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A simple method for bone positioning of mandibular segments
Int. J. Oral Maxillofac. Surg. 2006; 35: 856–860 doi:10.1016/j.ijom.2006.03.004, available online at http://www.sciencedirect.com
Technical Note Reconstructive Surgery
A simple method for bone positioning of mandibular segments
K. Tominaga, I. Yoshioka, A. Khanal, N. Furuta, M. Habu, J. Fukuda Department of Oral and Maxillofacial Surgery, Kyushu Dental College, 2-6-1 Manazuru, Kokurakita, Kitakyushu 803-8580, Japan
K. Tominaga, I. Yoshioka, A. Khanal, N. Furuta, M. Habu, J. Fukuda: A simple method for bone positioning of mandibular segments. Int. J. Oral Maxillofac. Surg. 2006; 35: 856–860. # 2006 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. A simple bone-positioning technique is reported, using a combination of bone plates and a flexible tube filled with acrylic polymer. The flexible tube is solidified by injection of acrylic monomer. This technique is applicable for bone positioning after mandibular resection as well as positioning of the proximal segment after sagittal split ramus osteotomy. This technique has the advantages of greater simplicity and flexibility compared to previously reported methods of bone positioning.
In surgery of the mandible, precise positioning of the resected or splitted bone is often required. In malignant tumours involving the lateral cortex of the mandible or in cases reconstructed with vascularized bone grafts, pre-bending of the bridging plate that is commonly used to place a plate before resection and is then removed is not possible. In reconstruction of the mandible, 3-dimensional positioning of the mandibular stumps is mandatory. Several surgeons used external fixators to maintain the positions1,7,10. In bilateral sagittal split ramus osteotomy (BSSO) for mandibular deformity, proximal segment positioning is also necessary for preventing postoperative joint dysfunction. To maintain this positioning various kinds of devices have been developed3,4,8,9, all of which are complex and have a limited indication. Reported 0901-5027/090856 + 05 $30.00/0
here is a simple technique for bone positioning with flexibility of usage. Surgical technique Components of the device
This system is composed of bone plates and a flexible tube filled with acrylic polymer (the tube is made of polypropylene, Shibase Co. Ltd, Japan; self-curing resin, Ortho Crystal, Nissin Dental Product, Japan). Both ends of the tube are sealed with silicone sealer and 18-gauge elastic needles were inserted. The tube can be sterilized with ethylene oxide gas. Preformed bone plates for orthognathic surgery and segmental resection are available. The authors use relatively thick miniplates (Pape mini-reconstruction plate, 1.27 mm thickness, Martin, Germany) but the operator can use any plate
Accepted for publication 2 March 2006 Available online 11 May 2006
system with at least 2 screws on each bone fragment. Mandibular resection case
In segmental resection of the mandible, after determination of adequate resection margins, a bone plate is fixed beyond the planned osteotomy field without interfering with the final plating (Fig. 1(a)). Then, acrylic monomer is injected into the tube from both sides (Fig. 1(b)). Since this is a closed system, the operator is not in direct contact with the acrylic monomer during the procedure. As the polymerization reaction reaches the doughy stage, the silicone seal at both ends of the tube is cut off, and one end of the tube is stabbed into the fixed plate while the free end is stabbed with another plate (Fig. 1(c)). Then the tube is bent and the free end plate is fixed during
# 2006 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Simple method for bone positioning
857
Fig. 1. Positioning steps for mandibular resection. (a) fix first plate outside of resection area; (b) acrylic monomer injection from both sides: gradually pull out needle while injecting monomer (arrow). Area infiltrated by monomer is indicated by colour change (arrow head). (c) Stab flexible tube into fixed first plate; (d) fix second plate beyond other side of resection area; (e) after removal of completed positioning device, mandibular resection is performed; (f) re-entry of positioning device; (g) permanent fixation with bridging plate; h: positioning device removed.
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Tominaga et al.
the polymerization period (Fig. 1(d)). After the self-polymerization reaction is over (usually about 2 min), the positioning device is completed. The device is then removed and mandibular resection performed (Fig. 1(e)). Next, the positioning device is reapplied by securing the bone plates to the stumps of the residual bone (Fig. 1(f)). After reconstruction with a bridging plate or microvascular bone grafting, the positioning device is finally removed (Figs 1(g and h) and 2). In the case of an extremely wide resection, such as subtotal mandibulectomy, a combination of 2 flexible tubes with a short plate in between can be used (Fig. 3). The bone plates used for this technique can be reused after removal of the acrylic tubes and sterilization. BSSO
In BSSO, we usually fix L-shaped bone plates bilaterally on the lateral oblique line transorally. One can use straight bone plates fixed on the lateral surface of the ramus via the transbuccal approach. To maintain the optimal condylar position, maxillo-mandibular fixation is performed using a centric relation splint. Then, the flexible tube is stabbed into the fixed plate
after acrylic monomer is injected. Another plate is also stabbed into the free end of the tube and fixed around the piriform rim (mainly in one-jaw surgery) or to the zygomatic buttress (mainly in 2-jaw surgery) (Fig. 4). After completion of self-polymerization, the devices and splint are removed and conventional osteotomies performed. Then the positioning devices are reapplied, and internal fixation between proximal and distal segments is performed. Finally, the devices are removed. Discussion
Since the mandible is supported by bilateral loose joints between the condyle and the temporal bone which have a wide range of motion, it is difficult to fix the residual bone fragments into their original position once bone continuity is severed. Inadequate positioning of the bone fragments can result in postoperative malocclusion and/or temporomandibular joint symptoms. EPKER & WYLIE3 suggested 3 main reasons for precise positioning of the proximal segment after BSSO. The first is to ensure the long-term stability of the surgical result. The second is to reduce the adverse effects on the temporomandibular joint. The third is to improve post-
Fig. 2. Clinical photograph of mandibular reconstruction with bridging plate.
operative masticatory function. VAN SICKELS et al.9 reported some cases that confirmed this view in a recent article. Various techniques have been developed for positioning of the osteotomized, split or resected bone1,3,4,7,8,10. Most of them are intraoperative mechanical positioning methods. The technique described here is based on the same concept. The advantage of this technique as compared to the previously reported methods is its convenience, in that the operator does not need to adapt the flexible tube to the bone contour. What the operator does is just to secure the secondary plate at the desired site and wait for self-polymerization of the acrylic inside the tube to occur. The time from injection of monomer to completion of polymerization is usually about 2 min, which is sufficient time to fix the secondary plate. If light-curing resin is available inside the tube, the operator has the advantage of time management, but additional equipment such as a light source will be needed. The authors have applied this technique to 32 cases of tumours or dentofacial deformities during 2003–2004. No difficulties were encountered and there were no redo cases. Nevertheless, there were a couple of points which the operator should keep in mind. The first is to mini-
Simple method for bone positioning
859
Fig. 3. Subtotal mandibular resection. Two flexible tubes are combined.
Fig. 4. Positioning devices for orthognathic surgery. (a) for 1-jaw surgery; (b) for 2-jaw surgery.
mize the volume of the injected monomer, since too much monomer delays the polymerization reaction. The second is to avoid injection of an air bubble into the tube, since bubble entrapment decreases the solidified tube’s strength. The solidified acrylic tube is strong enough as a positioning device, and seems to be much stiffer than metal adaptation plates. Bone-positioning methods based on different concepts have been reported. In BSSO, computer-assisted monitoring of proximal segment positioning was recently described2. This is a very sophisticated technique but the additional effort and expense required are very high. In segmental resection, use of a stereolithography model based on preoperative computed tomography was reported6. This is also a sophisticated technique and may have the advantage of shortening operation time, because a reconstruction plate can be prepared presurgically. Making a stereolithography model, however, is again expensive, and it is not practical for use in routine operations.
In mandibular resection, classic methods for the positioning of residual bone stumps are with Gunning splints, dentures or intraoperative templates5, but bone positioning using these methods is less precise. Using external fixators to maintain the original position has also been reported and is excellent for this purpose1,7,10. For the technique described here, the time needed for making the devices is within 3 min. UNG et al.10 reported that setting of external fixation devices for bone positioning needed 5–10 min. In conclusion, this technique appears to be the simplest and least time-consuming for the required purpose. It has great flexibility in usage for surgery of the mandible. References 1. Ameerally PJ, Hollows P. Use of an external fixator to stabilize the proximal mandibular segments during reconstruction. Br J Oral Maxillofac Surg 2004: 42: 354–356.
2. Bettega G, Dessenne V, Raphael B, Cinquin P. Computer-assisted mandibular condyle position in orthognathic surgery. J Oral Maxillofac Surg 1996: 54: 553–558. 3. Epker BN, Wylie GA. Control of the condylar-proximal mandibular segments after sagittal split osteotomies to advance the mandible. Oral Surg Oral Med Oral Pathol 1986: 62: 613–617. 4. Hiatt WR, Schelkun PM, Moore DL. Condylar positioning in orthognathic surgery. J Oral Maxillofac Surg 1988: 46: 1110–1112. 5. Kane WJ, Olsen KD. Enhanced bone graft contouring for mandibular reconstruction using intraoperatively fashioned templates. Ann Plast Surg 1996: 37: 30– 33. 6. Kernan BT, Wimsatt JA. Use of a stereolithography model for accurate, preoperative adaptation of a reconstruction plate. J Oral Maxillofac Surg 2000: 58: 349–351. 7. Louis P, Fernandes R. Temporary stabilization of the mandible with an external fixation device. J Oral Maxillofac Surg 2001: 59: 1374–1375.
860
Tominaga et al.
8. Luhr HG. The significance of condylar position using rigid fixation in orthognathic surgery. Clin Plast Surg 1989: 16: 147–156. 9. van Sickels JE, Tiner B, Alder ME. Condylar torque as a possible cause of hypomobility after sagittal split osteotomy: report of three cases. J Oral Maxillofac Surg 1997: 55: 398–402.
10. Ung F, Rocco JW, Deschler DG. Temporary intraoperative external fixation in mandibular reconstruction. Laryngoscope 2002: 112: 1569–1572. Address: K. Tominaga Department of Oral and Maxillofacial Surgery
Kyushu Dental College 2-6-1 Manazuru Kokurakita Kitakyushu 803-8580 Japan Tel: +81 93 582 1131 Fax: +81 93 582 1286 E-mail: [email protected]
Technical Note Reconstructive Surgery
A simple method for bone positioning of mandibular segments
K. Tominaga, I. Yoshioka, A. Khanal, N. Furuta, M. Habu, J. Fukuda Department of Oral and Maxillofacial Surgery, Kyushu Dental College, 2-6-1 Manazuru, Kokurakita, Kitakyushu 803-8580, Japan
K. Tominaga, I. Yoshioka, A. Khanal, N. Furuta, M. Habu, J. Fukuda: A simple method for bone positioning of mandibular segments. Int. J. Oral Maxillofac. Surg. 2006; 35: 856–860. # 2006 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. A simple bone-positioning technique is reported, using a combination of bone plates and a flexible tube filled with acrylic polymer. The flexible tube is solidified by injection of acrylic monomer. This technique is applicable for bone positioning after mandibular resection as well as positioning of the proximal segment after sagittal split ramus osteotomy. This technique has the advantages of greater simplicity and flexibility compared to previously reported methods of bone positioning.
In surgery of the mandible, precise positioning of the resected or splitted bone is often required. In malignant tumours involving the lateral cortex of the mandible or in cases reconstructed with vascularized bone grafts, pre-bending of the bridging plate that is commonly used to place a plate before resection and is then removed is not possible. In reconstruction of the mandible, 3-dimensional positioning of the mandibular stumps is mandatory. Several surgeons used external fixators to maintain the positions1,7,10. In bilateral sagittal split ramus osteotomy (BSSO) for mandibular deformity, proximal segment positioning is also necessary for preventing postoperative joint dysfunction. To maintain this positioning various kinds of devices have been developed3,4,8,9, all of which are complex and have a limited indication. Reported 0901-5027/090856 + 05 $30.00/0
here is a simple technique for bone positioning with flexibility of usage. Surgical technique Components of the device
This system is composed of bone plates and a flexible tube filled with acrylic polymer (the tube is made of polypropylene, Shibase Co. Ltd, Japan; self-curing resin, Ortho Crystal, Nissin Dental Product, Japan). Both ends of the tube are sealed with silicone sealer and 18-gauge elastic needles were inserted. The tube can be sterilized with ethylene oxide gas. Preformed bone plates for orthognathic surgery and segmental resection are available. The authors use relatively thick miniplates (Pape mini-reconstruction plate, 1.27 mm thickness, Martin, Germany) but the operator can use any plate
Accepted for publication 2 March 2006 Available online 11 May 2006
system with at least 2 screws on each bone fragment. Mandibular resection case
In segmental resection of the mandible, after determination of adequate resection margins, a bone plate is fixed beyond the planned osteotomy field without interfering with the final plating (Fig. 1(a)). Then, acrylic monomer is injected into the tube from both sides (Fig. 1(b)). Since this is a closed system, the operator is not in direct contact with the acrylic monomer during the procedure. As the polymerization reaction reaches the doughy stage, the silicone seal at both ends of the tube is cut off, and one end of the tube is stabbed into the fixed plate while the free end is stabbed with another plate (Fig. 1(c)). Then the tube is bent and the free end plate is fixed during
# 2006 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Simple method for bone positioning
857
Fig. 1. Positioning steps for mandibular resection. (a) fix first plate outside of resection area; (b) acrylic monomer injection from both sides: gradually pull out needle while injecting monomer (arrow). Area infiltrated by monomer is indicated by colour change (arrow head). (c) Stab flexible tube into fixed first plate; (d) fix second plate beyond other side of resection area; (e) after removal of completed positioning device, mandibular resection is performed; (f) re-entry of positioning device; (g) permanent fixation with bridging plate; h: positioning device removed.
858
Tominaga et al.
the polymerization period (Fig. 1(d)). After the self-polymerization reaction is over (usually about 2 min), the positioning device is completed. The device is then removed and mandibular resection performed (Fig. 1(e)). Next, the positioning device is reapplied by securing the bone plates to the stumps of the residual bone (Fig. 1(f)). After reconstruction with a bridging plate or microvascular bone grafting, the positioning device is finally removed (Figs 1(g and h) and 2). In the case of an extremely wide resection, such as subtotal mandibulectomy, a combination of 2 flexible tubes with a short plate in between can be used (Fig. 3). The bone plates used for this technique can be reused after removal of the acrylic tubes and sterilization. BSSO
In BSSO, we usually fix L-shaped bone plates bilaterally on the lateral oblique line transorally. One can use straight bone plates fixed on the lateral surface of the ramus via the transbuccal approach. To maintain the optimal condylar position, maxillo-mandibular fixation is performed using a centric relation splint. Then, the flexible tube is stabbed into the fixed plate
after acrylic monomer is injected. Another plate is also stabbed into the free end of the tube and fixed around the piriform rim (mainly in one-jaw surgery) or to the zygomatic buttress (mainly in 2-jaw surgery) (Fig. 4). After completion of self-polymerization, the devices and splint are removed and conventional osteotomies performed. Then the positioning devices are reapplied, and internal fixation between proximal and distal segments is performed. Finally, the devices are removed. Discussion
Since the mandible is supported by bilateral loose joints between the condyle and the temporal bone which have a wide range of motion, it is difficult to fix the residual bone fragments into their original position once bone continuity is severed. Inadequate positioning of the bone fragments can result in postoperative malocclusion and/or temporomandibular joint symptoms. EPKER & WYLIE3 suggested 3 main reasons for precise positioning of the proximal segment after BSSO. The first is to ensure the long-term stability of the surgical result. The second is to reduce the adverse effects on the temporomandibular joint. The third is to improve post-
Fig. 2. Clinical photograph of mandibular reconstruction with bridging plate.
operative masticatory function. VAN SICKELS et al.9 reported some cases that confirmed this view in a recent article. Various techniques have been developed for positioning of the osteotomized, split or resected bone1,3,4,7,8,10. Most of them are intraoperative mechanical positioning methods. The technique described here is based on the same concept. The advantage of this technique as compared to the previously reported methods is its convenience, in that the operator does not need to adapt the flexible tube to the bone contour. What the operator does is just to secure the secondary plate at the desired site and wait for self-polymerization of the acrylic inside the tube to occur. The time from injection of monomer to completion of polymerization is usually about 2 min, which is sufficient time to fix the secondary plate. If light-curing resin is available inside the tube, the operator has the advantage of time management, but additional equipment such as a light source will be needed. The authors have applied this technique to 32 cases of tumours or dentofacial deformities during 2003–2004. No difficulties were encountered and there were no redo cases. Nevertheless, there were a couple of points which the operator should keep in mind. The first is to mini-
Simple method for bone positioning
859
Fig. 3. Subtotal mandibular resection. Two flexible tubes are combined.
Fig. 4. Positioning devices for orthognathic surgery. (a) for 1-jaw surgery; (b) for 2-jaw surgery.
mize the volume of the injected monomer, since too much monomer delays the polymerization reaction. The second is to avoid injection of an air bubble into the tube, since bubble entrapment decreases the solidified tube’s strength. The solidified acrylic tube is strong enough as a positioning device, and seems to be much stiffer than metal adaptation plates. Bone-positioning methods based on different concepts have been reported. In BSSO, computer-assisted monitoring of proximal segment positioning was recently described2. This is a very sophisticated technique but the additional effort and expense required are very high. In segmental resection, use of a stereolithography model based on preoperative computed tomography was reported6. This is also a sophisticated technique and may have the advantage of shortening operation time, because a reconstruction plate can be prepared presurgically. Making a stereolithography model, however, is again expensive, and it is not practical for use in routine operations.
In mandibular resection, classic methods for the positioning of residual bone stumps are with Gunning splints, dentures or intraoperative templates5, but bone positioning using these methods is less precise. Using external fixators to maintain the original position has also been reported and is excellent for this purpose1,7,10. For the technique described here, the time needed for making the devices is within 3 min. UNG et al.10 reported that setting of external fixation devices for bone positioning needed 5–10 min. In conclusion, this technique appears to be the simplest and least time-consuming for the required purpose. It has great flexibility in usage for surgery of the mandible. References 1. Ameerally PJ, Hollows P. Use of an external fixator to stabilize the proximal mandibular segments during reconstruction. Br J Oral Maxillofac Surg 2004: 42: 354–356.
2. Bettega G, Dessenne V, Raphael B, Cinquin P. Computer-assisted mandibular condyle position in orthognathic surgery. J Oral Maxillofac Surg 1996: 54: 553–558. 3. Epker BN, Wylie GA. Control of the condylar-proximal mandibular segments after sagittal split osteotomies to advance the mandible. Oral Surg Oral Med Oral Pathol 1986: 62: 613–617. 4. Hiatt WR, Schelkun PM, Moore DL. Condylar positioning in orthognathic surgery. J Oral Maxillofac Surg 1988: 46: 1110–1112. 5. Kane WJ, Olsen KD. Enhanced bone graft contouring for mandibular reconstruction using intraoperatively fashioned templates. Ann Plast Surg 1996: 37: 30– 33. 6. Kernan BT, Wimsatt JA. Use of a stereolithography model for accurate, preoperative adaptation of a reconstruction plate. J Oral Maxillofac Surg 2000: 58: 349–351. 7. Louis P, Fernandes R. Temporary stabilization of the mandible with an external fixation device. J Oral Maxillofac Surg 2001: 59: 1374–1375.
860
Tominaga et al.
8. Luhr HG. The significance of condylar position using rigid fixation in orthognathic surgery. Clin Plast Surg 1989: 16: 147–156. 9. van Sickels JE, Tiner B, Alder ME. Condylar torque as a possible cause of hypomobility after sagittal split osteotomy: report of three cases. J Oral Maxillofac Surg 1997: 55: 398–402.
10. Ung F, Rocco JW, Deschler DG. Temporary intraoperative external fixation in mandibular reconstruction. Laryngoscope 2002: 112: 1569–1572. Address: K. Tominaga Department of Oral and Maxillofacial Surgery
Kyushu Dental College 2-6-1 Manazuru Kokurakita Kitakyushu 803-8580 Japan Tel: +81 93 582 1131 Fax: +81 93 582 1286 E-mail: [email protected]