Immediate Reconstruction of Mandibular Defects

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J Oral Maxillofac Surg65:883-890, 2007

Immediate Reconstruction of MandibularDefects: A Retrospective Report

of 242 CasesZubing Li, DDS, PhD,* Yifang Zhao, DDS, MSc,

Sheng Yao, DDS, MSc, Jihong Zhao, DDS, MSc,

Shibin Yu, DDS, PhD, and Wenfeng Zhang, DDS, MSc

Purpose: This study was conducted to evaluate the effects of routine protocols in immediate mandib-ular reconstruction.

Patients and Methods: A total of 242 patients who underwent immediate mandibular reconstructionwere reviewed retrospectively. The therapeutic evaluation was performed according to outcomes ofclinical and radiographic examination. The evaluated contents included facial symmetry, degree ofmouth opening, occlusal relationship, and temporomandibular joint symptoms. Statistical analysis was

also carried out to compare therapeutic differences between different methods for mandibular recon-

struction. SPSS 10.0 for Windows was used for statistical analysis.

Results: The follow-up showed satisfactory long-term outcome in 203 patients. Statistical analysisrevealed no significant difference in restoration of facial contour among several groups (2 0.05(15) 21.93; P .109 .05). Ten cases involved serious postoperative complications, including localinfection, exposure of rigid fixation plate, and serious pain.

Conclusions: Our findings indicate that autogenous bone graft is the best for reconstruction of smallmandibular defects. Frozen autogenous lesional mandible plus autogenous iliac or rib graft is recommendedfor reconstruction of large defects in the mandible. Strict patient selection, careful surgical procedure, andappropriate preoperative and postoperative nursing care are key factors in successful transplantation.

2007 American Association of Oral and Maxillofacial Surgeons

J Oral Maxillofac Surg 65:883-890, 2007

Loss of mandibular continuity, whether caused bytumor, trauma, or infection, produces significantfunctional disability, cosmetic deformity, and patho-

logical impairment.1 Thus, reconstructive surgery isnecessary to restore oral function and speech.2 How-ever, how best to successfully reconstruct mandibularbone defects has not yet been satisfactorily resolved3

and represents a challenge to oral and maxillofacialsurgeons.4

Since 1980, a total of 625 patients have undergoneimmediate mandibular reconstruction using autolo-gous or homologous bone grafts and biomaterials inour department. In this article, we review the findingsof clinical and x-ray examination of 242 follow-up

cases and evaluate the long-term effects of routinesurgical protocols in immediate mandibular recon-struction.

Materials and Methods

GENERAL DATA

A total of 242 patients with mandibular tumor orcyst were included in this retrospective study. Thestudy population comprised 156 males and 86 fe-males, with an age range of 9 to 73 years. The 242

cases included 136 ameloblastomas, 67 keratocysts,

Received from the Department of Oral and Maxillofacial Surgery,

School of Stomatology, Wuhan University, Wuhan, China, and Key

Laboratory of Oral Biomedical Engineering (Wuhan University),

Ministry of Education, Wuhan, China.

*Professor and Chairman.

Professor and Chairman.

Formerly, Research Associate; and Currently, Resident, Depart-

ment of Stomatology, First Hospital of Wuhan, Wuhan, China.

Associate Professor and Chairman.

Associate Professor and Chairman.

Professor and Chairman.

Address correspondence and reprint requests to Dr Li: Depart-

ment of Oral and Maxillofacial Surgery, School of Stomatology,

Wuhan University, Key Laboratory of Oral Biomedical Engineering,

Wuhan University, Ministry of Education, 237 Luoyu Road, Wuhan,

China; e-mail: [email protected]

2007 American Association of Oral and Maxillofacial Surgeons

0278-2391/07/6505-0010$32.00/0

doi:10.1016/j.joms.2006.06.282

883


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15 ossifying fibromas, and 24 other benign tumors.

The defects of 242 cases were classified according to

the HCL classification system suggested by Boydet al.5 In this system, H represents a lateral segment of

any length containing a condyle and not significantly

crossing the midline, L represents the same defect but

without a condyle, and C represents the anterior

segment between the incisive foramina. When C must

be included in the description, the vast majority of it

must compose part of the defect. Taking into account

the difficulties in restoring form and function and not

simply relying on the traditional anatomic landmarks,

the HCL classification system is suggested. The types

of mandibular lesions encountered and the classifica-

tion of mandibular defects are given in Table 1.The 242 cases were classified into 6 groups accord-

ing to the graft materials used: free autogenous bone

transplant (group A), frozen autogenous lesioned

mandible (group B), frozen autogenous lesioned man-

dibleiliac/rib compound (group C), vascularized au-

togenous bone transplant (group D), homologous

bone transplant (group E), and hydroxylapatite (HA)/

titanium plate (group F). General data for each group

are given in Table 2.

SURGICAL PROCEDURES FOR

MANDIBULAR RECONSTRUCTION

Free Autograft Transplantation

After resection of the lesioned mandible, autoge-nous iliac or rib was harvested according to the sizeand shape of the defect. Usually, the contralateral

seventh or eighth rib or ipsilateral unicortical iliacbone block was harvested. The remaining mandibularsegments and autografts were prepared, and chipgrafting or graft inlay was performed by fixing theirends to the remaining mandibular segments (Fig 1).

Transplantation of Autogenous Iliac Crest Plus

Rib Grafts

Generally, a contralateral rib graft was harvested for

reconstruction of the mandibular ramus and condyleprocess. An ipsilateral iliac crest graft was used torestore defects of mandibular body and angle. Fixa-tion was performed with wires or microplates and

screws.Reimplantation of Frozen Lesioned Mandible

The lesions, soft tissue, and teeth were removedfrom the resected mandible. The mandibular segment

was then hollowed out, and multiple fenestrationswere made in the bone surface. The bone segmentwas immersed in liquid nitrogen (196C) with 3freezethaw cycles of 10 minutes each, then sub-

merged into an antibiotic solution (400,000 U of gen-tamycin in saline solution) for 15 minutes. Then theprepared frozen bone segment was reimplanted intothe recipient site, and rigid fixation was carried out.

Transplantation of frozen autogenous lesionedmandible was performed in combination with autog-enous iliac grafting. The lesioned mandible was pre-pared as described previously. The lesioned mandibleand unicortical iliac block were fixed together to

augment a weak bone segment and restore the shapeof the mandibular body and the height of alveolarridge. In some cases, the lesioned mandible acted as aproper tray for the packing of marrow and bone chipsfrom the ilium (Fig 2).

Table 1. CLASSIFICATION OF MANDIBULAR DEFECTSAND PATHOLOGICAL DIAGNOSIS OF LESIONS

PathologicalDiagnosis

Classification of MandibularDefect

TotalH L C HC LCOther

Types*

Ameloblastoma 35 75 3 1 17 5 136Keratocyst 20 31 4 2 5 5 67Ossifying fibroma 4 7 0 2 1 1 15Other lesions 6 11 1 0 3 3 24Total 65 124 8 5 26 14 242

*Other types include LCL and HCL.

Li et al. Immediate Reconstruction of Mandibular Defects. J OralMaxillofac Surg 2007.

Table 2. GENERAL DATA FOR 242 PATIENTS WITH MANDIBULAR DEFECTS

GroupNo. of Cases

(Male/Female) Age (yrs)Size of Defect

(cm)Mean Size ofDefect (cm)

Follow-Up(months)

Classification of Mandibular Defect

H L C HC LC Other Types*

A 95 (64/31) 9 to 64 6 to 9 7.0 14 to 118 27 55 2 2 6 3B 14 (8/6) 11 to 58 4 to 6 5.0 19 to 105 1 0 3 1 7 2C 62 (37/25) 9 to 58 5 to 7 6.2 14 to 118 15 31 1 1 8 6D 27 (15/12) 14 to 73 3 to 10 6.0 3789 8 14 1 0 3 1E 28 (17/11) 10 to 61 3 to 12 6.4 45 to 98 7 19 0 0 1 1F 16 (9/7) 18 to 57 8 to 14 9.8 20 to 54 7 5 1 1 1 1

*Other types include LCL and HCL.

Li et al. Immediate Reconstruction of Mandibular Defects. J Oral Maxillofac Surg 2007.

884 IMMEDIATE RECONSTRUCTION OF MANDIBULAR DEFECTS


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Transplantation of Vascularized Bone

The vascularized bone transplantation included il-

iac bone and fibular bone. After resection of thelesioned mandible, vascularized iliac bone flap or fib-

ular bone flap was harvested according to the size andshape of the defect. The grafts were prepared toadapt to the defect in the mandible. Then the arteryand vein of the bone flap were anastomosed with the

vessels of the defect site, with the facial artery andexternal jugular vein and/or facial vein guaranteeingthe blood supply. Finally, the graft was fixed to the

remaining mandibular segments (Figs 3, 4).

Transplantation of Dried Frozen Homologous

Bone Grafts

The dried frozen homologous bone grafts were

kindly provided by a Russian specialist, Professor Plot-

nikov Nevobeef. The surgical procedure for mandib-

ular reconstruction was carried out as described pre-viously. A 2-layer closure was performed after copiousirrigation of the graft site (Fig 5).

HA Implantation

The dense HA block was provided by Western

China Medical University. After necessary shape mod-ification, the HA block was inserted into the site ofthe bone defect and fixed with transosseous wires.

Titanium Functional Reconstruction

Plate Implantation

The titanium functional reconstruction plate wascontoured according to the shape of mandible aftersegmental resection of the mandible. The plate was

FIGURE 2. Transplantation of frozen antogenous lesioned mandiblewith autogenous iliac graft for mandibular reconstruction. A, Preoper-ative frontal view (ameloblastoma of right mandible). B, Frontal view 6months after operation. C, Radiographic view of ameloblastoma ofright mandible. D, Radiographic view of transplantation of frozenantogenous lesioned mandible with autogenous iliac graft (6 monthsafter operation).


FIGURE 1. Free autogenous iliac bone transplantation for mandibular

reconstruction. A, Preoperative frontal view (keratocyst of left mandi-ble). B, Frontal view months after operation. C, Radiographic view ofkeratocyst of left mandible. D, Radiographic view of free autogenousiliac bone transplantation for mandibular reconstruction (6 months afteroperation).


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then implanted into the defect and fixed to the endsof remaining mandibular segments (Fig 6).

NURSING PROCEDURES FOR

MANDIBULAR RECONSTRUCTION

Careful and appropriate preoperative and postop-erative nursing care was given to all patients. Besidesnormal nursing procedures (ie, preoperative dentalcleaning, postoperative incision cleaning, oral cavitycleaning, and the observation of healing), psycholog-ical consolation and sufficient conversation were alsoincluded in the nursing care, to help the patientsbetter understand the mandibular reconstruction pro-

cedure. Appropriate therapy was provided when ab-

normal conditions (eg, exposure of rigid fixation

plates, infection, dehiscence) occurred.

EVALUATION OF THERAPEUTIC RESULTS

On follow-up, clinical and radiographic examina-tions were performed at l, 3, and 6 months and 1 year

after operation, respectively. Restoration of functionwas performed either through conventional dentureuse or with an implant-supported prosthesis. Criteriafor evaluating the reconstruction performance werebased on our departments guidelines and included

facial profile, occlusal relationship, mouth opening,and the condition of the temporomandibular joint(TMJ). Based on these criteria, each reconstruction

was classified as Class I, II, III, or IV. In Class I, thepatient has a satisfactory and symmetrical facial pro-file, an almost-normal occlusal relationship, normalmouth opening, and no symptoms of TMJ dysfunc-tion. Class II is characterized by a normal occlusalrelationship and no TMJ pain with slight excavation of

the operated face and little restriction of mouth open-ing. Class III involves an asymmetric facial profile andinsufficient grafting. Cases involving implant removalare considered Class IV.

The 2 test, using SPSS 10.0 for Windows (SPSS,Chicago, IL) was performed to compare the differ-ences among groups. In statistical analysis, a P valueless than .05 was considered significant.

Results

Postoperative follow-up results are summarized inTable 3. Good functional and esthetic results wereobtained in most patients (83.88%), with no evidenceof recurrence of the primary lesion in all cases. Allpatients were satisfied with their postsurgical facial

contour except for slight disfigurement in 18 cases.Mandibular movement was almost normal in the vastmajority of patients. X-ray film revealed that the den-sity of the transplanted grafts appeared to decreaseearly after operation and gradually became nearlynormal.

Statistical analysis revealed no significant difference

among the different groups (2 0.05(15) 21.93; P.109 .05). However, comparison between 2 groups

revealed significant differences between groups A andC, groups C and D, and groups C and E. Clinically, thepatients in groups A, B, and C achieved satisfactorycosmetic restoration. Frozen autogenous affectedmandible plus autogenous lilac or rib graft was par-ticularly suitable for reconstruction of a large range ofmandibular defects.

Serious postoperative complications, including lo-cal infection, exposure of the rigid fixation plate, and

serious pain, occurred in 10 patients (Table 4). No

FIGURE 3. Vascularized fibular bone transplant for mandibular re-construction. A, Preoperative frontal view (ameloblastoma of the leftmandible). B, Frontal view 6 months after operation. C, Radiographicview of ameloblastoma of left mandible. D, Radiographic view ofvascularized fibular bone transplantion (6 months after operation).




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significant difference in complication rate was foundamong the various groups.

Discussion

Modern studies have shown that mechanisms ofbone graft healing include bone conduction and os-teoinduction.1,6-9 During bone graft healing, the graftsmay act as a supporting framework for the surgicaldefect and new bone formation. Once the mineral

matrix in a block graft resorbs, it is completely re-placed by newly formed bone arising from residual

host bone through osteoinduction. Both healingmechanisms rely heavily on the cellularity and vascu-larity of the soft and hard tissues of the recipient siteand on the presence of bone morphogenic protein(BMP).1 BMP can induce chondrosoteoblastic differ-entiation by its action on undifferentiated or proto-differentiated mesenchymal cells.10 This osteoinduc-tive action is directly proportional to the quantity ofBMP contained in the graft.11 Periosteum at the recip-

ient site also plays an important role in bone graft

healing.12 Several authors have demonstrated thatnontraumatized cancellous bone provides viable mes-enchymal cells that produce osteoid shortly after

transplantation.13

Our clinical approach to immediate mandibular re-construction is based on the mechanisms of bonegraft healing. Therefore, it is important to describethese mechanisms and help reviewers understandthe concepts. The early osteoreparative capacity of afresh autograft is attributed mainly to abundant osteo-

blasts in the bone graft itself. In groups B and C, bonegrafts serve only as a supporting framework and have

no osteogenic capability at an early stage, because thefreezing procedure destroys both normal and tumorcells through the formation of ice crystals betweenthe cells, which induces intracellular dehydration,leading to cell death.3 The transplanted bone is grad-ually replaced by new healthy bone arising from meta-plastic osteoblasts in recipient connective tissue.Transplanted HA is finally fixed by fibrous tissue andmineralized bony tissue that enters into the HA milli-

pores without biological degradation.

FIGURE 4. Vascularized iliac bone transplantion. A, Preoperative frontal view (ameloblastoma of left mandible). B, Frontal view 6 months afteroperation. C, Radiographic view of ameloblastoma of right mandible. D, Radiographic view of vascularized iliac bone transplantion for mandibularreconstruction (6 months after operation). E, F, and G, Tooth implantation after the operation.


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In our study, only 10 cases experienced significant

postoperative complications. We attribute this lowrate of postoperative complications to careful selec-tion of patients and to favorable clinical conditions ofthe mandibular defects, with no soft tissue defects.Infection (5 cases) was the most common postoper-ative complication, followed by exposure of the rigid

fixation plate. The study variablesage, gender, de-fect type, and material used for reconstructiondidnot differ significantly among the groups. The lownumber of cases of complications precludes drawingany conclusions about the difference in postoperativecomplication rate among the various groups.

Generally, autologous bone grafts are preferred forsmall defects; however, the addition of homologous

bone grafts and biomaterials is normally necessary forlarge defects.3 Autografts have sufficient bone andnonantigenicity and are easy to perform; they also canintegrate quickly with residual mandibular segments.However, obtaining bone autografts entails increased

morbidity of the donor site and increased operationtime; moreover, there is a limited supply of bone inchildren.3

In our experience, ipsilateral iliac crest autograftsare suitable for reconstructing defects in the mandib-ular ramus and angle because of a good radian. Theramus height is usually insufficient when the condyleis resected for a tumor and the defect is reconstructedby autogeneous iliac bone graft. Hemimandibular de-fects can be repaired with rib autografts. Rib trans-plantation is also a good choice for TMJ reconstruc-tion, because costal cartilage can act as the head of

FIGURE 5. Dried frozen homologous bone grafts for mandibularreconstruction. A, Preoperative frontal view (keratocyst of the rightmandible). B, Frontal view 3 months after operation. C, Radiographicview of keratocyst of the right mandible. D, Radiographic view of driedfrozen homologous bone grafts for mandibular reconstruction (3months after operation).


FIGURE 6. Titanium functional plate insertion for mandibular recon-struction. A, Preoperative lateral view (gingival carcinoma of rightmandible). B, Frontal view 1 month after operation. C, Radiographicview of gingival carcinoma of right mandible. D, Radiographic view oftitanium functional plate insertion for mandibular reconstruction (1month after operation).




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the condyle to avoid ankylosis of the TMJ and resorp-tion of bone after the operation. The ribs greatestdrawback is its lack of bulk. It can be used with iliactransplantation to reconstruct larger mandibular de-

fects.Using frozen autogenous lesioned mandible to re-

construct surgical defects has several advantages.First, the bone graft is autogenous and thus has noantigenicity. Second, a good esthetic result is usuallyobtained, because the shape of the bone graft coin-cides with the surgical defect. Especially in the sym-physeal area, it is impossible to find a bone withinthe human skeleton that perfectly fulfills the sym-

physeal anatomic shape. Finally, the surgery is sim-plified by avoiding or reducing bone grafts fromanother part of the body. However, in cases withextensive tumor involvement, this approach shouldbe used cautiously; insufficient supporting soft tis-

sue around the graft bed can lead to infection ornecrosis of grafts.5 Progressive resorption of the trans-plant can also result in pathological fracture; thus, wesuggest using this method only in cases with good

continuity of lesioned bone.In our study, HA grafts have good histocompatibil-

ity without rejecting reaction, as well as general or

local toxic and side effects. However, some research-ers suggest that this method has several disadvan-tages, including exfoliation of HA particles,13,14 in-complete integration with recipient bone, lack of

osteoinduction capability, extended time for bonehealing, pathological fracture, neurosensory deficits,and esthetic changes. Even though dried frozen ho-mologous bone is readily available, currently it is notrecommended for extensive application in the clinicsetting, because elimination of antigen is a very com-plicated procedure. A titanium functional reconstruc-tion plate can be used as an alterative method formandibular reconstruction in older patients with

poor health condition or patients with malignant man-dibular tumor.15 One drawback of this approach isthat the construction plate cannot provide adequatealveolar height for denture construction.

Most of the patients in the present study achieved

good long-term results. We attribute this success toproper patient selection and careful surgical proce-dure. Scrupulous nursing care, including preoperativepreparation, oral hygiene, and postoperative observa-

tion of incisional healing, was also important.The main difference among the various groups lies

in the degree of patient satisfaction with restoration

Table 3. THERAPEUTIC RESULTS FOR 242 PATIENTS AFTER OPERATION

Group

I II III IV

No. of Cases % No. of Cases % No. of Cases % No. of Cases %

A 50 52.7 27 28.4 15 15.8 3 3.2B 9 64.3 4 28.6 1 7.1 0 0C 46 74.2 13 21.0 2 3.2 1 1.6D 12 44.4 9 33.3 5 18.5 1 3.8E 12 42.9 8 28.6 6 21.4 2 7.1F 7 43.8 6 37.5 1 6.3 2 12.4Total 136 56.2 67 27.7 30 12.4 9 3.7


Table 4. POSTOPERATIVE COMPLICATIONS

No. Diagnosis Complication GroupPostoperative

DayType ofDefect Treatment

1 Ameloblastoma Infection C 3 H Antibiotic2 Ossifying fibroma Infection B 5 H Antibiotic3 Ameloblastoma Infection A 5 L Antibiotic4 Keratocyst Exposure of rigid

fixation plateC 7 L Removal of plates

and refixation5 Osteoblastoma Infection A 3 L Antibiotic6 Ameloblastoma Dehiscence C 7 L Suture7 Keratocyst Exposure of rigid

fixation plateC 6 LC Removal of plates

and refixation8 Ossifying fibroma Ache A 4 L Analgesia9 Ameloblastoma Dehiscence C 6 LC Suture

10 Keratocyst Infection C 4 H Antibiotic


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of the facial contour. A frozen autogenous lesioned

mandible with or without iliac graft can closely coin-cide with the surgical defect, producing better func-tional and cosmetic results. As described earlier, non-absorbable HA has potential side effects and noosteoinductive capability; how best to enhance itsosteoinduction necessitates further study.

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enous bone graft reconstruction of mandibular discontinuity: A12-year longitudinal study of 31 patients. Int Oral MaxillofacImplants 13:767, 1998

2. Schmelzeisen R, Schon R: Microvascular reanastomosed allog-enous iliac crest transplants for the reconstruction of bonydefects of the mandible in miniature pigs. Int J Oral MaxillofacSurg 27:377, 1998

3. Redondo LM, Herandez VH, Cantera JMG, et al: Repair ofexperimental mandibular defects in rats with autogenous, de-mineralized, frozen and fresh bone. Br J Oral Maxillofac Surg35:166, 1997

4. Dong YJ, Zhang GZ, Li ZB, et al: The use of immediate frozen

autogenous mandible, for benign tumor mandibular recon-struction. Br J Oral Maxillofac Surg 34:58, 1996

5. Boyd JB, Gullane PJ, Rotstein LE, et al: Classification of man-dibular defects. Plast Reconstruction Surg 92:1266, 1993

6. Stone D, Zacarian SA, Diperi C: Comparative studies of mam-malian normal and cancer cells subjected to cryogenic temper-ature in vitro. J Cryosurg 2:43, 1969

7. Albrektsson T: Repair of bone grafts, a vital microscopic andhistologic investigation in the rabbit. Scand J Plast ReconstrSurg 14:1, 1980

8. Reddi AH, Huggins CB: Lactic/malic dehydrogenase quotientsduring transformation of fibroblasts into cartilage and bone.Proc Soc Exp Bio Med 137:127, 1971

9. Marx RE: Mandibular reconstruction. J Oral Maxillofac Surg51:466, 1993

10. Mark DE, Hollinger JO, Hastings C, et al: Repair of calvarialnonunions by osteogenin, a bone-inductive protein. Plast Re-constr Surg 86:623, 1990

11. Urist MR, Sato K, Brownell AG, et al: Human bone morpho-genetic protein (hBMP). Proc Soc Exp Bio Med 173:194,1983

12. Abbott LE, Schottstaedt ER, Sannders JB, et al: The evaluation ofcortical and cancellous bone as grafting materials: A clinicaland experimental study. J Bone Joint Surg 29:381, 1947

13. Mercier P, Bellavance F: Low incidence of severe adverseeffects after mandibular ridge reconstruction using hydrox-

ylapatite. Int J Oral Maxillofac Surg 28:273, 199914. Wittenberg JM, Small LA: Five-year follow-up of mandibular

reconstruction with hydroxylapatite and the mandibular staple

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Immediate Reconstruction of Mandibular Defects

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