Zygomatico-Coronoid Fixation in a Segmental Mandibular Reconstruction With a Free Vascularized Flap: a Simple and Correct Repositioning Method Without Interfering Reconstructive and Microsurgical Procedures

Hitoshi Yoshimura DDS, PhD, Division of Dentistry and Oral Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
Seigo Ohba DDS, PhD, Division of Dentistry and Oral Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
Takayoshi Tobita DDS, PhD, Department of Regenerative Oral Surgery, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
Masato Yasuta MD, PhD, Department of Dermatology, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
Kunihiro Nakai MD, PhD, Department of Plastic and Reconstructive Surgery, University of Fukui Hospital, Fukui, Japan
Shigeharu Fujieda MD, PhD, Division of Otorhinolaryngology Head and Neck Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
Kazuo Sano DDS, PhD, Division of Dentistry and Oral Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
Restoration of the mandible after oncological resection is one of the most challenging procedures. In the reconstruction of the segmented mandible with a free vascularized flap, reproducing the three-dimensional relationship between the condyle and the glenoid fossa and reproducing the correct occlusion are necessary. In this report, we examine the functionality of the repositioning technique of the segmented mandible using a combination of bone plate fixation of the zygomatic buttress and the coronoid process (zygomatico-coronoid fixation: ZCF) and the maxillo-mandibular fixation (MMF), which is a modified repositioning method in orthognathic surgery. Seven cases (five men, two women: mean age 66 years old, range 51-77 years old) were treated with this method during segmental resectioning of the mandible and the subsequent reconstruction with a free vascularized flap. All cases were tumors of the mandible, five cases were squamous cell carcinoma and two cases were ameloblastoma. The mean length of the bone defect was 77 mm (range: 64-102 mm), and the defect pattern was classified as four cases of RBSHand three cases of RBS (according to the classification described by Urken ML). MMF and ZCF were performed before resectioning of the mandible. The lateral surface of the coronoid process and zygomatic buttress were exposed and fixed using a bone plate. Intermaxillary fixation (IMF) screws or arch bars were used for MMF, and a bite plate was applied to stabilize the occlusion in patients who were edentulous or had few remaining teeth. Next, the ZCF and MMF were first released before segmental resection of the mandible, and were adapted again for repositioning of the major and minor segments after resectioning. Of the seven cases, five cases were reconstructed with a fibula osteocutaneous flap, and two cases were reconstructed with a combination of mandibular reconstruction plates and either an abdominis myocutaneous free flap or an anterolateral thigh free flap. The microvascular anastomoses were performed under a microscope. Finally, ZCF and MMF were released again, and the movement of condyle and occlusion were examined. The mean duration of the follow-up was 21 months (range 7-45 months). There were no instances of vascular compromise and the flap survival rate was 100%. All patients were determined to have stable mandibular union and good facial contour. There were no fractures of the titanium plates and screws. The preoperative occlusion was maintained, and there was no postoperative dysfunction of the temporomandibular joint and mastication. The proposed technique has several advantages. First, the technique is notably easy to perform and specialized skills are not required. The positions of the screws do not chosen to accommodate both the resection margins and the reconstruction plates. Second, this method can reposition the segmented mandible correctly as described in sagittal split ramus osteotomy of orthognathic surgery. Both segments are held in a stable position with respect to each other with the condyles being correctly seated in the glenoid fossae. Third, this technique has the advantages of not interfering with the reconstructive and microsurgical procedure. It is easy to perform a determination of the volume and the position of the free flap as well as microvascular anastomosis. For all of these reasons, this method is useful for managing the three-dimensional relationship of the occlusion and the relationship between the condyle and glenoid fossa. We recommend this technique as a reliable method for contemporary microvascular mandibular reconstruction.

References

1. Urken ML, Weinberg H, Vickery C, et al: Oromandibular reconstruction using microvascular composite free flaps. Arch Otolaryngol Head Neck Surg 117: 733, 1991

2. Hiatt WR, Schelkun PM, Moore DL. Condylar positioning in orthognathic surgery. J Oral Maxillofac Surg 46: 1110, 1988

See more of: Poster Session
See more of: Abstract/Poster Sessions
<< Previous Abstract | Next Abstract >>