Hello, I'm Dr. Kevin Wallace. Today I'd like to demonstrate the delivery of a mandibular advancement device that uses a removable thermoplastic liner for retention. The bite was taken at a protrusive position of 60% and a vertical dimension that allowed for a minimum thickness of four millimeters of device materials. Now it has come back from the laboratory and we've checked it on the model to be sure that the laboratory has followed our prescription and that the midlines are where we intended them to be and at the same time, there has been no increase or decrease in the vertical dimension position of the bite that we sent to the laboratory. This device is in an attached bilateral compression style with Herbst arm propulsion. The retention for this device is a removable thermal resin that will become liquid when heated to 160 degrees. The thermal resin appears opaque and white at room temperature or mouth temperature but when heated completely to its liquid state, it becomes clear. In this case, I've asked the laboratory to pre-mold the material to the models of the teeth. This way, I can try it in the mouth before I begin the final remolding. Plus, I don't have to heat it to its completely fluid state but merely soften it slightly so I can remold it to my patient's teeth. In other words, I will place it in a 160 degree water bath for just a few seconds. This also provides another advantage and then I can have one tray seated in the mouth as I reheat and remold the other. You'll see that I'll ask the patient to bite her teeth together while the material is still warm to ensure even occlusal contacts between the trays. Before beginning, it's important to examine the patient's mouth to remind myself of any excessive undercuts. I want to avoid having the material harden and lock into place either interproximally or beyond exaggerated heights of contour. Luckily, my patient today has very little recession so I'm not concerned that the hardened resin will lock into place. This is my patient, Joanna. She has never worn a mandibular advancement device before so she may be a little surprised at how bulky it feels once it's placed in her mouth. My staff has already shown her the device on the models and provided home care instructions. They have also shown her the propulsion mechanism and the tool that's used for advancement so she is more comfortable with how the device functions. Having staff perform these steps first may help to put the patient at ease. Since she was part of the decision making process during the design of this device, she's aware that it has a removable thermal plastic liner. But I'll want to warn her that the material will feel warm as it goes on her teeth and will be held in place for 20 to 30 seconds. This water was heated to 160 degrees. To soften the thermoplastic resin, I'll submerge the device tray into the hot water for only a few seconds. It is not my goal to liquefy all the thermal resin but rather to only soften it enough so that it inserts easily into the mouth and forms itself more precisely to the patient's teeth. Since the lab has premolded both the upper and lower trays, I'll put the premolded lower tray in place as I warm and fit the upper tray. Joanna, this will feel a little warm when I place it. And if you can close, please, good. Now we'll wait 20 to 30 seconds. When I go to remove it, I'll be able to feel a little frictional retention. I'll be repeating the same process with the lower tray before connecting them together with the Herbst arms. I wanna see precise adaptation of the white thermal resin material to the contours of the teeth. If some material appears to have extended itself too far in approximately, I can use a curved scissors or a blade to remove excess material. Then when I try it in and out of the mouth, I wanna be able to feel a little friction between the teeth and the mouth. I'll be able to feel a little friction When I try it in and out of the mouth, I wanna feel adequate retention and resistance to removal. You can bite down again, please. Take it out again. So now I've completed the same process with the lower tray and reconnected the trays by attaching the Herbst arm mechanism to both sides. At this point, I can check the bite and verify that the device is molded and seating properly. I wanna be sure that the patient will be successful with insertion and removal, so now I will ask her to put it in for me so I can check the bite. Okay, Joanna, I'm gonna have you put the upper appliance in first, separating them, and seat it, the upper, with your thumbs. And then I'll have you slowly move the lower jaw forward and seat the lower appliance with your index fingers and then bite it into place. Great, Joanna. And now if you could just tap your teeth together and tell me, does that feel even on both sides? At this point, I usually use articulating paper or you can use shim stock to check that occlusion bilaterally. Open, please. And tap. Open, please. And tap. And grind. And open. Great. And bite. And tap and grind. Perfect. Very good. That feel good? Okay. Next, Joanna, if I could have you try to remove the appliance by using your thumbs to remove the lower appliance first by pressing up and open. And then on the upper appliance, in the back by the molars, push down and remove the appliance. Very good. With these steps complete, it is a good time to ask the patient how they feel with the device in place. They have become used to it as you've inserted and removed it several times and are less likely to react to the bulk and awkwardness of having trays attached to their teeth. With a thermal liner, a patient rarely feels unequal or excessive pressure on any of their teeth. So the only adjustments needed may be to improve the ease of placement or removal. As with any device, before the patient leaves this visit, they will need to sign a proof of delivery form plus express understanding of device calibration instructions, home care instructions, and use of morning exercises and guide in addition to common side effects. Patients should always be encouraged to watch for symptomatic improvement and to contact the office when they have questions or concerns. Thank you for joining me for this presentation on device delivery with a thermal plastic liner. I hope you found it helpful for your clinical practice.

mandibular advancement device

removable thermoplastic liner

retention

thermal resin

patient education