Application of Digital Design, Three-Dimensional Printing and Surgical Navigation Technique on Maxillary Reconstruction with Free Fibula Flap

Background: Maxillary reconstruction with a free fibula flap is widely used after oncologic resection because it allows functional and esthetic restoration of the maxillary arch and implant-retained prostheses. The purpose of this study was to explore the application of digital design, 3D printing technology and surgical navigation on maxillary reconstruction with free fibula flap. Methods: Eleven patients requiring maxillary reconstruction were enrolled in our study. Each case underwent digital design and 3D printing technique to get the 3D model. The lost maxilla model was copied from the opposite side. According to the 3D model, the titanium mesh was then rebuilt to have an accurate stereo shape. Demographic data, surgical factors, and perioperative and postoperative results were evaluated. Results: All patients underwent digital design, 3D printing technology preoperative planning and surgical navigation for resection of the tumor and reconstruction. 11 cases were followed up for 8-22 months, all flaps were successful, no complications such as infection, diplopia or exophthalmos had occurred. Only one patient local recurrence, no recurrence of the remaining cases. Conclusion: Digital design, 3D printing technology, and surgical navigation allowed for precise planning of the tumor resection and accurate size of the fibula flaps. Maxillary reconstruction with a free fibular flap can obtain excellent functional and acceptable esthetic outcomes. Introduction Maxillary defects resulting from tumor resection or trauma can cause severe functional and cosmetic deformities. A maxillectomy can cause defects of the alveolar bone, gingiva, palate, maxilla, zygomatic bone, and orbital floor. Loosing of these key structures can lead to enophthalmos, orbital dystopia, feeding and speech problems, and midfacial projection loss. Surgical reconstruction might provide a better phonation and deglutition function than prosthetic reconstruction [1]. The main goals of maxillary reconstruction are to heal the wound, separate the oral and sinonasal cavities, recreate the alveolar ridge, restore the midfacial projection, and provide orbital support [2,3]. It has been proved feasible in maxillary reconstruction with vascularized free fibula flap, scapular flap, iliac crest free flap, etc [4,5]. Free fibula flap as a source of vascularized bone has gained widespread use since its first description by Taylor in 1975 [6]. In 1993, Schusterman reported the first midface reconstruction with a free fibula flap [7]. The using of this flap with osseo integrated implants can provide satisfactory results esthetically and functionally in the long term. Thus, fibula flaps are the ideal choice for maxillary reconstruction. Traditionally, fibular shaping is done after cutting the pedicle. Adjusting the length of the bone designing and performing the osteotomies increase ischemia time, this may be crucial for flap survival. This process also lengthens the total operative time. In addition, using traditional techniques makes it difficult to recreate the original maxillary contour accurately. Achieving good bony contraction may also be difficult, which compromises the ossification process. A functional and esthetically good outcome is important for the patient’s quality of life. In order to address these problems, three-dimensional (3D) technology has been utilized in reconstructive surgery [8,9]. Digital design, 3D printing technology, and surgical navigation have been developed to avoid errors in the traditional model process. Utilization of digital design, 3D printing technology, which allows for preoperative virtual planning and the manufacture of customized cutting guides and prebend plates, has become more popular in maxillary reconstruction. Zhang et al demonstrated that Application of computer-assisted techniques such as virtual planning and surgical navigation significantly Research Article | Short Name: Syntax J Biotechnol Bioeng | Copyright© all rights reserved by Xiaojuan Tang Syntax Journal of Biotechnology and Bioengineering Application of Digital Design, Three-Dimensional Printing and Surgical Navigation Technique on Maxillary Reconstruction with Free Fibula Flap 02 Citation: Tang X. Application of Digital Design, Three-Dimensional Printing and Surgical Navigation Technique on Maxillary Reconstruction with Free Fibula Flap. Syntax J Biotechnol Bioeng. 2018; 1: 101. improve the clinical outcomes of maxillary reconstruction with free fibula flaps [10]. Avraham et al. evaluated a large series of mandibular defects reconstructed with fibula flaps utilizing this technique and also reported reduced operative times and a very high dental rehabilitation rate [11]. These previous findings support the application of Digital design, 3D printing technology, and surgical navigation prior to surgical reconstruction. We studied the effects of Digital design, 3D printing technology and surgical navigation in 11 consecutive patients undergoing maxillary reconstruction with a free fibula flap. We aimed to improve the outcomes of reconstruction with free fibula flap and titanium mesh by using these new techniques. Materials and Methods The Ethical Review Board of the First Affiliated Hospital of Zhengzhou University granted our study. Eleven consecutive patients (7 men and 4 women) with maxillary defects underwent reconstruction of the maxilla using the free fibula flap at Department of Stomatology at the First Affiliated Hospital of Zhengzhou University from September 2013 to February 2016. Patient ages ranged from 28 to 63 years, with a median age of 45 years. The primary diseases in the 11 patients were benign tumors in 5patients, malignant tumors in 6 patients. All patients met the following inclusion criteria: they had clinical and radiographic evidence of dental maxillofacial deformities and no craniofacial syndrome; had no previous orthognathic operation or previous maxillary or mandibular trauma. Surgical Planning and Procedure Preoperatively, patients underwent high-resolution Computed Tomography (CT) of the maxillofacial and lower leg regions. After CT scanning, a Web meeting was organized and 3D virtual planning of the tumor resection and reconstruction was done using ProPlan CMF. The resection planes of the maxillary, positioning of the plate, fibula length, and osteotomy angles were established. Customized cutting guides for maxillary resections and fibular osteotomies and prebend plates were manufactured according to the plan. A three-dimensional resin stereo-model was printed, based on the mirrored plan through rapid prototyping techniques. Figure 1: A three-dimensional resin stereo-model. The model was used to pre-bend one pieces of titanium mesh (0.6 mm, AO CMF, Synthes, Switzerland), which would be used to support the orbital floor and restore the maxillary contour Figure 2: Titanium mesh pre-bent on a printed 3D resin model. A two-team approach was used for the operation; routine pre-operative lower limbs CTA check the lower limbs peroneal artery and vein in order to understand the blood supply and vascular patency of variation. Figure 3: Pre-operative lower limbs CTA. Tumor resection and maxillary resection were performed according to the virtual plan by using the navigation system. Application of Digital Design, Three-Dimensional Printing and Surgical Navigation Technique on Maxillary Reconstruction with Free Fibula Flap 03 Citation: Tang X. Application of Digital Design, Three-Dimensional Printing and Surgical Navigation Technique on Maxillary Reconstruction with Free Fibula Flap. Syntax J Biotechnol Bioeng. 2018; 1: 101. Figure 4: The position of the maxillary resection is confirmed using the navigation system. The donor’s leg was ipsilateral to the maxillary resection site. The fibula flap was harvested, as described by Hidalgo, A resin surgical plate was printed before the surgery, according to the virtual plan, and used as a template for fibula molding. Figure 5: A resin template used for flap molding. The fibula flap was transferred to the recipient site, and the pedicle was placed within a tunnel in the submandibular region to promote anastomosis. Intraoperative arterial anastomosis uses 8-0 atraumatic suture conventional hand-stitched arteries. Artery anastomosis select blood reflux good accompanying veins use of the venous coupler for vascular anastomosis. Figure 6: Venous coupler device used in free fibula flap transfers. The three-dimensional fibular and titanium mesh position was confirmed to match the position in the virtual plan. Figure 7: The prepared fibula and titanium mesh were inserted into the maxillary defect. Patient demographic data, surgical factors, and perioperative and postoperative results were collected and analyzed. Results All patients underwent Digital design, 3D printing technology and surgical navigation for resection of the tumor and reconstruction. The length of the fibula bone for maxillary reconstruction ranged from 5.6 to 7.8 cm, with a mean length of 6.56 cm. The height of the fibula bone ranged from 1.0 to 2.1 cm, with a mean height of 1.4cm. The length of vascular pedicles ranged from 7.5 to 10.5cm, with a mean length of 8.9 cm. One patient with squamous cell carcinoma had a local recurrence on the 10 months after surgery. No local recurrence or distant metastases were found in the other patients. Dental implants were placed for two patients. The mean total operative time for all patients was 475 minutes. One patient had local recurrence was found in this patient during the follow-up period. Symmetric appearance and ideal fibular segment position were achieved, as indicated by the three-dimensional CT reconstructions. All patients were satisfied with their postoperative appearance. Mean ischemia time was 75 minutes (range 57-95 minutes). They were found to be good and the flaps fitted into the defects precisely. There were no significant gaps between bone surfaces and therefore autologous b