Transport distraction osteogenesis for maxillomandibular reconstruction: current concepts and applications

Versatility of Transport Distraction Osteogenesis for Reconstruction of Lateral Mandibular Ablative Defects

Introduction

The reconstitution of form and function after maxillofacial tumor resection or traumatic bony defects is a challenge when considering reconstructive options. The reconstructive options will depend upon whether the tissues to be replaced included bone alone or both bone and soft tissue (composite resection).

Methodology

This study was carried out on nine patients who with benign tumors or cysts of the mandible that required segmental resection. Mandibular reconstruction using mandibular transport distraction osteogenesis was performed for all the cases. Depending on whether the condyle was spared or sacrificed, the type of mandibular transport distractor either fixed on the remnant condyle-ramus unit or had a condylar component replacing the resected condyles. Depending on the location of the defect, transport distraction was carried our anterior to posterior or posterior to anterior.

Results

A total of nine cases of benign mandibular pathologies were operated. Segmental resection with condylar preservation was carried out in seven cases, segmental resection with condylar resection was carried out in two cases. In cases with condylar resection, the reconstruction plate of the distractor device had a condylar component. Anterior to posterior transport distraction was carried out in seven cases, and posterior to anterior transport distraction carried out in two cases. The amount of distracted bone ranged from 38 to 46 mm.

Conclusion

Mandibular transport distraction osteogenesis offers a modality of reconstruction where the patient's native host bone is osteotomized and gradually distracted to induce the formation of regenerated osseous structure and soft tissue. Being cost-effective, not requiring a steep learning curve/long operative time, and not technically demanding as vascularized bone grafts/flaps, it is feasible in the Indian setup as a practical reconstructive option for benign jaw tumors.

Mandibular reconstruction after excision of recurrent odontogenic keratocyst using a novel mandibular distraction osteogenesis method- a case report

BACKGROUND

Odontogenic keratocyst is one of the most common benign odontogenic neoplasms with a high recurrence rate. Its resection has the potential to lead to mandibular segmental defects. In this case report, we describe a patient with odontogenic keratocyst who underwent radical resection using a novel distraction osteogenesis (DO) method to reconstruct mandibular segmental defect.

CASE PRESENTATION

This case report describes a 19-year-old woman with odontogenic keratocyst of the mandible that recurred after multiple curettages and eventually necessitated radical resection. Mandibular segmental defect after radical resection was reconstructed using a novel DO method that involved directly contacting the segment ends of the defect without the transport disk. However, the distractor broke during the retention period, and a molding titanium plate was used for fixation. This novel distraction method achieved mandibular reconstruction and restored mandibular function and contour.

Distraction Osteogenesis and Customized Temporomandibular Joint Prosthesis in the Reconstruction of a Large Mandibular Defect - A Case Report

The Rationale:

Mandibular resections involve esthetic and functional impairment and impose a challenge during the reconstruction. This case report is a successful reconstruction with distraction osteogenesis (DO) and customized temporomandibular joint (TMJ) prosthesis.

Patient Concerns:

A 51-year-old male patient presented with a complaint of facial asymmetry, mastication, and speech difficulties.

Diagnosis:

As the patient had undergone a hemimandibulectomy procedure 20 years ago, clinical examination showed facial asymmetry. Radiographic examination exhibited the defect and a radiopaque image representing Kirschner's wire.

Treatment:

DO by bone transport was performed, followed by dental implant and TMJ prosthesis placement.

Outcomes:

DO is a viable treatment option in resections, even when the defect was generated by an ancient injury. The follow-up is around 7 years after the osteogenic distraction, with no complaints and functional capacity.

Take-away Lessons:

The major challenge in mandibular reconstructions through DO is to reproduce the curve of the arch.

Tissue-engineered vascularized patient-specific temporomandibular joint reconstruction in a Yucatan pig model

PURPOSE

Current pediatric temporomandibular joint (TMJ) reconstruction options are limited. The aim of this project was to develop a proof-of-principle porcine model for a load-bearing, customized, 3D-printed and bone morphogenic protein 2 (BMP-2)-coated scaffold implanted in a pedicled (temporal) flap as a regenerative approach to pediatric TMJ mandibular condyle reconstruction.

MATERIALS AND METHODS

Scaffolds were customized, 3D-printed based on porcine computed tomography, and coated with BMP-2. Two operations occurred: (1) implantation of the scaffold in temporalis muscle to establish vascularity and, (2) 6 weeks later, unilateral condylectomy and rotation of the vascularized scaffold (with preservation of superficial temporal artery) onto the defect. Six months later, pigs were sacrified. The experimental side (muscle-scaffold) and control side (unoperated condyle) were individually evaluated by clinical, mechanical, radiographic, and histologic methods.

RESULTS

Scaffolds maintained physical properties similar in appearance to unoperated condyles. Vascularized scaffolds had new bone formation. Condyle height on the reconstructed side was 68% and 78% of the control side. Reconstructed condyle stiffness was between 20% and 45% of the control side.

CONCLUSION

In our porcine model, customized 3D-printed TMJ scaffolds coated with BMP-2 and implanted in vascularized temporalis muscle have the ability to (1) reconstruct a TMJ, (2) maintain appropriate condylar height, and (3) generate new bone, without impacting functional outcomes.

The Skeletal-Protecting Action and Mechanisms of Action for Mood-Stabilizing Drug Lithium Chloride: Current Evidence and Future Potential Research Areas

Lithium, the lightest natural-occurring alkali metal with an atomic number of three, stabilizes the mood to prevent episodes of acute manic and depression. Multiple lines of evidence point to lithium as an anti-suicidal, anti-viral, anti-cancer, immunomodulatory, neuroprotective and osteoprotective agent. This review article provides a comprehensive review of studies investigating the bone-enhancing effects of lithium and its possible underlying molecular mechanisms. Most of the animal experimental studies reported the beneficial effects of lithium in defective bones but not in healthy bones. In humans, the effects of lithium on bones remain heterogeneous. Mechanistically, lithium promotes osteoblastic activities by activating canonical Wingless (Wnt)/beta (β)-catenin, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) and bone morphogenetic protein-2 (BMP-2) transduction pathways but suppresses osteoclastic activities by inhibiting the receptor activator of nuclear factor-kappa B (RANK)/receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) system, nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and calcium signaling cascades. In conclusion, lithium confers protection to the skeleton but its clinical utility awaits further validation from human clinical trials.

Creation of Bone and Soft Tissue in Postmaxillectomy Patients Using Curvilinear Transport Distraction Osteogenesis

BACKGROUND

Large surgical defects in the maxilla due to trauma or tumor are usually reconstructed with revascularized-free fibula flaps (RFFF). In the past, the use of curvilinear transport distraction osteogenesis (CTDO) has been shown to be an efficacious way in closing large defects in the maxilla, but it had limitations which have now been overcome by the present development. The present distractor is an improvement upon the previous three prototypes and employs the concept of tetrafocal distraction by means of hybridizing the bone with the tooth in the transport disc segment. This article aims to prove that tetrafocal distraction provides a viable alternative to the RFFF.

MATERIALS AND METHOD

In a prospective cohort study of six postmaxillectomy patients, the method of CTDO was applied and investigated to ascertain the outcome. The regenerate bone was compared with the parent bone, using a new maxillary transport distractor. A linear bicortical fracture was created in the maxilla in a vertical direction (segmentally) to develop a mobile, vascularized transport disk. This transport disk underwent further subdivision to produce the concept of tetrafocal distraction.

RESULTS

After osseointegration of the dental implants, prosthetic rehabilitation of the dentition was successful. The authors report the successful outcome of two of the six cases subjected to CTDO to treat defects ranging from 25 mm (using bifocal distraction) to 80 mm along a curved trajectory (using tetrafocal distraction).

CONCLUSIONS

The production of curvilinear bone and soft tissue along a horizontal plane has been demonstrated. From a clinical perspective, the new alveolar bone achieved the correct width and height to create a physiological vestibule and an esthetic zone for dental implants. In addition, the shape of the palatal vault is also reconstituted. The tetrafocal method of the CTDO is a reliable method of maxillary reconstruction.

Horizontal alveolar transport distraction osteogenesis followed by implant placement

Alveolar transport distraction osteogenesis (ATDO) is an alternative treatment method to vertical alveolar distraction osteogenesis in cases of large bony defects, especially when the bone is limited in size. ATDO was performed in 10 patients with 12 defects. The mean age of the patients was 39.1years. The average bone length gain was 18.2mm. Implants were inserted following a 3-month consolidation period. Three patients needed additional bone grafting for horizontal widening. Final prosthetic rehabilitation was performed at least 3 months following implant insertion. The mean follow-up period was 63 months and the survival rate of the 25 implants placed was 92%. All failures (n=2) occurred during the early healing period. Although the results are not totally predictable, it can be concluded that ATDO can be effective in the reconstruction of the alveolar crest prior to implant placement.

Nonvascularized Free Transport Distraction Osteogenesis to Reconstruct the Mandibular Defect of a Patient With an Ossifying Fibroma: A Case Report

We report on a case in which trifocal distraction osteogenesis was applied in a patient with a mandibular defect caused by resection of an ossifying fibroma. During the surgical procedure, we accidentally dissected the surrounding periosteal tissue of the left transport completely in the process of transport disc preparation and made the disc into a free bone graft. However, we still used this transport and successfully completed the distraction osteogenesis. The patient's facial and occlusal function were regained after treatment.