Prosthetic reconstruction following resection of the hard and soft palate

SC

I. KENNETH

MAXILLOFACIAL PROSTHETICS TEMPOROMANDIBULAR JOINT Prosthetic reconstruction hard and soft palate Mohamed Eye and

A. Aramany, D.M.D.,

Ear

Hospital

of Pittsburgh

University

of Pittsburgh,

PLANNING

Comprehensive treatment planning for the rehabilitation of patients with defects arising from lossof the oronasal partition depends upon teamwork. In addition to the surgeon and maxillofacial prosthodontist, the head and neck nurse oncologist, social service worker, and speech pathologist are involved in the planning phase. The nurse oncologist is most useful in coordinating the overall effort, supervising the nursing care and the arrangement of the many small details necessaryfor success. The dental consultation takes place concurrently with the medical examination when the patient is Presented before the American Prosthodontic Society, Las Vegas, Nev. Supported in part by National Cancer Institute Contract NIHNCI-55 184-05. *Professor of Prosthodontics, School of Dental Medicine, University of Pittsburgh; Director, Regional Center for Maxiilofacial Prosthetic Rehabilitation. **Professor and Chairman, Department of Otolaryngology, School of Medicine, University of Pittsburgh; Chief, Department of Otolaryngology, Eye and Bar Hospital; Professor of Oral Pathology, University of Pittsburgh School of Dental Medicine.

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ADISMAN J. BOUCHER

IMPLANTS of the

M.S.,* and Eugene N, Myers, M.D.** and

esection of the hard and soft palate and related structures rest&s in a variety of anatomic and functional defects in the oral cavity and oropharynx. These defects are tremendously inconvenient to the patient because of the loss of oronasal separation which substantially interferes with the important functions of speech and swallowing. The extent to which an ablative technique may reasonably be applied in this anatomic region is determined by the degree to which restoration of satisfactory function and acceptable appearance may be achieved. Teamwork between the head and neck surgeon and maxillofacial prosthodontist is necessaryto provide a solution to these problems.

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admitted to the hospital. Thorough dental examination, radiographs, and impressions are routinely made. Oral hygiene protocol is mandatory in dentulous patients. Surgery may be delayed to complete as many dental restorations on the remaining teeth as possible. Preservation and restoration of such teeth provide a much better fitting prosthesis. Patients with poor oral hygiene, rampant decay, or advanced periodontal diseasemay have surgery postponed to correct these problems. Healing of large intraoral wounds is improved by good oral hygiene. Dentulous patients who receive postoperative radiation therapy or who have been previously radiated will receive fluoride treatments on a continuing basis.Where the need for surgical obturators is apparent, impressions of the dental arches are made and the surgical obturator constructed prior to the time of surgery. The surgeon and the maxillofacial prosthodontist consult and mark on the diagnostic casts what structures will be involved in the resection. This helps the prosthodontist in planning the prosthesis. It is also helpful for the surgeon to know what structures should be preserved to maximize effective rehabilitation efforts without compromising the ablative procedure. The speech pathologist plays an important role later in the postoperative period, assessingthe prosthesiswith respect to its ability to meet the phonetic requirements for normal speech. In addition, the speechpathologist identifies and isolates any speech defects that might be present which are attributable to sourcesother than surgery or prosthetic design.

PROBLEMS

IN PROSTHETIC

RESTURATIUN

Defects resulting from ablative surgery produce varying degreesof disability and the need for prosthetic restoration of the hard palate, soft palate, or both. The palatal defects may be classified as hard or soft palate defects.’

9022-3913/78/0240-0174WO.50/0

0 1978 The C. V. Mosby

Co.

PROSTHETIC

RECONSTRUCTION

OF PALATE

Fig. 1. View of a palate of a patient who has had total soft palate resection. The pharyngeal muscles are shown during contraction. Note ledgelike prominence of the pharyngeal wall.

Fig. 2. Median defect of a part of the hard and soft palate. Activation of the soft palate muscles results in palatopharyngeal seal. However, the oronasai communication is still present.

Defects in the hard palate are less difficult to manage than those of the soft palate. The primary concern is that the opening in the hard palate be obturated. Since this is based upon replacement of a passive rather than a dynamic anatomic unit, important aspects to be considered are location and size of the defect and retention and comfort of fit of the obturator. In edentulous maxillae, anterior maxillary defects leading to midfacial collapse, total hard palate resection, and previous radiation make these problems more difficult. Lack of patient acceptance of previous dentures lessens the acceptance of the obturator. The restoration of the soft palate presents a challenge completely different from that of the restoration of defects of the hard palate. The mobility of the soft palate tends to interfere with the prosthetic extension on the soft palate. The reduction of the size of the soft palate extension to prevent impingement upon the movable margins of the defect will lead to insufficient oronasal separation during functional activities. To understand the complexity of the problem of restoration of a soft palate defect, the mechanism of velopharyngeal closure will be reviewed.

pharyngeal closure. This closure is effected at the level of the hard palate of the normal subject in the vicinity of the anterior tubercle of the atlas bone. Opinions regarding the specific muscles responsible for these patterns of movement are almost as numerous as the authors who discuss them. However, we have noticed that on the activation of the velopharyngeal mechanism, the soft palate tends to elevate posteriorly and superiorly against the posterior pharyngeal wall. At the same time, the lateral pharyngeal walls are displaced medially and posteriorly against the sides of the velum to obliterate the pharyngeal orifice. Normal physiologic movement is interrupted as a result of surgical removal of the tumors of the soft palate. The muscle function of the soft palate is disrupted in a variety of wavs depending on the site and size of the defect. Defects may be classified into the following categories: Total resection of the soft palate, retaining a part of the hard palate. In this type of resection the soft palate is totally removed, including all its muscles. The function of the superior constrictor muscle of the pharynx remains intact. On eliciting the contraction of the superior constrictor muscle of the pharynx, there is a forward movement of the posterior wall and a lateral advancement of the lateral walls to move forward short of effecting oronasal communication. This is similar to the unrepaired congenital cleft of the palate (Fig. 1). Median resection of the palate. The resection may involve parts of the hard and soft palate. However, the levators, tensor, uvula, palatoglossus, and paiatopharyngeous muscles are left functionally intact. The normal physiologic movement of thv palate will

VELOPHARYNGEAL

MECHANISM

In normal subjects, the muscles which are responsible for the velopharyngeal closure include the superior constrictor, levator, tensor, palatopharyngeus, and salpingopharyngeus muscles. During the act of swallowing and in speech, the velum elevates and moves posteriorly. The posterior pharyngeal wall contracts and moves anteriorly, and both lateral pharyngeal walls move medially to effect the velo-

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Fig. 3. Lateral defect of the soft palate. Note the lateral pharyngeal region exposed through the palatal defect. Contraction of the lateral pharyngeal wall is evident during muscular activity.

Fig. 4. Total loss of the soft palate due to resection of a huge mixed salivary gland tumor obliterating the oropharynx. This results in a constant oronasal communication. take place on eliciting the velopharyngeal mechanism, whereas the presence of the defect will make this movement functionally inadequate. The anterior margin of the defect is not mobile, whereas the posterior aspect of the defect will move superiorly and posteriorly, increasing the size of the oronasal communication (Fig. 2).

Lateral resection involving approximately half of the soft palate. The resection of the tumor involves functional interruption of half the paired muscles of the palate. The resection may be for a primary tumor; however, often integrity of this half of the soft palate unit is resected to provide adequate surgical margins for tumors of tonsil, retromolar trigone, and buccal mucosa. If the resection involves a lesion on the left side of the palate, the right levator, tensor, palatopharyngeus, palatoglossus, and uvula muscles are left intact. Since the palate is intended to

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Fig. 5. speech during between speech

AND

MYERS

The patient shown in Fig. 4 is treated with a aid prosthesis. Pharyngeal muscle contraction function will lead to a complete separation the nasopharynx and oropharynx essential for and deglutition.

function through a paired mechanism, the loss of one half of the mechanism drastically alters the function of the palate during swallowing and speech. The soft palate tends to elevate more laterally toward the normal side and more superiorly, since there is no limiting action of the muscles on the other side (Fig. 3). Attempts to cover the surgical defect in the soft palate as a defect in the hard palate is covered are not functionally adequate. The patient has problems with speech and a problem of escape of fluids through the nasal cavity. A different design for each category must be followed to give the patient a functionally adequate restoration.

PROSTHETIC TREATMENT

OF SOFT PALATE

We do not use surgical obturators in conjunction with resection of soft palate tumors, a practice we use in hard palate resections. However, a base prosthesis which is modified and inserted before the patient leaves the hospital is designed and constructed. The temporary prosthesis is used by the patient during the hospital stay and is modified during the first few months. The final design of the prosthesis is then reproduced in the definitive obturator. Three different obturator designs are used to restore the soft palate. 1. Prosthesis for total soft palate resection. A speech aid prosthesis extending posteriorly from the base of the prosthesis into the pharyngeal region separates the oropharynx from the nasopharynx. The success of this prosthesis is dependent upon the action of the superior constrictor muscle of the pharynx separating the two cavities during speech

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OF PALATE

Fig. 6. Median palatal defect as a result of a surgical removal of a lesion at the junction of the hard and soft palate.

Fig. 8. Activation of the soft palate musculature an effective seal of the palatal structures.

Fig. 7. Prosthesis for a median palatal defect is in place. The soft palate is in a relaxed position.

Fig. 9. A gate prosthesis with a retrovelar extension in position. Note that the lateral pharyngeal wa1I is relaxed and a space exists for nasal breathing.

and swallowing. At rest position there is a space around the pharyngeal part of the prosthesis to effect nasal breathing. This type of prosthesis is similar to speech aids constructed for congenital cleft patients (Figs. 4 and 5). 2. Prostheses for median palatal defects. The functional defect in this group is confined to the soft palate. The velopharyngeal mechanism is intact. The extension from the parent prosthesis passes through the soft palate defect to permit the sphincter action of the margins of the defect to produce an oronasal seal. The posterior extension of the prosthesis does not extend to the posterior or lateral pharyngeal wall (Figs. 6 to 8). The velar extension passes through the defect, and at rest position a space is present between the prosthesis and the posterior margin of the defect (Fig. 9). During speech or swallowing, the levator and tensor muscles contract and the margins of the

defect elevate to separate the oropharynx from the nasopharynx. The size and shape of this extension is adjusted as healing and reorganization of the defect progresses. 3. Prosthesis for lateral soft palate defects, The defect in this group involves one side of the soft palate. The loss of bilateral function of the palatal muscles is evident. The level of the muscular activity of the remaining segment of the soft palate is considerably higher in the pharyngeal region than in the intact palate. If the defect is small, velopharyngeal closure may be effected without the help of a prosthesis. If the defect is large or the patient is unable to develop compensatory movement, a retrovelar speech aid is constructed. A pharyngeal extension from the base of the prosthesis passes through the defect and fills the potential space behind the remaining segment of the soft palate. Velopharyn-

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geal closure is attained by the levator action of the remaining soft palate and the contraction of the pharyngeal muscles against the pharyngeal extension of the prosthesis. In fairly sizeable defects, after the patients have used the prosthesis for a period of time they tend to regain the ability of velopharyngeal closure without the prosthesis. A program of gradual reduction of the size of the pharyngeal extension is followed as the mechanism becomes effective. It seems that the presence of the pharyngeal extension of the prosthesis stimulates the muscle function or that some patients have the ability to spontaneously develop compensatory movements. Rehabilitation may also be made more complex if partial segmental resection of the mandible at the angle has been included in the resection. A guiding mandibular prosthesis may need to be constructed along with the maxillary deviation. This may not be difficult in the dentuious patient, but in the edentulous patient it may not be possible to overcome this problem. Patients with lateral soft palate defects are the most difficult to manage prosthetically. The more advanced tumors seen in this region tend to involve multiple anatomic sites. The more extensive resections required for tumor control produce more severe functional disability. The large regional pedicle flaps currently utilized for reconstruction provide static rather than dynamic replacement for the resected oropharyngeal musculature. This eliminates the pharyngeal component of velopharyngeal closure mechanism against the retrovelar speech aid. Many of these patients are edentulous, which makes adequate retention of these large prostheses difficult. Radiation therapy, applied to the oral cavity as part of the therapeutic program, may make wearing the prosthesis uncomfortable due to irritation of tissues.

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MYERS

Patient motivation and acceptance of the prosthesis is a necessary, albeit unmeasurable, fact in the success of the rehabilitative effort. The lifestyle of patients with cancer in edentulous regions is unique and most often includes alcoholism, self-neglect, and poor self-image. Many patients have rejected their dentures even prior to the discovery of the tumor. These difficulties make it necessary for the patient, the surgeon, and the prosthodontist to enter into the rehabilitative effort with realistic expectations to maximize their possibilities of success without undue disappointment, CONCLUSION The restoration of the soft palate presents a challenge completely different from that of the hard palate. The mobility of the soft palate tends to interfere with velar extensions. The reduction in size of the soft palate extension to prevent impingement upon the mobile margins of the defect will lead to insufficient oronasal separation during functional activities. The solution is to construct a specially designed prosthesis to attain the maximum utilization of the remaining structures and their motility. Although each pharyngeal extension is different in shape, they give the patient an effective functional mechanism that enhances speech and swallowing. REFERENCE 1.

Aramany, M. A., and Matalon, V.: Prosthetic management of postsurgical soft palate defects. J PROSTHET BENT 24:304. 1970.

Reprint requests to: DR. MOHAMEI) A. ARAUANV EYE AND EAR HOSPITAL OF PITTSBURGH

'230 LOTHROP R~SBURGH,

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PA. 15213

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