Segmental mandibular defects represent one of the most challenging reconstructive problems, particularly when curvilinear parts are involved. Microvascular bone free flaps remain the gold standard in large defect reconstruction.1–3 However, the morbidity associated with long operating and hospitalization times suggests the need for less invasive reconstructive techniques in selected patients with increased surgical anesthetic risks.3,4 Additionally, donor-site morbidity remains a concern particularly in young active patients, especially when limbs or iliac crest are selected. In such cases, distraction osteogenesis (DO) has been proposed as a valuable treatment option, despite the extended treatment time, the need for multistage procedures and bone grafting for bone union at the compression focus and vector control difficulties.5–7 These disadvantages could be obviated, by the technique developed by the first author, used to treat 2 patients with large curvilinear defects.
A 20-year-old man, presented with severe facial asymmetry (Fig. 1) consequent to the treatment of a right temporal fossa malignancy at age 1, with surgical excision and radiotherapy (40 rad).
A stereolithographic model was constructed for preoperative planning (Fig. 2).
The buccal cortex of the parasymphyseal area was subperiosteally dissected through a submandibular approach, and a vertical osteotomy was performed immediately distal to the canine, creating a 5-cm transport disk. The premolded distractor device was fixed.
Distraction protocol was followed reaching 6 cm (Table 1).
The second procedure was performed 1 week after the end of the distraction phase. The distractor device was approached trough the previous scar. Dissection over the body and footplates allowed for safe removal of the device avoiding damage of the regenerate identified between the bone stumps. The premolded reconstruction plate was fixed first at the symphysis. A nonlocking screw was placed at the most mesial stump of the transported segment, to act as a rotating axis, and manipulation with bone forceps was applied distally, to rotate the entire transported segment through 45° in a clockwise direction. Another nonlocking screw was tightened at the distal end of the transport segment, completing adaption to the plate in the ideal position. Additional locking screws were placed to reinforce the fixation.
No complications occurred, facial symmetry was achieved (Fig. 1), and good consolidation was confirmed by computed tomography allowing for dental implant placement 3 months after the second procedure (See figures, Supplemental Digital Content 1, https://links.lww.com/PRSGO/A365; Supplemental Digital Content 2, https://links.lww.com/PRSGO/A366; Supplemental Digital Content 3, https://links.lww.com/PRSGO/A367; and Supplemental Digital Content 4, https://links.lww.com/PRSGO/A368).
A 52-year-old man, presented with a tridimensional mandible defect resulting from the excision of intraoral squamous cell carcinoma 6 years before. The buccal aspects of the remaining ascending ramus and symphysis were subperiosteal dissected using a submandibular approach. Two transport disks of 2 cm were created and were fixed with distractor devices (Fig. 3). Distraction protocol was followed reaching 7 cm (Table 1).
The second operative procedure was performed 1 week after the end of the longest posterior distraction phase and 17 days after the end of the shorter anterior distraction phase. Distractor devices and the regenerated segments were approached as described in Case 1. The devices were removed and a premolded reconstruction plate was fixed to the mandibular stumps. After axial manipulation, the transport disks were brought together to close contact and were fixed in the ideal position, utilizing nonlocking screws for perfect adaptation to the plate.
No complications were recorded, and good consolidation with bone continuity of the mandible arch was observed on computed tomography 1 year after the second procedure (See figures, Supplemental Digital Content 5, https://links.lww.com/PRSGO/A369; Supplemental Digital Content 6, https://links.lww.com/PRSGO/A370).
Microvascular bone flaps remain the gold standard technique for the reconstruction of segmental mandibular defects, although donor-site morbidity, difficult adaptation to the defect, technical requirements, and contraindications in high-risk patients argue in favor of alternatives such as DO.
Internal distractors offer important advantages, including better stability, a lower incidence of infection, a lower incidence of unaesthetic scars, and greater patient comfort.8–11 Both patients described in this article were treated with internal devices and were able to pursue normal lives during the distraction phase.
Problems attributed to bone transport include difficult distraction vector planning and control, the need for bone grafting, and long treatment times. Additional difficulties arise when curvilinear segments need to be reconstructed. In such cases, curvilinear distraction represents an alternative, but requires even longer treatment times and/or additional operations.4,8,12
In this article, we describe a new technique that obviates most of these problems. In the initial phase, without the restriction imposed by previous reconstruction plate fixation, a regenerate is created that is larger than the defect. This eliminates the need for additional bone grafting. The second stage, performed before consolidation, allows for ideal tridimensional repositioning of segments guided by premolded plates. These support the new regenerate in position even in curvilinear segments, avoiding soft-tissue compression and regenerate retraction. The total length of treatment is shortened because the consolidation phase with distractors in place is eliminated, and only 2 surgeries are required.
At the 5-year follow-up, both patients had achieved stable curvilinear reconstructed segments, one in the region of the mandibular angle, and the other in the parasymphyseal region, demonstrating that early open callus manipulation can be safely performed in both sagittal and axial planes. Full reconstruction was obtained with DO alone with no requirement for additional bone grafting. Each patient underwent only 2 operations, and the duration of treatment and hospitalization was reasonable compared with alternative procedures (Table 1).
Closed callus molding was reported, using external distraction devices or orthodontic elastics to prevent problems related to vector planning or control.13–15 Experimental studies performed by Kunz show that molding can be performed immediately after the end of the distraction phase.16,17 Additionally, Wei et al18 have shown that molding could be successfully performed 8 weeks into the consolidation phase. Pereira19 was the first to report about open callus manipulation in bone transport for maxillary reconstruction. As far as we know, this article represents the first report of this technique in mandibular reconstruction.
Because these are the first and only 2 reported cases, further clinical experience is needed to evaluate the predictability of this technique. Experimental studies are needed to establish the safety of the procedure regarding consolidation and to determine the optimal timing of open callus manipulation.
We describe a new technique wherein DO reconstruction of large curvilinear segmental mandibular defects is effective and stable, requiring only 2 surgical procedures, eliminating the consolidation phase and using the second surgical procedure for distraction device removal, open manipulation and fixation of segments in the ideal position without the need for additional bone grafting.
The patient provided written consent for the use of his image.
1. Muñoz Guerra MF, Naval Gías L, Campo FR, et al. Marginal and segmental mandibulectomy in patients with oral cancer: a statistical analysis of 106 cases.J Oral Maxillofac Surg2003611289–1296
2. Chang E, Jenkins M, Patel S, et al. Long-term operative outcomes of preoperative computed tomography-guided virtual surgical planning for osteocutaneous free flap mandible reconstruction.Plast Reconstr Surg20161372619
3. Torroni A, Marianetti TM, Romandini M, et al. Mandibular reconstruction with different techniques.J Craniofac Surg201526885–890
4. González-Garcia R, Rubio-Bueno P, Naval-Gías L, et al. Internal DO in mandibular reconstruction: clinical experience in 10 cases.Plast Reconstr Surg2008121563–575
5. Block MS, Otten J, McLaurin D, et al. Bifocal distraction osteogenesis for mandibular defect healing: case reports.J Oral Maxillofac Surg1996541365–1370
6. Sawaki Y, Hagino H, Yamamoto H, et al. Trifocal distraction osteogenesis for segmental mandibular defect: a technical innovation.J Craniomaxillofac Surg199725310–315
7. Shvyrkov MB, Shamsudinov AKh, Sumarokov DD, et al. Non-free osteoplasty of the mandible in maxillofacial gunshot wounds: mandibular reconstruction by compression-osteodistraction.Br J Oral Maxillofac Surg199937261–267
8. Whitesides LM, Wunderle RC, Guerrero C. Mandible reconstruction using a 2-phase transport disc distraction osteogenesis: a case report.J Oral Maxillofac Surg200563261–266
9. Takenobu T, Nagano M, Taniike N, et al. Mandibular reconstruction using intraoral trifocal bone transport: report of case.Oral Surg Oral Med Oral Pathol Oral Radiol Endod2007103630
10. Kashiwa K, Kobayashi S, Nohara T, et al. Efficacy of distraction osteogenesis for mandibular reconstruction in previously irradiated areas: clinical experiences.J Craniofac Surg2008191571–1576
11. Rubio-Bueno P, Naval-Gías L, Rodríguez-Campo F, et al. Internal DO for reconstruction of MSD: preliminary clinical experience in five cases.J Oral MaxillofacSurg200563528
12. Herford AS. Use of a plate-guided distraction device for transport distraction osteogenesis of the mandible.J Oral Maxillofac Surg200462412
13. Hoffmeister B, Wolff K. The floating bone concept in intraoral mandibular distraction.J Craniomaxillofac Surg26Suppl. 176
14. McCarthy JG, Hopper RA, Hollier LH Jr, et al. Molding of the regenerate in mandibular distraction: clinical experience.Plast Reconstr Surg20031121239–1246
15. Kunz C, Hammer B, Prein J. Manipulation of callus after linear distraction: a “lifeboat” or an alternative to multivectorial distraction osteogenesis of the mandible?Plast Reconstr Surg2000105674–679
16. Kunz C, Adolphs N, Buescher P, et al. Possible problems of moulding the regenerate in mandibular distraction osteogenesis – experimental aspects in a canine model.J Craniomaxillofac Surg200533377–385
17. Kunz C, Adolphs N, Buescher P, et al. Distraction osteogenesis of the canine mandible: the impact of acute callus manipulation on vascularization and early bone formation.J Oral Maxillofac Surg20056393–102
18. Wei S, Scadeng M, Yamashita DD, et al. Manipulating the mandibular distraction site at different stages of consolidation.J Oral Maxillofac Surg200765840–846
19. Pereira AR, Montezuma N, Oliveira L, et al. Immediate reconstruction of large full-thickness segmental anterior maxillary defect with bone transport.Craniomaxillofac Trauma Reconstr20169305–312