold the tongue without discomfort all night in the space shown below.

  

                                                                 SPACE FOR HOLDING TONGUE

A lower tongue gripping plate is shown below left and an upper tongue gripping plate is shown below right.

 

To prevent accidental release of the tongue during sleep, at least one of the upper tongue gripping plates (usually the upper for patients with teeth and the lower for denture patients) is spring mounted to create a cushioned grip that prevents accidental tongue release during the submaximal mandible and tongue movements that occur during normal sleep. The cushioned grip continues until the mouth is opened wide enough to release the tongue. 

In most people, the target position for the tongue is just far enough forward for its tip to maintain light contact with the lips closed around it, as shown below. Patients go to sleep with the tongue in this target position, and they awake with the tongue in the same target position, because the tongue cannot escape during sleep.

STAGE 4 - If follow-up sleep testing shows that the apnea persists, the remaining airway blockage occurs down lower in the hypopharynx. To treat this condition, the tongue base is gradually pried off the pharyngeal wall by adjusting the positions of its tail sesgments using incremental adjustment mechanisms called tongue base titraters mounted on the back of the upper tongue gripping plate. Shifting the tongue base titraters shifts the tail segments of the upper tongue gripping plate in progressive increments further down and back as the patient gets accustomed to them.    

 

The three rows of apertures in the tongue base titraters enable the direction of adjustment of the tail segments to be varied by 25 degrees, as shown below. 

    UNADJUSTED           DOWN AND BACK          DOWN AND FORWARD

CLINICAL CONSIDERATIONS - FACTORS COMPLICATING TREATMENT

MOUTH BREATHERS - Mouth breathing is devastating to health, because the air that hits the back of the throat has not been warmed, filtered, and moistened by the nose; which leads to more frequent upper respiratory infections. Some people are obligate mouth breathers, because their nasal cavity is too narrow to allow adequate airway flow. Other people have a nasal cavity that is just wide enough to allow normal nasal airway flow, and thehy become obligate mouth breathers whenever allergies or rhinitis causes swelling of the nasal mucous membranes.

Obligate mouth breathers can sometimes become nose breathers after undergoing palatal expansion to widen their nasal airway. The process requires 3 to 6 months using the appliance most of the time (not just during sleep). However, palate expansion rarely eliminates apnea, because the area that is widened is located far from the back of the throat where the obstruction occurs. 

Habitual mouth breathers use an oral airway despite having an adequate nasal airway passage. Their mouth breathing habit can usually be eliminated by almost any mechanism that can hold the mouth closed; including chin straps, lip taping, thick foam cervical collars, or vertical (interarch) orthodontic elastics connecting the upper and lower members of a mandibular advancement appliance that fits on the teeth tightly enough to resist being pulled off them by the weight of the lower jawbone. 

TMJ DISORDERS - can make it difficult to advance the mandible rapidly or extensively, but they usually resolve by middle age when OSA begins, so they  rarely prevent gradual mandibular advancement, and they do not prevent soft palate elevation or tongue holding.  

BITE CHANGES - are frequent consequences of mandibular advancement due to a combination of tooth movement and jawbone growth. Patients usually find that their back teeth no longer fit well together in the morning and then throughout the day, because the upper front teeth have shifted backward, the lower front teeth have shifted forward, and the mandible has elongated. The resulting "posterior openbite" can make chewing less effective. Chewing capacity can be easily restored by having your dentist adjust your bite forward, but dentists are trained to adjust bites backward rather than forward.