Prosthetic Management of Velopharyngeal Dysfunction
David J. Reisberg
○ Velopharyngeal dysfunction may be congenital or acquired.
○ Surgical intervention is the ideal means to correct velopharyngeal dysfunction.
○ Prosthetic rehabilitation is a reasonable alternative approach to correct velopharyngeal dysfunction when surgery is not an option.
○ An obturator is used to correct velopharyngeal insufficiency.
○ A palatal lift is used to correct velopharyngeal incompetency.
○ The fabrication of either an obturator or a palatal lift requires several office visits to allow the patient time to become accustomed to the shape, size, and position of the prosthesis.
Velopharyngeal dysfunction (VPD) can occur in congenital conditions such as cleft palate. It may also be associated with acquired conditions, such as after ablative tumor surgery that affects the soft palate or pharynx, head trauma, or degenerative neuromuscular conditions. In any of these situations, the velopharyngeal mechanism may fail to achieve adequate closure, resulting in hypernasality or nasal regurgitation.
Surgical intervention is the most ideal and natural way to manage VPD; however, surgical reconstruction may not be recommended in some cases. Limiting considerations may include patient age, cause of the condition, size of the soft tissue deficiency, available soft tissue for reconstruction, patient health, and the willingness of the patient to undergo surgery. Surgical reconstruction is more common with congenital causes than conditions related to tumor ablation, trauma, or neuromuscular disorders. In any of these situations, however, prosthetic rehabilitation may be employed, either on an interim or a definitive basis.
Maxillofacial prosthetics is a dental specialty that provides functional and cosmetic rehabilitation in cases of congenital or acquired deficiencies of the head and neck. In general, maxillofacial prosthodontists construct oral or facial prostheses that restore speech, swallowing, feeding, and appearance to improve quality of life. The history of maxillofacial prosthetics dates to the sixteenth century and possibly even earlier.1 Prosthodontics has always played an important role in cleft care. In fact, the original name of the American Cleft Palate-Craniofacial Association, when founded in 1943, was the American Academy of Cleft Prosthesis. A maxillofacial prosthodontist is an integral member of the cleft and craniofacial team and works closely with other team members to achieve the most optimal outcome for each patient.
Surgical reconstruction is the more common and preferred option for patients with cleft palate because it eliminates the need for the patient to rely on a removable prosthesis for normal function. Several techniques for surgical repair of the cleft can be used to resolve VPD; surgery is often performed by 1 year of age and improves velopharyngeal (VP) function for both speech and feeding.2,3 In some cases, however, VPD may persist, requiring additional surgical procedures as the child grows and develops. In rare instances, a medical condition may preclude additional surgical procedures. When VPD persists or develops after palatoplasty, a speech-aid prosthesis may correct the condition. Ideally, the prosthesis is intended only as a temporary measure until corrective surgery can be performed. In some cases, however, a prosthesis may be used as the definitive treatment for VPD.
COMPONENTS OF VELOPHARYNGEAL DYSFUNCTION
VPD may have a single or multiple components. Velopharyngeal insufficiency (Fig. 67-1, A) occurs when adequate muscle movement may or may not be present but the soft tissue volume of the soft palate is inadequate to achieve velopharyngeal closure during function. A pharyngeal obturator is indicated in this situation.
In velopharyngeal incompetency (Fig. 67-1, B), normal anatomic structures are present but neuromuscular movement in the soft palate or pharyngeal walls is inadequate to achieve closure. A palatal lift prosthesis is used in this condition. In patients with cleft palate, VPD most commonly results from insufficiency, although it may include either or both of these conditions. In rare cases a combination of a lift and an obturator is needed for speech improvement. Most often, nasal regurgitation is not a problem. Patients with cleft palate often demonstrate a greater ability to adapt to their abnormal VP structure and function during swallowing than do patients with acquired conditions, who therefore more commonly exhibit nasal regurgitation.
Fig. 67-1 A, Velopharyngeal insufficiency. B, Velopharyngeal incompetency.
The decision to refer a patient to a prosthodontist for a speech-aid prosthesis will come from the speech and language pathologist (SLP) in consultation with the surgeon, parents, and other members of the cleft team. The team psychologist may also provide input on any abnormal developmental or behavior issues. Although VPD may be evident at an early age, the developmental status of the patient may be a limiting factor in deciding when to initiate prosthetic treatment. A considerable level of cooperation is required to make either speech-aid prosthesis, particularly the palatal lift. By age 7 or 8 years, most children will be able to cooperate well enough to fabricate an obturator, although it may occasionally be possible to construct a prosthesis for patients as young as 5 years of age. Once the need for a prosthesis is identified, it should be initiated as soon as possible to facilitate effective articulation therapy.
A pharyngeal obturator contains three sections: the palatal, velar, and pharyngeal portions (Fig. 67-2). Because most prostheses are fabricated to be used as an interim therapy until definitive surgery can be performed, they are made of acrylic resin and wrought wire. The palatal portion comprises a resin base with wrought wire clasps.
The velar portion may be made of 10- or 12-gauge round wire that extends from the palatal portion and into the pharyngeal portion to strengthen and reinforce all sections of the obturator. The velar portion of the wire may be covered with resin. The pharyngeal portion is made of acrylic resin. If a prosthesis is to be the definitive treatment, a more durable prosthesis of cast chromium cobalt and acrylic resin is made, usually in late adolescence, once the secondary dentition is complete and aligned (Fig. 67-3).
Before fabrication of a prosthesis, the patient should be seen by a pediatric or general dentist to ensure overall health of the dentition. Ideally, the dentist is a member of the cleft team, but this is not always the case. The dentist may also play a role in adding composite resin or orthodontic brackets to abutment teeth on the buccal surfaces to provide retention for the clasps that will retain the prosthesis. Abutment teeth are usually the maxillary second deciduous molars in a primary dentition, the first permanent molars in a mixed dentition, and the second molars in a permanent dentition.