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Use of acrylic external splint after mandibular resection
Use of Acrylic External Splint after Mandibular Resection IRVIN D. FLEMING, JOE HALL MORRIS,
Resection of a portion of the mandible is required in the treatment of many intraoral carcinomas and primary tumors of the mandible. Although the resulting defect is compatible with comfort and maintenance of nutrition, there is considerable cosmetic deformity and loss of function associated with mandibular resection. Attempts to overcome this loss with metallic or other implant fixation, bone grafts, and prosthetic appliances all too often have been unsatisfactory [1-41. Some objections to the early reconstruction of the mandible after tumor resection include the following : (1) Reconstructive considerations may influence the adequacy of tumor resection. (2) Foreign body reaction and infected grafts may mimic or obscure recurrent tumor. (3) Grafts and prosthetic devices in the mandible have often failed in the past. Because of these objections, many head and neck surgeons simply accept the cosmetic defect and functional loss and do not attempt any reconstructive procedures [5]. A method of external fixation developed over the past twenty years at the Oral Surgery Department of the University of Tennessee has been used with gratifying results in the treatment of unstable and complicated fractures of the mandible [S]. The high degree of reliability of this procedure when utilized for mandibular bone grafting in patiente with trauma has led to the implementation of this technic after resection for neoplasm. (Fig. 1.) The long-term stability of this method of From the Head and Neck Service. Department of Surgery, and the Department of Oral Suraerv. University of Tennessee College; of Medicine and D&t&y, Memdhis. Tennessee. Presented at the Fifteenth Annual Meeting of The Society of Head and Neck Surgeons, Mexico City, Mexico, March 1619, 1969. 708
M.D., Memphis, Tennessee D.D.S., Memphis, Tennessee
fixation has as one of its advantages the choice of either immediate or delayed reconstruction depending on the clinical setting. No compromilse in tumor eradication is implied or permitted. It must be acknowledged that the architecture of the mandible remaining in some situations is not suitable for pin placement. In such cases this procedure is not applicable. Operative
Technic
The tumor resection is usually accomplished by a combined procedure with radical neck dissection as described by Martin et al. [?‘I. The indicated amount of mandible is resected en bloc with the tumor and soft tissue. The mucosal and submucosal tissues are then closed, preferably in two layers. If there is adequate tissue for closure of the oral defect, and if the area has not been heavily irradiated, the graft is accomplished immediately using a ‘segment of ilium or rib. The stumps are prepared to receive the graft either as butt joints or even better by vertical or horizontal stepping. The screw sites are prepared by returning the soft tissue flap to as near passive anatomic position as possible and making a ais inch buttonhole skin incision in the flap exactly over the site on the mandibular stump where the drill hole will be made. It is important to the procedure that the special bone screws are placed in the bone in such a manner that they do not distort the soft tissue and develop tension at the screw site. A 313a inch twist drill is used to prepare the holes in the mandible. This size is correct for the special vitallium screw which has an outside diameter of ‘is inch with threads pitched at twenty two per inch and a gimlet point. This screw The American
Journal
of Surgery
Acrylic External Splint after Mandibular
design and method of placement has assured the biomechanical stability necessary for longterm fixation which was not consistently achieved with previous methods. (Fig. 2.) In portions of the ramus and angle where the mandible is thin and the medial and lateral cortical plates may be contiguous, the smaller inch twist drill is preferred for prepar5/64 ing the proximal and distal fragments. The screws in each fragment must be at least 3/4 of an inch apart, but may be separated more than this if feasible. Prior to drilling, the drill bit is placed into the skin wound so that the tissues are perfectly passive and the axis of the bit is perpendicular to the lateral cortex of the mandible. An infant’s nasal speculum, with blades positioned on either side of the drill point, may be used to serve as a retractor, and thus prevent soft tissues from being entwined in the drill. It is also used to locate the drill hole at the time the vitallium screw is seated in the bone. When the four bone screws have been situated, the primary mechanical splint is attracted to one screw in each fragment and positioned to give maximum access to the surgical field. (Fig. 3.) With a screw clamp rigidly fixed to one screw in each of the fragments and with both rod clamps completely unlocked, the appropriate gap between the Btumps of the mandible is positioned and the rod clamps are tightened to rigidly hold this position. The graft is tailored to fit the defect. When the desired contour of the graft is accomplished, it is secured in place with wire sutures. If a graft is not to be immediately utilized, the gap is left between the two fragments of mandible and the wound closed in the usual way. As soon as closure is effected, a plastic bar is made of autopolymerizing acrylic. This is shaped in a mold and removed in a pliable rubber-like state and adapted to the machine end of the bone screws. After a short period of polymerization the acrylic becomes a hard, resilent, light bar. Care should be taken to insure that the acrylic bar is not in contact with the soft tissue during the set period because of the heat generated. As soon as the acrylic has returned to room temperature and is hard, the bar is secured with washer-faced nuts and the primary mechanical splint is removed. A simple gauze dressing may be applied to the base of the screws for twentyfour hours. This plastic bar and vitallium Vol. 118, November 1969
Resection
Fig. 1. Acrylic splint in place nine months supporting mandibular graft.
Fig. 2.
Vitaflium
bone screws; note coarse threads.
Primary mechanical Fig. 3. acrylic bar hardens.
splint
still in place as
sc;*ew splint serve as an effective support for up to twelve months. The exceptionally long life of the splint makes possible delayed grafting. If this is preferred, the splint is left in place until the wound is healed and the tissues have softened, at which time the graft is implanted in a conventional manner. 709
Fleming
TABLE
and Morris
I
Case No. *2 4 5 6 7 8 9 10 11 12 13 14 15 16 * Onlv tumor is no e;idence
Results
in Sixteen
Patients
with External
Tumor Pathology Oral carcinoma Oral carcinoma Oral carcinoma Ameloblastoma Ameloblastoma Oral carcinoma Fibro-osseous Ameloblastoma Oral carcinoma Oral carcinoma Oral carcinoma Giant cell Oral carcinoma Oral carcinoma Oral carcinoma Oral carcinoma recurrence
(recurrent)
in series occurred
Type of Graft
Splints Follow-up Period (mo.)
11
Rib, immediate Rib, delayed Ilium, delayed Rib, immediate Rib, immediate Ilium, immediate Ilium, immediate Rib, immediate Ilium, immediate Splint only Rib, delayed Splint only Ilium, immediate Ilium, immediate Splint only Splint only at twelve
months
20 14 12 17 8 13 19 25 4 15 7
6 6 after grafting;
Graft Satisfactory Recurred; resected Some resorption of graft Satisfactory Satisfactory Satisfactory Sequestrium removal Graft fracture Satisfactory Graft planned Satisfactory No graft Satisfactory Graft exposed No graft Graft planned
resection
was performed
and there
of disease.
Occasionally a screw site will exhibit a slight tissue weeping or manifest a nonsuppurative moisture, which generally responds well to a simple application of per cent methylene blue for several days. Removal of the acrylic splint is a simple office procedure. First, the washer-faced nuts are removed, then with a dental burr the acrylic bar is freed from the screws. The vitallium bone screw may then be removed without anesthesia, and with no significant discomfort to the patient. The screw sites heal without complication. Results In the past three years, sixteen patients who underwent mandibular resection for tumor have been treated with this external splint. (Table I.) Eleven resections were performed for intraoral carcinoma and five resections for other mandibular lesions. Twelve bone grafts have been accomplished using iliac crest or rib. Delay grafts were utilized when the tissues had been heavily irradiated or when soft tissue was insufficient to effect closure without tension. Eleven patients have had no complications. Two grafts have resorbed and fractured, with one requiring additional onlay of graft. One recent graft has had intraoral exposure of a small area of bone which is being followed with 710
Acrylic
no treatment. Several patients are now wearing dentures over the mandibular graft. There has been only one recurrent tumor and this recurrence was intraoral at the anterior margin of resection one year post grafting. The recurrent lesion with the anterior portion of the graft has been resected and to date, twelve months after resection, there is no evidence of recurrent tumor. Conclusion A technic of mandibular support is presented, which is a reliable method of fixation allowing either immediate or delayed mandibular reconstruction. The essential aspects of this include a special vitallium screw which is well tolerated by both bone and soft tissue, and a firm light splint, which affords the longterm rigid fixation necessary for mandibular grafting. Although this procedure is not applicable to all types of mandibular resection, it has proved to be another useful method of mandibular reconstruction to be added to the surgeon’s armamentarium. References 1. 2.
3.
GAISFORD,J. C. Reconstructions of head and neck deformities. S. C&n. North America, 47: 295,1967. IVY, R. H. Bone grafting for restoration of defects of the mandible. Pbst. & Reconstruct. Surg., 9: 333, 1951. MILLARD, D. R., MAISELS, D. O., and BATSThe American Journal of Surgery
Acrylic External
4.
5.
TON, J. F. Immediate repair of the anterior arch of the lower jaw. Phst. & Reconstruct. Surg., 39: 153, 1967. CONLN, J. J. A technique for immediate bone grafting in the treatment of benign and malignant tumors of the mandible. Cancer, 6: 568, 1953. HAROLD,C. C. Problems in the surgical treatment of cancer of mouth. In Cancer Man-
Vol. 118, November 1969
6.
7.
Splint after Mandibular
Resection
agement, p. 311. Philadelphia, 1969. J. B. Lippincott Co. MORRIS, J. H. Biphase connector: external skeletal splint for reduction and fixation of mandibular fractures. Oral Surg., 2: 1382, 1949. MARTIN, H., VALLE, V. D., EHRLICH, H., and CAHAN, W. G. Neck dissection. Cancer, 4: 441, 1951.
711
Resection of a portion of the mandible is required in the treatment of many intraoral carcinomas and primary tumors of the mandible. Although the resulting defect is compatible with comfort and maintenance of nutrition, there is considerable cosmetic deformity and loss of function associated with mandibular resection. Attempts to overcome this loss with metallic or other implant fixation, bone grafts, and prosthetic appliances all too often have been unsatisfactory [1-41. Some objections to the early reconstruction of the mandible after tumor resection include the following : (1) Reconstructive considerations may influence the adequacy of tumor resection. (2) Foreign body reaction and infected grafts may mimic or obscure recurrent tumor. (3) Grafts and prosthetic devices in the mandible have often failed in the past. Because of these objections, many head and neck surgeons simply accept the cosmetic defect and functional loss and do not attempt any reconstructive procedures [5]. A method of external fixation developed over the past twenty years at the Oral Surgery Department of the University of Tennessee has been used with gratifying results in the treatment of unstable and complicated fractures of the mandible [S]. The high degree of reliability of this procedure when utilized for mandibular bone grafting in patiente with trauma has led to the implementation of this technic after resection for neoplasm. (Fig. 1.) The long-term stability of this method of From the Head and Neck Service. Department of Surgery, and the Department of Oral Suraerv. University of Tennessee College; of Medicine and D&t&y, Memdhis. Tennessee. Presented at the Fifteenth Annual Meeting of The Society of Head and Neck Surgeons, Mexico City, Mexico, March 1619, 1969. 708
M.D., Memphis, Tennessee D.D.S., Memphis, Tennessee
fixation has as one of its advantages the choice of either immediate or delayed reconstruction depending on the clinical setting. No compromilse in tumor eradication is implied or permitted. It must be acknowledged that the architecture of the mandible remaining in some situations is not suitable for pin placement. In such cases this procedure is not applicable. Operative
Technic
The tumor resection is usually accomplished by a combined procedure with radical neck dissection as described by Martin et al. [?‘I. The indicated amount of mandible is resected en bloc with the tumor and soft tissue. The mucosal and submucosal tissues are then closed, preferably in two layers. If there is adequate tissue for closure of the oral defect, and if the area has not been heavily irradiated, the graft is accomplished immediately using a ‘segment of ilium or rib. The stumps are prepared to receive the graft either as butt joints or even better by vertical or horizontal stepping. The screw sites are prepared by returning the soft tissue flap to as near passive anatomic position as possible and making a ais inch buttonhole skin incision in the flap exactly over the site on the mandibular stump where the drill hole will be made. It is important to the procedure that the special bone screws are placed in the bone in such a manner that they do not distort the soft tissue and develop tension at the screw site. A 313a inch twist drill is used to prepare the holes in the mandible. This size is correct for the special vitallium screw which has an outside diameter of ‘is inch with threads pitched at twenty two per inch and a gimlet point. This screw The American
Journal
of Surgery
Acrylic External Splint after Mandibular
design and method of placement has assured the biomechanical stability necessary for longterm fixation which was not consistently achieved with previous methods. (Fig. 2.) In portions of the ramus and angle where the mandible is thin and the medial and lateral cortical plates may be contiguous, the smaller inch twist drill is preferred for prepar5/64 ing the proximal and distal fragments. The screws in each fragment must be at least 3/4 of an inch apart, but may be separated more than this if feasible. Prior to drilling, the drill bit is placed into the skin wound so that the tissues are perfectly passive and the axis of the bit is perpendicular to the lateral cortex of the mandible. An infant’s nasal speculum, with blades positioned on either side of the drill point, may be used to serve as a retractor, and thus prevent soft tissues from being entwined in the drill. It is also used to locate the drill hole at the time the vitallium screw is seated in the bone. When the four bone screws have been situated, the primary mechanical splint is attracted to one screw in each fragment and positioned to give maximum access to the surgical field. (Fig. 3.) With a screw clamp rigidly fixed to one screw in each of the fragments and with both rod clamps completely unlocked, the appropriate gap between the Btumps of the mandible is positioned and the rod clamps are tightened to rigidly hold this position. The graft is tailored to fit the defect. When the desired contour of the graft is accomplished, it is secured in place with wire sutures. If a graft is not to be immediately utilized, the gap is left between the two fragments of mandible and the wound closed in the usual way. As soon as closure is effected, a plastic bar is made of autopolymerizing acrylic. This is shaped in a mold and removed in a pliable rubber-like state and adapted to the machine end of the bone screws. After a short period of polymerization the acrylic becomes a hard, resilent, light bar. Care should be taken to insure that the acrylic bar is not in contact with the soft tissue during the set period because of the heat generated. As soon as the acrylic has returned to room temperature and is hard, the bar is secured with washer-faced nuts and the primary mechanical splint is removed. A simple gauze dressing may be applied to the base of the screws for twentyfour hours. This plastic bar and vitallium Vol. 118, November 1969
Resection
Fig. 1. Acrylic splint in place nine months supporting mandibular graft.
Fig. 2.
Vitaflium
bone screws; note coarse threads.
Primary mechanical Fig. 3. acrylic bar hardens.
splint
still in place as
sc;*ew splint serve as an effective support for up to twelve months. The exceptionally long life of the splint makes possible delayed grafting. If this is preferred, the splint is left in place until the wound is healed and the tissues have softened, at which time the graft is implanted in a conventional manner. 709
Fleming
TABLE
and Morris
I
Case No. *2 4 5 6 7 8 9 10 11 12 13 14 15 16 * Onlv tumor is no e;idence
Results
in Sixteen
Patients
with External
Tumor Pathology Oral carcinoma Oral carcinoma Oral carcinoma Ameloblastoma Ameloblastoma Oral carcinoma Fibro-osseous Ameloblastoma Oral carcinoma Oral carcinoma Oral carcinoma Giant cell Oral carcinoma Oral carcinoma Oral carcinoma Oral carcinoma recurrence
(recurrent)
in series occurred
Type of Graft
Splints Follow-up Period (mo.)
11
Rib, immediate Rib, delayed Ilium, delayed Rib, immediate Rib, immediate Ilium, immediate Ilium, immediate Rib, immediate Ilium, immediate Splint only Rib, delayed Splint only Ilium, immediate Ilium, immediate Splint only Splint only at twelve
months
20 14 12 17 8 13 19 25 4 15 7
6 6 after grafting;
Graft Satisfactory Recurred; resected Some resorption of graft Satisfactory Satisfactory Satisfactory Sequestrium removal Graft fracture Satisfactory Graft planned Satisfactory No graft Satisfactory Graft exposed No graft Graft planned
resection
was performed
and there
of disease.
Occasionally a screw site will exhibit a slight tissue weeping or manifest a nonsuppurative moisture, which generally responds well to a simple application of per cent methylene blue for several days. Removal of the acrylic splint is a simple office procedure. First, the washer-faced nuts are removed, then with a dental burr the acrylic bar is freed from the screws. The vitallium bone screw may then be removed without anesthesia, and with no significant discomfort to the patient. The screw sites heal without complication. Results In the past three years, sixteen patients who underwent mandibular resection for tumor have been treated with this external splint. (Table I.) Eleven resections were performed for intraoral carcinoma and five resections for other mandibular lesions. Twelve bone grafts have been accomplished using iliac crest or rib. Delay grafts were utilized when the tissues had been heavily irradiated or when soft tissue was insufficient to effect closure without tension. Eleven patients have had no complications. Two grafts have resorbed and fractured, with one requiring additional onlay of graft. One recent graft has had intraoral exposure of a small area of bone which is being followed with 710
Acrylic
no treatment. Several patients are now wearing dentures over the mandibular graft. There has been only one recurrent tumor and this recurrence was intraoral at the anterior margin of resection one year post grafting. The recurrent lesion with the anterior portion of the graft has been resected and to date, twelve months after resection, there is no evidence of recurrent tumor. Conclusion A technic of mandibular support is presented, which is a reliable method of fixation allowing either immediate or delayed mandibular reconstruction. The essential aspects of this include a special vitallium screw which is well tolerated by both bone and soft tissue, and a firm light splint, which affords the longterm rigid fixation necessary for mandibular grafting. Although this procedure is not applicable to all types of mandibular resection, it has proved to be another useful method of mandibular reconstruction to be added to the surgeon’s armamentarium. References 1. 2.
3.
GAISFORD,J. C. Reconstructions of head and neck deformities. S. C&n. North America, 47: 295,1967. IVY, R. H. Bone grafting for restoration of defects of the mandible. Pbst. & Reconstruct. Surg., 9: 333, 1951. MILLARD, D. R., MAISELS, D. O., and BATSThe American Journal of Surgery
Acrylic External
4.
5.
TON, J. F. Immediate repair of the anterior arch of the lower jaw. Phst. & Reconstruct. Surg., 39: 153, 1967. CONLN, J. J. A technique for immediate bone grafting in the treatment of benign and malignant tumors of the mandible. Cancer, 6: 568, 1953. HAROLD,C. C. Problems in the surgical treatment of cancer of mouth. In Cancer Man-
Vol. 118, November 1969
6.
7.
Splint after Mandibular
Resection
agement, p. 311. Philadelphia, 1969. J. B. Lippincott Co. MORRIS, J. H. Biphase connector: external skeletal splint for reduction and fixation of mandibular fractures. Oral Surg., 2: 1382, 1949. MARTIN, H., VALLE, V. D., EHRLICH, H., and CAHAN, W. G. Neck dissection. Cancer, 4: 441, 1951.
711