Internal Distraction Osteogenesis in Mandibular Reconstruction: Clinical Experience in 10 Cases:

Wide Excision with Immediate Reconstruction of the Mandible Using Free Fibular Flap in Ameloblastoma of the Mandible-A Need of Time: Our Experience of 37 Cases

Background  Ameloblastoma is a benign yet locally aggressive odontogenic tumor of the jaw with high recurrence rates. Despite many studies, the search is still on for the treatment approach which can render the acceptable recurrence rates with good functional and esthetic results.

Methods  In this prospective study, we operated on 37 patients of mandibular ameloblastoma between 2009 and 2018. Two patients were treated with curettage and chemical sterilization of the cavity. Resection of a tumor with a 2-cm margin was performed in the rest of 35 patients. The mandibular defect was primarily reconstructed with the microvascular free fibular flap in 29 patients.

Results  The follow-up ranged from 6 months to 7.7 years with a mean of 5.1 years. A tumor recurred within a year in all two patients (100%) treated with curettage. Out of 35 radical excisions, only one patient (2.85%) developed recurrence 3 years after the disease-free interval. Good mouth opening, intelligible speech, satisfactory lower jaw shape, and facial profiles were achieved in all 29 patients who were treated with primary free fibular flap.

Conclusion  We prefer wide excision with 2-cm margins on each side of a tumor with the primary reconstruction of the mandible in all cases of mandibular ameloblastoma. The free fibular microvascular flap is our treatment of choice as all defects of the mandible can be reconstructed with the free fibular flap. Wide excision is the key to prevent a recurrence.

Mandibular Reconstruction for Pediatric Patients

: Mandibular reconstruction in pediatric patients is controversial. The scant pediatric experience and the infrequent occurrence of this type of pathology in children complicate therapeutic decisions. The literature contains different treatment protocols and describes the bone graft alternatives to be used.

MATERIALS AND METHOD

This is a retrospective review of patients under the age of 15 who were subjected to resection and reconstruction.

RESULTS

A total of 18 patients were included in the study: 8 women and 10 men. The age on the date of diagnosis ranged from 2 years to 13 years and the average was 7 years. Five patients underwent resective surgery for a malign pathology, 7 for a benign pathology, 4 for aggressive lesions of odontogenic origin, and 1for the effects of a fracture that was complicated by osteomyelitis.

CONCLUSIONS

In conclusion, treating pediatric patients with tumor pathology requires an experience pediatric team to get good outcomes. Surgeons must consider that pediatric patients are in constant growth and development but that must not be an issue in resection and reconstruction decisions. Literature review shows that, as in adults, free flaps seem to be the criterion standard for big resections in mandibles defects, and are safe to use in pediatric patients.

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.

Is Distraction Osteogenesis of the Irradiated Craniofacial Skeleton Contraindicated?

BACKGROUND

Craniofacial distraction osteogenesis (DO) is a common treatment modality today. Despite its numerous advantages, however, concerns have been expressed regarding the use of DO in the irradiated setting.

METHODS

A systematic review was performed to identify all published reports of patients who underwent DO of the irradiated craniofacial skeleton. The following parameters were of particular interest: postoperative complications, specifically, insufficient bone formation, fracture, and hardware exposure (intraoral and cutaneous), as well as the need for additional bone grafting.

RESULTS

The initial search retrieved a total of 183 articles of which 20 articles (38 patients) met predetermined inclusion criteria. The most common site of distraction was the mandible (76.3%). The median radiation dose was 50.7 Gy (range, 30-70 Gy). Bone defects ranged from 30 to 80 mm (median, 42.5 mm). Complications were encountered in 19 patients (50%), with insufficient bone formation being most common (9 patients; 23%). The overall incidence of complications was not significantly associated with radiation dosage (P = 0.79). The remaining procedural and demographic variables also failed to meet statistical significance when compared against the overall complication rate (P = 0.27-0.97).

CONCLUSION

The complication rate associated with craniofacial DO of the irradiated skeleton does not appear to be substantially higher than what is reported for DO in the nonirradiated setting. As such, patients should be offered this treatment modality, particularly in light of the fact, that it offers the option to decrease patient morbidity as well as treatment complexity.

Resorbable Plates Prevent Regression in Pediatric Mandibular Distraction Osteogenesis

BACKGROUND

Mandibular distraction osteogenesis is an important technique to correct the pediatric hypoplastic mandible. Regression of the mandible after distraction continues to be a challenge, with some studies reporting up to 22% to 56% decrease toward predistraction length in the first year. We hypothesize that a resorbable plate placed after removal of the distractor will provide additional stability to newly formed bone, allowing further time for consolidation and minimizing regression.

METHODS

This is a retrospective review of neonatal and pediatric patients between 2010 and 2015 who had mandibular distraction osteogenesis performed by the senior author (D.J.). Five patients, including 1 control and 4 intervention subjects, who had preoperative, postdistraction, and follow-up imaging were evaluated. Mandibular distraction was performed via internal devices (KLS Martin, Jacksonville, Fla) and followed by a consolidation period of 6 to 8 weeks. At the second operation when the distractors were removed, the intervention group had a SonicWeld Resorbx (KLS Martin) resorbable plate placed across the bone regenerate. A digital imaging and communications in medicine viewer was used to create a 3-dimensional reconstruction of each of the computed tomography scans and measurements of the mandible were made in the lateral cephalometric view. We then determined distraction distance, regression distance and percent regression.

RESULTS

The average mandible distraction distance was 8.2 mm for the control group, and 9.9 mm for the intervention group (range, 6.7-12 mm). The average distance that the mandible regressed after distraction (regression distance) was 2.7 mm for the control group, and 0.5 mm for the intervention group (range, 0.2-0.9 mm). The average percent regression was 32.9% for the control group, and 5.1% for the intervention group (range 1.8 to 7.5%).

CONCLUSIONS

The results of this study suggest that resorbable plate placement after removal of distractors helps prevent regression in pediatric mandibular distraction osteogenesis. The improvement was readily apparent both radiographically and clinically.

Curvilinear Segmental Mandibular Reconstruction Utilizing Distraction Osteogenesis and Early Open Callus Manipulation

Supplemental Digital Content is available in the text.

The authors present a new technique for reconstruction of large curvilinear mandibular defects with distraction osteogenesis and early open callus manipulation. In phase 1, transport disks are created from mandibular bone and distracted across the entire length of the defect, without the restriction from a mandible plate fixation. This allows for full-length distraction until enough regenerate is obtained to reconstruct the defect without the need for additional bone grafts. Taking advantage of the soft moldable regenerate, the second and final operative procedure allows for the manipulation, repositioning, and fixation of the transported segments in the ideal position creating perfect tridimensional form and symmetry of the mandible arch. In addition, the consolidation phase is shortened by the early removal of distractors, substantially reducing the total length of treatment. This article describes 2 clinical cases treated according to this technique, one with a 6-cm mandibular defect where a sagittal plane manipulation was performed, and the other with a 7-cm defect and axial plane manipulation. Five years postsurgery, both patients had achieved full stable reconstruction without the need for bone grafting, and had obtained good facial symmetry, with no recorded complications. This technique serves to establish bone transport as a valuable alternative to bone free flaps in the reconstruction of large curvilinear segmental mandibular defects.

Recurrent giant mandibular ameloblastoma in young adults

BACKGROUND

The purpose of the study was to define the most appropriate management of the giant mandibular ameloblastoma (GMA) in young adults.

METHODS

A retrospective study was performed on patients with GMA <30 years old. The data collected included initial treatment, tumor margins, reconstruction, and follow-up. Patients evaluated speech, chewing, swallowing, and facial appearance after definitive treatment.

RESULTS

Thirteen patients were identified with recurrent solid/multicystic disease requiring further treatment. Definitive treatment involved segmental mandibulectomy and reconstruction with free fibular flap in all patients. Seven patients had immediate reconstruction (group A) and 6 had secondary (group B). Mandibular resection was planned at least 2 cm beyond the radiological limit, free margins were achieved in all patients, and all flaps were transplanted successfully. In group A, functional score was 13.7 ± 0.45 and facial appearance score was 4.5 ± 0.49, whereas in group B were 11.16 ± 0.37 and 3.3 ± 0.5, respectively (both p < .05).

CONCLUSION

Aggressive resection of the GMA and immediate reconstruction is strongly advised. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1947-E1954, 2016.

Treatment of large calvarial defects with bone transport osteogenesis: a preclinical sheep model

BACKGROUND

Bone transport osteogenesis (BTO), distraction of a free portion of bone across a defect, offers an autologous solution to large cranial defects that may allow treatment without permanent hardware implantation. This study establishes a sheep model to evaluate the feasibility and distraction kinetics of BTO.

METHODS

Subtotal cranial defects (3.5 × 3.5 cm) were created in 10 young adult sheep and a transport segment (3.5 × 2 cm) traversed the defect at varying distraction rates (0, 0.5, 1.0, and 1.5 mm/day) using semi-buried cranial distractors. After a 6-week consolidation period, sheep were euthanized and the resultant bone was analyzed by CT, histology, and mechanical testing.

RESULTS

Gross examination, histology, and 3D CT revealed that control animals had fibrous nonunion whereas distraction animals had ossified defects with fibrous nonunion at the distal docking site. There was one premature consolidation in the 0.5 mm/day group. The volume of bony regenerate in the 0.5, 1.0, and 1.5 mm/day distraction rate groups was statistically indistinct (P = 0.16). The mean flexural moduli (MPa) of non-decalcified samples from the control cranium, transport segment, and bone regenerate were found to be 4.50 ± 4.9, 6.17 ± 2.1, and 4.14 ± 4.8, respectively (P = 0.24).

CONCLUSIONS

This experiment provides proof of concept for BTO for large calvarial defects in a sheep model. Distraction at a rate of 0.5 mm per day may place individuals at higher risk for premature consolidation, but distraction rates did not have significant effects on regenerate quantity or quality. Future work will include the use of curvilinear distraction devices for 3-dimensional contour.

Bone regeneration and docking site healing after bone transport distraction osteogenesis in the canine mandible

PURPOSE

Bone transport distraction osteogenesis provides a promising alternative to traditional grafting techniques. However, existing bone transport distraction osteogenesis devices have many limitations. The purpose of this research was to test a new device, the mandibular bone transport reconstruction plate, in an animal model with comparable mandible size to humans and to histologically and mechanically examine the regenerate bone.

MATERIALS AND METHODS

Eleven adult foxhounds were divided into an unreconstructed control group of 5 animals and an experimental group of 6 animals. In each animal, a 34-mm segmental defect was created in the mandible. The defect was reconstructed with a bone transport reconstruction plate. Histologic and biomechanical characteristics of the regenerate and unrepaired defect were analyzed and compared with bone on the contralateral side of the mandible after 4 weeks of consolidation.

RESULTS

The reconstructed defect was bridged with new bone, with little bone in the control defect. Regenerate density and microhardness were 22.3% and 42.6%, respectively, lower than the contralateral normal bone. Likewise, the anisotropy of the experimental group was statistically lower than in the contralateral bone. Half the experimental animals showed nonunion at the docking site.

CONCLUSION

The device was very stable and easy to install and activate. After 1 month of consolidation, the defect was bridged with new bone, with evidence of active bone formation. Regenerate bone was less mature than the control bone. Studies are underway to identify when the regenerate properties compare with normal bone and to identify methods to augment bone union at the docking site.

Two-step transport-disk distraction osteogenesis in reconstruction of mandibular defect involving body and ramus

One-step transport-disk distraction osteogenesis (TDDO) is effective for repairing segmental mandibular defects. The authors studied whether it was effective for reconstructing angled large mandibular defects using a two-step TDDO procedure in seven patients suffering from neoplasm. In the two-step TDDO procedure, the first distraction (horizontal distraction) was initiated immediately after mandibulectomy, aimed at restoring the mandibular body. It was followed by the second distraction, which was obliquely vertical and aimed at restoring the height of the ramus. The distraction rate was set at twice 0.4mm/day. The treatment lasted for 14-18 months. The horizontal distraction length ranged from 48 to 55mm, and the vertical one from 33 to 43mm, with full ossification in the distraction area. No obvious shift of mandible, malocclusion or mouth opening limitation was observed. Patients had a regular diet and spoke clearly. In conclusion, the two-step TDDO is still an option for the reconstruction of large angled mandibular defects when patients are prudently selected, despite the long treatment period required.

Biomechanical configurations of mandibular transport distraction osteogenesis devices

Mandibular bone transport (MBT) distraction osteogenesis devices are used for achieving reconstruction of mandibular defects in a predictable way, with few complications, less complexity than other alternative surgical procedures, and minimal tissue morbidity. However, selection of appropriate MBT device characteristics is critical for ensuring both their mechanical soundness and their optimal distraction function for each patient's condition. This article assesses six characteristics of currently available MBT devices to characterize their design and function and to classify them in a way that assists the selection of the best device option for each clinical case. In addition, the present work provides a framework for both the biomechanical conception of new devices and the modification of existing ones.

Vascularized free fibular flap for the reconstruction of mandibular defects: clinical experience in 42 cases

OBJECTIVE

Since the advent of modern microvascular techniques, the fibula has become a reliable method for the reconstruction of partial or total mandibular defects. The purpose of this study is to evaluate our experience with the use of the vascularized free fibular flap for the reconstruction of mandibular defects following surgical resection.

PATIENTS AND METHODS

During a 5-year period, 102 consecutive patients were treated in our department for reconstruction of oral and maxillofacial defects, using microvascularized free flaps. Forty-two patients were reconstructed by means of the free vascularized fibular flap with or without a skin paddle. Patients underwent resection for benign (n = 15) and malignant (n = 27) entities. Fourteen patients received preoperative radiotherapy and only 1 patient received preoperative chemotherapy. The donor site was closed primarily in 7 cases, whereas an abdominal full-thickness skin graft was used in 35 cases.

RESULTS

Thirty-eight patients were treated by means of an osteocutaneous flap, whereas only 4 developed an osseous flap. Five patients developed complications related to the vascular anastomosis and needed a second surgical look. One patient died in the immediate postoperative period. The skin island flap was completely viable in 37 cases (88%). Considering bone survival as the main objective, an overall flap survival rate of 92.85% was achieved in the whole series. Endosseous dental implants were placed in 11 patients with adequate outcome. In 5 of these cases the double-barrel technique was performed.

CONCLUSION

Our results reveal that the vascularized free fibular flap is a reliable method for reconstructing mandibular defects with an acceptable low morbidity rate. The use of the osteocutaneous flap provides good reconstruction of composite mandibular defects. It constitutes an adequate support for dental implants.