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Maxillofacial deformities and maxillofacial prosthetics
MAXILLOFACZAL
MAXILLOFACIAL
PROSTHESIS
DEFORMITIES
JOHN MARQUIS CONVERSE, New York
University,
AND MAXILLOFACIAL
PROSTI-IETICS
M.D."
School
of Medicine,
New York, N. Y.
WIDE VARIETY of maxillofacial deformities resulting from COngenital mlformation, trauma, or excision of malignant tissue, restoration of function and of facial form is achieved by replacement of missing soft tissue, sectioning and repositioning misplaced bone, bone grafting of osseous defects, and normal contour. There are various types of deformities and malformations of the jaws in which it is necessary to employ prostheses. In these cases,the surgeon and the prosthodontist must work hand in hand. In severe compound comminuted fractures of the mandible or maxilla with 10~s of tissue such as are seen in gunshot wounds or in other severe maxillofacial injuries, the provision of a surgical prosthesis is an essential part of treatment. The prosthesis serves not only to maintain the anatomic position of the remaining fragments, but also as a framework over which the soft tissues are sutured. In this manner, the normal contour of the face is maintained (Fig. 1). There are many deformities with defects of the bony framework of the face in which a prosthetic appliance is needed, either in the form of a denture, or to restore contour. As a rule, the prosthesis is fitted into a surgical cavity which must be lined with skin by a technique often designated as the “epithelial inlay.”
I
THE
N THE
EPITHELIAL
INLAY
TECHNIQUE
Successful skin grafting within the oral cavity is often a prerequisite to the fitting and wearing of a satisfactory prosthesis. The term “epithelial inlay” was used by Esser’ who devised this technique of intraoral skin grafting. Esser was a Dutch surgeon who worked with the Austrian army during World War I. He conceived the method for the purpose of establishing a buccal sulcus for patients who had t’he mandible reconstructed by bone grafts. The purpose of creating the sulcus was to make possible the retention of a denture. He made an incision through the skin in the submandibular area, extending the incision to the lower border of the reconstructed mandible, then upward along the buccal aspect of the mandible as far as the mucosa of the floor of the mouth. Tnto this cavity he molded a piece of softened Presented *Institute
before the American Academy of Reconstructive Plastic Surgery,
of Maxillofacial Prosthetics in Philadelphia, New York University Medical Center.
Pa.
572
CONVERSE
J. I’ros. Den. May-Ju~le, 1963
Fig. l.-Prosthetic support in the early treatment of a facial injury. A, Loss of tissue from a gunshot wound. The anterior part of the maxillae, including the alveolar process, has been destroyed. B, After reconstruction. A prosthesis replaces the lost bone and maintains the soft tissue contour.
dental modeling compound which made an impression of the cavity produced on the buccal side of the reconstructed mandible. Around this mold he wrapped a split-thickness skin graft, placed the compound mold in the cavity, and sutured the submandibular incision. In a second stage operation, a number of weeks later, he incised through the mucosa of the floor of the mouth into the skin-grafted cavity, removed the dental compound mold, and extended the buccal flange of the patient’s denture into the newly created sulcus. Waldron modified the technique by placing the epithelial inlay directly into the new sulcus through an intraoral incision. Since World War I, the epithelial inlay technique has been used extensively to restore an adequate lining in the oral cavity. The typical epithelial inlay technique to restore a mandibular sulcus consists of three parts : the incision, the prosthesis, and the skin graft. THE
INCISION
The incision is made through the mucosa only (not through the periosteum) and extends downward along the buccal surface of the mandible. The purpose of leaving the periosteum intact over the bone is that grafting is more successful over the vascular bed provided by the periosteum. The incision is made on the buccal aspect of the alveolar ridge and the mucosal flap thus formed is reflected forward and partially lines the buccal aspect of the new sulcus (Fig. 2). This type of
\‘olullle 13 .\:uml~er 3
MAXILLOFACIAL
DEFORMITIES
AND
PROSTHETICS
573
iucision is a refinement in the technique and has the advantage that the cut edges of the oral mucosa are not situated at the sanie level (Fig. 2,C j, thus a constrictive scar band is not formed at the junction line bet\veen the skin graft and the mucosa after the skin graft has healed. Careful hemostasis is obtained by pinching the bleeding vessels with fine forceps and sealing them off by means of electrocoagulation. Complete hemostasis is essential to prevent hematoma which would interfere with the revascularization of the skin graft. The essential process in successful skin grafting is revascularization from the host bed. There is an early connection between the vessels of the graft and the vessels of the host bed and penetration of nutrient fluid into the graft. This process which has been designated as “plasmatic circulation” is a temporary one. Concomitantly, the definitive vasculature of the graft is furnished by the rapid ingrowth of host vessels into the graft. This process starts early after skin transplantation and continues until the third or fourth day, the vasculature finally becoming differentiated and furnishing the means for the flow of blood into and from the graft. In order that this ingrowth of host vessels into the graft may occur without interference, two conditions must be met. First, the contact between graft and host must be as intimate as possible and there must be no interposition of blood or serum which would act as a barrier to the ingrowth of host vessels. Second, good fixation and immobilization must be provided in order that the newly grown host vessels are not torn during the period of penetration into the graft. Jn large epithelial inlays, considerable distention of the soft tissues in the region of the symphysis is necessary to permit the introduction of a modeling compound mold of sufficient size. In such cases, it may be necessary to sever the lower
Fig. Z.-The technique of inserting incision over the buccal aspect of the reflected forward, the sulcus deepened, the inadequate width of the compound the sulcus. C, The correct shape of the sulcus.
an epithelial inlay. A, The scarred vestibule and site of residual alveolar ridge. B, The mucosal flap has been and a modeling compound mold has been made. Note mold which allows contraction of the graft to obliterate mold which fills and dilates the cul-de-sac of the new
574
J. Pros. May-June,
CONVERSE
Den. 1963
attachments of the musculature of the lower lip and the platysma in order to permit adequate stretching of the soft tissues. THE
PROSTHESIS
Two features are essential in the construction of the dental modeling compound mold. First, it must represent an accurate impression of the surgically created cavity, and, second, it must be considerably larger than the cavity in order to distend the tissues in every direction (Fig. 2,C). Both of these features are essential to produce accurate coaptation of the skin graft to the raw tissue. Hematoma which would interfere with the revascularization of the graft is thus prevented. All skin grafts tend to contract during the healing period, and if the skin graft is placed on a mold which is too large, an excess of skin graft will be transplanted, thus counteracting the eventual contraction of the graft. Newly developed synthetic materials (resins) have made possible the fabrication of a definitive prosthesis while the patient is in the operating room. However, considerable delay has occurred in this fabrication despite the rapidity of curing of some of the new resins. It is more practical in most complicated cases to prepare two appliances. The first is a temporary bite block (occlusion rim) which serves to anchor the modeling compound mold for the primary skin grafting procedure, and a second which is a definitive appliance with the denture ; this second appliance will replace the first after the initial postoperative dressing. The size of the second appliance is gradually reduced during the weeks subsequent to the operation. The shaping of the mold is important. It should fill the entire cavity and be of a shape that will insure its retention. THE
SKIN
GRAFT
Split-thickness skin has been employed through the years to reline surgical cavities. Recently, split-thickness grafts of oral mucosa have also been employed. Mucosa is superior to skin for this purpose because it does not have the malodorous sebaceous secretion of skin and does not grow hair. Split-thickness grafts of mucosa are suitable for relatively small epithelial inlays, such as those used for the deepening of an upper buccal sulcus in the final rehabilitation of cleft-lip patients. In large epithelial inlays, skin is required because the supply of oral mucosa is limited. A number of mechanical means are available for removing split-thickness skin grafts of accurat.e thickness. Originally, the epithelial inlay was made from a very thin split-thickness graft (Thiersch graft), The thin graft has the advantage of becoming vascularized rapidly, and having what is referred to as an excellent “take.” The inconvenience of the Thiersch graft is its contraction during the postoperative healing period. For this reason, thicker varieties of split-thickness skin grafts are now employed. The skin graft should be removed from a hairless area of the body to prevent subsequent growth of hair inside of the oral cavity. FIXATION
OF
THE
PROSTHESIS
FOR
EPITHELIAL
The fixation of the appliance which created sulcus varies according to whether
INLAY
maintains the skin graft in the newly or not the patient has teeth. When the
Volume Number
13 3
MAXILLOFACIAL
DEFORMITIES
AND
PROSTHETICS
575
patient has teeth, it is possible to provide fixation of the partial denture by means of wiring around the teeth. When the patient is edentulous, a complete denture or a bite block (occlusion rim) is maintained by circumferential wiring around each side of the body of the mandible (Fig. 3 ‘i . POSTOPERATIVE
CARE
The skin graft is immobilized for a period of approximatively the modeling compound mold is removed under sedation, regional
7 days; then, anesthesia, or
Fig. 3.-Circumferential wiring for the fixation of a prosthesis which supports a skin graft in the epithelial inlay technique. A, Incising the new sulcus. B and C, Circumferential wire being placed around the edentulous mandible. D, An occlusion rim with a modeling compound extension (mold) into the sulcus. E, The prosthesis carrying the skin graft is maintained in position by circumferential wires.
576
CONVERSE
J. Pros. May-June,
Den. 1963
general anesthesia. Any excess of the skin graft overlapping the edges of the sulcus, and any points where granulation tissue is seen, are trimmed and cauterized with a silver nitrate stick. The duplicate acrylic resin mold is used to replace the primary mold. This resin prosthesis is left undisturbed for another 4 or 5 days when it is removed for cleaning. After this, it is removed every few days. The molds should be made grossly oversized for all large epithelial inlays. After a period varying between 3 and 5 weeks, the size of the acrylic resin prosthesis is reduced by grinding it progressively down to the desired size and shape. All skin grafts contract; the period of maximum contracture occurs between the third and fifth weeks postoperatively. Progressive diminution of the edema of inflammatory reaction occurs over a period of many weeks, and the reduction in size should be slow and progressive. The best results are obtained if a period of about 8 to 10 weeks is spent in developing the final size and shape of the prosthesis. THE
EPITHELIAL
INLAY
IN
MANDIBULAR
DEFECTS
After bone grafting for the restoration of the continuity of the body of the mandible, the new sulcus must be made in order that a denture can be retained in position. It is essential that the surgeon allow for the added contour of the denture in planning his reconstruction. This is particularly true in bony restoration of the anterior part of the body of the mandible and the symphysis. After the reconstruction of the anterior half of the body of the mandible and the symphysis, the extension of the sulcus downward into the region of the chin is usually necessary to secure good retention for the denture. Thus, the buccal flange of the denture contributes to the contour of the chin for these patients. Should the surgeon not allow for the thickness of the denture, the chin might appear to be too prominent, and the patient might appear prognathic. Therefore, it is necessary not to fully correct the contour by means of the bone grafting and allow the prosthesis to restore the contour of the chin. In patients with an atresic mandible (micrognathia), often the jaw is edentulous. The facial form of these patients can be restored by means of a denture which extends into the region of the chin. It is necessary to create a labial sulcus into which the denture can fit. The sulcus is extended down to the level of the skin in the submental region and fills the cavity thus produced with impression material, which is then covered by a skin graft (Fig. 4). FREEING
THE
TONGUE
AFTER
RADICAL
SURGERY
The tongue is often used as a means of obliterating a cavity following an extensive resection of the mandible with neck dissection in continuity. If the tongue was simply freed from the floor of the mouth, the raw surface on the undersurface of the tongue and the floor of the mouth would become adherent, and the tongue would resume its former position bound down to the floor of the mouth by scar tissue. An incision is made laterally to the adherent portion of the tongue, and the undersurface of the tongue is freed from the floor of the mouth. Dental modeling compound is then molded into this cavity and hardened “in situ.” Then a split-thickness graft is wrapped around the modeling compound and introduced
Volume Number
13 3
MAXILLOFACIAI,
DEFORMITIES
AND
PROSTHETICS
577
in1:o the cavity, and the incision along the lateral aspect of the tongue is suture Al ‘ter an interval of a few weeks, the incisioli is reopened, the modeling conlpou of the tongtw is freed from the floor of t lll( Ad is removetl, and the remainder
A.
c.
n.
Fig. 4.-The epithelial inlay in micrognathia. mandible. C and D, The appearance an infantile An extension of the labial flange in1 a.y technique.
A and B, The appearance of the patient w ith of the patient after treatment by the epithe’ lid of the denture supports the chin.
J. Pros. Den. May-June, 1963
CONVERSE
c.
D.
Fig. 5 .-A nasomaxillary epithelial inlay. A, The patient with a nasomaxillary recese ;ion wh tich was the result of the destruction of intranasal structures. B, The appearance after n; soma lxillary epithelial inlay had been inserted. C, The overdistention of the sulcus necessary for SU( xessful skin grafting. The prosthetic mold is progressively reduced in size during subsequ .ent ‘eks. 0, The patient holding the appliance. Note the nasal extension from the denture.
XAXILLOFACIAL
Fig. B.-The intranasal epithelial around the mold. C, The mold carries it there.
DEFORMITIES
AND
PROSTHETICS
570
inlay. A and B, The split-thickness skin graft is wrapped the graft into position in the nasal cavity and maintains
Fig. 7.-Prosthetic support in (stenosis of the nasal airways and nasal deformity. A, The patient after unsuccessful plastic surgery. Note the collapsed alae of the nose. B, After secondary plastic surgery and the relief of na al stenosis by means of intranasal skin grafting and support by a prosthetic appliance. C, A pr operative view showing the collapse of the alae. D, A postoperative view showing the intran i sal prosthetic appliance worn by the patient. (From: Converse; Corrective Surgery of the N&al Tip, The Laryngoscope 67: 16, 1957.)
J. Pros. Den. May-June, 1963
CONVERSE
mouth. The healed skin graft covers floor of the mouth. NASOMAXILLARY
EPITHELIAL
the surface under the tongue and over the
INLAY
A gross deformity results when the nasal bones and the middle portion of the maxillae have been destroyed or are underdeveloped as a result of trauma in childhood. The condition has been referred to as “dishface.” The nasal cavity is lined to permit the insertion of a prosthesis, which is designed to support the soft tissues of the nose, and to replace the missing maxillary bone and teeth. Under intratracheal anesthesia, an incision is made in the upper buccal sulcus ; the nasal fossa is entered from within the sulcus ; the external nasal structures are freed of adhesions, and an extensive raw area results. The nasal spine is removed. A modeling compound mold is then constructed to fit a pyramidshaped cavity. The apex of the mold points upward in order that the mold will have a nonretentive shape and can be inserted and removed easily. The modeling compound mold is duplicated in a permanent acrylic resin prosthesis. A split-thickness graft from the inner aspect of the arm is spread over the mold with its raw surface outward, and inserted into the nasal cavity. The tissues should be distended by the compound mold in order to insure close coaptation of the graft around the soft tissues and to counteract possible subsequent contraction of the graft. The acrylic
A.
I?.
Fig. 8.-A, A complex deformity with a bony union between the upper and lower jaws on the right side, and a soft tissue defect. R, After separation of the bony union and intraoral skin grafting, occlusion rims were made, and a spring attachment assists in the mobilization of the mandible. C, The occlusion rims and spring attachment. D, The patient wearing an upper denture. E, The patient at the completion of treatment.
\ olunle N umbvr
13 3
MAXILLOFACIAL
DEFORIvIITIES
AND
PROSTI~l’TICS
581
is esanlinctl and cleaned. resin prosthesis is removed after 2 weeks, alit1 the cavity At intervals during subsequent weeks, ihe size of the mold is reduced. After a period of 6 to 8 weeks, a permallellt acrylic resin support attached to an upper dentljre is employed to maintain the nornlal contour of the nose. The nasomaxillary epithelial inlay technique, originally developed by Gillies for the treatment of the syphilitic nose deformity (Fig. 5) is indicated occasiopally for traumatic nasomaxillary deformities, particularly for edentulous patients. SKIN
GRAFTING
WITHIN
THE
NOSE
If the obstruction consists of more than a weblike band of scar tissue, a neu lining for the nose is provided by skin grafting. The scars are excised and the lateral wall of the nose is freed from the septum. A split-thickness skin graft, pre-
582
J. Pros. May-June,
CONVERSE
Den. 1963
ferably from the inner aspect of the arm, a full-thickness graft from the upper eyelid, or a graft of oral mucosa may be used. Provision is made for immobilization of the skin graft within the nose. A temporary mold of modeling compound serves as the carrier for the graft. The modeling compound is softened and molded into an oval-shaped cone, cooled, and hardened. The surface of the cone is covered with petroleum jelly and flamed; the inner part of the modeling compound cone is not soft,ened. Then, the cone is reintroduced into the nostril, molded against the lateral wall of the nose, and removed. A small amount of Dermatome cement is dabbed on the mold and the graft is wrapped around it with the raw surface outward, and it is then inserted into the nostril (Fig. 6). The mold is retained in position for 4 to 5 days. The original temporary compound mold is duplicated in acrylic resin. When the temporary mold is removed, the hollowed acrylic resin mold is introduced into the nostril. Thus, shrinkage and constriction of the graft are minimized ; the resiliency of the septal and nasal cartilages prevents recurrence of stenosis. The postoperative mold is retained for a number of months. When stenosis is the result of excessive removal of lateral and alar cartilage as well as nasal lining (Fig. 7), the prosthesis supports the deficient cartilaginous structures and is retained permanently to assure patency of the airway. Mucosal grafts removed from the oral mucous membrane may also be employed for intranasal grafts. Mucosa.does not tend to crust or produce a fetid odor. COMBINED
EFFORTS
OF PLASTIC
SURGEON
AND
PROSTHODONTIST
A E-year-old Panamanian boy needed the combined efforts of a plastic surgeon and a maxillofacial prosthodontist. When first examined, this patient showed an unusual deformity (Fig. &A). There was a temporomandibular ankylosis due to the bony fusion between the maxilla and mandible on the right side, and an absence of tissue of three-quarters of the upper lip and of the adjacent part of the cheek on the right side. The origin of the malformation was thought to be congenital. In the first operation, the bone joining the upper and lower jaws was sectioned and a segment of bone and the teeth was removed. Then, the cut surfaces of the bone were covered by a split-thickness skin graft placed raw surface outward over a dental modeling compound mold which was wedged between the cut bony surfaces. After the skin graft had healed, an appliance consisting of two baseplates and a spring was constructed which mobilized the temporomandibular joints and increased the degree of opening between the jaws (Fig. 8,B and C). Two months later an alveolectomy, following extraction of the lower incisors, canine, and first bicuspid on the left, was done in order to facilitate the wearing of a lower denture. Upper and lower dentures were made for the patient. The right upper sulcus was extended by incising along the buccal aspect of the hard palate, and placing a split-thickness skin graft maintained on an acrylic resin extension attached to the upper denture. Modeling compound placed on the right side of the denture was molded into the surgically created sulcus. Then, the modeling compound extension from the denture was duplicated with cold-curing acrylic resin. The skin graft was placed on the extension, raw surface outward, so that the den-
tu:re maintained the graft in the sulcus (Fig. S,L?). After the intraoral operation was completed, the soft tissue defect was repaired by means of an Abbe-Estlander flap (Fig. 8,E ). The physical change in the patient was not limited to the orofacial area. The patient underwent a period of rapid growth and weight increase which was attributed to the improvement of his nutrition made possible by the restoration of his masticatory function.
Maxillofacial prosthodontics is an essential adjunct to reconstructive surgery in many types of deformations and malformations of the jaws. Among the indications for prosthetic appliances are: (1) severe facial injuries with loss of bony framework, (2,) defects of the mandible requiring bone grafting, (3) micrognathia, and (4 ) nasomaxillary atresia. The epithelial inlay technique for skin grafting in the oral or nasal cavities has been described, and a number of applications of the epithelial inlay technique have been illustrated. Close collaboration of the plastic surgeon and the prosthodontist is essential in the treatment of many types of orofacial defects. REFERENCE
1. E&r. J. F. :
Studies
in
NEW YORK UUIVERSITY .SCHOOL OF MKDICINE 550 FIRST AVE. :NEW YORK 16. N. Y.
Plastic
Surgery
of the Face,
A4nn. Surg.
65297,
1917.
MAXILLOFACIAL
PROSTHESIS
DEFORMITIES
JOHN MARQUIS CONVERSE, New York
University,
AND MAXILLOFACIAL
PROSTI-IETICS
M.D."
School
of Medicine,
New York, N. Y.
WIDE VARIETY of maxillofacial deformities resulting from COngenital mlformation, trauma, or excision of malignant tissue, restoration of function and of facial form is achieved by replacement of missing soft tissue, sectioning and repositioning misplaced bone, bone grafting of osseous defects, and normal contour. There are various types of deformities and malformations of the jaws in which it is necessary to employ prostheses. In these cases,the surgeon and the prosthodontist must work hand in hand. In severe compound comminuted fractures of the mandible or maxilla with 10~s of tissue such as are seen in gunshot wounds or in other severe maxillofacial injuries, the provision of a surgical prosthesis is an essential part of treatment. The prosthesis serves not only to maintain the anatomic position of the remaining fragments, but also as a framework over which the soft tissues are sutured. In this manner, the normal contour of the face is maintained (Fig. 1). There are many deformities with defects of the bony framework of the face in which a prosthetic appliance is needed, either in the form of a denture, or to restore contour. As a rule, the prosthesis is fitted into a surgical cavity which must be lined with skin by a technique often designated as the “epithelial inlay.”
I
THE
N THE
EPITHELIAL
INLAY
TECHNIQUE
Successful skin grafting within the oral cavity is often a prerequisite to the fitting and wearing of a satisfactory prosthesis. The term “epithelial inlay” was used by Esser’ who devised this technique of intraoral skin grafting. Esser was a Dutch surgeon who worked with the Austrian army during World War I. He conceived the method for the purpose of establishing a buccal sulcus for patients who had t’he mandible reconstructed by bone grafts. The purpose of creating the sulcus was to make possible the retention of a denture. He made an incision through the skin in the submandibular area, extending the incision to the lower border of the reconstructed mandible, then upward along the buccal aspect of the mandible as far as the mucosa of the floor of the mouth. Tnto this cavity he molded a piece of softened Presented *Institute
before the American Academy of Reconstructive Plastic Surgery,
of Maxillofacial Prosthetics in Philadelphia, New York University Medical Center.
Pa.
572
CONVERSE
J. I’ros. Den. May-Ju~le, 1963
Fig. l.-Prosthetic support in the early treatment of a facial injury. A, Loss of tissue from a gunshot wound. The anterior part of the maxillae, including the alveolar process, has been destroyed. B, After reconstruction. A prosthesis replaces the lost bone and maintains the soft tissue contour.
dental modeling compound which made an impression of the cavity produced on the buccal side of the reconstructed mandible. Around this mold he wrapped a split-thickness skin graft, placed the compound mold in the cavity, and sutured the submandibular incision. In a second stage operation, a number of weeks later, he incised through the mucosa of the floor of the mouth into the skin-grafted cavity, removed the dental compound mold, and extended the buccal flange of the patient’s denture into the newly created sulcus. Waldron modified the technique by placing the epithelial inlay directly into the new sulcus through an intraoral incision. Since World War I, the epithelial inlay technique has been used extensively to restore an adequate lining in the oral cavity. The typical epithelial inlay technique to restore a mandibular sulcus consists of three parts : the incision, the prosthesis, and the skin graft. THE
INCISION
The incision is made through the mucosa only (not through the periosteum) and extends downward along the buccal surface of the mandible. The purpose of leaving the periosteum intact over the bone is that grafting is more successful over the vascular bed provided by the periosteum. The incision is made on the buccal aspect of the alveolar ridge and the mucosal flap thus formed is reflected forward and partially lines the buccal aspect of the new sulcus (Fig. 2). This type of
\‘olullle 13 .\:uml~er 3
MAXILLOFACIAL
DEFORMITIES
AND
PROSTHETICS
573
iucision is a refinement in the technique and has the advantage that the cut edges of the oral mucosa are not situated at the sanie level (Fig. 2,C j, thus a constrictive scar band is not formed at the junction line bet\veen the skin graft and the mucosa after the skin graft has healed. Careful hemostasis is obtained by pinching the bleeding vessels with fine forceps and sealing them off by means of electrocoagulation. Complete hemostasis is essential to prevent hematoma which would interfere with the revascularization of the skin graft. The essential process in successful skin grafting is revascularization from the host bed. There is an early connection between the vessels of the graft and the vessels of the host bed and penetration of nutrient fluid into the graft. This process which has been designated as “plasmatic circulation” is a temporary one. Concomitantly, the definitive vasculature of the graft is furnished by the rapid ingrowth of host vessels into the graft. This process starts early after skin transplantation and continues until the third or fourth day, the vasculature finally becoming differentiated and furnishing the means for the flow of blood into and from the graft. In order that this ingrowth of host vessels into the graft may occur without interference, two conditions must be met. First, the contact between graft and host must be as intimate as possible and there must be no interposition of blood or serum which would act as a barrier to the ingrowth of host vessels. Second, good fixation and immobilization must be provided in order that the newly grown host vessels are not torn during the period of penetration into the graft. Jn large epithelial inlays, considerable distention of the soft tissues in the region of the symphysis is necessary to permit the introduction of a modeling compound mold of sufficient size. In such cases, it may be necessary to sever the lower
Fig. Z.-The technique of inserting incision over the buccal aspect of the reflected forward, the sulcus deepened, the inadequate width of the compound the sulcus. C, The correct shape of the sulcus.
an epithelial inlay. A, The scarred vestibule and site of residual alveolar ridge. B, The mucosal flap has been and a modeling compound mold has been made. Note mold which allows contraction of the graft to obliterate mold which fills and dilates the cul-de-sac of the new
574
J. Pros. May-June,
CONVERSE
Den. 1963
attachments of the musculature of the lower lip and the platysma in order to permit adequate stretching of the soft tissues. THE
PROSTHESIS
Two features are essential in the construction of the dental modeling compound mold. First, it must represent an accurate impression of the surgically created cavity, and, second, it must be considerably larger than the cavity in order to distend the tissues in every direction (Fig. 2,C). Both of these features are essential to produce accurate coaptation of the skin graft to the raw tissue. Hematoma which would interfere with the revascularization of the graft is thus prevented. All skin grafts tend to contract during the healing period, and if the skin graft is placed on a mold which is too large, an excess of skin graft will be transplanted, thus counteracting the eventual contraction of the graft. Newly developed synthetic materials (resins) have made possible the fabrication of a definitive prosthesis while the patient is in the operating room. However, considerable delay has occurred in this fabrication despite the rapidity of curing of some of the new resins. It is more practical in most complicated cases to prepare two appliances. The first is a temporary bite block (occlusion rim) which serves to anchor the modeling compound mold for the primary skin grafting procedure, and a second which is a definitive appliance with the denture ; this second appliance will replace the first after the initial postoperative dressing. The size of the second appliance is gradually reduced during the weeks subsequent to the operation. The shaping of the mold is important. It should fill the entire cavity and be of a shape that will insure its retention. THE
SKIN
GRAFT
Split-thickness skin has been employed through the years to reline surgical cavities. Recently, split-thickness grafts of oral mucosa have also been employed. Mucosa is superior to skin for this purpose because it does not have the malodorous sebaceous secretion of skin and does not grow hair. Split-thickness grafts of mucosa are suitable for relatively small epithelial inlays, such as those used for the deepening of an upper buccal sulcus in the final rehabilitation of cleft-lip patients. In large epithelial inlays, skin is required because the supply of oral mucosa is limited. A number of mechanical means are available for removing split-thickness skin grafts of accurat.e thickness. Originally, the epithelial inlay was made from a very thin split-thickness graft (Thiersch graft), The thin graft has the advantage of becoming vascularized rapidly, and having what is referred to as an excellent “take.” The inconvenience of the Thiersch graft is its contraction during the postoperative healing period. For this reason, thicker varieties of split-thickness skin grafts are now employed. The skin graft should be removed from a hairless area of the body to prevent subsequent growth of hair inside of the oral cavity. FIXATION
OF
THE
PROSTHESIS
FOR
EPITHELIAL
The fixation of the appliance which created sulcus varies according to whether
INLAY
maintains the skin graft in the newly or not the patient has teeth. When the
Volume Number
13 3
MAXILLOFACIAL
DEFORMITIES
AND
PROSTHETICS
575
patient has teeth, it is possible to provide fixation of the partial denture by means of wiring around the teeth. When the patient is edentulous, a complete denture or a bite block (occlusion rim) is maintained by circumferential wiring around each side of the body of the mandible (Fig. 3 ‘i . POSTOPERATIVE
CARE
The skin graft is immobilized for a period of approximatively the modeling compound mold is removed under sedation, regional
7 days; then, anesthesia, or
Fig. 3.-Circumferential wiring for the fixation of a prosthesis which supports a skin graft in the epithelial inlay technique. A, Incising the new sulcus. B and C, Circumferential wire being placed around the edentulous mandible. D, An occlusion rim with a modeling compound extension (mold) into the sulcus. E, The prosthesis carrying the skin graft is maintained in position by circumferential wires.
576
CONVERSE
J. Pros. May-June,
Den. 1963
general anesthesia. Any excess of the skin graft overlapping the edges of the sulcus, and any points where granulation tissue is seen, are trimmed and cauterized with a silver nitrate stick. The duplicate acrylic resin mold is used to replace the primary mold. This resin prosthesis is left undisturbed for another 4 or 5 days when it is removed for cleaning. After this, it is removed every few days. The molds should be made grossly oversized for all large epithelial inlays. After a period varying between 3 and 5 weeks, the size of the acrylic resin prosthesis is reduced by grinding it progressively down to the desired size and shape. All skin grafts contract; the period of maximum contracture occurs between the third and fifth weeks postoperatively. Progressive diminution of the edema of inflammatory reaction occurs over a period of many weeks, and the reduction in size should be slow and progressive. The best results are obtained if a period of about 8 to 10 weeks is spent in developing the final size and shape of the prosthesis. THE
EPITHELIAL
INLAY
IN
MANDIBULAR
DEFECTS
After bone grafting for the restoration of the continuity of the body of the mandible, the new sulcus must be made in order that a denture can be retained in position. It is essential that the surgeon allow for the added contour of the denture in planning his reconstruction. This is particularly true in bony restoration of the anterior part of the body of the mandible and the symphysis. After the reconstruction of the anterior half of the body of the mandible and the symphysis, the extension of the sulcus downward into the region of the chin is usually necessary to secure good retention for the denture. Thus, the buccal flange of the denture contributes to the contour of the chin for these patients. Should the surgeon not allow for the thickness of the denture, the chin might appear to be too prominent, and the patient might appear prognathic. Therefore, it is necessary not to fully correct the contour by means of the bone grafting and allow the prosthesis to restore the contour of the chin. In patients with an atresic mandible (micrognathia), often the jaw is edentulous. The facial form of these patients can be restored by means of a denture which extends into the region of the chin. It is necessary to create a labial sulcus into which the denture can fit. The sulcus is extended down to the level of the skin in the submental region and fills the cavity thus produced with impression material, which is then covered by a skin graft (Fig. 4). FREEING
THE
TONGUE
AFTER
RADICAL
SURGERY
The tongue is often used as a means of obliterating a cavity following an extensive resection of the mandible with neck dissection in continuity. If the tongue was simply freed from the floor of the mouth, the raw surface on the undersurface of the tongue and the floor of the mouth would become adherent, and the tongue would resume its former position bound down to the floor of the mouth by scar tissue. An incision is made laterally to the adherent portion of the tongue, and the undersurface of the tongue is freed from the floor of the mouth. Dental modeling compound is then molded into this cavity and hardened “in situ.” Then a split-thickness graft is wrapped around the modeling compound and introduced
Volume Number
13 3
MAXILLOFACIAI,
DEFORMITIES
AND
PROSTHETICS
577
in1:o the cavity, and the incision along the lateral aspect of the tongue is suture Al ‘ter an interval of a few weeks, the incisioli is reopened, the modeling conlpou of the tongtw is freed from the floor of t lll( Ad is removetl, and the remainder
A.
c.
n.
Fig. 4.-The epithelial inlay in micrognathia. mandible. C and D, The appearance an infantile An extension of the labial flange in1 a.y technique.
A and B, The appearance of the patient w ith of the patient after treatment by the epithe’ lid of the denture supports the chin.
J. Pros. Den. May-June, 1963
CONVERSE
c.
D.
Fig. 5 .-A nasomaxillary epithelial inlay. A, The patient with a nasomaxillary recese ;ion wh tich was the result of the destruction of intranasal structures. B, The appearance after n; soma lxillary epithelial inlay had been inserted. C, The overdistention of the sulcus necessary for SU( xessful skin grafting. The prosthetic mold is progressively reduced in size during subsequ .ent ‘eks. 0, The patient holding the appliance. Note the nasal extension from the denture.
XAXILLOFACIAL
Fig. B.-The intranasal epithelial around the mold. C, The mold carries it there.
DEFORMITIES
AND
PROSTHETICS
570
inlay. A and B, The split-thickness skin graft is wrapped the graft into position in the nasal cavity and maintains
Fig. 7.-Prosthetic support in (stenosis of the nasal airways and nasal deformity. A, The patient after unsuccessful plastic surgery. Note the collapsed alae of the nose. B, After secondary plastic surgery and the relief of na al stenosis by means of intranasal skin grafting and support by a prosthetic appliance. C, A pr operative view showing the collapse of the alae. D, A postoperative view showing the intran i sal prosthetic appliance worn by the patient. (From: Converse; Corrective Surgery of the N&al Tip, The Laryngoscope 67: 16, 1957.)
J. Pros. Den. May-June, 1963
CONVERSE
mouth. The healed skin graft covers floor of the mouth. NASOMAXILLARY
EPITHELIAL
the surface under the tongue and over the
INLAY
A gross deformity results when the nasal bones and the middle portion of the maxillae have been destroyed or are underdeveloped as a result of trauma in childhood. The condition has been referred to as “dishface.” The nasal cavity is lined to permit the insertion of a prosthesis, which is designed to support the soft tissues of the nose, and to replace the missing maxillary bone and teeth. Under intratracheal anesthesia, an incision is made in the upper buccal sulcus ; the nasal fossa is entered from within the sulcus ; the external nasal structures are freed of adhesions, and an extensive raw area results. The nasal spine is removed. A modeling compound mold is then constructed to fit a pyramidshaped cavity. The apex of the mold points upward in order that the mold will have a nonretentive shape and can be inserted and removed easily. The modeling compound mold is duplicated in a permanent acrylic resin prosthesis. A split-thickness graft from the inner aspect of the arm is spread over the mold with its raw surface outward, and inserted into the nasal cavity. The tissues should be distended by the compound mold in order to insure close coaptation of the graft around the soft tissues and to counteract possible subsequent contraction of the graft. The acrylic
A.
I?.
Fig. 8.-A, A complex deformity with a bony union between the upper and lower jaws on the right side, and a soft tissue defect. R, After separation of the bony union and intraoral skin grafting, occlusion rims were made, and a spring attachment assists in the mobilization of the mandible. C, The occlusion rims and spring attachment. D, The patient wearing an upper denture. E, The patient at the completion of treatment.
\ olunle N umbvr
13 3
MAXILLOFACIAL
DEFORIvIITIES
AND
PROSTI~l’TICS
581
is esanlinctl and cleaned. resin prosthesis is removed after 2 weeks, alit1 the cavity At intervals during subsequent weeks, ihe size of the mold is reduced. After a period of 6 to 8 weeks, a permallellt acrylic resin support attached to an upper dentljre is employed to maintain the nornlal contour of the nose. The nasomaxillary epithelial inlay technique, originally developed by Gillies for the treatment of the syphilitic nose deformity (Fig. 5) is indicated occasiopally for traumatic nasomaxillary deformities, particularly for edentulous patients. SKIN
GRAFTING
WITHIN
THE
NOSE
If the obstruction consists of more than a weblike band of scar tissue, a neu lining for the nose is provided by skin grafting. The scars are excised and the lateral wall of the nose is freed from the septum. A split-thickness skin graft, pre-
582
J. Pros. May-June,
CONVERSE
Den. 1963
ferably from the inner aspect of the arm, a full-thickness graft from the upper eyelid, or a graft of oral mucosa may be used. Provision is made for immobilization of the skin graft within the nose. A temporary mold of modeling compound serves as the carrier for the graft. The modeling compound is softened and molded into an oval-shaped cone, cooled, and hardened. The surface of the cone is covered with petroleum jelly and flamed; the inner part of the modeling compound cone is not soft,ened. Then, the cone is reintroduced into the nostril, molded against the lateral wall of the nose, and removed. A small amount of Dermatome cement is dabbed on the mold and the graft is wrapped around it with the raw surface outward, and it is then inserted into the nostril (Fig. 6). The mold is retained in position for 4 to 5 days. The original temporary compound mold is duplicated in acrylic resin. When the temporary mold is removed, the hollowed acrylic resin mold is introduced into the nostril. Thus, shrinkage and constriction of the graft are minimized ; the resiliency of the septal and nasal cartilages prevents recurrence of stenosis. The postoperative mold is retained for a number of months. When stenosis is the result of excessive removal of lateral and alar cartilage as well as nasal lining (Fig. 7), the prosthesis supports the deficient cartilaginous structures and is retained permanently to assure patency of the airway. Mucosal grafts removed from the oral mucous membrane may also be employed for intranasal grafts. Mucosa.does not tend to crust or produce a fetid odor. COMBINED
EFFORTS
OF PLASTIC
SURGEON
AND
PROSTHODONTIST
A E-year-old Panamanian boy needed the combined efforts of a plastic surgeon and a maxillofacial prosthodontist. When first examined, this patient showed an unusual deformity (Fig. &A). There was a temporomandibular ankylosis due to the bony fusion between the maxilla and mandible on the right side, and an absence of tissue of three-quarters of the upper lip and of the adjacent part of the cheek on the right side. The origin of the malformation was thought to be congenital. In the first operation, the bone joining the upper and lower jaws was sectioned and a segment of bone and the teeth was removed. Then, the cut surfaces of the bone were covered by a split-thickness skin graft placed raw surface outward over a dental modeling compound mold which was wedged between the cut bony surfaces. After the skin graft had healed, an appliance consisting of two baseplates and a spring was constructed which mobilized the temporomandibular joints and increased the degree of opening between the jaws (Fig. 8,B and C). Two months later an alveolectomy, following extraction of the lower incisors, canine, and first bicuspid on the left, was done in order to facilitate the wearing of a lower denture. Upper and lower dentures were made for the patient. The right upper sulcus was extended by incising along the buccal aspect of the hard palate, and placing a split-thickness skin graft maintained on an acrylic resin extension attached to the upper denture. Modeling compound placed on the right side of the denture was molded into the surgically created sulcus. Then, the modeling compound extension from the denture was duplicated with cold-curing acrylic resin. The skin graft was placed on the extension, raw surface outward, so that the den-
tu:re maintained the graft in the sulcus (Fig. S,L?). After the intraoral operation was completed, the soft tissue defect was repaired by means of an Abbe-Estlander flap (Fig. 8,E ). The physical change in the patient was not limited to the orofacial area. The patient underwent a period of rapid growth and weight increase which was attributed to the improvement of his nutrition made possible by the restoration of his masticatory function.
Maxillofacial prosthodontics is an essential adjunct to reconstructive surgery in many types of deformations and malformations of the jaws. Among the indications for prosthetic appliances are: (1) severe facial injuries with loss of bony framework, (2,) defects of the mandible requiring bone grafting, (3) micrognathia, and (4 ) nasomaxillary atresia. The epithelial inlay technique for skin grafting in the oral or nasal cavities has been described, and a number of applications of the epithelial inlay technique have been illustrated. Close collaboration of the plastic surgeon and the prosthodontist is essential in the treatment of many types of orofacial defects. REFERENCE
1. E&r. J. F. :
Studies
in
NEW YORK UUIVERSITY .SCHOOL OF MKDICINE 550 FIRST AVE. :NEW YORK 16. N. Y.
Plastic
Surgery
of the Face,
A4nn. Surg.
65297,
1917.