Utilization of a pre-bent plate-positioning surgical guide system in precise mandibular reconstruction with a free fibula flap

Functional and esthetic outcomes of virtual surgical planning versus the conventional technique in mandibular reconstruction with a free fibula flap: A retrospective study of 24 cases

This study aimed to compare the functional and esthetic results in patients following mandibular reconstruction with a free fibula flap (FFF) by virtual surgical planning (VSP) versus the conventional technique. Patients who had undergone mandibular reconstruction with a FFF by VSP or the conventional technique were retrospectively assessed. The two groups were compared regarding functional and esthetic variables with appropriate scales preoperatively, intraoperatively, and postoperatively. Twenty-four patients were evaluated in two groups: conventional (n = 8) and VSP (n = 16). The mean amount of mandibular asymmetry was 2.62 mm (SD = 1.59) in the conventional group and 1.19 mm (SD = 1.32) in the VSP group. Of the patients who underwent conventional surgery, 12.5% had mandibular asymmetry of <2 mm and 87.5% had asymmetry of 2-5 mm. Of the VSP patients, 61.5% had mandibular asymmetry of <2 mm and 38.5% had mandibular asymmetry of 2-5 mm (p = 0.03). The mean difference in size of mandibular angle on the surgical and control sides was not significantly different between the two groups (p = 0.62). The difference in mean length of the mandibular body on the surgical side relative to the control side was not significant between the two groups (p = 0.75). Differences in functional variables between the two groups were not significant. Within the limitation of the study, it seems that the VSP technique resulted in better facial symmetry and superior esthetic outcomes compared with the conventional technique.

A new classification of mandible defects and condyle changed after mandible reconstruction with FFF

Objectives

To explore a new classification of mandibular defects and changes in the preserved condyle after mandibular reconstruction with free fibular flap(FFF).

Study design

We reviewed patients who underwent mandibular reconstruction with FFF from 2015 to 2021 and classified the mandibular defects into five categories: classⅠ(unilateral-mandibular excluding condyle), classⅡ(unilateral-mandibular including condyle), classⅢ(bilateral-mandibular excluding condyle), classⅣ(bilateral-mandibular including one condyle), and classⅤ(bilateral-mandibular including both condyles). Cone Beam Computed Tomography (CBCT) data were collected preoperatively(T0), at 7-10 postoperative days(T1), 6 postoperative months(T2), and 1 postoperative year(T3). We calculated the condylar surface area, volume, and displacement.

Results

62 cases were collected. The condylar surface areas and volumes in T2 and T3 values were lower than those of T0 and T1(P < 0.01) The condylar displacement was the lowest in ClassI and the largest in ClassⅣ(P < 0.01), while no significant differences in classesⅠ-Ⅲ(P < 0.05). Displacement during T1-T0 was greater than that during T2-T0 and T3-T0(P < 0.05).

Conclusion

Mandibular reconstruction with FFF results in displacement and alteration of the condyle within a time interval, and this alteration stabilizes after 6 months. Mandibular defects that do not reach the midline, surgical alteration to preserve the condyle are not required. However, when the defects cross the midline, the condyle should be preserved as much as possible.

Cutting guides in mandibular tumor ablation: Are we as accurate as we think?

Purpose

Tumor margin status is critical in local tumor recurrence and is a significant prognostic factor in head and neck cancer survival. With the introduction of computer-assisted surgical planning, one of the main challenges is the accurate positioning of the surgical cutting guide but there is limited evidence of the accuracy of the 3D cutting guides in mimicking virtually planned osteotomy. This study evaluates the accuracy of osteotomy lines produced by 3D-printed cutting guides and assesses the overall accuracy of mandibular reconstruction.

Material and Methods

The pre and postoperative 3D models were aligned using an automated surface registration feature based on the iterative closest point algorithm. The differences in osteotomy line deviation, linear and angle measurements, and 3D volume quantification of the pre and post models were measured.

Results

We included 14 patients (8 men and 6 women with ages ranging from 13 to 75 years) with a segmental mandibular resection who met all of the inclusion criteria. The smallest defect size was 4.4 cm, the largest defect was 12.2 cm, and the average was 7.30 cm +/- 2.80 cm. The average deviation between virtually planned osteotomy and actual surgical osteotomy was 1.52 +/-1.02 mm. No covariates were associated with increased inaccuracy of the 3D-printed cutting guides.

Conclusion

The finding of this study suggests that virtual surgical planning is an unambiguous paradigm shift in the predictability of the surgical plan and achievement of the reconstruction goals. The 3D-printed cutting guides are a very accurate and reliable tool in translating virtual ablation plans to an actual surgical resection margin.

Introduction and preliminary application report for a novel 3D printed perforator navigator for fibular flap surgery

The aim of this study was to introduce and report on a 3D-printed perforator navigator and its clinical application. Integrated imaging and 3D printing techniques were employed for the design and manufacture of a perforator navigator. Key techniques included establishing a digital image coordinate system, localizing perforator fascia piercing points, creating a reference plane for the perforator course, and projecting the perforator course onto the body surface. All cases of maxillofacial defect repaired with free fibular myocutaneous flaps, from January 2019 to January 2022, were reinvestigated. Patients treated using traditional perforator localization methods were assigned into group Ⅰ, while those who had a navigator used during treatment were allocated to group Ⅱ. Outcome measurements included perforator positioning accuracy, perforator preparation time (PT), and flap growth score. Capillary refilling time and degree of flap swelling were recorded on the 1st, 3rd, and 7th days after surgery. On the 10th day after surgery, the flap survival situation was graded. In total, 25 patients were included in the study. Perforator preparation time for group Ⅱ was significantly less (p ＝ 0.04) than for group Ⅰ (1038.6 ± 195.4 s versus 1271.4 ± 295.1 s. In group Ⅱ, the mean positioning deviation for the perforator navigator was 2.12 cm less than that for the high-frequency color Doppler (p ＝ 0.001). Group Ⅱ also had a higher score than group Ⅰ for overall flap growth evaluation (nonparametric rank sum test, p ＝ 0.04). Within the scale of the study, it seems that perforator localization and navigation using a 3D-printed navigator is technically feasible, and helps to improve the clinical outcome of free fibular flaps. The perforator navigator will play a useful role in displaying the perforator course, improving the accuracy of perforator localization, reducing surgical injury, and ultimately enhancing flap success rate.

Automated calculation of ontology-based planning proposals: An application in reconstructive oral and maxillofacial surgery

BACKGROUND

Structured modelling of surgical knowledge and its automated processing is still challenging. The aim of this work is to introduce a novel approach for automated calculation of ontology-based planning proposals in mandibular reconstruction and conduct a feasibility study.

METHODS

The presented approach is composed of an RDF(S) ontology, a 3D mandible template and a calculator-optimiser algorithm to automatically calculate reconstruction proposals with fibula grafts. To validate the viability of the approach, a feasibility study was conducted on 164 simulated mandibular reconstructions.

RESULTS

The ontology defines 244 different reconstruction variants and 80 analyses for optimization. In 146 simulated cases, a proposal could be automatically calculated (average time 8.79 ± 4.03 s). The assessments of the proposals by three clinical experts indicate the viability of the approach.

CONCLUSIONS

Due to the modular separation between computational logic and domain knowledge, the developed concepts can be easily maintained, reused and adapted for other applications.

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.

From bench to bedside - current clinical and translational challenges in fibula free flap reconstruction

Fibula free flaps (FFF) represent a working horse for different reconstructive scenarios in facial surgery. While FFF were initially established for mandible reconstruction, advancements in planning for microsurgical techniques have paved the way toward a broader spectrum of indications, including maxillary defects. Essential factors to improve patient outcomes following FFF include minimal donor site morbidity, adequate bone length, and dual blood supply. Yet, persisting clinical and translational challenges hamper the effectiveness of FFF. In the preoperative phase, virtual surgical planning and artificial intelligence tools carry untapped potential, while the intraoperative role of individualized surgical templates and bioprinted prostheses remains to be summarized. Further, the integration of novel flap monitoring technologies into postoperative patient management has been subject to translational and clinical research efforts. Overall, there is a paucity of studies condensing the body of knowledge on emerging technologies and techniques in FFF surgery. Herein, we aim to review current challenges and solution possibilities in FFF. This line of research may serve as a pocket guide on cutting-edge developments and facilitate future targeted research in FFF.

Changes in condylar position and morphology after mandibular reconstruction by vascularized fibular free flap with condyle preservation

OBJECTS

Changes in condylar position and morphology after mandibular reconstruction are important to aesthetic and functional rehabilitation. We evaluated changes in condylar position and morphology at different stages after mandibular reconstruction using vascularized fibular free flap with condyle preservation.

MATERIALS AND METHODS

A total of 23 patients who underwent mandibular reconstruction with fibular flap were included in this retrospective study. CT data of all patients were recorded before surgery (T0), 7 to 14 days after surgery (T1), and at least 6 months after surgery (T2). Five parameters describing the condylar position and 4 parameters describing the morphology were measured in sagittal and coronal views of CT images. The association between clinical characteristics and changes in condylar position and morphology was analyzed. A finite element model was established to investigate the stress distribution and to predict the spatial movement tendency of the condyle after reconstruction surgery.

RESULTS

The condylar position changed over time after mandibular reconstruction. The ipsilateral condyles moved inferiorly after surgery (T0 to T1) and continually move anteriorly, inferiorly, and laterally during long-term follow-up (T1 to T2). Contrary changes were noted in the contralateral condyles with no statistical significance. No morphological changes were detected. The relationship between clinical characteristics and changes in condylar position and morphology was not statistically significant. A consistent result was observed in the finite element analysis.

CONCLUSION

Condylar positions showed obvious changes over time after mandibular reconstruction with condylar preservation. Nevertheless, further studies should be conducted to evaluate the clinical function outcomes and condylar position.

CLINICAL RELEVANCE

These findings can form the basis for the evaluation of short-term and long-term changes in condylar position and morphology among patients who have previously undergone mandibular reconstruction by FFF with condyle preservation.

3D printed PEKK bone analogs with internal porosity and surface modification for mandibular reconstruction: An in vivo rabbit model study

Polyetheretherketone (PEEK) and its derivative polyetherketoneketone (PEKK) have been used as implant materials for spinal fusing and enjoyed their success for many years because of their mechanical properties similar to bone and their chemical inertness. The osseointegration of PEEKs is datable. Our strategy was to use custom-designed and 3D printed bone analogs with an optimized structure design and a modified PEKK surface to augment bone regeneration for mandibular reconstruction. Those bone analogs had internal porosities and a bioactive titanium oxide surface coating to promote osseointegration between native bone and PEKK analogs. Our workflow was 3D modeling, bone analog designing, structural optimization, mechanical analysis via finite element modeling, 3D printing of bone analogs and subsequently, an in vivo rabbit model study on mandibular reconstruction and histology evaluation. Our results showed the finite element analysis validated that the porous PEKK analogs provided a mechanical-sound structure for functional loadings. The bone analogs offered a perfect replacement for segmented bones in the terms of shape, form and volume for surgical reconstruction. The in vivo results showed that bioactive titanium oxide coating enhanced new bone in-growth into the porous PEKK analogs. We have validated our new approach in surgical mandibular reconstruction and we believe our strategy has a significant potential to improve mechanical and biological outcomes for patients who require mandibular reconstruction procedures.

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.

Dual Application of Patient-Specific Occlusion-Based Positioning Guide and Fibular Cutting Guide for Accurate Reconstruction of Segmental Mandibular Defect

In this study, the authors introduced a dual application of patient-specific occlusion-based positioning guide and fibular cutting guide to obtain ideal occlusal relationship and mandibular contour in patients undergoing mandibular reconstruction. A retrospective review was performed in 21 patients who underwent mandibular reconstruction with a fibular osteocutaneous free flap. Using computed tomography and intraoral scanning data, fibular cutting guide and occlusion-based positioning guide were simulated in a modeling software and 3-dimensionally printed. Both guides were applied in 9 patients, defined as dual guide group, while the fibular cutting guide was solely used in the remaining patients, defined as single guide group. Functional outcomes including occlusion status, trismus, presence of osseointegrated implant were assessed at 1-year postoperative period. To evaluate the accuracy of the reconstruction, the discrepancy between the planned simulation and actual surgical result was quantified by measuring mandibular deviation angle and volume conformity. Regarding the functional outcomes, all patients in dual guide group showed satisfactory occlusion and intact oral capacity at postoperative 1-year assessment, while 3 patients in single guide group had prolonged malocclusion. The dual guide group showed significantly decreased deviation angle in coronal (right side, 2.93°±1.98° vs. 7.02°±2.81°, P =0.003) and axial plane (right side, 3.20°±2.04° vs. 7.63°±3.40°, P =0.006). The mean volume conformity between the simulation and actual fibular object was significantly higher in the dual guide group (75.27%±6.12% vs. 59.06%±8.57%, P =0.001). In conclusion, the use of occlusion-based positioning guide combined with the fibular cutting guide can enhance the accuracy of mandible reconstruction and functional outcomes.

New Technologies for Personalized Medicine in Head and Neck Oncologic and Reconstructive Surgery

The search for standardized protocols has been a constant concern in Head and Neck Reconstructive Surgery [...]

Clinical Outcomes and Cost Analysis of Fibula Free Flaps: A Retrospective Comparison of CAD/CAM versus Conventional Technique

(1) Background: A decrease in operative time can not only improve patient outcomes through a reduction in the risk of developing complications but can also result in cost savings. The aim of this study is to determine whether there an intraoperative time gain can be achieved by using the preoperative virtual planning of mandibular reconstruction using a free fibula flap compared with freehand plate bending and osteotomies. (2) Methods: A retrospective comparative study was carried out in the Oral and Maxillofacial Department of La Paz University Hospital, Madrid, Spain. The study compared 18 patients in the CAD/CAM group with 19 patients in the conventional freehand group. A comparison was made between the total surgical time, the comorbidities, and the hospital stay. The resource consumption was estimated using a cost analysis. (3) Results: Although CAD/CAM was a statistically more expensive procedure in the perioperative phase, no significant differences were observed in total health care costs between the two groups. There was a non-significant trend towards an increase in complications with conventional reconstruction plates compared to patient-specific plates (PSI). (4) Conclusions: CAD/CAM technology and a 3D printed cutting guide offer a significantly shorter surgical time, which is associated with a reduction in hospital days, PACU days, and complications. The cost of CAD/CAM technology is comparable to that of the conventional freehand technique.

3D Printing and Virtual Surgical Planning in Oral and Maxillofacial Surgery

Compared to traditional manufacturing methods, additive manufacturing and 3D printing stand out in their ability to rapidly fabricate complex structures and precise geometries. The growing need for products with different designs, purposes and materials led to the development of 3D printing, serving as a driving force for the 4th industrial revolution and digitization of manufacturing. 3D printing has had a global impact on healthcare, with patient-customized implants now replacing generic implantable medical devices. This revolution has had a particularly significant impact on oral and maxillofacial surgery, where surgeons rely on precision medicine in everyday practice. Trauma, orthognathic surgery and total joint replacement therapy represent several examples of treatments improved by 3D technologies. The widespread and rapid implementation of 3D technologies in clinical settings has led to the development of point-of-care treatment facilities with in-house infrastructure, enabling surgical teams to participate in the 3D design and manufacturing of devices. 3D technologies have had a tremendous impact on clinical outcomes and on the way clinicians approach treatment planning. The current review offers our perspective on the implementation of 3D-based technologies in the field of oral and maxillofacial surgery, while indicating major clinical applications. Moreover, the current report outlines the 3D printing point-of-care concept in the field of oral and maxillofacial surgery.

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.

Mandible reconstruction with free fibula flaps: Accuracy of a cost-effective modified semicomputer-assisted surgery compared with computer-assisted surgery - A retrospective study

A new individualized, cost-effective, modified semi-computer-assisted surgery (MSCAS) concept for free fibular flap mandibular reconstruction is reported and compared with the computer-assisted surgery (CAS) concept. Patients were divided into two groups and retrospectively reviewed. In the MSCAS and CAS groups, intraoperative guides were created using computer-aided design with manual fabrication and computer-aided design and manufacturing, respectively. Differences in specific linear and angular parameters on pre- and postoperative computed tomography scans were calculated for morphometric comparison, and clinical parameters and efficiency were analysed. RESULTS: Eighteen patients (CAS, 7; MSCAS, 11), were included. The morphometric comparison showed no significant differences between the groups. The mean deviation of the mandibular ramus length, body length, width 1 and width 2 was 0.82 ± 0.29 mm, 1.84 ± 0.43 mm, 1.89 ± 0.61 mm and 1.45 ± 0.61 mm in the CAS group versus 1.56 ± 0.54 mm, 1.72 ± 0.33 mm, 2.24 ± 0.55 mm and 2.36 ± 0.50 mm in the MSCAS group (p = 0.7804, p = 0.9997, p = 0.9814 and p = 0.6334). The mean deviation of the sagittal, axial and coronal mandibular angles was 1.56 ± 0.48°, 1.93 ± 0.50° and 2.15 ± 0.72° in the CAS group versus 2.19 ± 0.35°, 1.86 ± 0.35° and 1.94 ± 0.55° in the MSCAS group (p = 0.7594, p = 0.9996 and p = 0.9871). There were no significant differences in clinical parameters, efficiency or postoperative complications between the groups. CONCLUSION: The accuracy and operative efficiency of the MSCAS concept are comparable to those of the more expensive CAS concept. Therefore, in times of increasing clinical costs, this concept might be an adequate and inexpensive alternative to preoperative CAS.

Institutional-based and commercial virtual surgical planning in maxillomandibular reconstruction - Comparing the digital plan and postoperative scan

BACKGROUND

Virtual surgical planning (VSP) is increasingly used in maxillomandibular osseous free flap reconstruction. Non-commercial ('in-house') VSP may offer the same level of accuracy and other benefits, without the inflated costs and time delays inherent in using commercial providers. Comparisons between commercial and in-house methods are lacking. This study aims to determine the accuracy of VSP, compare in-house and commercially planned cases, and explore predictors of the reconstruction error.

METHODS

Seventy-six patients who had a virtually planned maxillomandibular reconstruction between January 2012 and July 2020 were retrospectively identified. The preoperative digital plan was compared to the postoperative CT scan in terms of length of bone segments, angle between adjacent segments and intercondylar, and intergonial angle distances (mandibular reconstructions only).

RESULTS

Forty-four patients fulfilled the inclusion criteria. The mean intergonial and intercondylar distances error was 1.7 ± 1.01 mm, mean segment length error was 1.3 ± 1.40 mm, and mean angles error was 1.9 ± 2.32°. The difference in error of in-house VSP compared to commercial VSP was not statistically significant for intercondylar and intergonial distance (p = 0.76), segment length (p = 0.15), or angle between segments (p = 0.92). The increased error was associated with osteoradionecrosis as the indication for surgery, greater number of segments, and secondary reconstructions.

CONCLUSION

VSP is an accurate method of maxillary and mandibular reconstruction. In-house VSP may be similar in accuracy to commercial VSP options. Higher levels of inaccuracy are likely to occur in more complex reconstructions, particularly secondary reconstructions, and in the setting of osteoradionecrosis.

Navigation-assisted maxillofacial reconstruction: accuracy and predictability

The aim of this study was to evaluate the accuracy of navigation-assisted maxillofacial reconstruction and to identify the predictors of the clinical outcomes. A total of 112 patients who underwent navigation-assisted maxillofacial reconstruction with free flaps between 2014 and 2019, performed by a single surgical team, were assessed. Accuracy was evaluated by superimposing the postoperative computed tomography data with the preoperative virtual surgical plan. Predictors of the clinical outcomes affecting the accuracy were identified and analysed. The mean deviation and root mean square (RMS) estimate of the orbital, maxillary, and mandibular reconstructions were 0.88 ± 3.25 mm and 3.38 ± 0.73 mm, 0.77 ± 3.44 mm and 3.69 ± 0.82 mm, and 1.07 ± 4.16 mm and 4.67 ± 3.95 mm, respectively (P < 0.05). There was no significant difference in orbital volume or projection between the preoperative, postoperative, and healthy orbits (P = 0.093 and P = 0.225, respectively). Multivariate linear regression analysis confirmed significant associations between the accuracy of navigation-assisted mandibular reconstruction and preservation of the condyle, type of reconstruction, type of osteosynthesis plate, and number of bony segments. Navigation-assisted midface reconstruction yielded a higher level of accuracy in the final surgical outcome when compared to mandibular reconstruction. Computer-assisted techniques and intraoperative navigation can be an alternative or adjunct to current surgical techniques to improve the final surgical outcome, especially in more complex maxillofacial reconstructions.

The Learning Curve of Computer-Assisted Free Flap Jaw Reconstruction Surgery Using 3D-Printed Patient-Specific Plates: A Cumulative Sum Analysis

Background

Computer-assisted jaw reconstruction (CAJR) has benefits in reducing operation time and improving reconstruction accuracy, compared to conventional freehand jaw reconstruction. However, no information is available regarding learning curves in CAJR with the use of 3D-printed patient-specific surgical plates (PSSP). The purpose of this study was to assess surgical outcomes and learning curve for the first 58 consecutive CAJR using 3D-printed PSSP performed by a single surgical team in a single institution.

Methods

In a prospective study, consecutive patients who underwent free flap CAJR using 3D-printed PSSP were included. The determination of proficiency, based on the cumulative sum of surgical success (no major adjustment of 3D-printed PSSP, flap survival) passing the acceptable boundary line of cumulative sum analysis, was the primary outcome. To find out any potential factors influencing the learning curve, baseline characteristics of patients were compared before and after proficiency achievement. Secondary outcomes included inflexion points of the total operation time, blood loss, length of hospital stay, and bone graft deviation, measured by the cumulative sum analysis.

Results

From December 2016 to November 2020, 58 consecutive cases underwent surgery performed by a single surgical team. The overall surgical success rate was 94.8% (55/58). A three-stage learning curve of primary outcome was observed. The proficiency was achieved after 23 cases. The proportions of advanced tumor staging and concomitant surgery after obtaining proficiency were significantly higher than those before achieving proficiency (p = 0.046 and p < 0.001, respectively). Mean values of operation time, intraoperative blood loss, length of hospital stay, and bone graft deviation were 532.5 ± 119.2 min, 1,006.8 ± 547.2 ml, 16.1 ± 6.3 days, and 0.9 ± 1.2 mm, respectively. Two trends of learning curve were observed in the CUSUM analyses of total operation time, length of hospital stay, and bone graft deviation, in which the first and second inflexion points occurred between 8 and 17 cases and between 43 and 46 cases, respectively.

Conclusion

Our results revealed a three-stage learning curve of CAJR with the use of PSSP, including initial learning, plateau, and overlearning. Based on CUSUM analysis, the surgical proficiency was achieved after 23 cases, and total operation time, length of hospital stay, and bone graft deviation stabilized after 8–17 cases.

Computer-Aided Design and Manufacturing versus Conventional Surgical Planning for Head and Neck Reconstruction: A Systematic Review and Meta-Analysis

BACKGROUND

Virtual surgical planning and computer-aided design/computer-aided manufacturing (CAD/CAM) for complex head and neck reconstruction has a number of cited advantages over conventional surgical planning, such as increased operative efficiency, fewer complications, improved osseous flap union, immediate osseointegrated dental implant placement, and superior functional and aesthetic outcomes. The authors performed a systematic review and meta-analysis of the available evidence on CAD/CAM maxillofacial reconstruction with the primary purpose of determining which approach is more efficacious.

METHODS

In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a PubMed and Embase database search was performed to identify English-language, human-subject studies of CAD/CAM-assisted head and neck reconstruction. All comparative studies were included in a meta-analysis to identify differences in operative time, ischemia time, surgical-site occurrence, microvascular complication, and partial or total flap loss between the two groups. All included studies (comparative and noncomparative) were used in the systematic review, summarizing the various flap characteristics, technical nuances, and functional and aesthetic outcomes.

RESULTS

Twelve articles were included in the meta-analysis, representing 277 patients in the CAD/CAM group and 419 patients in the conventional group. CAD/CAM was associated with 65.3 fewer minutes of operating room time (95 percent CI, -72.7 to -57.9 minutes; p < 0.0001) and 34.8 fewer minutes of ischemia time (95 percent CI, -38 to -31.5 minutes; p < 0.0001). There were no significant differences in surgical-site occurrence, nonunion, flap loss, microvascular complications, or hardware-related complications.

CONCLUSIONS

CAD/CAM is associated with shorter operating room and ischemia times. There are no significant differences in flap or hardware-related complications between CAD/CAM and conventional surgical planning.

Short and long-term outcomes of three-dimensional printed surgical guides and virtual surgical planning versus conventional methods for fibula free flap reconstruction of the mandible: Decreased nonunion and complication rates

BACKGROUND

To determine whether virtual surgical planning and three-dimensional printed cutting guides (3D/VSP) improved radiographic bone union compared to conventional methods (CM) in fibula free flap (FFF) reconstruction of the mandibles.

METHODS

Retrospective study from the years 2000-2018 at a tertiary hospital. Osseous union was evaluated by a radiologist blinded to each patient's treatment.

RESULTS

Two hundred sixty patients who underwent FFF tissue transfer, 28 with VSP and 3D cutting guides. Bony union was not achieved in 46 (20%) patients who underwent CM compared to 1 (4%) of patients with VSP and guides (p = 0.036). FFF complication was significantly higher in CM with 87 patients (38%) compared to three patients (11%) in 3D/VSP (p = 0.005). Median time to bony union for patients who underwent CM was 1.4 years compared to 0.8 years in 3D/VSP.

CONCLUSIONS

3D/VSP reduced the rate of radiographic nonunion and flap-related complications in FFF reconstruction for mandibular defects.

Feasibility of the application of mixed reality in mandible reconstruction with fibula flap: A cadaveric specimen study

BACKGROUND

In recent years, a new technology, mixed reality (MR), has emerged and surpassed the limitations of augmented reality (AR) with its inability to interact with hologram. This study aimed to investigate the feasibility of the application of MR in mandible reconstruction with fibula flap.

METHODS

Computed tomography (CT) examination was performed for one cadaveric mandible and ten fibula bones. Using professional software Proplan CMF 3.0 (Materialize, Leuven, Belgium), we created a defected mandibular model and simulated the reconstruction design with these 10 fibula bones. The surgical plans were transferred to the HoloLens. We used HoloLens to guide the osteotomy and shaping of the fibular bone. After fixing the fibular segments using the Ti template, all segments underwent a CT examination. Before and after objects were compared for measurements of the location of fibular osteotomies, angular deviation of fibular segments, and intergonial angle distances.

RESULTS

The mean location of the fibular osteotomies, angular deviation of the fibular segments, and intergonial angle distances were 2.11 ± 1.31 mm, 2.85°± 1.97°, and 7.24 ± 3.42 mm, respectively.

CONCLUSION

The experimental results revealed that slight deviations remained in the accuracy of fibular osteotomy. With the further development of technology, it has the potential to improve the efficiency and precision of the reconstructive surgery.

[Clinical application and accuracy analysis of occlusion-guided functional mandibular reconstruction]

Objective

To investigate the influence of the design and application of novel surgical template on the accuracy of reconstructed mandibula and implant position in occlusion-guided functional mandibular reconstruction, so as to provide guidance for clinical treatment.

Methods

Between January 2017 and May 2019, 11 patients with segmental mandible defects were treated, including 8 males and 3 females with an average age of 31.8 years (range, 19-45 years). There were 6 cases of ameloblastoma, 3 cases of keratocystic tumor, and 2 cases of ossifying fibroma. According to Urken classification of mandible defects, there were 1 case of CRB, 4 cases of RB, 2 cases of RBS, and 4 cases of SB. According to the occlusion relationship, a novel surgical template with the reconstruction titanium plate screws and implants drill-guided information was designed and manufactured. With the help of the novel surgical template, the "one and a half" fibula reconstruction mode was used for jaw functional reconstruction, and the implant supported denture was finally completed. The postoperative CT at 1 week were collected to analyze the morphology of the preoperative virtual design jaw and postoperative jaw. The coincidence of fibular reconstructed mandible (fibular upper barrel, fibular reconstructed ramus and condyle, and whole mandible) and implant in mandible were calculated. When the coincidence was less than 80%, it was considered that the deviation was obvious. Oral panoramic X-ray film and cone beam CT were examined at 6 months after operation to evaluate the osseointegration before implant repair.

Results

None of the 11 flaps had postoperative vascular crisis. One flap occurred necrosis at 1 month after reconstruction combined with 3 implants failed, and had been removed at 6 months after reconstructed surgery; the others had no flap necrosis. One week postoperatively, the coincidence of the fibular upper barrel was 87.55%±3.08%, the whole mandible was 82.68%±5.94%, and the implant in mandible was 88.00%, with significant differences ( t=8.131, P=0.000; t=2.118, P=0.046; Z=4.070, P=0.000) when compared to 80%, respectively. The fibular reconstructed ramus and condyle was 77.82%±3.54%, with no significant difference ( t=-2.042, P=0.068) when compared to 80%. Six months postoperatively, oral panoramic X-ray film and cone beam CT showed that all 22 implants achieved osseointegration and the palatal mucosa transplantation was performed, then finally completed the denture rehabilitation at 6-9 months after operation. All patients were satisfied with their postoperative appearance.

Conclusion

The novel surgical template can guarantee the accuracy of functional mandible reconstruction guided by occlusal guidance, and ultimately achieve the beautiful contour of jaw and occlusal function reconstruction, and improve the patient's life quality.

The Predictive Hole Technique: A Technical Note

We describe a novel technique in which predictive holes, normally unique to patient-specific plates, may be utilized with off the shelf stock plates. This allows for the numerous benefits of predictive holes in mandibular reconstruction while negating the added cost of a custom milled plate. Three case examples are presented for technique illustration.

Sequential application of novel guiding plate system for accurate transoral mandibular reconstruction

OBJECTIVES

The aim of this article is to introduce and share our experience in the sequential use of a novel guiding plate system for accurate mandibular reconstruction via transoral approach and evaluate its clinical effects.

METHODS

Ten patients were operated with transoral mandibulectomy and simultaneous mandibular reconstruction using a novel guiding plate system. Postoperatively, aesthetic assessment and quantitative evaluation were analyzed by measuring the parameters like discrepancy in osteotomy lines, mandibular similarity and symmetry. The independent samples t-test was used and P < 0.05 was considered as significant.

RESULTS

All patients underwent planned transoral surgical procedure successfully. The postoperative aesthetic assessment was rated as excellent. The discrepancy between virtual and actual osteotomy lines, at anterior and posterior regions was 0.80 ± 0.08 and 0.98 ± 0.37 mm, respectively. The postoperative evaluation revealed that mandibular similarity was 0.85 ± 0.03, coronal mandibular angle (CMA) 0.66 ± 0.40, axial mandibular angle (AMA) 1.97 ± 1.25, and sagittal mandibular angle (SMA) 1.97 ± 1.05. There was statistically significant difference in the mean values of osteotomy line discrepancy, mandibular similarity and symmetry, among novel guiding plate and traditional plate groups.

CONCLUSIONS

The novel guiding plate system is a viable and easy-to-use technology for improving the surgical outcomes in patients requiring transoral mandibulectomy and simultaneous mandibular reconstruction by overcoming the problem of limited access due to the presence of lips and cheeks. This can highly improve the precision in osteotomy, fixation of the prebent titanium reconstruction plate, spatial relation transfer, and achieving better symmetry and similarity of mandibular contour.

A surgical navigated cutting guide for mandibular osteotomies: accuracy and reproducibility of an image-guided mandibular osteotomy

PURPOSE

3D-printed cutting guides are the current standard to translate the virtual surgery plan to the intraoperative setting. The production of these patient-specific cutting guides is time-consuming and costly, and therefore, alternative approaches are currently subject of research. The aim of this study was to assess the accuracy and reproducibility of using a novel electromagnetic (EM) navigated surgical cutting guide to perform virtually planned osteotomies in mandible models.

METHODS

A novel 3D navigated cutting guide (dubbed Bladerunner) was designed and evaluated with a total of 20 osteotomies, performed on plaster mandibular models according to preoperative planning using EM navigation. The pre- and postoperative scans were registered, and the difference between the preoperatively planned osteotomy and the performed osteotomy was expressed as the distance between the planned and performed cutting planes, and the yaw and roll angles between the planes.

RESULTS

The mean difference in distance between the planned osteotomy and performed osteotomy was 1.1 mm (STD 0.6 mm), the mean yaw was 1.8° (STD 1.4°), and mean roll was 1.6° (STD 1.3°).

CONCLUSION

The proposed EM navigated cutting guide for mandibular osteotomies demonstrated accurate positioning of the cutting plane according to the preoperative virtual surgical plan with respect to distance, yaw and roll angles. This novel approach has the potential to make the use of 3D-printed cutting guides obsolete, thereby decreasing the interval between diagnosis and surgery, reduce cost and allow for adaptation of the virtual plan in case of rapid tumor proliferation or unanticipated in situ deviations from the preoperative CT/MR imaging.

Three-Dimensionally Printed Patient-Specific Surgical Plates Increase Accuracy of Oncologic Head and Neck Reconstruction Versus Conventional Surgical Plates: A Comparative Study

Background

Surgeons are pursuing accurate head and neck reconstruction to enhance aesthetic and functional outcomes after oncologic resection. This study aimed to investigate whether accuracy of head and neck reconstruction is improved with the use of three-dimensionally (3D)-printed patient-specific surgical plates compared with conventional plates.

Methods

In this comparative study, patients were prospectively recruited into the study group (3DJP16) with 3D-printed patient-specific surgical plates. The patients in control group with conventional surgical plates were from a historic cohort in the same unit. The primary end point of the study was the accuracy of head and neck reconstruction. The secondary end points were accuracy of osteotomy, intraoperative blood loss, total operative time, and length of hospital stay.

Results

The study recruited of 33 patients, including 17 in the study group and 16 in the control group. The patients’ baseline characteristics were similar between the two groups. The absolute distance deviation of the maxilla or mandible was 1.5 ± 0.5 mm in the study group and 2.1 ± 0.7 mm in the control group [mean difference, − 0.7 mm; 95% confidence interval (CI) − 1.1 to − 0.3; p = 0.003], showing superior accuracy of reconstruction for the patients with 3D-printed patient-specific surgical plates. Improved accuracy of reconstruction also was detected in terms of bilateral mandibular angles and bone grafts. Concerning the secondary end points, the accuracy of the osteotomy was similar in the two groups. No difference was found regarding intraoperative blood loss, total operative time, or length of hospital stay.

Conclusions

This is the first study to prove that compared with conventional plates, 3D-printed patient-specific surgical plates improve the accuracy of oncologic head and neck reconstruction.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08732-y) contains supplementary material, which is available to authorized users.

Accuracy of Computer-Aided Design/Computer-Aided Manufacturing-Assisted Mandibular Reconstruction With a Fibula Free Flap

BACKGROUND

The recent increase in computer-aided design and computer-aided manufacturing (CAD/CAM)-assisted surgery has warranted a thorough evaluation of the accuracy of virtual plan execution. Mandibular reconstructions with a fibula free flap were evaluated by comparing the fibular segments postoperatively with the virtual surgical plans.

METHODS

This study included computed tomography data for 20 patients (11 males; mean age 61.3 years, range 47-74) that received a mandibular reconstruction with a fibula free flap. Linear distances (superior and inferior borders) of 41 fibula segments and intercoronoid distances were measured.

RESULTS

The mean difference was 3.11 ± 2.80 mm for superior borders (range 0.02-12.20 mm), and 2.75 ± 2.61 mm for inferior borders (range 0.22-13.58 mm). The mean intercoronoid difference was 3.57 ± 1.80 mm (range 0.91-6.11 mm).

CONCLUSION

This study confirmed the presumed accuracy regarding the use of fibular and mandibular cutting guides. CAD/CAM is an attractive technique which enhances efficiency and assurance during surgery and preoperative planning.

Digital planning workflow for partial maxillectomy using an osteotomy template and immediate rehabilitation of maxillary Brown II defects with prosthesis

BACKGROUND

There is increasing evidence of benefits for the rehabilitation of Brown II defects with prosthesis in surgery. However, the current literature is sparse for maxillary tumour resection using osteotomy templates.

OBJECTIVES

To assess the accuracy of maxillectomy using a custom fabricated osteotomy template and to evaluate the prosthesis for surgical accuracy, appearance and functioning (speech, swallowing and occlusal force).

METHODS

Ten patients with Brown II defects caused by tumour resection were treated with precise partial maxillectomy using an osteotomy template. The immediate rehabilitation of the Brown II defect was completed with a prefabricated prosthesis. The post-operative three-dimensional images and the pre-operative virtual images were superimposed, and average deviation and maximum deviation were calculated. Speech intelligibility, swallowing, appearance and University of Washington Quality of Life Questionnaire (UW-QoL) were examined at 1, 3 and 6 months after surgery. Occlusal force was examined post-operatively at 6 months.

RESULTS

The maximum deviation between the actual and virtual surgery was 5.12 ± 0.44 mm, with an average of 1.02 ± 0.17 mm. Speech intelligibility, swallowing and UW-QoL improved significantly (P < .05) after wearing the prosthesis. The recovery index of the occlusal force on the affected side was 20.19%-32.28%. The skewed degree of the mouth corner, the difference in the height of the left and right lips, the maximum deviation distance and the change area volume decreased significantly (P < .05).

CONCLUSION

The precise rehabilitation of maxillary Brown II defects can be achieved using a prosthesis fabricated with an osteotomy template. The prosthesis restored appearance and functional capabilities (such as speech and occlusal force).

Virtual surgical planning in fibula free flap head and neck reconstruction: A systematic review and meta-analysis

BACKGROUND

The traditional approach to head and neck reconstruction is considered challenging, requiring a subjective assessment of an often-complex defect followed by careful modelling of a bony flap to match this. The introduction of Virtual Surgical Planning (VSP) has provided the surgeon with a means to increase efficiency, precision and overall patient outcomes. This study aims to compare VSP and traditional head and neck reconstructions utilising fibula free flaps with regards surgical efficiency and patient outcomes.

METHODS

A systematic search of the PubMed and Medline databases was performed from the date of their inception through to August 2018 to evaluate and compare VSP and non-VSP cohorts in the context of fibula free flap head and neck reconstruction. Primary comparative outcomes included operative and ischaemic time, with secondary outcomes including complications rates, measures of accuracy and financial benefits.

RESULTS

One hundred and fifty-three articles were identified. Twenty-three articles were included in the review, comprising a total of 713 patients. VSP was associated with significantly decreased intraoperative time (Standardised Mean Difference -1.01; 95% CI -1.23 to 0.80; p = 0.000) and ischaemic time (Standardised Mean Difference -1.55; 95% CI -1.87 to -1.23, p = 0.002). VSP was also associated with reduced orthognathic deviation from an ideal outcome when compared to conventional techniques. No statistically significant differences in complication rates between conventional and VSP techniques were identified.

CONCLUSION

The results of this meta-analysis suggests that VSP confers significant benefits with respect to improved orthognathic accuracy, ischaemic times and intraoperative times without any significant increase in complications. Recommendations for ongoing research are suggested.

The Biaxial Double-Barrel Fibula Flap-A Simplified Technique for Fibula Maxillary Reconstruction

PURPOSE

Previously described techniques for microvascular fibula reconstruction of Brown Class II to IV maxillectomy defects are complex, require multiple osteotomies, result in a short pedicle, and inadequately reconstruct the dental alveolus in preparation for endosseous implants. This report describes a simplified technique for Brown Class II to IV defects that re-creates facial support, allows for dental reconstruction with appropriately positioned implants, and maintains adequate pedicle length.

MATERIALS AND METHODS

A retrospective chart review was performed of all patients with Brown Class II to IV maxillectomy defects immediately reconstructed with a biaxial double-barrel fibula flap technique. The reconstructive surgeon evaluated each patient at least 1 month after reconstruction for enophthalmos, facial symmetry, nasal patency, satisfactory jaw position, deglutition, intelligible speech, and intraoperative need for vein grafting.

RESULTS

The sample was composed of 6 patients (mean age, 54 yr; range, 33 to 78 yr; 67% women) who underwent reconstruction with the biaxial double-barrel fibula flap technique for Brown Class II to IV defects. None of these patients required vein grafting. None of these patients had flap failure. Diagnoses for these patients were a hybrid odontogenic tumor (n = 1), squamous cell carcinoma (n = 3), adenoid cystic carcinoma (n = 1), and sinonasal melanoma (n = 1). All 6 patients had excellent facial contour and malar projection, regular oral intake, 100% intelligible speech, and a new maxillary skeletal Class I relation without need for intraoperative vein grafting. One patient developed enophthalmos related to inferior rectus sacrifice and removal of orbital fat. Complications included development of nasal synechia and occlusion of the maxillary sinus ostium (n = 1).

CONCLUSIONS

The biaxial double-barrel fibula flap technique achieves the goals of providing adequate facial support and an alveolar segment amenable to implant dentistry. It allows for intelligible speech, deglutition, orbital support, and separation of the oronasal, orbital, and sinus cavities. In addition, it minimizes the need for vein grafting.

Accuracy of computer-assisted surgery in mandibular reconstruction: A systematic review

Computer-assisted surgery (CAS) for mandibular reconstruction was developed to improve conventional treatment methods. In the past years, many different software programs have entered the market, offering numerous approaches for preoperative planning and postoperative evaluation of the CAS process of mandibular reconstruction. In this systematic review, we reviewed planning and evaluation methods in studies that quantitatively assessed accuracy of mandibular reconstruction performed with CAS. We included 42 studies describing 413 mandibular reconstructions planned and evaluated using CAS. The commonest software was Proplan/Surgicase CMF (55%). In most cases, the postoperative virtual 3-dimensional model was compared to the preoperative 3-dimensional model, revised to the virtual plan (64%). The commonest landmark for accuracy measurements was the condyle (54%). Accuracy deviations ranged between 0 mm and 12.5 mm and between 0.9° and 17.5°. Because of a lack of uniformity in planning (e.g., image acquisition, mandibular resection size) and evaluation methodologies, the ability to compare postoperative outcomes was limited; meta-analysis was not performed. A practical and simple guideline for standardizing planning and evaluation methods needs to be considered to allow valid comparisons of postoperative results and facilitate meta-analysis in the future.