A new classification for mandibular defects after oncological resection

Retrospective study of morphological and functional analysis of mandibular reconstructions using iliac and fibular flaps

OBJECTIVE

This retrospective study aims to evaluate and compare the morphological and functional characteristics of mandibular reconstructions performed using iliac and fibular flaps to determine their respective effectiveness and identify the technique that offers the best patient outcomes.

METHODS

Medical and imaging data were analysed from pre- and post-operative scans of 121 patients (84 with iliac flaps and 37 with fibular flaps). Mandibular reconstructions were assessed by comparing morphometric parameters (distances and angles) and symmetry between the affected and unaffected sides using Mimics software. The quality of life of patients was assessed using a modified version of the University of Washington Quality of Life Questionnaire (UW-QOL), version 4, which evaluates functional and psychosocial outcomes in head and neck cancer treatment RESULTS: The results show that the iliac group demonstrates significantly superior performance for distances D2 and D3 and for the CA angle on the unaffected side. In contrast, the fibular group shows no significant advantage in these parameters. Regarding symmetry, the iliac group achieves better results for distance D3, whereas the fibular group excels in angular measurements. Additionally, the iliac group maintains better stability for angle B. Regarding bone dimensions, the iliac flap better preserves alveolar base height (ABH) and width (ABW), providing more consistent and favorable outcomes than the fibular flap.No overall difference was observed between the two groups regarding quality of life (assessed using the UW-QOL questionnaire). However, specific variations were noted: the fibular group scores higher for pain, activity, and recreation, while the iliac group achieves better results in appearance and speech.

CONCLUSION

The iliac flaps are the preferred option for mandibular reconstruction, offering superior morphometric stability, better preservation of bone dimensions, and more robust structural consistency than fibular flaps. Although both techniques yield comparable overall quality-of-life results, iliac flaps demonstrate more pronounced clinical benefits, leading to optimal postoperative outcomes.

Vascularized iliac crest free flap in maxillofacial reconstruction: Pearls and pitfalls from 437 clinical application

OBJECTIVE

The vascularized iliac crest free (VICF) flap has been a cornerstone in maxillofacial reconstruction for decades. This study aims to provide a framework for guiding and managing maxillofacial reconstruction using the VICF flap, highlighting key techniques and potential pitfalls to optimize outcomes and reduce practice variability.

METHODS

A retrospective review was conducted on 437 patients (439 flaps) who underwent maxillofacial reconstruction with VICF flaps. The study summarized current practices, challenges, and strategies for successful flap application. Data were collected from electronic medical records and postoperative follow-ups.

RESULTS

The overall success rate of VICF flap transplantation was 98.4 %. Of the 439 VICF flaps, 37 were myo-osteocutaneous, 47 were myo-osseous, and 355 were osseous. Computer-assisted techniques (CATs) were used in 64.5 % (282/437) of cases. The average University of Washington Quality of Life score was 83.38, and the Harris Hip Score averaged 93.34. The incidence of serious complications was low, with 6 % (17/285) of patients reporting moderate-to-severe pain and 8.4 % (24/285) experiencing incisional hernia. Additionally, 11.9 % (34/285) of patients have completed implant-supported restoration.

CONCLUSION

VICF flaps offer significant morphological advantages and ample bone quantity for reconstruction; however, they are associated with some postoperative complications. With advancements in CAT and the application of chimeric perforator flaps, VICF can be successfully used to address most maxillofacial defects, including those caused by benign and malignant tumors in the neck, especially in cases with good vascular supply.

Unleashing the potency of multi-segmental DCIA flap in mandibular reconstruction with the aid of virtual surgery- A retrospective cohort study

Although the deep circumflex iliac artery (DCIA) flap is a mainstay in mandibular reconstruction, its multi-segmental utilization is infrequently reported, primarily due to concerns regarding the variable cutaneous component and potentially inadequate vascular supply to multi-block segments. This retrospective study analyzed the outcomes of 86 patients undergoing mandibular reconstruction with multi-segmental DCIA flaps, compared to 167 patients who received conventional single-segmental flaps. The survival rate for multi-segmental flaps was comparable to that of single-segmental flaps (100% vs. 98.2%, p = 0.553). Multi-segmental flaps were used to reconstruct longer bony defects (median: 9 cm vs. 6.5 cm, p < 0.001). Despite the longer operation times in the multi-segmental group (368.8 vs. 326.8 min, p < 0.001), there was no significant increase in the incidence of surgical complications. Furthermore, postoperative QoL and Harris Hip scores did not show significant differences, despite the increased graft lengths and segmentation in the multi-segmental group. The study underscores the underrecognized efficacy of multi-segmental DCIA flaps in complex mandibular reconstructions, particularly for specific types of defects such as Brown III, Brown I (Ic), and Brown II (IIc), which can be effectively and reliably reconstructed with the aid of virtual surgical techniques. This research also confirms that concerns regarding soft tissue management with multi-segmental DCIA flaps can be effectively addressed.

Marginal Mandibulectomy in Oral Cavity Cancers - Classification and Indications

Squamous cell carcinoma of the lip and oral cavity (OSCC) is a significant global health issue, particularly in low-income countries, with an estimated 390,000 cases detected annually. Although surgery remains the primary treatment option, complex resections are frequently required to attain clear margins. Traditionally, a part of the jaw bone close to the tumour is resected (segmental mandibulectomy) during the surgery. However, marginal mandibulectomy (MM), involving the resection of the mandibular rim while preserving its continuity, offers a less debilitating alternative to segmental mandibulectomy (SM) in selected cases. This review examines marginal mandibulectomy's oncological safety and efficacy and its current role in managing oral cavity cancers, as indicated by the most recent literature. MM is an effective treatment for tumours, which abut the mandible without bone invasion and provides comparable oncological outcomes to SM, with fewer functional and cosmetic deficits. The authors also propose a classification based on the plane of resection and location within the mandible. We believe this classification will be helpful in reporting the MM series done in various centres in a uniform fashion. However, there is a need for precise surgical planning before doing an MM for obtaining the optimal results.

Comparative Evaluation of Symmetrical Titanium and Polyetheretherketone (PEEK) Hollow Structures for Mandibular Reconstruction: Strength, Geometry, and Biomechanical Performance

This study introduces a novel titanium hollow structure for mandibular reconstruction designed to optimize mechanical stability and stress distribution. A comparative evaluation with a similar polyetheretherketone (PEEK) structure is performed to assess material-specific biomechanical behavior. Methods: Finite element analysis (FEA) simulations were conducted to evaluate stress distribution, displacement, and structural stability of the symmetrical titanium and PEEK hollow structures under physiological conditions. The reconstructions were designed based on Scherk minimal surfaces, integrating fixing plates to achieve optimal mechanical performance while maintaining symmetry. Results: The FEA simulations demonstrated that the titanium hollow structure exhibited higher mechanical stability, lower displacement, and more uniform stress distribution, ensuring structural integrity under applied forces. In contrast, the PEEK structure displayed greater flexibility, which reduced stress shielding but resulted in higher deformation and lower load-bearing capacity. While titanium inherently supports osseointegration, PEEK requires surface modifications to enhance bone integration and long-term stability. Conclusions: The titanium hollow structure presents a promising advancement in metal-based mandibular reconstruction, effectively balancing strength, durability, and biological integration. Future research should focus on using more structures, enhancing surface modifications and optimizing lattice structures to further improve the biological and biomechanical performance of PEEK-based and titanium-based implants in load-bearing conditions.

A Comparative Study of Speech and Swallowing Postoperative Outcomes in Oral Cancer: Impact of Lateral Mandibular Continuity Restoration

BACKGROUND

Surgical resection with mandibulectomy in advanced oral cancer results in complex defects. The influence of reconstruction of mandibular continuity on postoperative speech and swallowing function, though crucial, is not widely studied.

PURPOSE

The purpose of study was to compare the speech and swallowing outcomes of oral squamous cell carcinoma (OSCC) patients with lateral mandibulectomy, with or without the restoration of mandibular continuity.

STUDY DESIGN, SETTING, SAMPLE

This retrospective cohort study was performed at the Malabar Cancer Centre, Kerala, India, on patients who had undergone lateral mandibulectomy for OSCC from January 2016 to December 2021. Patients with recurrent or second primary OSCC, or with psychiatric disorders and cognitive impairment, or in whom any type of glossectomy was done, were excluded from the study.

PREDICTOR VARIABLE

The predictor variable was reconstruction status of mandibular continuity, coded as yes when it is restored and no for vice-versa.

MAIN OUTCOME VARIABLE(S)

The outcome variables were postoperative speech outcome measured with a 7-point rating speech intelligibility scale and swallowing outcome measured with functional oral intake scale.

COVARIATES

Covariates included age, sex, tumor subsite, mandibular defect, and adjuvant treatment.

ANALYSES

Data analyses included χ2, Fisher's exact test, independent t test, Spearman's correlation test, and one-way analysis of variance test. P values < .05 were considered statistically significant.

RESULTS

The study sample had 201 patients, with continuity restored in 74 (36.82%) patients and vice versa in 127 (63.18%) patients. The mean age in the continuity restored group was 54.97 ± 9.68 years, and in the continuity not restored group, it was 59.49 ± 9.95 years (P < .05). Both the groups had more male patients (P = .15). The speech scores in both groups at 1 month (P = .66), 3 months (P = .45), and 6 months (P = .33) of postoperative period were compared and had no statistically significant difference. The swallowing scores in groups at 1 month (P = .5), 3 months (P = .5), and 6 months (P = .7) of postoperative period were also compared and had no statistically significant difference.

CONCLUSION AND RELEVANCE

Reconstruction of lateral mandibular continuity was not associated with improved postoperative speech and swallowing.

Mandibular Reconstruction Modalities Using Virtual Surgical Planning and 3D Printing Technology: A Tertiary Care Centre Experience

Introduction

Mandibular reconstruction is often challenging. However, the revolution of computer-assisted design and computer-assisted manufacturing (CAD/CAM), virtual surgical planning (VSP) and 3D printing technology have changed this notion.

Patients and Methods

In this article, we have described six case scenarios where various aspects of VSP and 3D printing technology have been utilized for complex mandibular reconstruction procedures, to provide the patients with the best possible outcome in terms of form, function, and aesthetics.

Discussion

Virtual planning for tumour resection and fibula osteotomies and 3D printing of cutting guides and stereolith models have changed the face of mandibular reconstruction techniques. Increased accuracy, rehabilitation of normal anatomical configuration, appropriate dental rehabilitation, decreased intra-operative time and post-operative complications are some of the advantages. In addition, patient-specific implants eliminate the need for a separate donor site. 3D printed titanium cribs or meshes not only provide robustness, but also incorporates additional features that enable bone graft placement and excellent dental rehabilitation.

Conclusion

These modalities show promising results for reconstruction of complex mandibular defects.

A non-metallic PEEK topology optimization reconstruction implant for large mandibular continuity defects, validated using the MANDYBILATOR apparatus

In cases of large mandibular continuity defects resulting from malignancy resection, the current standard of care involves using patient-specific/custom titanium reconstruction plates along with autogenous grafts (fibula, scapula, or iliac crest segments). However, when grafts are not feasible or desired, only the reconstruction plate is used to bridge the gap. Unfortunately, metal osteosynthesis and reconstruction plates, including titanium, exhibit adverse effects such as stress-shielding and limitations in accurate postoperative irradiation (especially with proton-beam therapy). To address these issues, in this study we explore, develop and validate a non-metallic solution: a topology-optimized polyetheretherketone (PEEK) load-bearing implant for large non-grafted mandibular continuity defects. In order to thoroughly validate the developed PEEK reconstruction, a dedicated MANDYBILATOR testing apparatus was developed. Using the MANDYBILATOR finite element analysis results of the implant were confirmed and the PEEK implant was mechanically validated for both static and dynamic loading. Results show that the PEEK reconstructed mandible is comparably strong as the unreconstructed mandible and is unlikely to fail due to fatigue. Our PEEK implant design has the mechanical potential to act as a substitute for the current titanium plates used in the reconstruction of continuity defects of the mandible. This may potentially lead to optimised patient-specific reconstructions, with the implants matching the bone's stiffness and possessing radiolucent properties which are useful for radiographic follow-ups and radiotherapy. Furthermore, the addition of the dynamic/cyclic MANDYBILATOR apparatus allows for more realistic application of the in-vivo loading of the mandible and can provide added insights in biomechanical behaviour of the mandible.

Optimized design for using of double-barrel vascularized fibular flap in various types of mandibular defects

Background/purpose

The functional and aesthetic reconstruction of the mandible can be achieved by using the double-barrel vascularized free fibula flap. The purpose of this study was to use multiple integrated techniques to more effectively reconstruct the mandible, some contains of our unique ideas.

Materials and methods

21 patients were included in this study. Computed tomography (CT) data of the patient's mandible and fibula were acquired preoperatively. Individualized surgical simulation was performed by using computer-aided surgical simulation (CASS) technology, about 6 kinds of integrated 3D design ideas were simultaneously perfectly transferred to real surgery. The accuracy of reconstruction was evaluated by superimposing the postoperative and preoperative image of mandible, measuring the linear and angular deviation of landmarks between the planned and actual outcomes.

Results

The mandibular reconstruction was effectively performed on all patients, and the result analysis showed that the surgical plan was precisely performed. The facial contours of the postoperative patients were harmonized and the largest mean linear and angular differences were 1.47 ± 0.31 mm and 3.97 ± 0.63°, respectively.

Conclusion

This study system illustrates how to select and position the fibula for reconstruction of various types of segmental mandibular defects by using double-barrel vascularized free fibula flap. It will provide valuable guidance and enhance the accessibility and efficiency of mandibular defects treatment.

A new approach for vertical bone augmentation: Reconstructing bony peaks before GBR with a customized titanium mesh

This image article presents a single patient receiving a reconstructed fibular bony peak (BP) for guided bone regeneration (GBR) with a customized titanium mesh. The patient was informed and understood the objectives and signed a written informed consent document before surgery.

Mandibular Reconstruction with Osseous Free Flap and Immediate Prosthetic Rehabilitation (Jaw-in-a-Day): In-House Manufactured Innovative Modular Stackable Guide System

Background: Head and neck reconstruction following ablative surgery results in alterations to maxillofacial anatomy and function. These postoperative changes complicate dental rehabilitation. Methods: An innovative modular, stackable guide system for immediate dental rehabilitation during mandibular reconstruction is presented. The virtual surgical planning was performed in Materialise Innovation Suite v26 and Blender 3.6 with the Blenderfordental add-on. The surgical guides and models were designed and manufactured at the point of care. Results: The duration of the surgery was 9 h and 35 min. Good implant stability (>35 Ncm) and a stable occlusion were achieved. After 9 months of follow-up, the occlusion remained stable, and a mouth opening of 25 mm was registered. The dental implants showed no signs of peri-implant bone loss. Superposition of the preoperative planning and postoperative position of the fibula parts resulted in an average difference of 0.70 mm (range: -1.9 mm; 5.4 mm). Conclusions: The in-house developed stackable guide system resulted in a predictive workflow and accurate results. The preoperative virtual surgical planning was time-consuming and required extensive CAD/CAM and surgical expertise. The addition of fully guided implant placement to this stackable guide system would be beneficial. More research with longer follow-ups is necessary to validate these results.

Role of residual mandibular teeth after computer-assisted mandibular reconstruction using a fibular flap

Background

Computer-assisted mandibular reconstruction after mandibulectomy enables accurate reconstruction of the occlusal positions between the maxilla and mandible. Understanding the remaining teeth condition is essential for sensory mastication in patients with numerous tooth loss. However, no studies have examined the dental status of the remaining mandible after computer-assisted mandibular reconstruction using a fibular flap. This study evaluated the role of residual teeth and other factors in effective acquisition of oral intake after computer-assisted mandibular reconstruction using a fibular flap.

Patients and Methods

Postoperative oral intake and associated factors were retrospectively examined in 57 consecutive patients. Oral intake was assessed using the Functional Oral Intake Scale. Multivariate analysis was performed to evaluate the remaining teeth arrangement (Eichner's classification), mandibular dentures, extent of resection (Brown's classification), age, performance of glossectomy, history of radiation therapy, and computer-assisted methods.

Results

Multivariate analysis revealed that Eichner's classification had a positive (p<0.001) and radiation therapy had a negative (p<0.05) impact on oral intake. The patients with dentures anchored to the remaining teeth in the occlusal support area (i.e., premolar and molar) had higher Functional Oral Intake score than those with dentures anchored to the remaining teeth in the non-occlusal support area (6.78±0.03 vs. 6.10±0.07, p<0.005).

Conclusion

In computer-assisted mandibular reconstruction with accurate occlusion, the residual teeth in the occlusal support area are essential for good postoperative oral intake with dentures. During mandibulectomy, if oncologically acceptable, these teeth should be preserved, and selective placement of dental implants in the occlusal support area should be considered.

Functional Rehabilitation in Non-Reconstructed Hemimandibulectomy Patients

Background and Objectives: Functional rehabilitation in patients with hemimandibulectomy remains a challenge no matter what method of reconstruction is chosen by physicians. In this paper, we aim to evaluate the feasibility of an acceptable occlusal restoration in patients who have undergone hemimanidublectomy without the reestablishment of mandibular continuity. Materials and Methods: Data were collected retrospectively on 10 patients with varying degrees of mandible resection. The greatest challenge in the restoration of an acceptable occlusion form is the natural latero-deviation that occurs in patients whose mandibular continuity was not restored. This causes an unbalanced and uncoordinated occlusal plane. Based on our research, this deviation is highly dependent on three main factors: the presence of teeth (which allow for a proprioceptive stimulus that counteracts the deviation), the extension of the defect and the presence or lack of the coronoid process. Results: Based on the presence of dental elements or lack thereof, patients were either rehabilitated with implant-supported dentures or removable partial dentures. Although the gold standard of care for these patients remains the restoration of mandible continuity through use of bone grafts, an acceptable rehabilitation of occlusion and therefore function may be acquired in non-grafted patients. Conclusions: Both physicians and patients must manage their expectations carefully and be eager to find a compromise to provide the best possible solution given the challenges of the premises.

Loop-Neurorrhaphy Technique for Preventing Bone Resorption and Preserving Sensation in Mandibular Reconstruction

BACKGROUND

The aim of this study was to investigate whether using an innervated vascularized iliac bone flap could effectively prevent bone resorption and maintain sensory function in the lower lip.

METHODS

In the innervated group, the deep circumflex iliac artery and recipient vessels were anastomosed, with simultaneous microanastomosis of ilioinguinal nerve, mental nerve, and inferior alveolar nerve. Conversely, the control group underwent solely vascular anastomosis. Computed tomography was used to assess bone quality. Sensory recovery of the lower lip was recorded using 2-point discrimination and current perception threshold testing.

RESULTS

The study comprised a total of 40 subjects, with each group accounting for 20 participants, equally distributed in terms of gender. Hounsfield unit loss was significantly lower in the innervated group (13.26% ± 8.65%) as compared with the control group (37.98% ± 8.60%) ( P < 0.001). Moreover, 2-point discrimination values were lower in the innervated group (15.11 ± 8.39 mm) when compared with the control group (21.44 ± 7.24 mm) ( P = 0.02). The current perception threshold values for the innervated group were 176.19 ± 31.89, 64.21 ± 19.23, and 42.29 ± 18.96 at 2 kHz, 250 Hz, and 5 Hz, respectively, whereas in the control group, the current perception threshold values were 204.47 ± 36.99, 82.26 ± 27.29, and 58.89 ± 25.38 at 2 kHz, 250 Hz, and 5 Hz ( P = 0.02, P = 0.02, and P = 0.03, respectively).

CONCLUSION

The innervated vascularized iliac bone flap represents a safe and effective novel approach to preserving lower lip sensation and preventing bone resorption through functional mandibular reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

Comparison of reconstruction plates and miniplates in mandibular defect reconstruction with free iliac flap

OBJECTIVE

Given the increasing demand for precise and reliable reconstructive techniques in maxillofacial surgery, we try to offer valuable insights for clinicians in selecting optimal fixation methods.

MATERIALS AND METHODS

Patients were categorized into miniplate and reconstruction plate groups for accuracy and bone healing comparison. We measured gonial angle, intercondylar, intergonial and anterior-posterior distance for general accuracy and distance of segmental endpoint to the sagittal plane for partial accuracy. The bone healing rate of the two groups was compared with CT images at 3, 6 and 12 months after operation.

RESULT

Considering directional indicators, the miniplate group exhibited a wider intercondylar distance than the reconstruction plate group (p = 0.029). At 6 months postoperatively, the miniplate group demonstrated a higher bone healing rate compared to the reconstruction plate group, with no significant differences at other time points.

CONCLUSION

Over a nearly 5-year review, mandibular reconstruction with vascularized iliac bone flaps showed that reconstruction plates better maintained condylar position accuracy, while miniplates had superior bone healing rates at 6 months. No significant differences were found in other accuracy indices between the two plates.

CLINICAL RELEVANCE

Clinicians' selection of fixation plates frequently depends on personal preference rather than evidence-based criteria. This study compares the precision and postoperative osseous healing outcomes of miniplates and reconstruction plates to provide a more scientifically grounded basis for clinical decision-making.

Rotational path removable partial mandibular resection prostheses: A case series of patients with mandibular symphyseal defects

Rotational path removable partial mandibular resection prostheses (MRPs) offer advantages in the management of patients with acquired symphyseal defects of the mandible, including enhanced esthetics achieved through a reduced number of clasps, the provision of rigid retainers less prone to distortion compared with flexible alternatives, and the ability to engage prominent proximal undercuts in patients lacking buccal undercuts. Additionally, removable partial MRPs represent a suitable treatment option in scenarios where the cost of implant-retained prostheses is prohibitive or in patients where implant therapy is contraindicated, such as those with a history of head and neck radiation. While the use of rotational path removable prostheses has been well documented in conventional prosthodontics, its application in maxillofacial prosthetics remains less explored. This case series describes 3 patients, all of whom underwent mandibular resections involving the mandibular symphysis and subsequently received prosthetic rehabilitation incorporating rotational path removable partial MRPs.

Reliabilities of three methods used to evaluate computer-assisted mandibular reconstructions using free fibula flaps

Objective

This study compared the reliabilities of three different methods used to calculate surgical deviations after mandibular reconstructions using free fibular flaps.

Study design

This retrospective study involved 35 patients who underwent computer-assisted mandibular reconstructions using free fibula flaps. The deviations between the virtual surgical plans and the postoperative results were independently analyzed by two researchers using three distinct methods. In Method A, the fibular axis, the center of gravity, and the osteotomy plane served as landmarks when measuring surgical deviations. In Methods B and C, manually designated points were used to measure errors in the fibular length and intersegmental angle. The primary outcome variables were the intraclass correlation coefficients (ICCs) that revealed the inter-rater agreements for all three methods.

Results

The use of Method A was associated with good agreement in terms of the fibular length deviation (ICC = 0.765) and intersegmental angle (ICC = 0.897); both were higher than those afforded by Methods B (ICC = 0.158 and 0.108) and C (ICC = 0.406 and 0.463). The measurements of the fibular transfer osteotomy deviation (ICC = 0.888), linear deviation (0.926), and angular deviation (0.958) were very reliable.

Conclusions

Method A afforded the highest reliability in clinical practice when evaluating surgical deviations after mandibular reconstruction using fibular flaps.

Factors associated with mandibular deviation and proposed classification and treatment guidelines for applying mandibular guidance: A retrospective analysis of 185 patients with segmental mandibulectomy

STATEMENT OF PROBLEM

Mandibular guidance therapy is the preferred treatment for patients with segmental mandibulectomy after oncological surgeries. Clinicians face difficulty in decision making and delivering appropriate prosthetic treatment for the rehabilitation of these patients because of the lack of published information.

PURPOSE

The purpose of this retrospective analysis was to evaluate the factors associated with mandibular deviation and to introduce a classification system of mandibular deviation and prosthetic guidelines for rehabilitating patients with segmental mandibulectomy using a mandibular guidance appliance (MGA).

MATERIAL AND METHODS

A total of 185 patients with segmental mandibulectomies without bony reconstruction were evaluated from July 2019 to July 2022 for factors affecting the mandibular deviation and the feasibility of rehabilitating these patients with various types of MGA. Patients reconstructed with a free fibula osteocutaneous flap and those who underwent marginal mandibulectomies without mandibular deviation were excluded from the analysis. Based on the extent of mandibular deviation, the condition of oral tissues, and the functional activity, patients were classified into 1 of 5 classes and treated with an appropriate MGA. Data were analyzed with the Kruskal-Wallis and Fisher exact tests (α=.05).

RESULTS

Of 185 patients, 45 (24.3%) showed no mandibular deviation and were classified into class I without the need for a guidance appliance; 114 (61.6%) showed mild mandibular deviation, were classified into class II, and were treated with a mandibular guide plane prosthesis (MGPP); 7 (3.8%) showed moderate mandibular deviation, were classified into class III, and were treated with a progressive mandibular guide plane prosthesis (Progressive MGPP); 5 (2.7%) showed severe mandibular deviation with fibrosis, were classified into class IV, and were treated with an occlusal ramp prosthesis; and 14 (7.6%) showed compromised oral conditions, were classified into class V, and did not receive any type of MGA. Patients with M0, poorly differentiated squamous cell carcinoma and those who had received radiotherapy showed more mandibular deviation (P<.05). The degree of mandibular deviation increased from Class I to Class IV and was significantly associated with the time gap between surgical intervention and MGA delivery (P<.05).

CONCLUSIONS

Radiotherapy and delay in delivering the MGA had a significant effect on mandibular deviation. The proposed classification and prosthetic guidelines were based on the mandibular deviation and will help clinicians in decision making and planning treatment before delivering the MGA.

Jaw in a day surgery: early experience with 19 patients at an Australian tertiary referral center

BACKGROUND

The Jaw-in-a-Day (JIAD) procedure aims to achieve immediate functional occlusion via a single-stage approach to maxillofacial reconstruction. While JIAD has gained popularity since its inception by Levine and colleagues, efficacy and outcome data remain limited. In this report, we discuss our experience with the JIAD technique at an Australian tertiary referral centre.

METHODS

A retrospective review of all JIAD procedures performed from April 2022 to December 2023 was conducted. Clinicopathologic data reviewed included demographic information, primary diagnosis, anatomical site of disease, and history of pre-operative radiotherapy. Outcome measures of interest included operative time, number of implants placed, post-operative complications and implant survival.

RESULTS

Nineteen patients were identified for the study. Two maxillary and 17 mandibular JIAD procedures were performed. The most common indications were squamous cell carcinoma (n = 8) and ameloblastoma (n = 5). Surgical complications included recipient site wound infection (n = 3), flap dehiscence (n = 2), haematoma formation (n = 1), and neck abscess associated with partial flap failure (n = 1). No total flap failures were identified. Of the 55 total implants placed, one implant failure occurred 2-months post-operatively. No loss of irradiated implants (n = 21) was observed. The median time to adjuvant radiotherapy was 57 days (range, 32-61). Eighteen of 19 patients (95%) achieved immediate dental rehabilitation, and 15/19 patients (79%) retained a functional prosthesis by the end of the follow-up period.

CONCLUSIONS

Our series supports the feasibility of single-stage reconstruction for both benign and malignant indications. Further research is required to understand the long-term functional, aesthetic, and health-related quality-of-life outcomes with the JIAD technique.

Multi-factor early monitoring method based on D-dimer for iliac crest flap loss

BACKGROUND

In recent years, the utilization of autogenous vascularized iliac crest flap for repairing jaw defects has seen a significant rise. However, the visual monitoring of iliac bone flaps present challenges, frequently leading to delayed detection of flap loss. Consequently, there's a urgent need to develop effective indicators for monitoring postoperative complications in iliac crest flaps.

METHODS

A retrospective analysis was conducted on 160 patients who underwent vascularized iliac crest flap transplantation for jawbone reconstruction from January 2020 to December 2022. We investigated the changes in D-dimer levels among patients with or without postoperative complications. Additionally, multivariable logistic regression analysis was performed to explore potential individual risk factors, including surgical duration, age, pathology type, absolute and relative D-dimer levels, and gender, culminating in the development of a nomogram.

RESULTS

On the first day following surgery, patients who experienced thrombosis exhibited a substantial increase in plasma D-dimer levels, reaching 3.75 mg/L, 13.84 times higher than the baseline. This difference was statistically significant (P < 0.05) compared to patients without postoperative complications. Furthermore, the nomogram we have developed and validated effectively predicts venous thrombosis, assigning individual risk scores to patients. This predictive tool was assessed in both training and validation cohorts, achieving areas under the curve (AUC) of 0.630 and 0.600, with the 95% confidence intervals of 0.452-0.807 and 0.243-0.957, respectively.

CONCLUSIONS

Our study illustrates that postoperative plasma D-dimer levels can serve as a sensitive biomarker for monitoring thrombosis-induced flap loss. Moreover, we have developed a novel prediction model that integrates multiple factors, thereby enhancing the accuracy of early identification of patients at risk of thrombosis-associated flap loss. This advancement contributes to improving the overall management and outcomes of such procedures.

Current Concepts of Ablative Surgery in Oral Cavity Cancer

Introduction

Ablative surgery has evolved over the years with the attempt to extirpate the tumor in its entirety with the understanding of the molecular tumor biology, pattern of tumor invasion of the tumors, as well as availability of better instrumentations.

Materials and Methods

Subset-based evaluation and management of oral cancer.

conclusion

For oral cancer, surgery is still the primary therapeutic option. To establish surgical adequacy, a wide excision with sufficient margins in all three dimensions must be carried out.

Does Free Fibular Flap Reconstruction Affect the Quality of Life in Pediatric Patients With Various Extend of Mandible Defects?

BACKGROUND

The long-term outcomes in pediatric patients with various extents of mandible defects have not been well-documented.

METHODS

A retrospective case series in which this study looked at pediatric patients under the age of 13 who had mandibular reconstruction with free fibular flap and had not received another operation in the previous 6 months. The eating, swallowing, speech function, and quality of life are evaluated with EORTC QLQ-H&N35 after the mandible growth spurt has occurred.

RESULTS

A total of 7 patients were included in this study with operation ages ranging from 6 years 1 month to 12 years 2 months. The etiology of malignant tumors was found in 2 patients and benign tumors in 5 patients. The mandibular defect distribution consists of 1 class Ic, 1 class II, 2 class IIc, 2 class III, and 1 class IVc. All patients reported no swallowing or speech difficulties. However, transient eating trouble was seen in 1 patient due to the extensive defect size that causes tooth loss. Only 1 patient received dental rehabilitation. The patients displayed an overall good quality of life with an average score of 2.857.

CONCLUSIONS

Free fibular flap for mandibular reconstruction in children who have not reached their mandibular growth peak have a satisfying outcome, both in their function and quality of life.

A review on the classification of mandibulectomy defects and suggested criteria for a universal description

STATEMENT OF PROBLEM

Several mandibular defect classifications after oncological resection have been proposed with no universal acceptance among surgeons and prosthodontists. Established criteria for describing these mandibulectomy defects are lacking.

PURPOSE

The purpose of this systematic review was to analyze the classification systems of mandibular defects available in the scientific literature, provide a critical appraisal, and identify the criteria necessary for a universal description of mandibular discontinuity defects.

MATERIAL AND METHODS

An electronic search of the English language literature between 1971 and 2020 was performed on 2 electronic databases (PubMed and Cochrane Library). The search was conducted using MeSH terms and free text words: Mandible neoplasm AND Mandibular reconstruction OR Mandible resection OR Mandible defect AND classification, followed by the application of inclusion and exclusion criteria. Studies describing the classification of osteoradionecrosis of the mandible, mandibular fracture, impacted mandibular third molar, and mandibular endodontic or periodontal treatment were not included. The full texts of selected articles were reviewed in depth to provide a critical appraisal. The various descriptive factors of each classification system were tabulated to identify criteria suitable for the universal description of mandibular discontinuity defects.

RESULTS

The electronic search yielded a total of 239 titles and abstracts. Of these, 52 titles relevant to the review were identified by the 2 reviewers independently. Those studies that did not match the predetermined inclusion criteria and duplicates were excluded. By reviewing the 21 selected studies and applying exclusion criteria, 12 studies were selected for full-text reading. A manual search in the references of the selected publications was performed, which yielded 1 additional article that satisfied the inclusion criteria. Thus, a total of 13 full-text articles were included in the final review. After further qualitative analysis and tabulation of relevant information from selected classification systems, the 8 descriptive criteria and a pyramidal hierarchical chart were proposed that included the extent of bony defect, soft tissue defect, dental status, mandibular function, neurological status, condyle status, type of reconstruction, and combined resection.

CONCLUSIONS

The spectrum of patients with mandibulectomy defects following resection varies greatly. The question of the most ideal classification system remains unresolved. Eight different criteria for the description of mandibular discontinuity defects and the pyramidal hierarchical chart proposed will allow surgeons and prosthodontists to better communicate and conceptualize an individualized surgical and prosthetic treatment plan.

Comparison of Reconstruction of Maxilloalveolar Resections in Head and Neck Cancers with Chimeric Anterolateral Thigh Flap (ALT) versus Standard ALT Flap

Background  Oral malignancy that presents at a locally advanced stage needs complex surgical resections in which the maxillary cavity is usually left open. The constant maxillary secretions lead to problems like poor healing, fistula formation, and flap necrosis, causing longer hospital stays, delayed adjuvant therapy, and additional surgeries. Several methods have been tried to ameliorate this, each faced with its own difficulties. This study describes the use of chimeric free anterolateral thigh (ALT) with vastus lateralis (VL) muscle to tackle this problem. Materials and Methods  With the aim to assess the advantage of reconstruction of maxillo-alveolar resections using chimeric ALT + VL, we analyzed data from 20 cases reconstructed with chimeric free ALT + VL over a year. We compared them with twenty matched controls reconstructed with standard ALT. Analysis was done with respect to intraoperative ease, adequacy of maxillary sinus fill, postoperative secretions, length of hospital stay, duration to adjuvant therapy, and postoperative complications tabulated using the modified Clavien-Dindo classification. Results  It was found that chimeric ALT + VL gave greater freedom of movement to plug the maxillary cavity easily. The chimeric arm patients had fewer complications and a shorter mean hospital stay. Most of them received adjuvant therapy within their optimal time window. Conclusion  Chimeric ALT with vastus lateralis muscle is a reliable option for reconstructing complex defects, especially with dead space cavities like the maxillary sinus. Effective plugging of the maxillary sinus during the primary surgery results in better patient outcomes and must be done routinely.

Does the use of intraoperative frozen section of bone marrow from the cut end of the mandible help assess the adequacy of bone margins following mandibulectomy for oral cancer?

BACKGROUND

The adequacy of the cut end of the mandible following a segmental mandibulectomy done for oral cancer intraoperatively is at times assessed using a frozen section (FS) of the bone marrow (BM) at the cut ends. The study aimed to assess its utility to guide the intraoperative decision on the adequacy of bony margins.

MATERIALS AND METHODS

All patients with oral squamous cell carcinoma (OSCC) who underwent segmental mandibulectomy from January 2012 to December 2021 at our institute and for whom intraoperative FS of BM was utilized were included. We analyzed the sensitivity, specificity, and positive and negative predictive value (PPV, NPV) of this in predicting positive bone margins.

RESULTS

A total of 457 patients were included in the study. The majority of the cases were per premium cases (n = 372, 81.4%). The median age of the cohort was 52 years (range: 22-80 years). Most patients had T4 disease (n = 406, 88.8%). On FS, BM was positive in only 18 patients (3.9%) for whom the bone margin was revised. BM biopsy report in the final histopathology was positive in 12 patients (2.2%). The sensitivity, specificity PPV, and NPV were 52.3%, 98.65%, 64.7%, and 97.7% respectively. No factors predicting BM positivity on FS could be identified in this cohort.

CONCLUSIONS

The BM FS was positive in only a small percentage of patients, and it helped in reducing the bone margin positivity rate from 3.9% to 2.2% only. Hence the intraoperative BM FS seems to have limited utility as seen from our study.

Challenges during implant-assisted prosthetic rehabilitation in fibula reconstructed jaws and its management: a scoping review protocol

Introduction

Oral cancer is the sixth most prevalent cancer type worldwide. Patients are placed in a crippling predicament due to the functional and psychosocial difficulties brought on by the illness and its treatments. Both surgeons and maxillofacial prosthodontists may encounter challenges with reconstruction and therapy following cancer treatment. Over 20 years, the fibula has remained the mainstay of reconstructions for head and neck cancer. Maxillary and mandibular jaws with fibula reconstructions can use fixed or removable prosthetic rehabilitation solutions. The proposed scoping review aims to ascertain the volume and nature of evidence concerning the difficulties and corrective measures in the prosthetic rehabilitation of fibula-reconstructed head and neck cancer cases. The findings will aid in improving the prosthetic treatment care for the affected population.

Materials and Methods

The Joanna Briggs Institute (JBI) scoping review protocol will be followed in developing and reporting the scoping review methodology. Methods to identify the relevant literature will involve the systematic search of databases like PubMed, Scopus, Google Scholar, Cochrane Library, and gray literature sources for pertinent articles on the subject. Only papers published in English literature will be considered for the review, and the data collection period is limited to the past 20 years. The screening process will utilize defined inclusion/exclusion criteria for Title/Abstract and Full-text screening by two independent reviewers in covidence, and a third reviewer will resolve any conflicts. The data extracted will include specific details about the participants, concept, population, study methods, challenges encountered during prosthetic rehabilitation, and their management. Inductive thematic analysis and descriptive statistics will be applied where appropriate. The narrative synthesis of the evidence will be accomplished through data extraction in a tabular format, and the results will be presented as a narrative summary.

Segmental Mandibulectomy and Mandibular Reconstruction with Fibula-Free Flap Using a 3D Template

INTRODUCTION

The present study evaluates the influence of virtual surgical planning with a preoperative 3D resin model on aesthetic and functional outcomes in patients treated by segmental mandibulectomy and reconstruction with fibula-free flap for oral cancer.

METHODS

All consecutive patients who underwent segmental mandibulectomy and mandibular reconstruction with a fibula-free flap using a 3D template at our department from January 2021 to January 2023 were included in the study. "Patients control" were patients treated by reconstruction with a fibula-free flap without using a 3D template. Three-dimensional modeling was performed by converting from preoperative computed tomography to a stereolithography format to obtain the resin 3D models. Qualitative analysis of anatomical and aesthetic results consisted of the evaluation of the patients' aesthetic and functional satisfaction and the symmetry of the mandibular contour observed at clinical examination. Quantitative analysis was based on the assessment of the accuracy and precision of the reconstruction by comparing preoperative and postoperative computed tomograms as objective indicators.

RESULTS

Seven patients (five males and two females, mean age of 65.1 years) were included in the study. All patients showed a symmetric mandibular contour based on the clinical examination. After recovery, six patients (85.7%) considered themselves aesthetically satisfied. The quantitative analysis (assessed in six/seven patients) showed that the mean difference between preoperative and postoperative intercondylar distance, intergonial angle distance, anteroposterior dimension, and gonial angle improved in the 3D template-assisted group.

CONCLUSION

The 3D-printed template for mandibular reconstruction with microvascular fibula-free flap can improve aesthetic outcomes in comparison with standard approaches.

Capturing cerium ions via hydrogel microspheres promotes vascularization for bone regeneration

The rational design of multifunctional biomaterials with hierarchical porous structure and on-demand biological activity is of great consequence for bone tissue engineering (BTE) in the contemporary world. The advanced combination of trace element cerium ions (Ce3+) with bone repair materials makes the composite material capable of promoting angiogenesis and enhancing osteoblast activity. Herein, a living and phosphorylated injectable porous hydrogel microsphere (P-GelMA-Ce@BMSCs) is constructed by microfluidic technology and coordination reaction with metal ion ligands while loaded with exogenous BMSCs. Exogenous stem cells can adhere to and proliferate on hydrogel microspheres, thus promoting cell-extracellular matrix (ECM) and cell-cell interactions. The active ingredient Ce3+ promotes the proliferation, osteogenic differentiation of rat BMSCs, and angiogenesis of endotheliocytes by promoting mineral deposition, osteogenic gene expression, and VEGF secretion. The enhancement of osteogenesis and improvement of angiogenesis of the P-GelMA-Ce scaffold is mainly associated with the activation of the Wnt/β-catenin pathway. This study could provide novel and meaningful insights for treating bone defects with biofunctional materials on the basis of metal ions.

Oral rehabilitation and associated quality of life following mandibular reconstruction with free fibula flap: a cross-sectional study

Introduction

Mandibular reconstruction with the free fibula flap (FFF) has become a standardized procedure. The situation is different with oral rehabilitation, so the purpose of this study was to investigate the frequency of implant placement and prosthetic restoration. Additionally, the patients' situation, motivation, and treatment course were structurally assessed.

Materials and methods

All cases between January 2013 and December 2018 that underwent mandibular reconstruction in our department with a free fibula flap and gave written informed consent to participate were interviewed with two structured questionnaires about their restoration and quality of life. Additionally, medical records, general information, status of implants and therapy, and metric analyses of the inserted implants were performed.

Results

In total 59 patients were enrolled and analyzed in this monocentric study. Overall, oral rehabilitation was achieved in 23.7% at the time of investigation. In detail, implants were inserted in 37.3% of patients and showed an 83.3% survival of dental implants. Of these implanted patients, dental implants were successfully restored with a prosthetic restoration in 63.6. Within this subgroup, satisfaction with the postoperative aesthetic and functional result was 79.9% and with the oral rehabilitation process was 68.2%. Satisfaction with the implant-borne prosthesis was 87.5%, with non-oral-squamous-cell-carcinoma patients being statistically significantly more content with the handling (p=0.046) and care (p=0.031) of the prosthesis.

Discussion

Despite the well-reconstructed bony structures, there is a need to increase the effort of achieving oral rehabilitation, especially looking at the patient's persistent motivation for the procedure.

Computer-aided designed 3D-printed polymeric scaffolds for personalized reconstruction of maxillary and mandibular defects: a proof-of-concept study

PURPOSE

To investigate the potential reconstruction of complex maxillofacial defects using computer-aided design 3D-printed polymeric scaffolds by defining the production process, simulating the surgical procedure, and explore the feasibility and reproducibility of the whole algorithm.

METHODS

This a preclinical study to investigate feasibility, reproducibility and efficacy of the reconstruction algorithm proposed. It encompassed 3 phases: (1) scaffold production (CAD and 3D-printing in polylactic acid); (2) surgical simulation on cadaver heads (navigation-guided osteotomies and scaffold fixation); (3) assessment of reconstruction (bone and occlusal morphological conformance, symmetry, and mechanical stress tests).

RESULTS

Six cadaver heads were dissected. Six types of defects (3 mandibular and 3 maxillary) with different degree of complexity were tested. In all case the reconstruction algorithm could be successfully completed. Bone morphological conformance was optimal while the occlusal one was slightly higher. Mechanical stress tests were good (mean value, 318.6 and 286.4 N for maxillary and mandibular defects, respectively).

CONCLUSIONS

Our reconstructive algorithm was feasible and reproducible in a preclinical setting. Functional and aesthetic outcomes were satisfactory independently of the complexity of the defect.

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.

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.

Use of customized 3-dimensional printed mandibular prostheses with a dental implant pressure-reducing device in mandibular body defect: A finite element study performing multiresponse surface methodology

Background/purpose

Segmental body defects of the mandible result in the complete loss of the affected region. In our previous study, we investigated the clinical applicability of a customized mandible prosthesis (CMP) with a pressure-reducing device (PRD) in an animal study. In this study, we further incorporated dental implants into the CMP and explored the use of dental implant PRD (iPRD) designs.

Materials and methods

By employing a finite element analysis approach, we created 4 types of CMP: CMP, CMP with iPRD, CMP-PRD, and CMP-PRD with iPRD. We developed 2 parameters for the iPRD: cone length (CL) in the upper part and spring pitch (SP) in the lower part. Using the response surface methodology (RSM), we determined the most suitable structural assignment for the iPRD.

Results

Our results indicate that CMP-PRD had the highest von Mises stress value for the entire assembly (1076.26 MPa). For retentive screws and abutments, CMP with iPRD had the highest von Mises stress value (319.97 and 452.78 MPa, respectively). CMP-PRD had the highest principal stress (131.66 MPa) in the anterior mandible. The iPRD reduced principal stress in both the anterior and posterior mandible. Using the RSM, we generated 25 groups for comparison to achieve the most favorable results for the iPRD and we might suggest the CL to 12 mm and the SP to 0.4 mm in the further clinical trials.

Conclusion

Use of the PRD and iPRD in CMP may resolve the challenges associated with CMP, thereby promoting its usage in clinical practice.

Biomechanical feasibility of non-locking system in patient-specific mandibular reconstruction using fibular free flaps

Mandibular reconstruction with free fibular flaps is frequently used to restore segmental defects. The osteosythesis, including locking and non-locking plate/screw systems, is essential to the mandibular reconstruction. Compared with the non-locking system that requires good adaption between plate and bone, the locking system appears to present a better performance by locking the plate to fixation screws. However, it also brings about limitations on screw options, a higher risk of screw failure, and difficulties in screw placement. Furthermore, its superiority is undermined by the advancing of patient-specific implant design and additive manufacturing. A customized plate can be designed and fabricated to accurately match the mandibular contour for patient-specific mandibular reconstruction. Consequently, the non-locking system seems more practicable with such personalized plates, and its biomechanical feasibility ought to be estimated. Finite element analyses of mandibular reconstruction assemblies were conducted for four most common segmental mandibular reconstructions regarding locking and non-locking systems under incisal biting and right molars clenching, during which the influencing factor of muscles' capacity was introduced to simulate the practical loadings after mandibular resection and reconstruction surgeries. Much higher, somewhat lower, and similar maximum von Mises stresses are separately manifested by the patient-specific mandibular reconstruction plate (PSMRP), fixation screws, and reconstructed mandible with the non-locking system than those with the locking system. Equivalent maximum displacements are identified between PSMRPs, fixation screws, and reconstructed mandibles with the non-locking and locking system in all four reconstruction types during two masticatory tasks. Parallel maximum and minimum principal strain distributions are shared by the reconstructed mandibles with the non-locking and locking system in four mandibular reconstructions during both occlusions. Conclusively, it is feasible to use the non-locking system in case of patient-specific mandibular reconstruction with fibular free flaps based on the adequate safety, comparable stability, and analogous mechanobiology it presents compared with the locking system in a more manufacturable and economical way.

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.

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.

Effect of segmental versus marginal mandibular resection on local and lymph node recurrences in oral squamous cell carcinoma: is tumorous bone infiltration or location and resulting soft tissue recurrences a long-term problem?

PURPOSE

Oral squamous cell carcinomas (OSCCs) adjacent to the mandible or with clinically suspected bone infiltration are surgically treated either with marginal or segmental resections. This retrospective study compared both resections regarding local recurrence and lymph node recurrence or secondary lymph node metastases.

METHODS

All consecutive primary OSCC cases between January 2007 and December 2015 that underwent mandibular marginal or segmental resection were included. Rates of local and lymph node recurrences or secondary metastases and possible risk factors such as tumor localization according to Urken's classification were recorded.

RESULTS

In total, 180 patients with 85 marginal (group I) and 95 segmental (group II) mandibular resections were analyzed. The local recurrence rates were comparable between the groups (28.2% vs. 27.4%; p = 0.897). Lymph node recurrences or secondary metastases were higher in group I (9.4% (n = 8) vs. 6.2% (n = 6); p = 0.001). Tumor localization appears to affect the outcomes. Significantly fewer local and lymph node recurrences/metastases were found for Urken's classification SB and S calculated by two-proportion z-test (p = 0.014 and 0.056, respectively). Local recurrences mostly emerged from soft tissues, which should be resected more radically than the bones.

CONCLUSION

While bone infiltration appears technically well controllable from an oncologic point of view, local recurrences and lymph node recurrences/metastases remain an issue. Regular clinical aftercare with imaging is crucial to detect recurrences.

Double Arterialized Scapular Tip Free Flap for Mandibular Reconstruction

INTRODUCTION

Scapular tip free flap (STFF) has become today one of the workhorse flaps for maxillary reconstruction; recently, the possibility of extending the vascular supply by adding to the angular branch of the circumflex pedicle up to its periosteal entrance in the lateral border of the scapula has been proposed as a reliable technique to improve the length of perfused bone when STFF is used for mandibular reconstruction. The purpose of this study was to evaluate the patients who had received microvascular reconstruction of the mandible with STFF vascularized by both the circumflex scapular artery via the periosteal branch and the thoracodorsal artery via the angular artery.

METHODS

A retrospective chart review was conducted for all patients who underwent reconstruction with an STFF for mandibular defect between January 2016 and December 2020 at the University Hospital of Parma. The outcome was evaluated by assessing dietary intake (unrestricted, soft, liquid, and tube feed) and speech (normal, intelligible, partially intelligible, and unintelligible).

RESULTS

The final study sample included 9 patients (5 men and 4 women). The average patient age was 68.9 years (range, 59.9-74.8 y) at the time of surgery. There was no flap loss. A 1-year postoperative computed tomography scan revealed full osteointegration of the flap.

CONCLUSIONS

Our results show that the STFF is a valuable reconstructive option, especially in patients with complex head and neck defects requiring soft and hard tissues.

Advances and Prospects in Materials for Craniofacial Bone Reconstruction

The craniofacial region is composed of 23 bones, which provide crucial function in keeping the normal position of brain and eyeballs, aesthetics of the craniofacial complex, facial movements, and visual function. Given the complex geometry and architecture, craniofacial bone defects not only affect the normal craniofacial structure but also may result in severe craniofacial dysfunction. Therefore, the exploration of rapid, precise, and effective reconstruction of craniofacial bone defects is urgent. Recently, developments in advanced bone tissue engineering bring new hope for the ideal reconstruction of the craniofacial bone defects. This report, presenting a first-time comprehensive review of recent advances of biomaterials in craniofacial bone tissue engineering, overviews the modification of traditional biomaterials and development of advanced biomaterials applying to craniofacial reconstruction. Challenges and perspectives of biomaterial development in craniofacial fields are discussed in the end.

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.

Measurement of Thickness at the Inferior Border of the Mandible Using Computed Tomography Images: A Retrospective Study including 300 Japanese Cases

Vascularised fibular free flaps are integral to reconstructive surgery for head and neck tumours. We investigated the morphological characteristics of the mandible to improve the incidence of plate-related complications after surgery. Using standard radiological software, thickness measurements of the inferior or posterior margin of the mandible were obtained from computed tomography images of 300 patients at seven sites: (1) mandibular symphysis, (2) midpoint between the mandibular symphysis and mental foramen, (3) mental foramen, (4) midpoint between the mental foramen and antegonial notch, (5) antegonial notch, (6) mandibular angular apex (gonion), and (7) neck lateral border of the dentate cartilage. Relationships between age, sex, height, weight, the number of remaining teeth in the mandible, and the thickness of each mandible were also investigated. Measurement point 1 had the largest median mandibular thickness (11.2 mm), and measurement point 6 had the smallest (5.4 mm). Females had thinner measurements than males at all points, with significant differences at points 1, 2, 3, 4, and 7 (p < 0.001). Age and number of remaining teeth in the mandible did not correlate with mandibular thickness; however, height and weight correlated at all points except point 6. Thickness measurements obtained at the sites provide a practical reference for mandibular reconstruction. Choosing the fixation method based on the measured thickness of the mandible at each site allows for sound plating.

Prosthetic rehabilitation of a patient with hemimandibulectomy by a double occlusal table prosthesis

The objective of prosthetic rehabilitation of patients with hemimandibulectomy is to regain the masticatory function, comfort, esthetics, and self-esteem. This article presents a plan for the management of hemimandibulectomy with a removable maxillary double occlusal table prosthesis. A male patient, aged 43 years, was referred to Prosthodontic Out Patient Department with complaints of compromised aesthetics, difficulty in speaking, and lack of ability to chew. The patient underwent surgery 3 years ago in which hemimandibulectomy was performed due to oral squamous cell carcinoma. The patient had a Cantor and Curtis Type II defect. The mandible was resected distally from canine region on the right side of the arch. A prosthodontic device was planned with a double occlusal table, also known as twin occlusion prosthesis. The rehabilitation of hemimandibulectomy patients with a double occlusal table is of considerable importance. This report describes a simple prosthetic device that will help patients in regaining their functional and psychological well-being.

Head and neck reconstruction in the vessel depleted neck using robot-assisted harvesting of the internal mammary vessels

We report a novel technique of robot-assisted harvesting of the internal mammary vessels to provide effective recipient vessels in a patient with bilateral vessel depleted neck (VDN). A 44-year-old with a Notani grade III osteoradionecrosis (ORN) of the anterior mandible underwent robot-assisted (Da Vinci® Surgical System, Intuitive Surgical) harvesting of the left internal mammary vessels (LIMA, LIMV). Reconstruction of the mandibular defect was done with a virtually planned composite fibular free flap and microvascular anastomosis of the peroneal vessels to the LIMA and LIMV. Successful reconstruction of the anterior mandible was achieved with excellent recipient arterial diameter and length, devoid of any significant thoracic morbidities resulting from robot-assisted harvesting of the internal mammary vessels. Robot-assisted harvesting of internal mammary vessels is a viable alternative to an open approach. The advantages in tissue handling, vessel length, and favourable profile of complications may extend the indications for this otherwise 'niche' solution in the VDN.

Tenants of Mandibular Reconstruction in Segmental Defects

The premises of mandibular reconstruction are the restoration of occlusion and mandibular contour for the purpose of preserving the facial identity, oral airway, and effective speech and mastication. Establishing functional occlusion is the primary tenant in all mandibular reconstruction. In cases of segmental defects, particularly in dentate regions of the mandible, there has been a paradigm shift over the past two decades in how surgeons are approaching the restoration of load-bearing mandibular continuity with capacity for dental implantation. Here we discuss considerations for deciding the most effective method of reconstruction in segmental defects.

Mandibular reconstructions with free fibula flap using standardized partially adjustable cutting guides or CAD/CAM technique: a three- and two-dimensional comparison

Background

Mandibular reconstruction with the fibula free flap (FFF) is performed freehand, CAD/CAM-assisted, or by using partially adjustable resection/reconstruction aids. The two latter options represent the contemporary reconstructive solutions of the recent decade. The purpose of this study was to compare both auxiliary techniques with regard to feasibility, accuracy, and operative parameters.

Methods and materials

The first twenty consecutively operated patients requiring a mandibular reconstruction (within angle-to-angle) with the FFF using the partially adjustable resection aids between January 2017 and December 2019 at our department were included. Additionally, matching CAD/CAM FFF cases were used as control group in this cross-sectional study. Medical records and general information (sex, age, indication for surgery, extent of resection, number of segments, duration of surgery, and ischemia time) were analyzed. In addition, the pre- and postoperative Digital Imaging and Communications in Medicine data of the mandibles were converted to standard tessellation language (.stl) files. Conventional measurements - six horizontal distances (A-F) and temporo-mandibular joint (TMJ) spaces - and the root mean square error (RMSE) for three-dimensional analysis were measured and calculated.

Results

In total, 40 patients were enrolled (20:20). Overall operation time, ischemia time, and the interval between ischemia time start until end of operation showed no significant differences. No significant difference between the two groups were revealed in conventional measurements of distances (A-D) and TMJ spaces. The Δ differences for the distance F (between the mandibular foramina) and the right medial joint space were significantly lower in the ReconGuide group. The RMSE analysis of the two groups showed no significant difference (p=0.925), with an overall median RMSE of 3.1 mm (2.2-3.7) in the CAD/CAM and 2.9 mm (2.2-3.8) in the ReconGuide groups.

Conclusions

The reconstructive surgeon can achieve comparable postoperative results regardless of technique, which may favor the ReconGuide use in mandibular angle-to-angle reconstruction over the CAD/CAM technique because of less preoperative planning time and lower costs per case.

The Role of Imaging in Mandibular Reconstruction with Microvascular Surgery

Imaging plays a critical role in the diagnosis, staging, and management of segmental mandibular defects. Imaging allows mandibular defects to be classified which aids in microvascular free flap reconstruction. This review serves to complement the surgeon's clinical experience with image-based examples of mandibular pathology, defect classification systems, reconstruction options, treatment complications, and Virtual Surgical Planning.

Comparing Free-Flap Reconstruction After Robot-Assisted Neck Dissection via a Retroauricular Approach and a Traditional Transcervical Approach: Single-Surgeon Experiences of 90 Consecutive Cases

BACKGROUND

Predominant traditional approaches for most patients who have advanced-stage oral cancer with transcervical incision lines left irreversible scars. To address this, surgeons have continuously refined minimally invasive surgery (MIS) techniques, including robot-assisted neck surgeries. This article introduces and discusses the feasibility, versatility, and availability of free-flap reconstruction via the retroauricular approach (RA), considered difficult to date.

METHODS

This study retrospectively analyzed 90 consecutive patients who had free-flap reconstruction performed by a single surgeon (D.K.) in the Department of Oral and Maxillofacial Surgery, Yonsei University, from March 2021 to April 2022. The type of defects and flaps, hospitalization days, total operation time, and type of vessels and anastomoses were compared statistically.

RESULTS

The type of vessels used did not differ between the RA and the transcervical approach (TA) groups, nor in duration of hospital stays. Likewise, the total reconstruction time did not differ significantly between the TA group (240 min) and the RA group (245 min) (p = 0.756). However, the total operation time was about 1 h less in the TA group, a statistically significant difference (TA group [593 ± 152 min] vs. RA group [655 ± 117 min]; p = 0.044). All flaps were successful in the RA group, whereas one flap in the TA group led to a total loss (TA group [98.3%] vs. RA group [100.0%]; p = 1.000).

CONCLUSIONS

Even for patients with advanced oral cancer who require massive tumor ablation, it is feasible to obtain an aesthetic and functional surgical outcome by performing free-flap reconstruction via the retroauricular approach.

Cutting-edge patient-specific surgical plates for computer-assisted mandibular reconstruction: The art of matching structures and holes in precise surgery

Objectives

Cutting-edge patient-specific surgical plates (PSSPs) are supposed to improve the efficiency, precision, and functional outcomes of mandibular reconstruction. This study characterized the premium role of PSSPs in precise surgery and explored their working principles in computer-assisted mandibular reconstruction (CAMR).

Methods

The PSSPs-enhanced surgical precision was investigated through the model surgery and representative cases. Spatial deviations of reconstruction were characterized by comparing the reconstructed mandible with the virtually designed mandible. Working principles of PSSPs were distinguished by a review of evolving surgical techniques in CAMR.

Results

In the model surgery, spatial deviations between the virtually planned mandible and the reconstructed mandible were 1.03 ± 0.43 mm in absolute distance deviation, 1.70 ± 1.26 mm in intercondylar length, and 1.86 ± 0.91 mm in intergonial length in the study group of PSSPs, significantly smaller than in the control group of conventional prebent surgical plates. Meanwhile, in the study group, distance deviations were 0.51 ± 0.19 mm in bone-plate distance and 0.56 ± 0.28 mm in drilled screw holes, indicating the art of matching structures and holes. The PSSPs-enhanced CAMR was further demonstrated in three representative cases of mandibular reconstruction. Finally, four primary techniques of CAMR were summarized based on a review of 8,672 articles. The premium role of PSSPs was distinguished by the benefits of matching structures and holes.

Conclusions

The PSSPs-enhanced surgical precision was verified through the model surgery and demonstrated in human surgery. Compared to other surgical techniques of CAMR, PSSPs contributed to the precise surgery by the art of matching structures and holes.