61.Oral Devices for Eating: Dentures, PAP, and PLP

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Explanation

Among the oral devices used in eating, dentures are the mostly widely used. The palatal augmentation prosthesis (PAP) is mainly used for strengthening the contact between the tongue and the palate after resection of oral cancers. Swalloaid is a denture-like device used only on the maxilla and is used by patients who are not using dentures over the long term or patients who can't use mandibular dentures. With this device, we can expect the maxilla and mandible to be stabilized to allow normal tongue movement during swallowing.

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Explanation

Full dentures are used with people who are edentulous. On the left we see the front view of full dentures with the maxillary denture on the top and the mandibular denture on the bottom. On the right is the view of the back side. The shape of full dentures varies according to the condition of the oral cavity in individual patients, so patients can't use someone else's dentures. The shape and size of the dentures are also determined by the balance of the cheek and tongue muscles with the dentures worn. As we can see, the artificial teeth in the photos are made to fit the wearer's own way of chewing.

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Explanation

Upper left photo: Without dentures. Bottom left photo: With dentures. Right photo: Front view of maxillary and mandibular partial dentures.
Partial dentures are devices for people with some remaining teeth. In partial dentures, various types of hooks (springs) are fabricated to keep dentures stably in place. When patients have many remaining teeth, springs can be applied to multiple teeth and so exert little stress on the remaining teeth. However, as we can see in the photo, when patients have a few remaining teeth, we need to consider how to reduce stress on these teeth when designing the denture.. Depending on which maxillary and mandibular teeth remain, it can be difficult to make dentures that allow for any food to be chewed.

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Explanation

Dentures play an important role as an oral device that aids eating orally. If people without teeth don't wear dentures, they can't chew food and this greatly restricts the types of foods they can eat orally. Because they also can't clench the maxilla and mandible together, they can't stabilize the hyoid, so adequate pressure for swallowing can't be achieved, which adversely affects the pharyngeal phase of swallowing. Because they can't clench the maxilla and mandible together, they will try to compensate for this by putting the tongue between them, which results in abnormal tongue movements. If the appropriate dentures, which allows to eat sufficiently, are used, it is possible to maintain normal oral functions, and preserve the stimulation to the brain through the trigeminal nerves by chewing. Also, dentures that allow eating can help them converse with others. The significance of ensuring suitable function in the preparatory and oral phases, sensory input to the brain, and improvement in esthetics are also important.

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Explanation

The key value that dentures offer is to eating. When evaluating swallowing function, rather than only checking for the presence or absence of dentures, it's more important to check when they are worn and whether they allow for eating. It's also crucial to check whether dentures are adequately attached by suction at the base of the maxilla and mandible, that they don't fall out when the mouth is opened or when moving the tongue or cheek, and that there's no pain while eating.

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Explanation

There are several points to keep in mind when patients use dentures as oral devices during meals.

As with any device, it takes some time for patients to get used to wearing dentures, and sometimes several adjustments may be needed.
We need to create an oral environment that is suitable for using dentures before delivering them.
Dentures should always be worn after cleaning. With partial dentures, the teeth that hold the springs need to be cleaned.
It's difficult for someone who hasn't worn dentures for many years to newly wear them.
In the acute phase, there are no clear guidelines on the level of consciousness where we allow the patients to start using dentures.
There is debate over whether dentures should be removed or kept on during nighttime sleep.
Different dentists may use different techniques to make dentures.

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Explanation

The palatal augmentation prosthesis (PAP) is a device used-whether due to an organic defect or functional impairment-when the tongue doesn't sufficiently contact the hard palate during the transport of food or doesn't contact with sufficient pressure, so the bolus can't be transported from the oral cavity to the pharynx.
Upper left photo: Oral cavity of a patient who underwent subtotal glossectomy due to tongue cancer and reconstruction with the rectus abdominis muscles. The tongue and hard palate don't make contact using normal dentures in this situation.
Upper right photo: Applying thick soft material to the palatal surface of a temporary denture and instructing the patient to perform saliva swallowing and fluid swallowing, the contact area of the tongue is marked onto the palatal surface of the temporary denture (recording how much contact there is with the tongue). Increase the amount of the soft material until an adequate imprinted area is obtained.
Bottom photo: The fabricated PAP. Note how the posterior part of the PAP is made so that it gradually transitions to the hard palate.

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Explanation

Upper left photo: Photo of the oral cavity in a patient 7 years after subtotal glossectomy for carcinoma of the floor of the mouth, segmental mandibulectomy, and reconstruction with the rectus abdominis muscle.
Lower left photo: The PAP with spring that the patient uses.
Upper right photo: Placement of the PAP.
Lower right photo: Note the contact between the rectus abdominis flap and the PAP during swallowing.

Even when the PAP facilitates surface contact between the tongue and palate, we are still not recreating the fine coordination of the tongue, hard palate, and soft palate that patients originally had. So, it's important that we concomitantly use compensatory methods, such as posture adjustment, while continuing oral function training the includes the remnant tongue. We should also consider that many muscle flaps atrophy over time. With flaps that contain a lot of fat such as the rectus abdominis flap, we should be mindful of changes in muscle flap volume with changes in body weight.

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Explanation

The palatal lift prosthesis (PLP) was invented by Gibbons et al. in 1985 and is mainly used in patients with paralysis of the soft palate (palatoplegia) due, for example, to congenital neuromuscular abnormality, cerebral palsy, or trauma. The indication for PLP is velopharyngeal insufficiency with decreased mobility, with more than a certain amount of length of the soft palate and pharynx motility. In the field of swallowing rehabilitation, the PAP is often used in patients with dysarthria and reflux into the nasal cavity during swallowing. However, depending on the disease, using a PAP may be disadvantageous to swallowing in some instances, so it's advisable to pay careful attention when applying the PLP.

Upper photo: This PLP is composed of 3 parts: the plate covering the hard palate, the extension to elevate the soft palate posteriorly and superiorly, and the junction between them.
Lower left photo: Position of the soft palate before using the PLP.
Lower right photo: Position of soft palate using the PLP. The soft palate is elevated with the device, and it contacts the posterior phalangeal wall at the level of the palatal plane.

As a rule of thumb for the elevation provided by the PLP, because the elevated soft palate contacts the posterior pharyngeal wall at the center of the soft palate, we should elevate the soft palate as much as possible as much as the patient can tolerate. Also, we need to check for difficulty in breathing in the supine position, check for nasal leakage using the nasal mirror test, and evaluate appropriate elevation of soft palate under endoscopy.
Immediately after placement, patients may experience a foreign body sensation, have a feeling of nasal obstruction, or experience difficulty in swallowing. So we must explain these effects to patients. Start with just several minutes wearing the device per day and gradually lengthen the placement time. If there are no problems, patients can wear the device for several hours per month, and the entire process may take 6-12 months.

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Explanation

A special type of PLP

Upper photo: Bulb-type PLP
Lower left photo: Endoscopic findings during rest
Lower right photo: Endoscopic findings during swallowing

With a bulb-type PLP, because the area of the velopharyngeal insufficiency may be reduced with elevation of the soft palate, the bulb may be smaller than with a conventional speech aid.

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