Analysis of the effects of mandibular reconstruction based on microvascular free flaps after oncological resections in 21 patients, using 3D planning, surgical templates and individual implants
Introduction
The process of computer-assisted surgery (CAS) in mandibular reconstruction involves planning, modelling, surgical [1], [2], [3], and postoperative evaluation phases [4], [5]; but the evaluation phase is not performed in all studies. In the planning phase (Fig. 1a), a computed tomography (CT) scan of the craniofacial skeleton and a CT (with or without angiography) of the donor site is obtained and saved as Digital Imaging and Communications in Medicine (DICOM) files. These 2-dimensional (2D) DICOM images can be subsequently converted into 3-dimensional (3D) surface models in the Standard Tessellation Language (STL) file format. In the revised/evaluation phase (Fig. 1b), a computed tomography (CT) scan of the craniofacial skeleton of the operative site is obtained and saved as DICOM images. After that, these DICOM images are converted into 3D models in STL file format. The preoperative 3D model and postoperative 3D model are compared. Comparison of the preoperative and postoperative data makes it possible to assess the virtual surgical planning (VSP) for each included study. The evaluation approach consists of both pre- and postoperative CT scans of the patient’s skull, followed by an accuracy analysis comparing the postoperative result with the preoperative virtual plan. Examination pre- and postoperative STL models on volume similarity should rule out volume inaccuracies between the two models as much as possible since they can influence the accuracy measurements. Valid comparisons of postoperative accuracy results in computer-assisted reconstruction of the skeletal structures are difficult due to heterogeneity in the imaging modalities, bone defect classification, and evaluation methodologies between studies. [6], [7], [8]. However, the post-operative evaluation is crucial, because of lack of possibility to predict the final position of prosthesis, that depends on the possibility of the acetabulum fixation at the skull base.
De Maesschalck et al. (2017) pioneered an evaluation method for hard tissue accuracy of mandibular reconstruction using CAS, bypassing the need for osteotomy plane determination, and bypassing the use of a superimposition tool [8]. In 2016, Schepers et al. proposed an excellent postoperative evaluation method for virtually planned dental implants in mandibular reconstruction using CAS by measuring the central point deviation [mm] and angular deviation [°] per dental implant [10]. The main limitation of this method is the quantity of measurements per implant which decreases the feasibility, and results in the loss of an overview of the accuracy of the entire reconstruction.
In this article, we propose a more simplified method for the evaluation of the 3D VSP precision and repeatability, for the purposes of reconstructive surgery of the head and neck in children and adolescents. The proposed method is based on easily measurable morphometric measurements (3 angles, 3 linear dimensions), allowing a three-dimensional quantitative assessment of postoperative outcomes. The method uses correlates with the assessment standard that has applied since 2020. The method is suitable regardless of the type of mandibular reconstruction technique used and provides the opportunity to evaluate the results and compare them.
Section snippets
Material and Methods
Ethics approval for this study was received from the Maria Skłodowska-Curie Memorial Cancer Center Ethics Committee in Gliwice (KB 430–15/17). Patients and their legal guardians provided informed consent. Patients treated due to mandible malignancy and treated with microvascular flaps designed by 3D VSP and supported with individual implants according to previously described protocols using virtual imaging, stereolithographic models, production of 3D custom-made resection templates and
Results
A total of 21 patients (14 males/ 7 females) aged 4–17 years old, treated between 2015 and 2019 due to malignant/benign tumors or congenital deformities affecting the mandible and TMJ, were enrolled in the study (Tab. 1). 17 patients had reconstruction performed by free fibula flap (FFF), regardless of the Brown’s defect type (p > 0,056), showing that this type of the flap is the most universal in the reconstruction of the mandible.
Four patients had iliac crest flap (ICF). Reconstructions were
Discussion
3DVSP has already been described as helpful tool in planning surgical procedures in the head and neck, as it provides increased accuracy of the reconstruction, decreased intraoperative time and ease of use. However, quantitative data evaluating preoperative/postoperative CT scans, and comparison, and superimposition of the reconstructed mandible structures have only been reported sparsely so far [2]. Metzler et al. (2014) described 10 retrospective cases where 3D VSP was used for mandible
Conclusion
The main aim of the study was to present the possibility of using virtual planning of a surgical procedure with the implantation of personalized plates within the mandible, as well as the analysis of the precision of 3D VSP and individual implants. The proposed method of evaluation with the use of 3-dimensional morphometrical analysis should be considered in case of planning and surgery. The inaccuracies that can occur during the surgery appear to be well compensated during the planning
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgement
Authors would like to thank the ChM Sp. z o.o. company, the manufacturer of surgical guides and personalized implants, that was used in this research.
References (20)
- et al.
Advances in oncologic head and neck reconstruction: systematic review and future considerations of virtual surgical planning and computer aided design/computer aided modeling
J Plast Reconstr Aesthet Surg.
(2014) - et al.
Use of computer-aided design and computer-aided manufacturing to produce orthognathically ideal surgical outcomes: a paradigm shift in head and neck reconstruction
J Oral Maxillofac Surg.
(2009 Oct) - et al.
Accuracy of secondary maxillofacial reconstruction with prefabricated fibula grafts using 3D planning and guided reconstruction
J Craniomaxillofac Surg.
(2016) - et al.
Three-dimensional virtual surgery accuracy for free fibula mandibular reconstruction: planned versus actual results
J Oral Maxillofac Surg.
(2014 Dec) - et al.
Accuracy of virtually planned mandibular distraction in a pediatric case series
J Craniomaxillofac Surg.
(2021) Precise osteotomies for mandibular distraction in infants with Robin sequence using virtual surgical planning
Int J Oral Maxillofac Surg.
(2018 Jan)- et al.
Multi-modality 3D mandibular resection planning in head and neck cancer using CT and MRI data fusion: A clinical series
Oral Oncol.
(2018) - et al.
Comparison of the Planned Versus Actual Jaw Movement Using Splint-Based Virtual Surgical Planning: How Close Are We at Achieving the Planned Outcomes?
J Oral Maxillofac Surg.
(2019 Aug) - et al.
A CAD/CAM-prototyped anatomical condylar prosthesis connected to a custom-made bone plate to support a fibula free flap
Med Biol Eng Comput.
(2012) - et al.
Evaluation of Mandibular Growth and Symmetry in Child with Congenital Zygomatic-Coronoid Ankylosis
Symmetry.
(2021)
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