Instructions For Dentists

The new add-on airway components that control the tongue and elevate the soft palate can be attached to most oral appliances and denture base plates made of dental acrylic.  They cannot be attached to oral appliances made of nylon or polymers other than acrylic, such as the Narval and Panthera appliances, and they cannot function properly in appliances that do not allow opening and closing, such as TAP, EMA, Silent Night, and monobloc appliances.      

ADDING MANDIBULAR ADVANCEMENT HARDWARE TO EXISTING DUAL ARCH ORAL APPLIANCES

The high push Herbst hardware can be added to maxillary and mandibular oral appliances as long as the buccal walls have sufficient structural support for the retentive anchors.  Some maxillary appliances such as aligners will need support added to the labial and buccal walls to resist the posteriorly directed forces applied to them by pushing the mandible anteriorly; and some mandibular appliances will need support added to the lingual surfaces, especially from canine to canine, to resist the anteriorly directed forces applied to them by being pushed anteriorly.  

When bonding the anchors onto the appliances, the loops on the upper appliance are usually located just distal to the first molars, and the loops on the lower appliance are usually located just distal to the canines. However the positions of the anchors can be altered as needed.  For example, if a lower first premolar is located buccally far beyond the canine, the loop of the lower anchor can usually be placed in the interproximal area distal to the first premolar instead of the canine.  Similarly, if an upper first molar is displaced buccally, the loop of the upper anchor may be located just medial to the first molar.  To determine the optimal locations for the anchor loops, the path for the telescopic components between upper and lower retentive anchor loops are visualized by looking at the appliances on mounted models. If the maxillary second molars are located very close to the mandibular canines in the construction bite, single tubes would have to be cut very short, and they may be difficult to handle and adjust without accidentally coming apart due to the rods sliding out of the tubes.   

ADDING TONGUE HOLDING COMPONENTS TO EXISTING DUAL ARCH ORAL APPLIANCES

If titrated mandibular advancement fails to eliminate a patient’s OSA, the next step in multi-level treatment is to advance the tongue together with the mandible.  

CHOOSE THE TARGET TREATMENT POSITION - The target treatment position has a mandibular and a tongue component.  The mandibular component should have been established by titration of the mandibular advancement appliance.  The tongue component is included by having the patient remove the titrated mandibular advancement appliance (usually after having worn it overnight or at least for as long as possible before the appointment) and then bite down lightly on the tongue tip.  In this position, with the tongue tip between the incisors, inject a thick bodied bite registration material between the molars on both sides, slightly displacing any portions of the tongue that are resting between them.  After that bite registration material sets, have the patient remove the tongue tip from between the anterior teeth while maintaining the occlusion on the bite registration material between the molars, and inject more bite registration material between the premolars and anterior teeth.  The construction bite for use in determining the height of the occlusal stops will be obtained by mounting the models of the patient’s teeth in this bite and then opening the articulator an additional 1-2 mm to make room for the thickness of the lower tongue gripping surface over the lower incisors.

Only very rarely does the tongue need to be held so far forward in its target position that it violates the lip seal.  The lip seal keeps the tongue tip moist, prevents drooling, and sometimes helps prevent mouth breathing; but violating the lip seal poses no significant health risk, especially compared to OSA.  If the tongue needs to be protruded beyond the lip seal, the patient must be able to tolerate the increase in vertical dimension needed to hold a larger part of the tongue between the incisors and must be willing to deal with the drooling or dry mouth that can result from lack of a lip seal during sleep.  The patient can protect the tongue tip from drying out with coconut oil. 

In edentulous patients, there is much more variability in potential target tongue positions, and the one chosen determines the forces that will be placed on the denture.  The tongue is a tangle of muscles that all have resting postures, and the farther the tongue is repositioned from its resting posture, the more force it will place on the denture.  Any anterior positioning of the tongue in the target position requires an upper denture with a sound anterior alveolar ridge that can resist posteriorly directed forces. If the upper denture cannot resist the posteriorly directed forces needed to hold the tongue as far anteriorly as necessary, its resistance can be increased by incorporating reverse-pull headgear connected to the upper denture using low force elastics.

The vertical dimension of the new tongue holding device is also a big variable in edentulous patients.  If the vertical dimension is too low, the tongue will tend to pull inferiorly on the upper denture and can unseat it.  If the vertical dimension is excessive (tall), the passive stretch of the elevator muscles can produce too much pressure on the soft tissues.  IThe upper tongue gripping surface is normally left flat in a transverse plane.  However, if the vertical dimension is excessive and incorporating a large tongue threatens to increase it further, the flat front portion of the upper tongue gripping surface can be curved to fit the concavity of the hard palate.  The tongue in its resting posture will immediately expand to fill the available space.

IMPRESSIONS

To take an impression of the tongue top when the tongue is in its target position, while the patient protrudes the tongue as far as possible for a few seconds, quickly inject fast set PVS bite registration material onto the fork shaped piece of polyester mesh (included in the kit) resting on the tongue and extending as far back as possible on the sides of the tongue where there are few gag reflexes, as shown below left.  Then, as the patient begins to pull the tongue back toward a more comfortable position, keep injecting onto the tongue body. Finally ask the patient to bite lightly on the tongue tip in the target position while the material sets as shown below right, and close the lips around the tongue tip.  The mesh fork allows the impression to be removed quickly if the patient begins to gag.                       

After cutting it sagitally, the tongue top impression can be placed on a model and used to judge the contours of the tongue in its target position, such as where it changes its orientation from horizontal to more vertical in the area beneath the soft palate.  That information can then be used to adjust the shape of the upper tongue gripping surface in order to make it closely fit the tongue in its target position, which helps keep the tongue in its target position throughout the night.         

To take an impression of the floor of the mouth with the tongue in its target treatment position, while the patient raises the tongue, inject a light body VPS into the floor of the mouth and up onto the lingual aspects of the lower teeth; then have the patient place the tongue in the target position and bite down lightly on it while the VPS sets.  Placing the resulting impression on a model of the lower teeth can provide a guide for shaping the lower tongue gripping surface to ensure that it does not prevent the patient from being able to protrude the tongue into the target position.                                                                                                                                    

ADDING A SOFT PALATE ELEVATOR 

If you want to add a soft palate elevator to a maxillary appliance, the impression of the maxillary arch should include enough posterior landmarks to enable you to identify the midline of the soft palate, where the silicone rubber bulb should push upward.  The antero-posterior location of the rubber ball is much less critical than its midline location, because it can still tent the soft palate whether it is located near the front or near the back of the soft palate.  Soft palate tenting devices can be easily added to upper dentures, because elevating the soft palate rarely requires enough force to cause unseating of the posterior end of the denture.  

SEND TO LAB WITH PRESCRIPTION

Include the oral appliance to be amended, the components to be added, and all necessary impressions.

CHECK THE AMENDED APPLIANCE WHEN IT RETURNS FROM THE LAB

If you had high push Herbst components added to a pair of upper and lower oral appliances, check to be sure that there is adequate space for the tubes between upper and lower anchors and the acrylic covering them.  When the appliances are mounted on models fully closed in the construction bite, the tubes should not be pressed against the acrylic and should be free to move around a little from side to side, as felt with fingers.  If the tubes are pinched against the acrylic, articulating paper placed under the tube while the articulator is closed and moved into excursions can identify the pinch point.

If you had a biased upper tongue gripping surface added to a dual arch mandibular advancement appliance, mount the newly amended appliance in the construction bite on an articulator and ensure that there is sufficient space (about 2 mm) for the upper tongue gripping surface to move up and down relative to the appliance to be sure the tongue will not be pinched when the patient bites down on the occlusal stops.  From the anterior teeth to the first molars, there should be about 2 mm of space visible between the lower tongue gripping surface and the upper teeth or the seated upper tongue gripping surface.  The sides of the patient’s tongue should be able to squeeze out into this space when the patient bites on the occlusal stops.                 

DELIVERING AN APPLIANCE WITH A TONGUE HOLDING DEVICE

Before the patient inserts the tongue, have the patient put in the appliance and bite down on the occlusal stops to ensure the appliance is fully seated with stable bilateral support.  Then explain to the patient that, after inserting the tongue, it can be released immediately anytime just by opening the mouth wide.  Finally have the patient insert the tongue by opening a little, pushing the tongue tip into the space between the anterior teeth, biting down forcefully again, and closing the lips around the tongue tip.  After a minute for the tongue gripping surfaces to seat into the surface of the tongue, you can check their ability to hold the tongue against retrusion by verifying that the patient cannot pull the tongue back out of the tongue holding device without first opening widely enough to release the tongue.  At this time, you should also check to see that the occlusal stops have adequate height by ensuring that the patient can bite down forcefully without causing pain or redness from excessive pressure on the tongue tip.  

TROUBLESHOOTING AT DELIVERY

If the patient cannot tolerate the tongue holding device without gagging, the tail sections of the upper tongue gripping surface can be trimmed, especially medially where the gag reflexes are located.

If the patient reports pain at the back of the tongue when biting down forcefully, the contour of the upper tongue gripping surface is too steep, and it can be shallowed by holding it by its tether and dipping it in boiling water for 10 seconds before bending it with the fingers.  If the patient can pull the tongue back out from between the tongue gripping surfaces without first opening wide, the curve of the upper tongue gripping surface is too flat, and it can be increased by bending it with boiling water.

If the patient reports pain at the front of the tongue when biting down forcefully, check to be sure that the front portion of the tongue gripping surface can seat fully below the occlusal plane of the maxillary anterior teeth and canines on the model. For example, in the photo below, the front of the upper tongue gripping surface is not adequately seated and could pinch at the canine area.

If the patient reports pinching of the sides of the tongue when biting down forcefully, check to make sure the sides of the upper tongue gripping surface fit entirely within the palatal borders of the trough prepared in the upper appliance and below the occlusal plane, leaving room for the sides of the tongue to squeeze out between the occlusal surfaces of the canines, premolars, and first molars.  When the appliance is in the patient’s mouth, you should be able to push the suspended upper tongue gripping surface slightly further upward into its seat on the upper appliance using a finger.  If there is no movement of the upper tongue gripping surface possible, the upper tongue gripping surface may need to be narrowed or the portion of the appliance covering the palatal surfaces of the premolars, canines, or anterior teeth may need thinning.

You can check the fit of the upper tongue gripping surface against the tongue in its target position by injecting light bodied regular set VPS directly onto the gripping side (the tongue velcro) of the upper tongue gripping surface, quickly inserting the appliance, and having the patient close with the tongue in the target position while the VPS sets.  If the fit is good, the VPS should leave a thin uniform layer.  Later the VPS can be easily removed from the tongue velcro in one piece using an explorer or any sharp instrument.          

If the patient seems unable to protrude the tongue into the target position, either the lingual frenum is blocked in the midline just lingual to the mandibular incisors or the lingual flanges are too long to allow the floor of the mouth to rise with the tongue.  In such cases, the barrier to tongue protrusion can be identified by injecting a light bodied VPS onto the lower tongue gripping surface while the appliance is in the mouth, and then having the patient protrude the tongue and move it a little side to side, like border molding a denture.               

If the patient reports any pain in the soft palate or even any sensation there when inserting the appliance, the thin flat arm of the soft palate elevator can be easily bent with a three prong pliers or even just fingers.  The position of the soft palate elevator can also be easily reset after using a rotary wire wheel to release the retentive barbs from the acrylic.  To check the position of the soft palate elevator in the patient’s mouth, you can take an impression of the soft palate area with the soft palate elevator in place.   Simply lubricate the silicone rubber ball of the soft palate elevator lightly with coconut oil or a similar lubricant that is safe for human consumption so it does not stick to VPS, inject VPS on and around it, and insert the appliance.