Computer-assisted versus traditional technique in fibular free-flap mandibular reconstruction: A CT symmetry study

Comparison of condylar position after free fibular flap mandibular reconstruction using computer-assisted and traditional techniques

OBJECTIVES

To compare the changes in condylar position after mandibular reconstruction with free fibular flap(FFF) and the differences between computer-assisted techniques and traditional methods on CT images.

METHODS

Thirty-four patients who underwent mandibular reconstruction with free fibular flap were selected according to the inclusion and exclusion criteria. In the 3D group, virtual surgical planning (VSP) with osteotomy cutting plate and placement guiding plate were used, while the traditional group underwent freehand reconstruction. The CT data of 68 temporomandibular joints (TMJs) were recorded before and immediately after surgery. The condylar position was evaluated by measuring the anterior space (AS), posterior space (PS) and superior space (SS), and the ln (PS/AS) was calculated according to the method proposed by Pullinger and Hollender.

RESULTS

In the patients included in the 3D group, the condyle on the ipsilateral side moved slightly backward; however, in the patients in the traditional group, the ipsilateral side moved considerably anteroinferior. No obvious changes on the contralateral side were noted. In the 3D group, 33% of ipsilateral condyles were in the posterior position postoperatively when compared with the preoperative position (13%). In the traditional group, the number of ipsilateral condyles in the anterior position increased from 4 to 10, accounting for 53% postoperatively. Contrary to the traditional group, the 3D group presented less condylar displacement on the ipsilateral side postoperatively.

CONCLUSIONS

This study showed a decreased percentage of change in condylar position postoperatively when VSP was used. Virtual surgical planning improved the accuracy of FFF mandibular reconstruction and made the condylar position more stable.

Innovative principle of implant-oriented fibula placement in mandibular reconstruction using double-barrel fibula and simultaneous implants: A technical note

Simultaneous or secondary inserted implants with double-barrel fibula to reconstruct the mandible have become a common method. However, difficulties in later restoration caused by placement errors of fibula or incipiently placed implants have also been reported in some studies. This note describes a novel technique of implant-oriented guide plates helpful for mandible ablation, fibula segmentation and positioning, and implant placement. We design a series of guide plates especially an implant-fibula placing guide plate, and record and fix the relative spatial positions of the remaining teeth, the simultaneous implants and upper fibula. During surgery, the placement of upper fibula is oriented towards appropriate placement of implants. Therefore, the position of upper fibula can meet the requirements of simultaneous implant as much as possible. Within the limits of present observation, we believe that this technique may increase the manipuility while reducing the errors and the risk of complications.

Deep Circumflex Iliac Artery Flap Reconstruction in Brown Class I Defect of the Mandible Using a Three-Component Surgical Template System

BACKGROUND

Computer-assisted surgery is widely used in mandibular reconstruction, but the process is not well described for cases using the deep circumflex iliac artery flap (DCIA) as the donor site. This study aimed to present a DCIA-based three-component surgical template system (3-STS) in patients with a mandibular Brown class I defect.

METHODS

This retrospective cohort study compared clinical outcomes of mandibular reconstruction with DCIA flap using 3-STS or conventional surgical templates. The primary outcome of the study was the accuracy of reconstruction, and the secondary outcomes included surgical time and bone flap ischemia time. Surgery-related parameters and functional outcomes were also recorded and compared.

RESULTS

Forty-four patients (23 in the 3-STS group and 21 in the control group) between 2015 and 2021 were included. Compared with the control group, the 3-STS group had higher accuracy of reconstruction, indicated by lower deviation in absolute distance (1.45 ± 0.76 mm versus 2.02 ± 0.89 mm; P = 0.034), and less deviation in coronal and sagittal angles (0.86 ± 0.53 degree versus 1.27 ± 0.59 degrees, P = 0.039; and 2.52 ± 1.00 degrees versus 3.25 ± 1.25 versus, P = 0.047) between preoperative and postoperative computed tomographic imaging. Surgical time and bone flap ischemia time were significantly reduced in the 3-STS group compared with the control group (median time, 385 minutes versus 445 minutes and 32 minutes versus 53 minutes, respectively; P < 0.001). In addition, masseter attachment was preserved in the 3-STS group but not in the control group. No differences were found in adverse events or other clinical variables.

CONCLUSION

The 3-STS can improve accuracy, simplify intraoperative procedures to increase surgical efficiency, and preserve functionality in mandibular reconstruction for Brown class I defects.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Application of a modified osteotomy and positioning integrative template system (MOPITS) based on a truncatable reconstruction model in the precise mandibular reconstruction with fibula free flap: a pilot clinical study

BACKGROUND

Mandibular defects can greatly affect patients' appearance and functionality. The preferred method to address this issue is reconstructive surgery using a fibular flap. The current personalized guide plate can improve the accuracy of osteotomy and reconstruction, but there are still some problems such as complex design process and time-consuming. Therefore, we modified the conventional template to serve the dual purpose of guiding the mandible and fibula osteotomy and facilitating the placement of the pre-bent titanium.

METHODS

The surgery was simulated preoperatively using Computer-Aided Design (CAD) technology. The template and truncatable reconstruction model were produced in the laboratory using 3D printing. After pre-bending the titanium plate according to the contour, the reconstruction model was truncated and the screw trajectory was transferred to form a modified osteotomy and positioning integrative template system (MOPITS). Next, the patient underwent a composite template-guided vascularized fibula flap reconstruction of the mandible. All cases were reviewed for the total operative time and accuracy of surgery.

RESULTS

The procedures involved 2-4 fibular segments in 15 patients, averaging 3 fibular segments per procedure. The osteotomy error is 1.01 ± 1.02 mm, while the reconstruction angular error is 1.85 ± 1.69°. The preoperative and postoperative data were compared, and both p > 0.05. During the same operation, implant placement was performed on four patients, with an average operative time of 487.25 ± 60.84 min. The remaining malignant tumor patients had an average operative time of 397.18 ± 73.09 min. The average postoperative hospital stay was 12.95 ± 3.29 days.

CONCLUSIONS

This study demonstrates the effectiveness of MOPITS in facilitating precise preoperative planning and intraoperative execution of fibula flap reconstruction. MOPITS represents a promising and reliable tool for reconstructive surgery, particularly for inexperienced surgeons navigating the challenges of mandible defect reconstruction.

A retrospective study on application of fibula/iliac flap surgical techniques to mandibular defects

This study group consists of a total of 61 patients who underwent fibula flap and iliac flap surgeries to repair mandibular defects. Patients' Quality Of life (QOL) at 6 and 24 months after surgery is investigated and compared by the EORTC-QLQ-H&N and OHIP-14. The base data of the two groups of patients are collected and analysed by the SPSS 20.0 statistical software. Independent sample t test was conducted for EORTC-QLQ-H&N and OHIP-14 scores at two time points in each group. The 61 cases of free flap all survived and the difference in the location of the primary tumor between the two groups is statistically significant. The EORTC-QLQ-H&N showed that the score of speech, diet, social contact, and teeth all went up at 6 months after surgery, but went down dramatically at 24 months after surgery. The OHIP-14 showed that there was significant reduction in functional limitation at 24 months after surgery, with statistical significance (p < 0.05) between the groups of iliac flap (19.16 ± 5.33) and fibula flap (33.77 ± 7.71). Therefore, it is suggested that patients suffering from mandibular defects receive surgery utilizing the iliac flap, while those with a larger range of defects or lesions involving the condyle and chin should receive corrective surgery utilizing the fibular flap.

Application of digital guide plate with drill-hole sharing technique in the mandible reconstruction

Background/purpose

With the development of computer-assisted surgery, digital guide plate was widely used in vascularized bone flap grafts for mandibular reconstruction. The purpose of this study was to design and manufacture a digital guide plate with drill-hole sharing for mandibular reconstruction and assess for surgical accuracy.

Materials and methods

17 patients that required mandibular reconstruction using fibula free flap or iliac crest free flap were included in the study. The computed tomography (CT) data of the patient's mandible and pelvis or fibula were acquired preoperatively. A surgical simulation was then performed using computer-aided surgical simulation (CASS) technology based on above date, which allowed the design of two cutting guide and a repositioning guide for mandibular reconstruction. After surgery, the accuracy of reconstruction was evaluated by superimposing the postoperative image onto the preoperative image of mandible, recording the linear and angular deviation of landmarks, measuring the differences between the planned and actual outcomes.

Results

The osteotomy and repositioning of fibula or iliac crest segments were successfully performed as planned using surgical guides. The digital guide plate with drill-hole sharing showed excellent accuracy, When the iliac crest or the fibula free flap were used for mandibular reconstruction, the largest mean differences between the preoperative and postoperative were 1.11 mm and 2.8° or 1.3 mm and 3.87°.

Conclusion

The digital guide plate with drill-hole sharing designed preoperatively provides a reliable method of for the mandibular reconstruction. This can assist surgeons in accurately performing osteotomy and repositioning fibula or iliac crest segments during the mandibular reconstruction.

Advantages of a Training Course for Surgical Planning in Virtual Reality for Oral and Maxillofacial Surgery: Crossover Study

BACKGROUND

As an integral part of computer-assisted surgery, virtual surgical planning (VSP) leads to significantly better surgery results, such as for oral and maxillofacial reconstruction with microvascular grafts of the fibula or iliac crest. It is performed on a 2D computer desktop screen (DS) based on preoperative medical imaging. However, in this environment, VSP is associated with shortcomings, such as a time-consuming planning process and the requirement of a learning process. Therefore, a virtual reality (VR)-based VSP application has great potential to reduce or even overcome these shortcomings due to the benefits of visuospatial vision, bimanual interaction, and full immersion. However, the efficacy of such a VR environment has not yet been investigated.

OBJECTIVE

This study aimed to demonstrate the possible advantages of a VR environment through a substep of VSP, specifically the segmentation of the fibula (calf bone) and os coxae (hip bone), by conducting a training course in both DS and VR environments and comparing the results.

METHODS

During the training course, 6 novices were taught how to use a software application in a DS environment (3D Slicer) and in a VR environment (Elucis) for the segmentation of the fibula and os coxae, and they were asked to carry out the maneuvers as accurately and quickly as possible. Overall, 13 fibula and 13 os coxae were segmented for each participant in both methods (VR and DS), resulting in 156 different models (78 fibula and 78 os coxae) per method (VR and DS) and 312 models in total. The individual learning processes in both environments were compared using objective criteria (time and segmentation performance) and self-reported questionnaires. The models resulting from the segmentation were compared mathematically (Hausdorff distance and Dice coefficient) and evaluated by 2 experienced radiologists in a blinded manner.

RESULTS

A much faster learning curve was observed for the VR environment than the DS environment (β=.86 vs β=.25). This nearly doubled the segmentation speed (cm³/min) by the end of training, leading to a shorter time (P<.001) to reach a qualitative result. However, there was no qualitative difference between the models for VR and DS (P=.99). The VR environment was perceived by participants as more intuitive and less exhausting, and was favored over the DS environment.

CONCLUSIONS

The more rapid learning process and the ability to work faster in the VR environment could save time and reduce the VSP workload, providing certain advantages over the DS environment.

Aesthetic Reconstruction of Onco-surgical Mandibular Defects Using Free Fibular Flap with and without CAD/CAM Customized Osteotomy Guide: A Randomized Controlled Clinical Trial

BACKGROUND

Reconstruction of mandibular defects following ablative surgery remains a challenge even for experienced surgeons. Virtual planning and guided surgery, including computer-aided design/computer-aided manufacturing (CAD/CAM), afford optimized ways by which to plan complex surgery. This study aimed to evaluate and compare aesthetic outcome and surgical efficiency of free fibular flap (FFF) with and without CAD/CAM customized osteotomy guide (COG) for reconstruction of onco-surgical mandibular defects.

METHODS

Twenty-two patients indicated for segmental mandibulectomy were randomly assigned to either CAD/CAM with COG group or that without COG- Model based reconstruction (MB group) at a 1:1 ratio. Aesthetic outcomes were evaluated by means of morphometric assessment and comparison for each differential area (DAr) and angle (DAn) in the affected side to the contralateral side of the mandible using computerized digital imaging analysis (CDIA) based on the post-operative 3D CT-scan. Subjective evaluation was performed using the Visual Analogue Scale (VAS) and Patient's Satisfaction Score (PSS). Surgical efficiency was a secondary outcome and evaluated as total operative time and ischemia time.

RESULTS

The mean sagittal DAr was significantly lower in the COG group (277.28 ± 127.05 vs. 398.67 ± 139.10 mm², P = 0.045). Although there was an improvement in the axial DAr (147.61 ± 55.42 vs. 183.68 ± 72.85 mm²), the difference was not statistically significant (P = 0.206). The mean differences (Δ) in both sagittal and coronal DAn were significantly lower in the COG group than in the MB group (6.11 ± 3.46 and 1.77 ± 1.12° vs. 9.53 ± 4.17 and 3.44 ± 2.34°), respectively. There were no statistically significant differences in the axial DAn between the two groups (P = 0.386). The PSS was significantly higher in the COG group, reflecting better aesthetic satisfaction than in the MB group (P = 0.041). The total operation and ischemia time were significantly shorter in favor of the COG group with a mean of (562.91 ± 51.22, 97.55 ± 16.80 min vs. 663.55 ± 53.43, 172.45 ± 21.87 min), respectively.

CONCLUSION

The CAD/CAM with COG is more reliable and highly valuable in enhancing aesthetic outcomes and surgical efficiency of mandibular reconstruction by FFF compared to that without COG (MB reconstruction).

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov .

REGISTRATION NUMBER

NCT03757273. Registration date: 28/11/2018.

Standardized and axially vascularized calcium phosphate-based implants for segmental mandibular defects: A promising proof of concept

The reconstruction of massive segmental mandibular bone defects (SMDs) remains challenging even today; the current gold standard in human clinics being vascularized bone transplantation (VBT). As alternative to this onerous approach, bone tissue engineering strategies have been widely investigated. However, they displayed limited clinical success, particularly in failing to address the essential problem of quick vascularization of the implant. Although routinely used in clinics, the insertion of intrinsic vascularization in bioengineered constructs for the rapid formation of a feeding angiosome remains uncommon. In a clinically relevant model (sheep), a custom calcium phosphate-based bioceramic soaked with autologous bone marrow and perfused by an arteriovenous loop was tested to regenerate a massive SMD and was compared to VBT (clinical standard). Animals did not support well the VBT treatment, and the study was aborted 2 weeks after surgery due to ethical and animal welfare considerations. SMD regeneration was successful with the custom vascularized bone construct. Implants were well osseointegrated and vascularized after only 3 months of implantation and totally entrapped in lamellar bone after 12 months; a healthy yellow bone marrow filled the remaining space. STATEMENT OF SIGNIFICANCE: Regenerative medicine struggles with the generation of large functional bone volume. Among them segmental mandibular defects are particularly challenging to restore. The standard of care, based on bone free flaps, still displays ethical and technical drawbacks (e.g., donor site morbidity). Modern engineering technologies (e.g., 3D printing, digital chain) were combined to relevant surgical techniques to provide a pre-clinical proof of concept, investigating for the benefits of such a strategy in bone-related regenerative field. Results proved that a synthetic-biologics-free approach is able to regenerate a critical size segmental mandibular defect of 15 cm³ in a relevant preclinical model, mimicking real life scenarii of segmental mandibular defect, with a full physiological regeneration of the defect after 12 months.

Virtual planning and 3D-printed guides for mandibular reconstruction: Factors impacting accuracy

Objectives

Examine accuracy and factors impacting accuracy for mandibular reconstruction with virtual surgical planning, 3D printed osteotomy guides and preoperatively bent mandibular reconstruction plate (VSP/3Dprinted-guide/plate).

Method

Retrospective review of osseous-free-flap mandibular reconstructions with VSP/3Dprinted-guide/plate between January 2015 and July 2020 at a single academic medical center.Patient demographics, disease, and treatment variables were extracted. Accuracy was assessed by 3D-model-overlay with cephalometric and donor-bone segment length measurements. Multivariate analyses were performed to determine factors impacting cephalometric accuracy.

Results

60 cases met criteria: 41 (68%) cancer, 14 (23%) osteoradionecrosis (ORN), 5 (8%) secondary mandibular reconstruction. Thirteen cases (22%) were Brown class III or IV. Thirty-nine cases (65%) had ≥2 flap bone segments. Average donor-bone length was 82 mm (SD: 28). 3D-model-overlay accuracy demonstrated minimal deviation between planned and actual reconstruction: intercondylar distance = 2.10 mm (SD: 2.2); intergonial distance = 2.23 mm (SD: 1.9); anterior-posterior distance (APD) = 1.76 mm (SD: 1.5); gonial angle (GA) = 3.11 degrees (SD: 2.4). Mean change in donor-bone segment length inferiorly was 2.67 mm (SD: 2.6) and superiorly 3.27 mm (SD: 3.2). Higher number of donor-bone segments was associated with decreased accuracy in GA (p = .023) and longer donor-bone length was associated with decreased accuracy in APD (p = .031).

Conclusion

To our knowledge this is the largest series assessing surgical accuracy of VSP/3Dprinted-guide/plate for osseous-free-flap mandibular reconstruction. We demonstrate highly accurate results, with increased number of donor-bone segments and donor-bone length associated with decreased accuracy. Our findings further support VSP/3Dprinted-guide/plate as a reliable and accurate tool for mandibular reconstruction.

Level of Evidence

Level 4.

Osseous Union after Mandible Reconstruction with Fibula Free Flap Using Manually Bent Plates vs. Patient-Specific Implants: A Retrospective Analysis of 89 Patients

The aim of this monocentric, retrospective clinical study was to evaluate the status of osseous union in uni- and poly-segmental mandible reconstructions regarding conventional angle-stable manually bent osteosynthesis plates (Unilock 2.0 mm) versus titan laser-melted PSI patient-specific implant’s (PSI). The clinical impact of PSI’s high stiffness fixation methods on bone healing and regeneration is still not well addressed. The special interest was in evaluating the ossification of junctions between mandible and fibula and between osteotomized fibula free flap (FFF) segments. Panoramic radiograph (OPT), computed tomography (CT) scans, or cone-beam CTs (CBCT) of patients who underwent successful FFF for mandible reconstruction from January 2005 to December 2020 were analyzed. A total number of 89 cases (28 females (31.5%), 61 males (68.5%), mean age 58.2 ± 11.3 years, range: 22.8–82.7 years) fulfilled the chosen inclusion criteria for analysis (conventional: n = 44 vs. PSI: n = 45). The present study found an overall incomplete ossification (IOU) rate of 24.7% (conventional: 13.6% vs. PSI: 35.6%; p = 0.017) for mandible to fibula and intersegmental junctions. Between osteotomized FFF segments, an IOU rate of 16% was found in the PSI-group, while no IOU was recorded in the conventional group (p = 0.015). Significant differences were registered for IOU rates in poly-segmental (p = 0.041), and lateral (p = 0.016) mandibular reconstructions when PSI was used. Multivariate logistic regression analysis identified plate exposure and type of plate used as independent risk factors for IOU. Previous or adjuvant radiotherapy did not impact incomplete osseous union in the evaluated study sample. PSI is more rigid than bent mini-plates and shields functional mechanical stimuli, and is the main reason for increasing the rate of incomplete ossification. To enhance the functional stimulus for ossification it has to be discussed if patient-specific implants can be designed to be thinner, and should be divided into segmental plates. This directs chewing forces through the bone and improves physiological bone remodeling.

Comparing the use of conventional and three-dimensional printing (3DP) in mandibular reconstruction

Background

There are a number of clinical disorders that require mandibular reconstruction (MR). Novel three-dimensional (3D) printing technology enables reconstructions to be more accurate and beneficial to the patient. However, there is currently no evidence identifying which techniques are better suited for MR, based on the type of clinical disorder the patient has. In this study, we aim to compare 3D techniques with conventional techniques to identify how best to reconstruct the mandible based on the clinical cause that necessitates the reconstructive procedure: cancerous or benign tumours, clinical disorders, infection or disease and trauma or injury.

Methods

PubMed, Scopus, Embase and Medline were searched to identify relevant papers that outline the clinical differences between 3D and conventional techniques in MR. Data were evaluated to provide a clear outline of suitable techniques for surgery.

Results

20 of 2749 papers met inclusion criteria. These papers were grouped based on the clinical causes that required MR into four categories: malignant or benign tumour resection; mandibular trauma/injury and other clinical disorders.

Conclusions

The majority of researchers favoured 3D techniques in MR. However, due to a lack of standardised reporting in these studies it was not possible to determine which specific techniques were better for which clinical presentations.

Patient-Specific 3D-Printed Miniplates for Free Flap Fixation at the Mandible: A Feasibility Study

Background

This study was conducted to evaluate the feasibility, clinical outcomes, and accuracy of patient-specific 3D-printed miniplates for mandible reconstruction with fibula free flaps.

Methods

A feasibility study was conducted with 8 patients. Following virtual planning, patient-specific 1.0 mm titanium non-locking miniplates were produced via laser selective melting. 3D-printed cutting and drilling guides were used for segmental mandible resection and flap harvesting. Flap fixation was performed with two 4-hole miniplates and 2.0 mm non-locking screws (screw length 7 mm) for each intersegmental gap. Clinical follow-up was at least 6 months. Preoperative and postoperative CT/cone beam CT data were used for 3D accuracy analysis and evaluation of bone healing. Plate-related complications were monitored clinically.

Results

Patient-specific miniplate fixation of all flaps was successfully conducted (4 mono-segmental, 4 dual-segmental) with high accuracy (3.64 ± 1.18 mm) between the virtual plan and postoperative result. No technical complications were encountered intraoperatively. Osseous union occurred in all intersegmental gaps (1 partial, 18 complete) after 10 ± 2 months. No material fracture, dislocation, or plate exposure was observed.

Conclusions

Based on this pilot observational study including a limited number of patients, free flap fixation for mandibular reconstruction with patient-specific 3D-printed miniplates is feasible and associated with high accuracy, bone healing, and remote soft tissue complications.

A Comparative Study of Analog Preoperative Planning Versus Virtual Preoperative Planning for Mandibular Reconstruction With Fibula Free Flap

ABSTRACT

Mandibular reconstruction is a challenging procedure, especially in cancer patients with defects that are greater than 6 cm. Free vascularized fibular flap is the gold standard treatment in these cases since it allows three-dimensional restoration of the lost segments after ablative surgery in addition to providing the possibility of a subsequent implant-supported rehabilitation improving the functional and aesthetic outcomes of the surgery.To obtain accurate results, preoperative planning must be done with detail. Approaches for the preoperative planning include both the conventional analog planning and the virtual planning that are valid alternatives in meeting the trans-surgical requirements.This study makes a comparative analysis of 2 clinical cases with a diagnosis of squamous cell carcinoma that were reconstructed using a vascularized fibular free flap. The first case was planned using the conventional analog method whereas the second case was planned using the virtual planning approach.The impact of virtual planning and conventional analog planning on preoperative planning time, ischemia period, and total surgical time is analyzed according to the experience obtained in the cases presented. In addition, the authors described the technique used for each planning method along with a literature review in which the results are contrasted and discussed.

Deviation Analyses of Computer-Assisted, Template-Guided Mandibular Reconstruction With Combined Osteotomy and Reconstruction Pre-Shaped Plate Position Technology: A Comparative Study

Background

Computer-assisted and template-guided mandibular reconstruction provides higher accuracy and less variation than conventional freehand surgeries. The combined osteotomy and reconstruction pre-shaped plate position (CORPPP) technique is a reliable choice for mandibular reconstruction. This study aimed to evaluate the accuracy of CORPPP-guided fibular flap mandibular reconstruction and analyze the possible causes of the deviations.

Patients and Methods

From June 2015 to December 2016, 28 patients underwent fibular flap mandibular reconstruction. Virtual planning and personalized CORPPP-guided templates were applied in 15 patients while 13 patients received conventional freehand surgeries. Deviations during mandibulectomy and fibular osteotomy, and overall and triaxial deviation of the corresponding mandibular anatomical landmarks were measured by superimposing the pre- and postoperative virtual models.

Results

The deviation of the resection line and resection angle was 1.23 ± 0.98 mm and 4.11° ± 2.60°. The actual length of fibula segments was longer than the designed length in 7 cases (mean: 0.35 ± 0.32 mm) and shorter in 22 cases (mean: 1.53 ± 1.19 mm). In patients without ramus reconstruction, deviations of the ipsilateral condylar head point (Co.), gonion point (Go.), and coracoid process point (Cor.) were 6.71 ± 3.42 mm, 5.38 ± 1.71 mm, and 11.05 ± 3.24 mm in the freehand group and 1.73 ± 1.13 mm, 1.86 ± 0.96 mm, and 2.54 ± 0.50 mm in the CORPPP group, respectively, with significant statistical differences (p < 0.05). In patients with ramus reconstruction, deviations of ipsilateral Co. and Go. were 9.79 ± 4.74 mm vs. 3.57 ± 1.62 mm (p < 0.05), and 15.17 ± 6.53 mm vs. 4.36 ± 1.68 mm (p < 0.05) in the freehand group and CORPPP group, respectively.

Conclusion

Mandibular reconstructions employing virtual planning and personalized CORPPP-guided templates show significantly higher predictability, convenience, and accuracy of mandibular reconstruction compared with conventional freehand surgeries. However, more clinical cases were required for further dimensional deviation analysis. The application and exploration of clinical practice would also continuously improve the design of templates.

Fibula Graft Cutting Devices: Are 3D-Printed Cutting Guides More Precise than a Universal, Reusable Osteotomy Jig?

Individual cutting guides for the reconstruction of lower jaw defects with fibular grafts are often used. However, the application of these osteotomy tools is costly and time intensive. The aim of this study was to compare the precision of osteotomies using a 3D-printed guide with those using a universal, reusable, and more cost-efficient Multi-Use Cutting Jig (MUC-Jig). In this non-blinded experimental study, 10 cranio-maxillofacial surgeons performed four graft removals each in a randomized order using the same osteotomy angle, both proximally (sagittal cut) and distally (coronal cut), of a graft (45°, 30°, 15°, or 0°), first with the MUC-Jig then with the 3D-printed cutting guide. The 40 fibula transplants (Tx) of each method (n = 80) were then analyzed concerning their Tx length and osteotomy angles and compared to the original planning data. Furthermore, the surgeons’ subjective perception and the duration of the two procedures were analyzed. The mean relative length and mean relative angle deviation between the MUC-Jig (−0.08 ± 1.12 mm; −0.69° ± 3.15°) and the template (0.22 ± 0.90 mm; 0.36° ± 2.56°) group differed significantly (p = 0.002; p = < 0.001), but the absolute deviations did not (p = 0.206; p = 0.980). Consequently, clinically comparable osteotomy results can be achieved with both methods, but from an economic point of view the MUC-Jig is a more cost-efficient solution.

Patient-Specific Surgical Implant Using Cavity-Filled Approach for Precise and Functional Mandible Reconstruction

Mandibular reconstruction is a complicated task because of the complex nature of the regional anatomy. Computer-assisted tools are a promising means of improving the precision and safety of such complex surgeries. The digital techniques utilized in the reconstruction of mandibular defects based on medical data, computer-aided-design approaches, and three-dimensional (3D) printing are widely used to improve the patient’s aesthetic appearance and function, as well as the accuracy and quality of diagnosis, and surgical outcomes. Nevertheless, to ensure an acceptable aesthetical appearance and functional outcomes, the design must be based on proper anatomical reconstruction, mostly done in a virtual environment by skilled design engineers. Mirroring is one of the widely used techniques in the surgical navigation and reconstruction of mandibular defects. However, there are some discrepancies and mismatches in the mirrored anatomical models. Hence, in order to overcome these limitations in the mirroring technique, a novel approach called the cavity-filled technique was introduced. The objective of this study was to compare the accuracy of the newly recommended cavity-filled technique with the widely used mirror reconstruction technique in restoring mandibular defects. A prominent 3D comparison technique was employed in this work, where the resected and the reconstructed mandibles were superimposed to quantify the accuracy of the two techniques. From the analysis, it can be inferred that the cavity-filled technique with a root-mean-square value of 1.1019 mm produced better accuracy in contrast to the mirroring approach, which resulted in an error of 1.2683 mm. Consequently, by using the proposed cavity-filled design, the discrepancy between the reconstruction plate and the bone contour was mitigated. This method, owing to its high precision, can decrease the number of adjustments and the time of surgery, as well as ensure a quick recovery time with better implant tissue in-growth.