Osteosynthesis and simultaneous irregular trifocal distraction osteogenesis for segmental mandibular defect after tumor ablative surgery: a case report

Biomechanical validation of a modified genioplasty distractor

PURPOSE

Genioplasty is a surgical procedure that is used to enhance the shape and appearance of the chin. It can be performed alone or in combination with other jaw-related surgeries either for medical or cosmetic purposes. Recently many studies have been reported for mandibular reconstruction with distraction osteogenesis. However, these distractors can cause some complications such as incorrect prolongation of hard tissues due to the lack of guiding section. The purpose of this study is to manufacture a novel genioplasty distractor and measure its biomechanical stability and reliability for different activation lengths in mandibular bone.

METHODS

The modified genioplasty distractor was manufactured from grade 2 and grade 5 (Ti6AI4V) titanium alpha + beta alloy which was biocompatible and adequately rigid for possible in situ application in the future and a sample holder was manufactured for compressive strength testing.

RESULTS

Test results showed that our modified genioplasty distractors withstood 300 N compression force for activation lengths from 0 to 11 mm. Recorded stress values were in the range of 0.110 MPa to 0.389 MPa.

CONCLUSION

The modified genioplasty distractor developed and tested here is a promising surgical tool that has the potential to reduce genioplasty related complications especially in demanding cases.

Reconstruction of Mandibular Segmental Detects Using Transport Disk Distraction Osteogenesis

BACKGROUND

Distraction osteogenesis (DO) has become an important alternative for bone defect reconstruction. The study aims to investigate the clinical feasibility and efficiency of transport disc DO (TDDO) for reconstruction of segmental defect of mandible and further dental implant treatment.

METHODS

A serial of 6 patients diagnosed with ameloblastoma or keratocystic odontogenic tumor were included in this study. Computed tomography (CT) scanning and panoramic radiograph were performed for preoperative evaluation and surgery planning. Transport disc DO was applied simultaneously with tumor resection for reconstruction of mandibular defects. The postoperative panoramic radiographs and CT scans were taken for evaluation of the ossification level. Then a second surgery was performed for removal of the distraction apparatus. Bone graft and rigid internal fixation were also used to fill the gap between the transport disc and the stump of the residual ramus. Further dental implant treatment was also finished or in progress.

RESULTS

All patients finished the whole treatment period, and no distraction device failure or tumor recurrence occurred. The distraction length ranged from 35 to 48 mm and the whole treatment period of TDDO ranged from 21 to 33 weeks. High degree of ossification was confirmed at the end of treatment by postoperative radiographs and intraoperative observation. Infection occurred in 1 of the 6 patients, and the symptom was controlled by surgical dressing change and flushing. Results of final facial profile in all patients were good. Three patients finished dental implant treatment with good occlusion.

CONCLUSION

Results in this study suggest the clinical feasibility and efficiency of TDDO for reconstruction of segmental defect of mandible and further dental implant treatment.

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.

Mandibular reconstruction using nonvascularized autogenous bone grafting

PURPOSE OF REVIEW

This paper will discuss reconstruction of the mandible with autogenous nonvascularized bone grafting. New developments in this area will be investigated by reviewing the most recent literature on this topic as compared with other techniques currently employed. With the advances of vascularized free flap reconstruction it is important to investigate the indication for nonvascularized techniques.

RECENT FINDINGS

Replacement of a portion of the mandibular bone is a common procedure for patients undergoing ablative cancer surgery or for infection as well as temporomandibular joint replacement secondary to disease or trauma. The subject of mandibular reconstruction has seen great advances in recent years with the advent of vascularized free tissue transfer. Other newer areas of mandibular replacement include tissue engineering and distraction osteogenesis. Traditional nonvascularized autogenous bone graft replacement can still play a vital role in rehabilitating these patients.

SUMMARY

Although vascularized free flap reconstruction of mandibular defects has become the more common method of treating the postablative cancer surgery patient, there remain indications for nonvascularized reconstruction of mandibular defects as well as other techniques.