Distraction osteogenesis of a fibula free flap used for mandibular reconstruction: preliminary report

Unique Techniques Utilizing Rib Grafts for Mandibular Reconstruction in the Pediatric Population

INTRODUCTION

Pediatric mandibular reconstruction requires a grafted segment of sufficient height and stability to support dental implant placement. Double barreling and mandibular distraction osteogenesis (MDO) after reconstruction are two techniques to achieve this, but they have only been reported with fibular grafts. Rib grafts not only have a lower donor site morbidity than fibular grafts, but they also provide adequate defect coverage in children. As such, we propose their use with either a double barrel technique or with MDO.

METHODS

Three pediatric patients underwent mandibular resection and reconstruction using rib grafting. One patient underwent single rib graft placement with subsequent vertical rib distraction. In the remaining two patients, a double-barreled rib technique was used, stacked horizontally in one patient and vertically in the other.

RESULTS

From March 2018 to May 2019, three patients with an average age of 11 underwent resection of mandibular tumors or tumor-like lesions followed by immediate reconstruction with rib graft. Due to postoperative wound complications, the graft was completely removed in one patient. The remaining two patients had an uneventful recovery with dental implants planned for one and fully osseointegrated in the other. None of the patients experienced donor-site complications.

CONCLUSION

This case series supports the utility and versatility of autogenous rib grafts as a reconstructive option in children. Not only is rib an excellent bone source with low donor site morbidity, but its height can be augmented through MDO or double barreling, facilitating the successful placement of implants and oral rehabilitation in pediatric patients.

Pediatric Mandible Reconstruction: Controversies and Considerations

Mandibular reconstruction in pediatric patients has some unique considerations. The method of reconstruction has to factor in the growth potential of the neo-mandible, the native mandible, and the donor site. The condyle is considered the main growth center of the mandible. Current literature indicates that fibula, iliac crest, and scapula osseous flaps do not have the ability to grow. Costochondral grafts exhibit growth because of the costal cartilage component, although the growth is unpredictable. Preservation of the mandibular periosteum can result in spontaneous bone regeneration. Fibula bone harvest in a child mandates close follow-up till skeletal maturity, to monitor for ankle instability and valgus deformity. Dental rehabilitation maintains occlusal relationships, which promotes normal maxillary development. Elective hardware removal should be considered to facilitate future dental implant placement and possible revision procedures. After completion of growth, if occlusion or symmetry is not satisfactory, secondary procedures can be performed, including distraction osteogenesis, orthognathic-type bone sliding operations, and segmental ostectomy.

Thinned-out skin paddle versus collagen matrix as an optimized peri-implant soft tissue following fibula osteoseptocutaneous free flap: 3-year retrospective study

The objective of this study was to compare the implant longevity following two methods of peri-implant soft tissue optimization following free fibula flap (FFF): thinning of skin paddle (SP) and collagen matrix (CM). All patients who underwent rehabilitation with dental implants after mandibular reconstruction with FFF between June 2009 to May 2014 were retrospectively reviewed. Two methods of peri-implant soft tissue optimization were applied: (1) SP group, (2) CM group. Outcome measurements were: modified plaque index (mPI), modified sulcus bleeding index (mSBI), probing depth (PD), marginal bone loss (MBL), implant success rate and complication rates. A total of 24 patients with 69 implants were included in the study, with 8.7% (n = 6) of implants lost in 3 years. No statistically significant difference was found regarding the outcome measurements in both groups. Failed implants presented with statistically significant higher mPI, mSBI, PD and MBL scores during prosthesis delivery and subsequent follow-ups (P<0.03). In the SP group, one patient experienced SP necrosis which later underwent soft tissue optimization using CM. CM is an alternative peri-implant soft tissue, while thinning of SP is feasible if thickness is well controlled.

Vertical distraction osteogenesis of a reconstructed mandible with a free vascularized fibula flap: a report of two cases

Background

The free vascularized fibula flap presents many advantages such as sufficient length of the bony segment, good vascularization, better quality of the bone, and a long vascular pedicle, but it is also associated with some disadvantages with regard to prosthetic rehabilitation because of its limited height. Improvement in bone height is necessary for ideal dental implant treatment of reconstructed mandibles.

Case presentation

For two squamous cell carcinoma patients, mandibular bone reconstruction was performed secondarily with the peroneal flap after tumor resection. Since the bone height was insufficient at the time of implant treatment, occlusion reconstruction by dental implant was performed after vertical distraction osteogenesis.

Conclusions

Vertical distraction osteogenesis is a suitable treatment option for alveolar ridge deficiency resulting from fibula transplantation for mandibular reconstruction following tumor surgery.

Osseous Changes Over Time in Free Fibular Flap Reconstruction

OBJECTIVES/HYPOTHESIS

Evaluate bone resorption in free fibular grafts and document resorption behavior as compared to dentulous and edentulous autochthonous mandibular bone.

STUDY DESIGN

Retrospective Chart review.

METHODS

Postoperative computed tomography images were used to evaluate fibular graft resorption rates and corresponding sites of the dentulous or edentulous mandible. Bone height, width, and cortical thickness were measured.

RESULTS

Eighteen patients underwent fibula free flap reconstruction following resection of a primary head and neck cancer. Mandibular defects were classified using Jewer's classification. The average interval loss of osseous height was 0.23 ± 0.09 mm/yr for fibula flap, 0.55 ± 0.13 mm/yr for dentulous native mandible, and 0.98 ± 0.41 mm/yr in edentulous native mandible. Change in osseous width was 0.19 ± 0.08 mm/yr, 0.55 ± 0.33 mm/yr, and 0.73 ± 0.15 mm/yr, respectively. Rate of superior cortical resorption was 0.33 ± 0.34 mm/yr, 0.35 ± 0.13 mm/yr, and 0.53 ± 0.11 mm/yr in fibula flap, dentulous, and edentulous mandible, respectively. Inferior cortical resorption rates were quantified as 0.30 ± 0.11 mm/yr, 0.35 ± 0.08 mm/yr, and 0.51 ± 0.08 mm/yr.

CONCLUSIONS

Fibula free flap reconstruction of the mandible provides excellent functional results and allows for stable outcomes. Bone resorption is significantly lower in fibular graft compared with both edentulous and dentulous mandible. Edentulous bone displays significantly increased rates of atrophy in comparison to the dentulous mandible. This may have implications with regard to long-term viability of both the fibular flap and native mandible. The role of dental restoration on overall osseous stability warrants further research.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:1113-1116, 2019.

The use of computer-aided design/manufacturing (CAD/CAM) technology to aid in the reconstruction of congenitally deficient pediatric mandibles: A case series

BACKGROUND

Microvascular reconstruction of the pediatric mandible, particularly when necessitated by severe, congenital hypoplasia, presents a formidable challenge. Complex cases, however, may be simplified by computer-aided design/computer-aided manufacturing (CAD/CAM) assisted surgical planning. This series represents the senior authors' preliminary experiences with CAD/CAM assisted, microvascular reconstruction of the pediatric mandible.

METHODS

Presented are two patients with hemifacial/bifacial microsomia, both with profound mandibular hypoplasia, who underwent CAD/CAM assisted reconstruction of their mandibles with vascularized fibula flaps. Surgical techniques, CAD/CAM routines employed, complications, and long-term outcomes are reported.

RESULTS

Successful mandibular reconstructions were achieved in both patients with centralization of their native mandibles and augmentation of deficient mandibular subunits. No long-term complications were observed.

CONCLUSIONS

CAD/CAM technology can be utilized in pediatric mandibular reconstruction, and is particularly beneficial in cases of profound, congenital hypoplasia requiring extensive, multi-planar, bony reconstructions.

In Vivo Osteogenic Potential of Biomimetic Hydroxyapatite/Collagen Microspheres: Comparison with Injectable Cement Pastes

The osteogenic capacity of biomimetic calcium deficient hydroxyapatite microspheres with and without collagen obtained by emulsification of a calcium phosphate cement paste has been evaluated in an in vivo model, and compared with an injectable calcium phosphate cement with the same composition. The materials were implanted into a 5 mm defect in the femur condyle of rabbits, and bone formation was assessed after 1 and 3 months. The histological analysis revealed that the cements presented cellular activity only in the margins of the material, whereas each one of the individual microspheres was covered with osteogenic cells. Consequently, bone ingrowth was enhanced by the microspheres, with a tenfold increase compared to the cement, which was associated to the higher accessibility for the cells provided by the macroporous network between the microspheres, and the larger surface area available for osteoconduction. No significant differences were found in terms of bone formation associated with the presence of collagen in the materials, although a more extensive erosion of the collagen-containing microspheres was observed.

Mandibular reconstruction with vascularized fibula flap and osseointegrated implants: a clinical report

Primary and secondary reconstruction of mandibular discontinuity defects with vascularized flap is currently the standard of care in many institutions. The most commonly used donor site for such flaps is fibula. Fibula provides enough bone length, allows 2-team approach, and has low donor site morbidity and abundant periosteal blood supply. The placement of endosseous implants in the vascularized fibula flap also facilitates functional dental rehabilitation. This clinical report describes the prosthetic rehabilitation and the complications of 2 mandibular discontinuity defects treated with vascularized fibula flap and implant-supported fixed prosthesis.

Reconstruction of head and neck defects: a systematic approach to treatment

Reconstruction of composite maxillofacial defects after tumor excision or trauma is difficult. The role of the reconstructive surgeon is to have a diverse armamentarium of reconstructive options to enable an aesthetic and functional reconstruction while minimizing the morbidity to the patient. This article will present a systematic review of composite maxillofacial reconstruction with free tissue transfer.

Meta-analysis of mandibular distraction osteogenesis: clinical applications and functional outcomes

BACKGROUND

Mandibular distraction osteogenesis has been used effectively to treat syndromic craniofacial deformities. In recent years, its scope of application has widened to include treatment of airway obstruction in adults and children and nonsyndromic class II mandibular hypoplasia. So far, there has been no evidence-based review of mandibular distraction osteogenesis for mandibular lengthening.

METHODS

Two rounds of searches were performed by two independent assessors. The first-round PubMed search used the keywords "mandible" and "distraction osteogenesis." In the second-round search, the reference lists of the articles were retrieved. For both rounds, abstracts and then full articles were reviewed and selected on the basis of a set of inclusion and exclusion criteria.

RESULTS

The 178 retrieved articles yielded 1185 mandibular distraction osteogenesis patients: 539 received unilateral mandibular distraction osteogenesis and 646 received bilateral mandibular distraction osteogenesis. Mandibular distraction osteogenesis was reported to improve facial asymmetry and retrognathia (50.1 percent), correct the slanted lip commissure (24.7 percent), and improve or level the mandibular occlusal plane (11.1 percent) in unilateral asymmetry cases, whereas bilateral mandibular distraction osteogenesis was shown to be effective in preventing tracheostomies for 91.3 percent of neonates or infants with respiratory distress, and in relieving symptoms of obstructive sleep apnea for 97.0 percent of children and 100 percent of adult patients.

CONCLUSIONS

Mandibular distraction osteogenesis is effective in treating craniofacial deformities, but further clinical trials are required to assess the long-term stability and to compare the treatment with conventional treatment methods, especially in cases of obstructive sleep apnea or class II mandibular hypoplasia.

Multiplanar distraction osteogenesis of fibula free flaps used for secondary reconstruction of traumatic maxillary defects

Traumatic maxillary bone loss, if not treated acutely, is accompanied by contracture of the overlying soft tissue envelope and loss of facial projection in three dimensions. Reconstruction aimed at replacing the bony architecture, expanding the soft tissue envelope and establishing a platform for dental rehabilitation can be accomplished in a staged approach. We present two patients who underwent replacement of missing maxillary segments with a free fibula flap, followed by distraction of the free fibula in three dimensions and eventual dental rehabilitation with osseo-integrated implants.

Atrophy of Free Fibular Grafts after Mandibular Reconstruction

BACKGROUND

In free fibular flap surgery, the graft's low vertical height and tendency to resorb over time have been considered potential drawbacks. This study investigated (1) short- and long-term bone resorption in free fibular grafts; (2) resorption behavior of fibular grafts versus dentulous and edentulous autochthonous mandibular bone; and (3) factors that potentially influence long-term bone atrophy, such as site of reconstruction, presence of osseointegrated dental implants, patient age, and adjuvant radiation therapy.

METHODS

Between 1992 and 2004, 113 patients received free fibular grafts. Fifty-four of these patients were examined retrospectively. Postoperative Panorex examinations assessed loss of bone height per month. Standardized miniplate measurements served as a reference to prevent errors caused by projection on magnification.

RESULTS

Follow-up ranged from 6 months to 12 years. According to Jewer's classification, the following defect types were found: L, 23 (42.6 percent); H, five (9.3 percent); C, two (3.7 percent); LC, 12 (22.2 percent); HC, nine (16.7 percent); and LCL, three (5.6 percent). Radiographic analysis revealed a monthly atrophy of 0.04 +/- 0.08 mm (mean +/- SD) for fibular bone, 0.14 +/- 0.11 mm for dentulous mandibula, and 0.20 +/- 0.17 mm for edentulous mandibula. The difference in bone loss between fibula and edentulous or dentulous bone was significant (Friedman's test and Wilcoxon paired-sample test, p < 0.0001 and p = 0.02, respectively). Investigated factors had no significant influence on bone resorption rate.

CONCLUSIONS

Fibular grafts show short- and long-term stability. Their rate of atrophy is significantly lower than that of edentulous or dentulous mandibular bone. Thus, implants can be inserted into this bone graft just as successfully as they are inserted into adjacent mandibular bone when the same bone height is present.

[Growth defects of fibular flaps in children]

BACKGROUND

Mandibular reconstruction with fibula free flap is a challenge in pediatric patients because of the size of the bone and absence of growth without epiphyseal transplantation.

CASE REPORT

We report 2 cases of free fibula flap in children for mandibular reconstruction. The 2 patients presented with growth insufficiency of the bone graft after few years of evolution.

DISCUSSION

Growth insufficiency was treated with different surgical procedures which were discussed We review the consequences on growth after fibula free flap and the specific indications to achieve epiphyseal fibular growth in children.

Surgical Planning in Reconstruction of Mandibular Defect With Fibula Free Flap: 15 Patients

The authors present a descriptive work on the reconstruction of large oromandibular defects with revascularized fibula free flaps in a group of patients treated by surgical resection of bony and soft tissues of the mandible. The principal objective is preoperative planning for the best morphological, functional, and aesthetic result. The authors report 15 reconstructions of wide oromandibular defects by revascularized fibula free flaps. The average patient age was 42 years. The mean follow-up period was 18 months. Correct surgical planning reduces surgical timing, minimizes the chance of failure during the reconstruction, and contemporaneously increases treatment efficacy and the best functional and aesthetic results.

[Free fibula transfer. Analysis of 76 consecutive microsurgical procedures and review of the literature]

Since its introduction by Taylor in 1975, microvascular free fibula transfer has become the gold standard in osseous reconstructions requiring vascularized bone transfer. Various modifications of the free fibula have been described in the literature. We reviewed a series of 76 free vascularized fibula transfers during a 7-year period. Data was retrospectively analyzed with respect to type of procedure and outcome, general surgical complications, and flap-related (specific) complications. Of all 76 free fibula flaps, 47 cases healed uneventfully (62%). Interestingly, 53% of all extremity reconstruction cases had at least one of the above complications, whereas in maxillofacial cases the complication rate was only 25%. Complete osseous consolidation at the time of evaluation was confirmed in 58 patients (76%). Complete flap failure occurred in four patients (5%). The complication rates reflect the complexity of the procedures and appear strongly related to the underlying disease and predisposing medical risk factors. Time will tell if advances, e.g., in the field of tissue engineering, will eventually replace autologous vascularized bone transfer.

Amniotic Band Sequence: The Use of Bone Grafting and Distraction Osteogenesis

Distraction has proven to be a useful technique in cases of severe bone deficiency in the craniofacial skeleton. This is a report of its use in the treatment of a child affected by amniotic band sequence. This 5 year old Hispanic female presented with transverse deficiences of one lower extremity and both upper extremities. Additionally, she was missing the mandible and overlying soft tissue from ramus to ramus. Although free fibula transfer was a possibility, due to the presence of only one lower extremity, it was elected to utilize the technique of distraction. After preliminary bone grafting to unite these two hemimanibles, the bone graft was distracted bilaterally to create a neomandible. Following consolidation and removal of the distraction devices, the child was markedly improved despite what appeared to be a pathologic fracture in the region of the mandibular angle. Repeat distraction was planned.

Complex oncologic reconstruction of a mandibular and floor of mouth defect with a fibula free flap in an achondroplastic patient

The fibular free flap is seen as one of the foremost technical options in mandibular reconstruction, especially in those defects where long bone is required. Cases with squamous-cell carcinoma of the floor of the mouth with mandibular spread and subsequent segmentary mandibular removal are the cornerstone examples. A case of squamous-cell carcinoma of the whole floor of the mouth with mandibular invasion is reported. Radical resection of the floor of the mouth and bilateral mandibular horizontal ramus was performed, with a bony defect extending from angle to angle. The patient revealed an achondroplastic condition, with remarkable dwarfism and long-bone morphological alterations, that minimized the potential fibular length to transfer. A microsurgical reconstruction with an osteocutaneous fibular free flap was undertaken. The flap design was technically compromised by the forward bowing of the fibula and the ossification of the interosseous membrane. Specific intraoperative strategies for dealing with anatomic variations are discussed. The fibular free flap is an excellent technique for mandibular reconstruction. Morphological deviations can modify the design of the flap. Achondroplasia is not a deterrent in successful use of the free fibula flap for reconstruction of the head and neck in adequately selected cases.

Reconstruction of segmental mandibular defects by distraction osteogenesis for mandibular reconstruction

BACKGROUND

Distraction osteogenesis is an established technique for the lengthening of long bones and correction of selected craniofacial deformities. Regenerate osteoid bone matrix formed during the distraction phase is malleable and can recreate the three-dimensional form of native bones. Animal experiments and early clinical experience have confirmed that distraction osteogenesis can be used for the reconstruction of segmental bony defects. Herein we discuss the principles of distraction osteogenesis in reference to reconstruction of segmental bony defects and report its clinical application of the mandible continuity defects.

PATIENTS AND METHODS

Four patients (age, 7-83 years) with critical segmental mandibular defects (range, 3.5 cm-6.5 cm), resulting from ablative oncologic head and neck surgery underwent primary mandibular reconstruction by transport distraction osteogenesis. Two defects were at the angle and body region, one at the body, and the other at the parasymphysis and body region. Synthes Titanium Multi-vector and Leibinger Multi-guide distractors in bifocal (n = 2) and trifocal (n = 2) architecture were used after the stabilization of the segmental continuity defect using a defect-bridging mandibular reconstruction plate. Osteodistraction was carried out at a rate of 1 mm per day, with once or twice a day rhythm, after a 1-week latency period. The consolidation period was equal to the period of distraction.

RESULTS

All patients tolerated the distraction procedure. Satisfactory bone formation was observed in two patients, and partial bone formation was seen in one patient. Treatment failure was encountered in one patient who had a second oral cavity primary tumor observed during the consolidation period, requiring interruption of the treatment sequence.

CONCLUSIONS

Mandibular reconstruction with distraction osteogenesis is a potentially useful technique in selected patients with segmental mandibular continuity defects after ablative head and neck cancer surgery.

The effects of irradiation and hyperbaric oxygen on bone formation during rabbit mandibular distraction

[18F-]fluoride positron-emission tomography (PET) was used to assess bone formation during mandibular distraction osteogenesis. There were three study groups: irradiation, irradiation+hyperbaric oxygen and control. The two experimental groups received a tumoricidal dose of irradiation to the mandible, and one group was also given hyperbaric oxygen (2.5 ATA (atmospheres absolute) for 90 min) 18 times preoperatively. Control animals received neither irradiation nor oxygen. A unilateral osteotomy was made and, after a period of latency, bone distraction was started, continued for 2 weeks, and the distraction generated was then allowed to consolidate for 4 weeks. The first PET study was performed at the end of distraction and the second at the end of consolidation. At the end of distraction, the metabolic activity of bone in the distracted area was significantly higher in the controls than in either experimental group; differences between the experimental groups were not statistically significant. By the end of consolidation, activity in the control group had diminished to the same as in the two experimental groups, in which no significant change had occurred. Radioactivity was still significantly higher at second imaging on the distracted than non-distracted side in the control and irradiation+hyperbaric oxygen groups, but not in the group that was only irradiated. The results indicate that previous irradiation disturbs bone formation during mandibular distraction osteogenesis. Hyperbaric oxygen was not able to prevent the suppression of osteogenesis caused by radiotherapy but it might improve bone formation by prolonging high osteogenic activity.

Osteodistraction of a previously irradiated mandible with or without adjunctive hyperbaric oxygenation: an experimental study in rabbits

The purpose of this study was to analyse the effects of irradiation and hyperbaric oxygenation (HBO) on mandibular osteodistraction (OD). Eighteen rabbits were divided into three groups: 1. Irradiation (R), 2. Irradiation+HBO (R-HO), and 3. Control group (C). Animals of groups R and R-HO received in the mandible irradiation 22.4 Gy in four 5.6 Gy fractions (equivalent to 50 Gy/25 fractions). In addition, group R-HO was given HBO at 2.5 ATA for 90 min per day 18 times preoperatively. Unilateral osteotomy was made 1 month after completion of radiotherapy. After a 1 week latency period bone distraction was started at rate of 1 mm per day, continued for 2 weeks, and left to consolidate for 4 weeks. Amount of new bone was measured histomorphometrically from midsagittal sections. Area of new bone was equal in all groups. Bone was more mature and bone spicules better organized in group C than in groups R and R-HO. Cartilaginous cells were found in distracted bone in all groups but larger chondroid islands were evident only in group R. It seems that despite delayed bone formation, OD can be performed after radiotherapy. HBO had a beneficial effect on bone quality of a previously irradiated mandible.

Reconstructive techniques for the repair of oral and maxillofacial oncological procedures: what are they, how do they work and what do they look like?

BACKGROUND

There are many different ways to reconstruct the oral and maxillofacial region post tumour ablation. In the past, the resection of oral tumours had been associated with significant disfigurement and loss of function. Modern techniques aim to restore function and improve cosmetics. This paper aims to describe the techniques used in patients treated at the Austin and Repatriation Medical Centre and to answer the more common questions associated with reconstructive techniques.

METHODS

A review of techniques of oral reconstruction used by our unit over the last nine years and a review of the literature.

RESULTS

Various techniques of reconstruction gained from our experience in treating patients with oral cancer are documented. There are a variety of techniques including grafts, local flaps, regional flaps and free vascularized flaps. Metallic implants such as osseointegrated dental implants may also be used for dental rehabilitation.

CONCLUSIONS

There are many different methods of reconstruction in patients who have had resection for oral tumours. It is important for general dental practitioners who may be involved with the care of such patients to have an understanding of the modern techniques of reconstruction that may be used.

Craniofacial distraction osteogenesis: a review of the literature: Part 1: clinical studies

A review of the literature dealing with distraction osteogenesis (DO) of the craniofacial skeleton, provided by a PUBMED search (National Library of Medicine, NCBI; revised 3 April 2000) from 1966 to December 1999 was conducted. Key words used in the search were distraction, lengthening, mandible, mandibular, maxilla, maxillary, midface, midfacial, monobloc, cranial, craniofacial and maxillofacial. This search revealed 285 articles. One hundred and nine articles were clinically orientated and were analysed in detail in this study. The type of distraction, indications, age, type of surgery, distraction rates and rhythms, latency and contention periods, amount of lengthening, follow-up period, relapse, complications and the nature of the distraction device were analysed. This review revealed that 828 patients underwent DO of the craniofacial skeleton; 579 underwent mandibular DO, 129 maxillary DO, 24 simultaneous mandibular and maxillary DO and 96 midfacial and/or cranial DO. Craniofacial DO has proven to be a major advance for the treatment of numerous congenital and acquired craniofacial deformities. Treatment protocols and success criteria for craniofacial DO are suggested on the basis of these results. There is still, however, a lack of sufficient data, especially on follow-up and relapse, so that treatment strategies have to be validated by long-term studies in the future.