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Non-free osteoplasty of the mandible in maxillofacial gunshot wounds: mandibular reconstruction by compression–osteodistraction
British Journal of Oral and Maxillofacial Surgery (1999) 37, 261–267 © 1999 The British Association of Oral and Maxillofacial Surgeons
BRITISH JOURNAL OF ORAL
& M A X I L L O FA C I A L S U R G E RY
Non-free osteoplasty of the mandible in maxillofacial gunshot wounds: mandibular reconstruction by compression–osteodistraction M.B. Shvyrkov, A.H. Shamsudinov, D.D. Sumarokov, I.I. Shvyrkova Maxillofacial Traumatology Department, Moscow Medical Stomatological Institute, Moscow, Russia SUMMARY. We have treated 33 young men with medium to large (3–8 cm) bony and soft tissue defects of the lower third of the face caused by gunshot wounds. After debridement, collapsing the proximal segments for primary approximation of soft and hard tissues and a closed osteotomy of a small fragment of mandible, we used an original compression–distraction device, designed in 1982 and tested during 1983 (analogous devices were absent at that time) to reposition the mandible and cause callus to form (during distraction) between the fragment and to use the remaining stumps of bone to fill in the defect. The soft tissues were repaired at the same time. Twenty-eight of the patients presented within a few hours of injury, and the remaining five had old injuries. The only complications were in the group with old injuries where four patients developed abscesses that required drainage, but these did not interfere with the process of osteogenesis. All 33 patients had good functional and aesthetic results within 3–4.5 months. The method allows a bloodless minimally traumatic procedure which can be carried out in one stage. The results compare very favourably with the classic methods of the treatment of mandibular gunshot injuries. and this results in the continuing activation of growth factors that cause pericapillary cells to transform into osteogenic cells. There is some evidence that bone stem cells play a part in bone repair, and are also influenced by growth factors,26,27 and this might explain why the osteogenesis persists for several months until sufficient callus is formed. Variations of this technique have been used in maxillofacial surgery for some years,28–36 particularly in the treatment of mandibular fractures without bony defects, for small defects after sequestrectomy, or for mandibular hypoplasia. However, we could find no reports of the technique being used for medium or large mandibular defects; the largest previously reported defect repaired was 3.75 cm. We present here our modification of Ilizarov’s technique. We have adapted it specifically to deal with the anatomy of the mandible, and have used it to treat patients with gunshot injuries or defects from old injuries.37,38 Our method allows us to repair not only the bone, but also the muscles, nerves, blood vessels, skin, and mucosa so that we have a full-thickness repair of the defect.
INTRODUCTION Mandibular defects are notoriously difficult to treat. Transplantation has been widely used, but the choice of material (bone grafts, polymers, metals, or ceramics) remains controversial.1–6 Contrast microangiography after mandibular osteoplasty has shown that the formalinized bone graft was either rejected or slowly revascularized and replaced by host bone. Combined biochemical and isotopic investigations have shown that the transplant remains metabolically inactive.7,8 Large, freeze-dried segments of homologous bone (which need supplementation by autologous bone chips) are eventually completely replaced by autologous bone.2,9 Embryonic bone is suitable for osteoplasty, but is not strong enough,10,11 and the process of transplantation and assimilation can be complicated by resorption or rejection.11 The technique of compression–distraction osteosynthesis that was first described by Ilizarov12,13 has revolutionized treatment of bony and soft tissue defects in trauma and orthopaedics. It is extremely effective in the treatment of fractures of the long bones, large bony defects, and traumatic osteomyelitis.14–17 Callus formed during gradual distraction has all the characteristics of an ideal transplant material that requires no mechanical stimulation, the main stimulator of bone growth being tension on the callus while the proximal fragments of bone are immobilized. A fracture or osteotomy initiates the regeneration of bone. Skeletal growth factors (bone morphogenic proteins) are activated.19–21 These are non-collagenous proteins that regulate the process of repair.22,23 Primitive cells develop into preosteoblasts and then into osteoblasts under the influence of these growth factors.24,25 Distraction causes absorption of callus,
PATIENTS AND METHODS The principle of the method is a closed osteotomy (preparation of a small fragment) of one or both of the mandibular stumps after initiation of osteogenesis by short-term compression of the fragments at the osteotomy site. Regeneration of bone is continued by distraction of the callus until it is large enough to close the defect. The small fragment of bone that is osteotomized and transplanted is usually about 2.5– 3 cm long, and as it is still connected to the surrounding 261
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Fig. 1 – Diagram of the non-free osteoplasty of the mandible used for the first group (A) the mandibular ends are fixed by the compression device, the site of the future osteotomy is marked with a dotted line, arrows show the direction of the mandibular ends; (B) the mandibular ends are approximated and the osteotomy created; (C) final result after restoration of the shape of the mandible, the defect is filled by immature callus.
tissues it has a good blood supply and innervation, high regenerative potential, and is mobile.17 We have treated 33 men, 20–35 years old. All had comminuted gunshot fractures of the mandible together with loss of surrounding soft tissue. The defects measured 3–8 cm (11–40% of the length of the body of the mandible). Twenty-eight of the 33 had recent wounds, and the other five had defects (soft and hard tissue) of varying age. We divided the patients into two groups depending on the size of the defect and the mobility of the stumps, as they required two slightly different approaches. The first group comprised seven patients with mandibular defects 3–4 cm long. The indication for osteoplasty was that the mandibular ends could be
Fig. 2 – Diagram of the osteoplasty used, for the second group: (A) the mandibular ends are fixed by the compression device and an osteotomy is created on the larger mandibular stumps to make a small mobile bone fragment; the arrow shows the direction of the mobile fragment; (B) final result after the two fragments have joined up; the defect is filled by immature callus.
closely approximated by the compression–distraction device. In some cases, however, there was no possibility of rapid knitting, and in others the mandibular ends were almost, but not quite, in contact with each other (Fig. 1). The second group (n=26) had defects 4–8 cm long on the lateral side of the mandible. In these cases we were able only to approximate the mandibular ends and reduce the size of the defect (Fig. 2). The site of the proposed closed osteotomy (small fragment) was marked on the skin, while the gunshot wound was being debrided. Two to four threaded screws were then inserted into each section of the mandible by drilling, and two to three threaded screws were drilled into what was to be the ‘small fragment’. The pins were united in groups by plates, which were transformed into a unified hard mobile system by means of a threaded arch bar (Figs 1 & 2). The device was designed to approximate the mandibular ends towards each other and although temporarily disturbing the occlusion, would reduce the size of the defect. As a result of this approximation, the soft tissue
Compression–osteodistraction in mandibular defects
A
C
B
D
Fig. 3 – (A) The small entrance wound is situated on the chin (below right retractor – arrow) and large lacerated exit wound on the left side of the the face; (B) occipitomental radiograph showing bursting fracture of the mandibular body along 1234567; (C) the patient’s face deformed after the mandibular stumps have been shifted towards the defect; (D) disturbance of dental occlusion: the right lower canine is situated opposite the left first upper incisor and the right lower premolar is between the right upper incisors; (E) the right lower canine is left in the same place and the right second premolar is shifted backwards together with the large mandibular stump as the distance between these teeth increases; (F) occipitomental radiograph shows the normal positions of the large mandibular stumps, the small mobile fragment has moved towards the left side and the defect at the osteotomy site is filled with immature callus; (G) the right lower canine and both incisors are in contact with the left upper premolars and molar, the right lower second premolar is in its normal position, between the lower teeth mentioned above, there is a considerable amount of gum formed by immature callus; (H) the same patient with removable denture; (I) occipito-mental radiograph showing the restored shape, size and continuity of the mandible, and well mineralized callus is seen at the site of the former mandibular defect.
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Fig. 3 – cont.
defects in the fresh wounds were reduced and we were always able to suture the mucous membrane and separate the oral cavity from the external wound despite substantial debridement of the wound edges. This is important in the prevention of infection. We then removed from the ends of the stumps, with either burs, tooth cutters, or a disc saw, 2–3 mm of dead bone and any bone with reduced regenerative capacity. Not only did this allow access to live bone containing growth factors, but removal of dead tissue helped healing, prevented infection and the development of gunshot osteomyelitis. In both groups, the closed osteotomy (preparation of the small segment) was completed with a wire saw, through a small incision in the submandibular region. The primary defect was then compressed with the compressive–distractive device, and the external gunshot wound repaired. The period of compression lasted for
10 days, after which we started the distraction. The ‘small fragment’ was separated at a rate of 1 mm/day by adjusting the device every 5–6 hours. We chose this rate because an osteon grows at a rate of 1 mm/day during regeneration. The fragment was displaced along the curved threaded bar (which had been shaped during the operation by the surgeon to correspond with the patient’s face) towards the defect. In bending the bar, the surgeon had programmed the future curvature of the body of the mandible. In the five patients with old defects the scar between the stumps was compressed during distraction by the small fragment. In four of the five cases this caused an abscess that had to be drained, but the inflammation did not spread to the bone. In each case there was room for direct contact between the mandibular end and the ‘small fragment’ and it was possible to trim the end surfaces through the wound to enable primary repair.
Compression–osteodistraction in mandibular defects
By the end of the 10-day period of compression, the soft tissue injury had usually healed, and during the distraction of the callus the soft tissues were also being stretched. This slow stretching stimulated growth and repair of muscles, vessels, mucosa, skin, and nerves and progressed at the same time as osteogenesis. When direct contact had been made between the small fragment and the opposite mandibular end we trimmed and freshened the compressed ends to obtain the maximum contact. The ends were then compressed again. By now, immature callus had started to ripen, and could be palpated inside the mouth. Depending on the size of the defect this would take from 1.5–2.5 months to mature. Three to four weeks after direct contact between the small fragment and the opposite mandibular end had been achieved, the patient was given a removable denture to wear. This improved speech, mastication, and accelerated reconstruction and mineralization of the callus. The compression–distraction device was removed after the arch bar had been taken off and the callus had been examined manually to make sure that it was stable. RESULTS All 33 patients had good functional and aesthetic results. There were no complications, except for the four abscesses that developed in four of the five patients with old wounds, and these had no effect on bony regeneration. The duration of treatment ranged from 3 to 4.5 months. CASE REPORT A 24-year-old man was admitted a few hours after a penetrating gunshot wound to the soft tissues of the left sublingual, submandibular, and cheek region. There was a bursting fracture of the mandibular body in the lower left 1234567, where the primary defect lay (Figs 3A & B). The submandibular gland was missing. All loose bony splinters were removed during debridement, leaving a bony defect about 8 cm long. Two groups of pins were inserted in the right body of the mandible, and one group in the ramus. The mandibular ends were displaced towards the defect, which resulted in the defect becoming smaller. The soft tissues were sutured in layers with continuous retention sutures. The right first premolar was then extracted and a closed osteotomy (small segment) made through the socket. This resulted in a small mobile fragment that contained the lower right 321. The osteotomy site was exactly halfway between the two groups of pins. The defect was then approximated, which resulted in the patient’s face and occlusion becoming temporarily deformed (Figs 3 C & D). Ten days later, we began distracting the desmal callus. The soft tissue wound had healed by primary intention. A month later, the mobile fragment had been considerably displaced towards the defect (to the left) and the large right stump had moved backwards into its normal position. Figures 3E and F show the defect between the mobile fragment and the left stump. Two and a half months after we had started distraction, the small fragment came into contact with the left mandibular end. The shape of the face had recovered, and occlusion
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was restored. The lower right 321 teeth were in contact with the lower left 56 (Fig. 4G). On bi-manual palpation, a hard elastic callus could be felt where previously there had been a defect. A radiograph showed that no correction of the ends of the small fragment or mandibular ends was necessary. The patient started using a removable lower denture. The period of fixation started. Eighteen days later, the arch bar of the device was removed so that we could check the strength of the callus; three days later no fragments had become displaced, which shows that the new bone was durable. All the pins were removed and the patient was discharged. Two months later the patient’s face and occlusion were normal, and he could chew any food. Well-mineralized callus could be seen on the radiograph at the site of the former mandibular bony defect (Fig. 3I). It therefore took us 4.5 months to repair an 8-cm defect in the mandible, and its associated soft tissue loss.
DISCUSSION Only if the recipient bed is healthy will a free osteoplasty (bone graft) succeed. However, gunshot wounds to the face usually result in both soft and hard tissue defects. Restoration of the mandibular defect also requires a repair of the soft tissue loss. The soft tissue bed must be healthy if it is to take a future bone transplant. Usually in such cases a pedicled, musculocutaneous or free flap is used to restore the soft tissues and repair usually requires several operations, which take a long time and often give poor aesthetic results. A few months later, a graft made of autologous or allogeneic bone, ceramic, metal or plastic will need to be inserted but nobody can predict the success of the graft. It may result in assimilation, resorption or rejection. There are many causes for resorption or rejection, and it is not possible to eliminate them all. The non-free osteoplasty of the mandible has many advantages. During compression, the desmogenous callus formation resembles bony embryogenesis, and is replaced by osteogenic tissue when distraction begins. The angiogenic callus that extends from the end of the small fragment has a good capillary blood supply and causes no immunological reaction. The new bone that forms during distraction may be grown to any size, forms easily, and quickly matures into organo-typical bone. It can be bent by the preformed arch bar (prepared by the surgeon in theatre) to the mandibular shape required. This technique compares favourably with bone grafts and alloplastic implants because it is not subject to resorption or rejection. Compression–distraction osteoplasty not only restores the mandible but during distraction the soft tissue is also repaired, which means that a bloodless restoration of the lower third of the fact is possible in one stage. It is always difficult to place a denture after bonegrafting, because the bone graft does not contain teeth. The mobilized and displaced small fragment, however, does have teeth and moves them into the defect, so it is relatively easy to fix a denture to them. Unlike bone-grafting, when we have no control over the processes of healing, we can easily regulate the degree of compression, distraction, and fixation.
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Compression can accelerate callus formation and is used in two ways in this technique. When ‘the small segment’ prepared reached the opposite mandibular end, the new union (primary site) is compressed for ten days with the compressive–distractive device causing an activation of osteogenesis. Ten days later, distraction is commenced at this site by displacing the small fragment backwards for a 6–7 day period. This allows compression of the regenerated bone and speeds up maturation of the previously formed callus and allows some further distraction at the primary site.
CONCLUSION Mandibular bony and soft tissue reconstruction can be achieved by non-free osteoplasty with the help of this compressive–distractive device. This method avoids the need for multiple extensive operative procedures on both soft and bony tissues. It does not require a bone graft or an implant with their unpredictable outcome (assimilation, resorption, rejection). The method of non-free osteoplasty compares very favourably with the classic methods of mandibular reconstruction. It is a relatively atraumatic, bloodless procedure, secures substitution of the combined soft and hard tissue defect in one stage and decreases the duration of treatment three- to four-fold. References 1. Calnan J. The use of inert plastic material in reconstructive surgery. I. A biological test for tissue acceptance. II. Tissue reaction to commonly used material. Br J Plast Surg 1963; 16: 1–22. 2. Bowerman JE, Conroy B. A universal kit in titanium for immediate replacement of the resected mandible. Br J Oral Surg 1969; 6: 223–228. 3. Tienkel G, Niederdellmann H. The possibilities afforded by the use of dense aluminium oxid ceramics in the reconstruction of temporomandibular joint. Quint Int 1977; 8: 19–26. 4. Viliams D, Rouf R. Implants in Surgery. 1978 (in Russian). 5. Shestakov UN, Kasparova NN, Dundukov BS. Mandible osteoplasty in children by boneplastic endoprosthetics. Stomatologiia (Mosc) 1985; 1: 64–66 (in Russian). 6. Van Mullem PJ, deWijn JR. Bone and soft connective tissue response to porous acrylic implants. A histokinetic study. J Craniomaxillofac Surg 1988; 16: 99–109. 7. Petrovich YA, Shamsudinov AH, Sumarokov DD, Shvyrkov MB. Ripening peculiarities of phosphor–calcium combinations in transplantation of bone processed with different mode. Stomatologiia (Mosc) 1984; 5: 12–15 (in Russian). 8. Shamsudinov AH, Shvyrkov MB. Bone matrix inductive properties characteristic after bone demineralization in different solutions. Stomatologiia (Mosc) 1984; 3: 41–43 (in Russian). 9. Plotnikiv NA. The Mandible and TMJ osteoplasty after trauma and its complications. In: Trauma of the Maxillofacial Region. Moscow: Medicina, 1986; 338–377 (in Russian). 10. Sysoliatin PG. Embryonic bone application in maxillofacial surgery. Dissertation. Novosibirsk, 1971 (in Russian). 11. Grigorian AS, Borisov GP, Dgebuadze NV, Gadziev SA. Bone defect osteoplasty with embryonic materials. Stomatologia (Mosc) 1983; 5: 23–27 (in Russian). 12. Ilizarov GA. Ostoeosynthesis with cross pins. Scientific work collection of Kurgan Region Medical Research Society. Kurgan 1954; 1: 136–145 (in Russian).
13. Ilizarov GA. New priciples of osteosynthesis with crossed pins and wheels. Scientific work collection of Kurgan Region Medical Research Society. Kurgan 1954; 1: 146–160 (in Russian). 14. Deviatov AA, Fadeev DI, Popov PS. Stable fixation importance in purulent complications prophylaxis in treatment of diaphyseal fractures. Scientific work collection of Leningrad Refresher Institute. Leningrad 1974; 127: 93–94 (in Russian). 15. Ilizarov GA, Deviatov AA, Kataev IA, Galanova RY, Veselov AY, Tureckaia VI. New method of treatment for shin open communited fractures. Scientific work collection of Kurgan Research Institute for Experimental and Clinical Orthopedics and Traumatology. Cheliabinsk 1976; 2: 4–10 (in Russian). 16. Bychkov VI. Diaphyseal shin fresh fractures treatment with compressive–distractive osteosynthesis. Scientific work collection of Leningrad Research Institute for Traumatology and Orthopedics. Leningrad 1979; 5: 51–54 (in Russian). 17. Sux RG. Osteoplasty by Ilizarov method in shin posttraumatic stamp formation. Scientific work collection of Krugan Research Institute for Experimental and Clinical Orthopedics and Traumatology. Kurgan 1982; 8: 47–51 (in Russian). 18. Ilizarov GA. Possibilities of bone and soft tissue regeneration control. Scientific work collection of Krugan Research Institute of Experimental and Clinical Orthopedics and Traumatology. Kurgan 1982; 8: 5–18 (in Russian). 19. Farley JR, Baylink BJ. Purification of a skeletal growth factor from human bone. Biochemistry 1982; 21: 3502–3507. 20. Simpson E. Growth factor which affects bone. Trends Biochem Sci 1984; 9: 527–530. 21. Kusen CM, Stoika OS. Molecule mechanisms in ploypeptide growth factor action. Moscow: Nauka, 1985 (in Russian). 22. Price PA, Gloper S. Concurrent warfarin treatment further reduces bone mineral levels in 1,25-dihydroxyvitamin D2treated rats. J Biol Chem 1983; 258: 6004–6007. 23. Sampath TK, Wientroub S, Reddi AH. Extracellylar matrix proteins involved in bone induction and vitamin D dependent. Biochem Biophys Res Commun 1984; 124: 825–839. 24. Madzuga PP. Blood capillaries and reticuloendothelial system of bone marrow. Naukova dumka Kiev, 1978 (in Russian). 25. Urist MR, Delang RJ, Finerman GA. Bone cell differentiation and growth factor. Science 1983; 220: 680–686. 26. Ilizarov GI, Palienko LA, Pereslygih PF et al. Participation of bone marrow precursor cells in bone regeneration in compressive–distractive osteosynthesis. Bull Exp Biol Med 1980; 4: 489–490 (in Russian). 27. Palienko LA, Shreiner AA. Comparative analyses of KOKF quantity and callus X-ray characteristics in experimental shin lengthening. Scientific work collection of Kurgan Research Institute of Experimental and Clinical Orthopedics and Traumatology. Kurgan 1982; 8: 56–65 (in Russian). 28. Ermolaiev II, Panikarovskiy VV, Kaganovich SI, Osipian EM. Compressive–distractive osteosynthesis of the mandible in non-union fractures and pseudarthrosis. Seventh All-Union Congress of Stomatogists. Moscow: Tex dokladov, 1981; 305–306 (in Russian). 29. Panikarovskiy VV, Grigorian AS, Kaganovich SI, Osipian EM. Reparative osteogenesis peculiarity in compressive–distractive osteosynthesis. Stomatologiia (Mosc) 1982; 3: 21–25 (in Russian). 30. Melkiy VI. Treatment of patients with mandibular fractures by compressive–distractive device. Stomatologiia (Mosc) 1983; 5: 57–59 (in Russian). 31. Kucevliak VI, Sukachiov BA. Experimental mandible distraction. Stomatologiia (Mosc) 1984; 4: 13–15 (in Russian). 32. McCarthy JG, Schreiber J, Karp N, Thorn CH, Grayson BH. Lengthening the human mandible by gradual distraction. Plast Reconstr Surg 1992; 89: 1–8. 33. McCarthy JG. The role of distraction osteogenesis in the reconstruction of the mandible in unilateral craniofacial microsomia. Clin Plast Surg 1994; 21: 625–631. 34. Klein C, Howald HP. Lengthening of the hypoplastic mandible by gradual distraction in childhood: a preliminary report. J Craniomaxillofac Surg 1995; 23: 68–74. 35. Sengezer M. Mandibular lengthening by gradual distraction. Plast Reconstr Surg 1993; 92: 372.
Compression–osteodistraction in mandibular defects 36. Diner PA, Kollar E, Martinez H, Vazquez MP. Submerged intraoral device for mandibular lengthening. J Craniomaxillofac Surg 1997; 25: 116–123. 37. Shvyrkow MB, Shamsudinov AH. Methods of simultaneous treatment of the mandible defects and the adjacent soft tissues. Acta Chirur Plast 1989; 31(4): 226–235. 38. Shvyrkov MB, Sumarokov DD, Shamsudinov AH. Osteoplasty of the mandible by local tissue. J Craniomaxillofac Surg 1995; 23: 377–381.
The Authors M.B. Shvyrkov MD, DMD, PhD A.H. Shamsudinov MD, PhD D.D. Sumarokov DBD, PhD I.I. Shvyrkova MD
Maxillofacial Traumatology Department Moscow Medical Stomatology Institute Moscow Russia Correspondence and requests for offprints to: Professor M.B. Shvyrkov, apt. 27, 3A, Krasnogvardeiski blvd, 123317 Moscow, Russia, Tel: +7 95 259 5259; Fax: +7 95 273 1118 Manuscript received 19 January 1998 Accepted 1 July 1998
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& M A X I L L O FA C I A L S U R G E RY
Non-free osteoplasty of the mandible in maxillofacial gunshot wounds: mandibular reconstruction by compression–osteodistraction M.B. Shvyrkov, A.H. Shamsudinov, D.D. Sumarokov, I.I. Shvyrkova Maxillofacial Traumatology Department, Moscow Medical Stomatological Institute, Moscow, Russia SUMMARY. We have treated 33 young men with medium to large (3–8 cm) bony and soft tissue defects of the lower third of the face caused by gunshot wounds. After debridement, collapsing the proximal segments for primary approximation of soft and hard tissues and a closed osteotomy of a small fragment of mandible, we used an original compression–distraction device, designed in 1982 and tested during 1983 (analogous devices were absent at that time) to reposition the mandible and cause callus to form (during distraction) between the fragment and to use the remaining stumps of bone to fill in the defect. The soft tissues were repaired at the same time. Twenty-eight of the patients presented within a few hours of injury, and the remaining five had old injuries. The only complications were in the group with old injuries where four patients developed abscesses that required drainage, but these did not interfere with the process of osteogenesis. All 33 patients had good functional and aesthetic results within 3–4.5 months. The method allows a bloodless minimally traumatic procedure which can be carried out in one stage. The results compare very favourably with the classic methods of the treatment of mandibular gunshot injuries. and this results in the continuing activation of growth factors that cause pericapillary cells to transform into osteogenic cells. There is some evidence that bone stem cells play a part in bone repair, and are also influenced by growth factors,26,27 and this might explain why the osteogenesis persists for several months until sufficient callus is formed. Variations of this technique have been used in maxillofacial surgery for some years,28–36 particularly in the treatment of mandibular fractures without bony defects, for small defects after sequestrectomy, or for mandibular hypoplasia. However, we could find no reports of the technique being used for medium or large mandibular defects; the largest previously reported defect repaired was 3.75 cm. We present here our modification of Ilizarov’s technique. We have adapted it specifically to deal with the anatomy of the mandible, and have used it to treat patients with gunshot injuries or defects from old injuries.37,38 Our method allows us to repair not only the bone, but also the muscles, nerves, blood vessels, skin, and mucosa so that we have a full-thickness repair of the defect.
INTRODUCTION Mandibular defects are notoriously difficult to treat. Transplantation has been widely used, but the choice of material (bone grafts, polymers, metals, or ceramics) remains controversial.1–6 Contrast microangiography after mandibular osteoplasty has shown that the formalinized bone graft was either rejected or slowly revascularized and replaced by host bone. Combined biochemical and isotopic investigations have shown that the transplant remains metabolically inactive.7,8 Large, freeze-dried segments of homologous bone (which need supplementation by autologous bone chips) are eventually completely replaced by autologous bone.2,9 Embryonic bone is suitable for osteoplasty, but is not strong enough,10,11 and the process of transplantation and assimilation can be complicated by resorption or rejection.11 The technique of compression–distraction osteosynthesis that was first described by Ilizarov12,13 has revolutionized treatment of bony and soft tissue defects in trauma and orthopaedics. It is extremely effective in the treatment of fractures of the long bones, large bony defects, and traumatic osteomyelitis.14–17 Callus formed during gradual distraction has all the characteristics of an ideal transplant material that requires no mechanical stimulation, the main stimulator of bone growth being tension on the callus while the proximal fragments of bone are immobilized. A fracture or osteotomy initiates the regeneration of bone. Skeletal growth factors (bone morphogenic proteins) are activated.19–21 These are non-collagenous proteins that regulate the process of repair.22,23 Primitive cells develop into preosteoblasts and then into osteoblasts under the influence of these growth factors.24,25 Distraction causes absorption of callus,
PATIENTS AND METHODS The principle of the method is a closed osteotomy (preparation of a small fragment) of one or both of the mandibular stumps after initiation of osteogenesis by short-term compression of the fragments at the osteotomy site. Regeneration of bone is continued by distraction of the callus until it is large enough to close the defect. The small fragment of bone that is osteotomized and transplanted is usually about 2.5– 3 cm long, and as it is still connected to the surrounding 261
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A
A
B
B
C
Fig. 1 – Diagram of the non-free osteoplasty of the mandible used for the first group (A) the mandibular ends are fixed by the compression device, the site of the future osteotomy is marked with a dotted line, arrows show the direction of the mandibular ends; (B) the mandibular ends are approximated and the osteotomy created; (C) final result after restoration of the shape of the mandible, the defect is filled by immature callus.
tissues it has a good blood supply and innervation, high regenerative potential, and is mobile.17 We have treated 33 men, 20–35 years old. All had comminuted gunshot fractures of the mandible together with loss of surrounding soft tissue. The defects measured 3–8 cm (11–40% of the length of the body of the mandible). Twenty-eight of the 33 had recent wounds, and the other five had defects (soft and hard tissue) of varying age. We divided the patients into two groups depending on the size of the defect and the mobility of the stumps, as they required two slightly different approaches. The first group comprised seven patients with mandibular defects 3–4 cm long. The indication for osteoplasty was that the mandibular ends could be
Fig. 2 – Diagram of the osteoplasty used, for the second group: (A) the mandibular ends are fixed by the compression device and an osteotomy is created on the larger mandibular stumps to make a small mobile bone fragment; the arrow shows the direction of the mobile fragment; (B) final result after the two fragments have joined up; the defect is filled by immature callus.
closely approximated by the compression–distraction device. In some cases, however, there was no possibility of rapid knitting, and in others the mandibular ends were almost, but not quite, in contact with each other (Fig. 1). The second group (n=26) had defects 4–8 cm long on the lateral side of the mandible. In these cases we were able only to approximate the mandibular ends and reduce the size of the defect (Fig. 2). The site of the proposed closed osteotomy (small fragment) was marked on the skin, while the gunshot wound was being debrided. Two to four threaded screws were then inserted into each section of the mandible by drilling, and two to three threaded screws were drilled into what was to be the ‘small fragment’. The pins were united in groups by plates, which were transformed into a unified hard mobile system by means of a threaded arch bar (Figs 1 & 2). The device was designed to approximate the mandibular ends towards each other and although temporarily disturbing the occlusion, would reduce the size of the defect. As a result of this approximation, the soft tissue
Compression–osteodistraction in mandibular defects
A
C
B
D
Fig. 3 – (A) The small entrance wound is situated on the chin (below right retractor – arrow) and large lacerated exit wound on the left side of the the face; (B) occipitomental radiograph showing bursting fracture of the mandibular body along 1234567; (C) the patient’s face deformed after the mandibular stumps have been shifted towards the defect; (D) disturbance of dental occlusion: the right lower canine is situated opposite the left first upper incisor and the right lower premolar is between the right upper incisors; (E) the right lower canine is left in the same place and the right second premolar is shifted backwards together with the large mandibular stump as the distance between these teeth increases; (F) occipitomental radiograph shows the normal positions of the large mandibular stumps, the small mobile fragment has moved towards the left side and the defect at the osteotomy site is filled with immature callus; (G) the right lower canine and both incisors are in contact with the left upper premolars and molar, the right lower second premolar is in its normal position, between the lower teeth mentioned above, there is a considerable amount of gum formed by immature callus; (H) the same patient with removable denture; (I) occipito-mental radiograph showing the restored shape, size and continuity of the mandible, and well mineralized callus is seen at the site of the former mandibular defect.
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I
Fig. 3 – cont.
defects in the fresh wounds were reduced and we were always able to suture the mucous membrane and separate the oral cavity from the external wound despite substantial debridement of the wound edges. This is important in the prevention of infection. We then removed from the ends of the stumps, with either burs, tooth cutters, or a disc saw, 2–3 mm of dead bone and any bone with reduced regenerative capacity. Not only did this allow access to live bone containing growth factors, but removal of dead tissue helped healing, prevented infection and the development of gunshot osteomyelitis. In both groups, the closed osteotomy (preparation of the small segment) was completed with a wire saw, through a small incision in the submandibular region. The primary defect was then compressed with the compressive–distractive device, and the external gunshot wound repaired. The period of compression lasted for
10 days, after which we started the distraction. The ‘small fragment’ was separated at a rate of 1 mm/day by adjusting the device every 5–6 hours. We chose this rate because an osteon grows at a rate of 1 mm/day during regeneration. The fragment was displaced along the curved threaded bar (which had been shaped during the operation by the surgeon to correspond with the patient’s face) towards the defect. In bending the bar, the surgeon had programmed the future curvature of the body of the mandible. In the five patients with old defects the scar between the stumps was compressed during distraction by the small fragment. In four of the five cases this caused an abscess that had to be drained, but the inflammation did not spread to the bone. In each case there was room for direct contact between the mandibular end and the ‘small fragment’ and it was possible to trim the end surfaces through the wound to enable primary repair.
Compression–osteodistraction in mandibular defects
By the end of the 10-day period of compression, the soft tissue injury had usually healed, and during the distraction of the callus the soft tissues were also being stretched. This slow stretching stimulated growth and repair of muscles, vessels, mucosa, skin, and nerves and progressed at the same time as osteogenesis. When direct contact had been made between the small fragment and the opposite mandibular end we trimmed and freshened the compressed ends to obtain the maximum contact. The ends were then compressed again. By now, immature callus had started to ripen, and could be palpated inside the mouth. Depending on the size of the defect this would take from 1.5–2.5 months to mature. Three to four weeks after direct contact between the small fragment and the opposite mandibular end had been achieved, the patient was given a removable denture to wear. This improved speech, mastication, and accelerated reconstruction and mineralization of the callus. The compression–distraction device was removed after the arch bar had been taken off and the callus had been examined manually to make sure that it was stable. RESULTS All 33 patients had good functional and aesthetic results. There were no complications, except for the four abscesses that developed in four of the five patients with old wounds, and these had no effect on bony regeneration. The duration of treatment ranged from 3 to 4.5 months. CASE REPORT A 24-year-old man was admitted a few hours after a penetrating gunshot wound to the soft tissues of the left sublingual, submandibular, and cheek region. There was a bursting fracture of the mandibular body in the lower left 1234567, where the primary defect lay (Figs 3A & B). The submandibular gland was missing. All loose bony splinters were removed during debridement, leaving a bony defect about 8 cm long. Two groups of pins were inserted in the right body of the mandible, and one group in the ramus. The mandibular ends were displaced towards the defect, which resulted in the defect becoming smaller. The soft tissues were sutured in layers with continuous retention sutures. The right first premolar was then extracted and a closed osteotomy (small segment) made through the socket. This resulted in a small mobile fragment that contained the lower right 321. The osteotomy site was exactly halfway between the two groups of pins. The defect was then approximated, which resulted in the patient’s face and occlusion becoming temporarily deformed (Figs 3 C & D). Ten days later, we began distracting the desmal callus. The soft tissue wound had healed by primary intention. A month later, the mobile fragment had been considerably displaced towards the defect (to the left) and the large right stump had moved backwards into its normal position. Figures 3E and F show the defect between the mobile fragment and the left stump. Two and a half months after we had started distraction, the small fragment came into contact with the left mandibular end. The shape of the face had recovered, and occlusion
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was restored. The lower right 321 teeth were in contact with the lower left 56 (Fig. 4G). On bi-manual palpation, a hard elastic callus could be felt where previously there had been a defect. A radiograph showed that no correction of the ends of the small fragment or mandibular ends was necessary. The patient started using a removable lower denture. The period of fixation started. Eighteen days later, the arch bar of the device was removed so that we could check the strength of the callus; three days later no fragments had become displaced, which shows that the new bone was durable. All the pins were removed and the patient was discharged. Two months later the patient’s face and occlusion were normal, and he could chew any food. Well-mineralized callus could be seen on the radiograph at the site of the former mandibular bony defect (Fig. 3I). It therefore took us 4.5 months to repair an 8-cm defect in the mandible, and its associated soft tissue loss.
DISCUSSION Only if the recipient bed is healthy will a free osteoplasty (bone graft) succeed. However, gunshot wounds to the face usually result in both soft and hard tissue defects. Restoration of the mandibular defect also requires a repair of the soft tissue loss. The soft tissue bed must be healthy if it is to take a future bone transplant. Usually in such cases a pedicled, musculocutaneous or free flap is used to restore the soft tissues and repair usually requires several operations, which take a long time and often give poor aesthetic results. A few months later, a graft made of autologous or allogeneic bone, ceramic, metal or plastic will need to be inserted but nobody can predict the success of the graft. It may result in assimilation, resorption or rejection. There are many causes for resorption or rejection, and it is not possible to eliminate them all. The non-free osteoplasty of the mandible has many advantages. During compression, the desmogenous callus formation resembles bony embryogenesis, and is replaced by osteogenic tissue when distraction begins. The angiogenic callus that extends from the end of the small fragment has a good capillary blood supply and causes no immunological reaction. The new bone that forms during distraction may be grown to any size, forms easily, and quickly matures into organo-typical bone. It can be bent by the preformed arch bar (prepared by the surgeon in theatre) to the mandibular shape required. This technique compares favourably with bone grafts and alloplastic implants because it is not subject to resorption or rejection. Compression–distraction osteoplasty not only restores the mandible but during distraction the soft tissue is also repaired, which means that a bloodless restoration of the lower third of the fact is possible in one stage. It is always difficult to place a denture after bonegrafting, because the bone graft does not contain teeth. The mobilized and displaced small fragment, however, does have teeth and moves them into the defect, so it is relatively easy to fix a denture to them. Unlike bone-grafting, when we have no control over the processes of healing, we can easily regulate the degree of compression, distraction, and fixation.
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Compression can accelerate callus formation and is used in two ways in this technique. When ‘the small segment’ prepared reached the opposite mandibular end, the new union (primary site) is compressed for ten days with the compressive–distractive device causing an activation of osteogenesis. Ten days later, distraction is commenced at this site by displacing the small fragment backwards for a 6–7 day period. This allows compression of the regenerated bone and speeds up maturation of the previously formed callus and allows some further distraction at the primary site.
CONCLUSION Mandibular bony and soft tissue reconstruction can be achieved by non-free osteoplasty with the help of this compressive–distractive device. This method avoids the need for multiple extensive operative procedures on both soft and bony tissues. It does not require a bone graft or an implant with their unpredictable outcome (assimilation, resorption, rejection). The method of non-free osteoplasty compares very favourably with the classic methods of mandibular reconstruction. It is a relatively atraumatic, bloodless procedure, secures substitution of the combined soft and hard tissue defect in one stage and decreases the duration of treatment three- to four-fold. References 1. Calnan J. The use of inert plastic material in reconstructive surgery. I. A biological test for tissue acceptance. II. Tissue reaction to commonly used material. Br J Plast Surg 1963; 16: 1–22. 2. Bowerman JE, Conroy B. A universal kit in titanium for immediate replacement of the resected mandible. Br J Oral Surg 1969; 6: 223–228. 3. Tienkel G, Niederdellmann H. The possibilities afforded by the use of dense aluminium oxid ceramics in the reconstruction of temporomandibular joint. Quint Int 1977; 8: 19–26. 4. Viliams D, Rouf R. Implants in Surgery. 1978 (in Russian). 5. Shestakov UN, Kasparova NN, Dundukov BS. Mandible osteoplasty in children by boneplastic endoprosthetics. Stomatologiia (Mosc) 1985; 1: 64–66 (in Russian). 6. Van Mullem PJ, deWijn JR. Bone and soft connective tissue response to porous acrylic implants. A histokinetic study. J Craniomaxillofac Surg 1988; 16: 99–109. 7. Petrovich YA, Shamsudinov AH, Sumarokov DD, Shvyrkov MB. Ripening peculiarities of phosphor–calcium combinations in transplantation of bone processed with different mode. Stomatologiia (Mosc) 1984; 5: 12–15 (in Russian). 8. Shamsudinov AH, Shvyrkov MB. Bone matrix inductive properties characteristic after bone demineralization in different solutions. Stomatologiia (Mosc) 1984; 3: 41–43 (in Russian). 9. Plotnikiv NA. The Mandible and TMJ osteoplasty after trauma and its complications. In: Trauma of the Maxillofacial Region. Moscow: Medicina, 1986; 338–377 (in Russian). 10. Sysoliatin PG. Embryonic bone application in maxillofacial surgery. Dissertation. Novosibirsk, 1971 (in Russian). 11. Grigorian AS, Borisov GP, Dgebuadze NV, Gadziev SA. Bone defect osteoplasty with embryonic materials. Stomatologia (Mosc) 1983; 5: 23–27 (in Russian). 12. Ilizarov GA. Ostoeosynthesis with cross pins. Scientific work collection of Kurgan Region Medical Research Society. Kurgan 1954; 1: 136–145 (in Russian).
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The Authors M.B. Shvyrkov MD, DMD, PhD A.H. Shamsudinov MD, PhD D.D. Sumarokov DBD, PhD I.I. Shvyrkova MD
Maxillofacial Traumatology Department Moscow Medical Stomatology Institute Moscow Russia Correspondence and requests for offprints to: Professor M.B. Shvyrkov, apt. 27, 3A, Krasnogvardeiski blvd, 123317 Moscow, Russia, Tel: +7 95 259 5259; Fax: +7 95 273 1118 Manuscript received 19 January 1998 Accepted 1 July 1998
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