Prosthodontic principles in surgical planning for maxillary and mandibular resection patients

MAXILLOFACIAL PROSTHETICS TEMPOROMANDIBULAR JOINT SECTION

. DENTAL

I. KENNETH

ADISMAN

LOUIS J. BOUCHER

Prosthodontic principles in surgical planning maxillary and mandibular resection patients Arthur 0. Rahn, D.D.S.,* Medical

IMPLANTS

EDITORS

College

Barry M. Goldman,

of Georgia, School of Dentistry,

D.D.S.,

Augusta,

M

any surgical considerations will enhance the success of an- oral prosthesis. When a surgeon suspects that a patient may need to be treated with a maxillofacial restoration, he should consult a prosthodontist prior to performing the surgery. The prosthodontist should suggest the advantages of removing or retaining tissue adjacent to the surgical site. Although the exact extent of the surgical margins may not be known in the presurgical conference, guidelines can be established. It is the responsibility of the prosthodontist to educate surgeons about the prosthodontic requirements for restoring the patient that must undergo ablative surgery. This knowledge aids the surgeon in preparing his patient to receive a successful prosthesis after surgery. In many localities, particularly in large medical centers, this sharing of knowledge is becoming less of a problem because the prosthodontist is an active member of oncologic, trauma, and cleft palate teams. This article describes some of the prevalent oral tissue considerations that are significant to the prosthodontist. Not only should prosthodontists be aware of these problems, but it is also vital for the dental profession to be cognizant of those situations in the hospital environment which can improve the rehabilitation process of their patients.

INTRAORAL

CONSIDERATIONS

As much of the soft palate as is possible retained for patients that require a partial

should be maxillec-

Presented in part at the Academy of Denture Prosthetics, kee, Wis. *Professor, Department of Prosthodontics. **Associate Professor, Department of Prosthodontics. ***Assistant Professor, Department of Prosthodontics.

0022-3913/79/1004’29

+ 05$00.50/06

1979 The C. V. Mosby

Milwau-

Co.

M.S.,**

for

and Gregory R. Parr, D.D.S.***

Ga.

tomy (Fig. l).’ This procedure is helpful in providing a good tissue seal and definite limits for the posterior extension of an obturator. A prosthesis that obturates the posterior and lateral pharyngeal walls is difficult to construct and is usually lacking in retention and stability, particularly if the patient is totally edentulous. The presence of the soft palate often allows additional retention by extending the prosthesis posteriorly over the anterior border. Another problem seen frequently in patients with palatal defects is that the surgeon leaves fibrous tissue or anatomic structures such as the vomer or nasal conchae in close proximity to the margins of the defect (Fig. 2). This prevents good obturation and retention in many instances because the obturator bulb cannot be extended far enough into the site of the defect to be effective. Also, the portion of the prosthesis that directly opposes such structures often must be relieved because of the soreness that develops after a short period of time. These sturctures will not resist upward displacement of the obturator in most patients. In addition, the patient may not be able to tolerate the pressure, and a potentially successful prosthesis may be sacrificed because of the numerous adjustments required. When resecting a dentulous maxilla, the prosthodontist should advise the surgeon that the medial incision should be through the middle of the alveolus of the most anterior tooth that is to be removed, rather than immediately adjacent to the last remaining tooth (Fig. 3).‘. a By following this procedure, bone adjacent to the tooth can be kept intact, which will lessen the chance of tooth mobility at a later date due to bone loss (Figs. 4 and 5). Teeth are important to the retention of oral restorations, and they should never be extracted without consulting a prosthodontist (Fig. 6). Often

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RAHN,

Fig. 1. Success of an obturator for a large defect was greatly enhanced by retaining the soft palate.

Fig. 2. Two anatomic structures which often prevent good obturation are the vomer and nasal conchae.

430

sectioning

through

the middle

of

AND

PARR

seemingly hopeless teeth can be restored and retained as future abutments. Tooth preservation should be of paramount consideration even though it might be a temporary measure. However, there may be instances where extraction of some or all of the remaining teeth may be indicated (Fig. 7). Teeth may be supererupted or form an undesirable occlusal plane which in turn would create unfavorable forces on the finished prosthesis.’ The dentist must evaluate these situations with the necessary preoperative diagnostic casts. The position of the lesion may require sacrificing an additional sound tooth to assure an adequate margin of healthy tissue around the tumor site. Fibrous attachments in the labial sulcus, particularly at the medial margin of a maxillary resection, should be prevented (Fig. 8). These attachments limit the extension of the prosthesis in this region, commonly causing a leakage problem with the obturator. This type of tissue is easily displaced. Consequently, it is difficult to accurately bordermold around fibrous attachments. The prosthesis in this region usually requires numerous adjustments due to the extreme sensitivity of the tissue to movement of the restoration. Similarly, the maxillary tuberosities should be left intact if at all possible, since they prevent the displacement of the obturator into the defect. In some instances the position of the lesion will make it possible to preserve both tuberosities, providing a tripod effect which in turn enhances the success of the prosthesis due to increased stability and vertical support of the obturator (Fig. 9).

PLACEMENT

Fig. 3. Recommended the alveolus.

GOLDMAN,

OF SKIN GRAFTS

Little emphasis has been placed on the importance of skin-grafted surfaces in the maxillary resection site relative to eventual success of the obturator. Clinical evidence has shown that lining the entire maxillary and orbital defect with split-thickness skin grafts is indicated to improve the patient’s function with the obturator (and orbital) prosthesis.5 The presence of the skin graft tends to enhance the patient’s ability to tolerate the surgical obturator in the early postoperative days. As healing progresses, the junction line of the skin graft with the buccal mucosa, the mucoderma1 scar band, contracts to form a continuous scar band in the lateral margin of the maxillary defect (Fig. IO). This mucodermal band provides a narrowing of the defect and a relative undercut superior to the band, thus allowing the obturator bulb to extend more superiorly and laterally to the band and create a better seal of the bulb portion. In some instances OCTOBER

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Fig. 4. A, Radiograph prior to a maxillary the mesial of a central incisor. Maxillary adjacent alveolus.

Fig. 5. Correctly performed, maxillary resection preserve bone to support the central incisors.

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resection. B, Radiograph showing loss of bone on resection was not properly carried through the

will

the mucodermal scar band provides support to the overall prosthesis, particularly when the band is firm and fibrous. The patient is usually more comfortable with a skin-grafted defect that is drier than oral mucosa. The superior extension of the obturator bulb for good speech is more easily tolerated in a defect lined with a skin graft than with oral mucosa, since the dermal surface responds well to slight pressure. However, the prosthodontist must still maintain careful long-term follow-up of the patient with skin-grafted maxillary defects to avoid harmful effects of the prosthesis as the remaining dentition and the defect undergo change. When surgeons perform hemimandibulectomies they often suture the lingual frenum to the crest of THE

RESECTIONS

Fig. 6. A, Retention of a few teeth to serve as abutments for a removable partial denture framework markedly helped this patient with the obturator. B, This hemimandibulectomy patient was successfully treated with a swing-lock unilateral partial denture. 431

RAHN,

Fig. 7. Super-erupted teeth and an incorrect occlusal plane can create many problems when treating a patient with a prosthesis.

Fig.

9.

GOLDMAN,

Patient with both tuberosities

AND

PARR

retained.

Fig. 10. Mucodermal scar band @rows) can be important to the success of a maxillary obturator.

Fig. 8. A, A fibrous attachment was improperly attached to the medial margin of a resected maxilla. B, A fibrous attachment which was more ideally placed. the residual alveolar ridge (Fig. 11). This superior position of the lingual frenum complicates the treatment of a patient with a lower denture and often lessens its stability. Whenever feasible, the lingual frenum should be sutured low on the residual ridge or to the floor of the mouth at the base of the ridge, which is a more desirable position. If this is not done,

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Fig. 11. The Iingual frenum the alveolar ridge.

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Fig. 12. Following the establishment of a lingual sulcus, extension of the lingual flange aided lower denture retention.

SURGICAL

RESECTIONS

it may be necessary at a later date to perform a frenoplasty to allow the tongue more freedom of movement and greater extension of the denture base. An attempt should always be made to preserve or establish some sort of lingual sulcus adjacent to the remaining mandible to aid in the retention and stability of the prosthesis (Fig. 12). Future vestibuloplasty or grafting must also be considered (Fig. 13). Those hemimandibulectomies where the tongue and cheek are contiguous are generally doomed to failure. The degree of prosthodontic success in treating mandibular resection patients depends upon several factors, such as (1) the presence of the anterior portion of the mandible, (2) the presence of teeth, (3) ridge relationships, (4) previous experience in wearing dentures, and (5) the determination of the patient to wear the prosthesis.

CONCLUSION Discussion between the surgeon and prosthodontist on surgical planning is important. It is necessary that they each be aware of the other’s problems. Only in this way can continuity be established between surgical and prosthetic procedures. This will provide a maximum level of treatment for the maxiliofacial patients, thereby returning them to society most expeditiously. REFERENCES 1.

2. 3.

Aramany, M. A., and Myers, E. N.: Prosthetic reconstruction following resection of the hard and soft palate. ,J PROSTHET DENT 40: 174, 1978. Rahn, A. O., and Boucher, L. J.: Maxillnfacial Prosthetics. Philadelphia, 1970, W. B. Saunders Co. Aramany, M. A.: Basic principles of obturator design for partially edentulous patients. Part 11: Design principles. J PROSTHET

4. 5.

Reprint

DENT

40:656,

1978.

Desjardins, R. P.: Early rehabilitative management of the maxillectomy patient. J PROSWET DENT X$:311, 1977. Desjardins, R. P.: Obturator prosthesis design for acquired maxillary defects. J PROSTHET DEWT 39:424, 1978. reqwsts to:

DR. ARTHUR 0. RAHN MEDICAL COLLEGE OF GEORGIA SCHOOL OF DENTISTRY AUGUSTA, GA. 30912

Fig. 13. A, A patient with partial hemimandibulectomy showed no lingual or buccal vestibular depth. B, The same mouth after a skin-graft vestibuloplasty had been performed.

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