Evaluation of Bone Height of the Free Fibula Flap in Mandible Reconstruction

Segmental mandibulectomy and microvascular reconstruction with fibula free flap: Comparison between intraoral and extraoral approaches

BACKGROUND

Segmental mandibulectomy and reconstruction of resulting defect can be performed via intraoral approach (IOA) or extraoral approach (EOA). Both approaches have advantages, disadvantages, indications, and contraindications to consider during their selection.

OBJECTIVE

To compare IOA vs EOA of segmental mandibulectomy and microvascular reconstruction with fibula free flap (FFF).

METHODS

We conducted a retrospective cohort study in which 51 patients who underwent segmental mandibulectomy and microvascular reconstruction with FFF from 2020 to 2024 were included, especially 17 patients by IOA and 34 patients by EOA, representing both groups of this study. Clinical characteristics, surgery parameters, and patients' prognosis were evaluated. Patients' satisfaction and Derriford Appearance Scale (DAS59) were assessed during follow-up.

RESULTS

Ameloblastoma was the most frequent diagnosis (52.9% managed by IOA vs 70.6% by EOA); FFF was frequently positioned as double barrel (94.1% managed by IOA vs 88.2% by EOA). Compared with EOA group, IOA group had less intraoperative blood loss (mean difference [MD] = -112.2, 95% confidence interval [CI]: -178.9 to -45.5, p = 0.001), higher satisfaction score (MD = 1.3, 95% CI: 0.9 to 1.7, p ˂ 0.001), and lower DAS59 score (MD = -0.5, 95% CI: -0.7 to -0.2, p ˂ 0.001).

CONCLUSION

Both IOA and EOA were found safe and feasible, presenting similar perioperative features and postoperative outcomes. Patients managed with IOA were more satisfied with aesthetic outcomes than patients managed with EOA. In the absence of simultaneous immediate implant during mandibular FFF reconstruction, after stability of FFF on the defect site, patients should always be referred to an implantologist and/or prosthodontist for teeth restoration to improve functional and aesthetic outcomes.

Postoperative volume maintenance rate of microvascular free flap in oral and maxillofacial region: Systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

The resorption of flap's volume can be frequently observed in the transplantation of microvascular free flaps, which could significantly affect postoperative function. Therefore, it's essential to comprehend the postoperative flap volume and the mechanisms behind before making clinical decisions.

METHODS

Literature search was conducted from database on PubMed, EMBASE, Cochrane Library, Chinese database and Google Scholar. A random effects model meta-analyses and descriptive systematic review were performed.

RESULTS

The search identified 420 articles, of which 9 studies included in meta-analysis and 14 studies included in descriptive systematic review. Postoperative flap volume maintenance rate is used to represent the volume change. The pooled mean postoperative flap volume maintenance rate was 62.82 % for soft tissue flap (95 %CI: 58.83 to 66.82, p = 0.076, I2=56.3 %) and 85.96 % for bone flap (95 %CI: 84.19 to 87.73, p = 0.274, I2=20.4 %). Weight loss, muscle atrophy, and decreased serum albumin levels are risk factors for postoperative volume reduction of soft tissue flaps. The bone resorption rate of bone flaps in women is higher than that in men.

CONCLUSION

When designing microvascular free flaps for oral and maxillofacial surgery, soft tissue flaps should consider an anticipated postoperative shrinkage of 37 %, while bone flaps should consider an anticipated postoperative shrinkage of 14 %.

Volumetric Bone Changes in Double Barrel Vascularized Fibula Flap Used for Mandibular Reconstruction: A Randomized Clinical Trial

AIM

To assess the volumetric bone changes in double barrel vascularized fibular flap used for mandibular reconstruction using 3D miniplate versus 3D titanium mesh tray.

MATERIALS AND METHODS

Twenty patients seeking mandibular reconstruction were selected for this 2-arm parallel randomized clinical trial with a 1:1 allocation ratio. Both groups underwent double-barrel fibula free flap for mandibular reconstruction with fixation of the superior barrel to the inferior barrel using a Titanium mesh (Group A) or a 3D plate (Group B). The primary outcome was volumetric bone changes (immediate to 6 months postoperatively).

RESULTS

Eleven participants (55%) were females, and 9 participants (45%) were males. The mean age of patients in group A was (28.8±8.9) years, while group B was (30.7±11.4) years. There was a statistically significant difference within each group in the volumetric bone changes with means of -7942.1±1804.8 mm3 and -6288.8±2607.3 for groups A and B, respectively. The difference between both groups was statistically insignificant with the mean of -1653.3±1002.8 mm3. The percentage of mean volumetric change relative to immediate postoperatively for group A was -14.15%, while in group B was -11.01%.

CONCLUSIONS

Both the titanium mesh tray and the 3D plate were effective in the fixation of the superior barrel of the vascularized fibular flap for mandibular reconstruction. There was no difference between both modalities regarding volumetric bone changes.

Accuracy of the surgical execution of virtually planned deep circumflex iliac artery flaps and their appropriateness for masticatory rehabilitation

BACKGROUND

Tumorous diseases of the jaw demand effective treatments, often involving continuity resection of the jaw. Reconstruction via microvascular bone flaps, like deep circumflex iliac artery flaps (DCIA), is standard. Computer aided planning (CAD) enhances accuracy in reconstruction using patient-specific CT images to create three-dimensional (3D) models. Data on the accuracy of CAD-planned DCIA flaps is scarce. Moreover, the data on accuracy should be combined with data on the exact positioning of the implants for well-fitting dental prosthetics. This study focuses on CAD-planned DCIA flaps accuracy and proper positioning for prosthetic rehabilitation.

METHODS

Patients post-mandible resection with CAD-planned DCIA flap reconstruction were evaluated. Postoperative radiograph-derived 3D models were aligned with 3D models from the CAD plans for osteotomy position, angle, and flap volume comparison. To evaluate the DCIA flap's suitability for prosthetic dental rehabilitation, a plane was created in the support zone and crestal in the middle of the DCIA flap. The lower jaw was rotated to close the mouth and the distance between the two planes was measured.

RESULTS

20 patients (12 males, 8 females) were included. Mean defect size was 73.28 ± 4.87 mm; 11 L defects, 9 LC defects. Planned vs. actual DCIA transplant volume difference was 3.814 ± 3.856 cm³ (p = 0.2223). The deviation from the planned angle was significantly larger at the dorsal osteotomy than at the ventral (p = 0.035). Linear differences between the planned DCIA transplant and the actual DCIA transplant were 1.294 ± 1.197 mm for the ventral osteotomy and 2.680 ± 3.449 mm for the dorsal (p = 0.1078). The difference between the dental axis and the middle of the DCIA transplant ranged from 0.2 mm to 14.8 mm. The mean lateral difference was 2.695 ± 3.667 mm in the region of the first premolar.

CONCLUSION

The CAD-planned DCIA flap is a solution for reconstructing the mandible. CAD planning results in an accurate reconstruction enabling dental implant placement and dental prosthetics.

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

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

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.

Osseointegration and Bone Resorption of Scapula Tip Free Flaps in Mandibular Reconstruction

OBJECTIVES

Bone resorption of more conventional vascularized bone grafts have been well described showing minimal resorption over time. Few studies have evaluated osseous union and bone resorption in scapula tip free flaps (STFF) in the reconstruction of mandibulectomy defects. We aimed to describe our series on STFF with respect to osseous union and bone resorption over time.

METHODS

Retrospective chart review of patients receiving STFF from January 2014-January 2017 (n = 25). A neuroradiologist analyzed follow-up CT scans to assess (1) STFF complete, partial, or no osseous union with native mandible and (2) STFF volume change over time in a subset with multiple follow-up scans (n = 18).

RESULTS

Twenty-three of 25 patients (92%) showed complete or partial STFF osseous union with native mandible either distally or proximally. STFF volume change ranged from +4.8 to -54% (median -0.5%) over median follow-up interval of 23 months. History of chemoradiation therapy, bisphophonate use, sex, age, or smoking history did not correlate with bone resorption.

CONCLUSIONS

STFFs shows high rates of osseous union and limited bone resorption that is equivalent to, or less than, vascularized fibular and iliac crest flaps. Clinically, this translates into both optimal healing and functional and cosmetic outcomes, especially in the setting of prior therapies.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2597-2602, 2023.

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.

MRONJ of the Mandible—From Decortication to a Complex Jaw Reconstruction Using a CAD/CAM-Guided Bilateral Scapula Flap

Medication-related osteonecrosis of the jaw (MRONJ) has been an integral part of the maxillofacial patient population for some time. The therapeutic concept ranges from conservative approaches over less extended decortications to major jaw resections, which can result in a considerable loss of quality of life. Based on three case reports, this paper presents the long-term history of patients with MRONJ of the mandible, whose disease ultimately resulted in partial or total mandibular resection and subsequent multisegmental reconstruction using a microvascular anastomosed bone flap. Furthermore, a suitable alternative for complex mandibular reconstruction is demonstrated when using a free fibula flap is not possible. The options are limited, particularly when multisegmental restoration of mandibular continuity is required. One case presents a mandible reconstruction using a CAD/CAM-guided bilateral scapular free flap (CAD/CAM = Computer-Aided Design and Manufacturing), which has not been described for this purpose before. Due to the complexity, computer-assisted surgery and patient-specific implants seem reasonable, which is why a special focus was applied to this topic.

Rehabilitation of long-term mandibular defects by whole-process digital fibula flap combining with implants: A case report

Currently, the gold standard and workhorse in mandibular reconstruction is the free vascularized fibula flap. Particularly for patients who have had mandibulectomy for a long time, it is still difficult to precisely reconstruct the mandibular contour and successfully restore the patient's chewing function and esthetics. For the restoration and rehabilitation of long-term mandibular abnormalities, three-dimensional (3D) virtual surgical planning (VSP) and 3D-printed surgical guides are essential. Digital design and manufacturing were used to improve the accuracy of prostheses and facilitate occlusal reconstruction. Therefore, equipped with the methods of 3D VSP, 3D-printed surgical guides, free vascularized fibular flap, and immediate dental implants, this clinical report provides a feasible solution for mandibular reconstruction.

Retrospective three-dimensional analysis of bone resorption volumes of free microvascular scapular and fibular grafts

Defects in head and neck regions are standardly treated with microvascular grafts, such as free scapular (SFF) and fibular flaps (FFF), which are subject to a certain amount of bone resorption over time. The aim of this study was the 3-dimensional evaluation of bone resorption volume in both grafts. Over a period of 10 years, computed tomograms (CT) of patients with mandibular reconstructions with SFFs and FFFs were examined. The respective grafts were segmented as well as 3-dimensionally measured. Furthermore, factors such as gender, age, nicotine abuse, previous disease with type 2 diabetes, and adjuvant therapies, were examined for their influence. A total of 211 CT scans from 67 patients (40 SFFs and 27 FFFs) were included in the study. SFFs showed slightly higher median bone volumes (87.60% at 730 days and 86.55% at 1500 days) than FFFs (84.40% at 730 days and 82.10% at 1500 days). When final volumes were considered, FFFs had higher mean volume values (88.22%) than SFFs (83.82%), with significant correlation between resorption volume and time progression (r = 0.357, p = 0.024). All previously mentioned factors had no significant effect on bone resorption. Bone volumes of FFFs showed postoperative volume reductions similar to those of SFFs, with isolated SFFs having markedly lower volume values. The choice of a microvascular graft for reconstruction in the mandible proves difficult regarding bone resorption. The presented results may support decisions about future transplantations.

Long-term Growth, Functional, and Aesthetic Outcomes after Fibula Free Flap Reconstruction for Mandibulectomy Performed in Children

Background:

The long-term outcome of mandible reconstruction when performed in children has not been well documented.

Methods:

This is a retrospective case series of patients who underwent immediate oncologic mandible reconstruction with a fibula free flap at younger than 18 years of age over a 20-year period, by a single surgeon, who had long-term follow-up.

Results:

A total of 10 patients met inclusion criteria. Patient age ranged from 3 years and 8 months to 17 years and 9 months (mean 11 years). The etiology was malignant tumors in seven patients and benign locally aggressive tumors in three patients. All fibula flaps survived. All donor sites were closed primarily. The mean follow-up duration was 10 years and 5 months (range 3–20 years). The mean patient age at follow-up was 21 years and 10 months (range 8 years and 9 months to 30 years and 9 months). All patients achieved a regular diet and normal speech. Final occlusion was normal in seven of 10 patients. The aesthetic outcome, as evaluated by clinical examination, was a symmetric mandible in eight patients (in the other two the aesthetic asymmetry and malocclusion was minor and did not require operative intervention). Dental implants were ultimately placed in three patients. Leg function was normal in eight patients. Achilles lengthening and tendon transfer was required in one patient, and one patient developed ankle pain associated with running.

Conclusion:

Mandible reconstruction in children with the fibula free flap provides excellent aesthetic and functional outcomes that are durable over time.

Interest and outcomes of alveolar distraction osteogenesis for dental implant rehabilitation following mandibular reconstruction

Introduction: Alveolar distraction osteogenesis (ADO) is one of vertical bone augmentation technique used to restore the vertical bone discrepancy between the transplanted graft and the residual alveolar bone after mandibular reconstruction. The aim of this article is to present the clinical outcomes of ADO applied to reconstructed mandible for three patients. Observation: Three patients underwent alveolar distraction osteogenesis procedure on mandibula reconstructed by fibula free flap (n = 2) or iliac crest free flap (n = 1). The mean bone height increase was 11 mm. 16 implants have been placed in all patients, with a success rate of 100% and a mean follow-up of 25 months. Two complications occurred without compromising the final outcome of the procedure: one fracture of the basal bone and one bony interference, both during activation phase. Commentaries: ADO can be performed on reconstructed mandible with free flap to restore alveolar height. An acceptable implant-to-crown ratio allows an optimal supported implant prosthesis. The particular antecedent of our patients can lead to uncommon complications such as basal bone fracture, but doesn't seem to compromise implant placement with good success rate. Conclusions: ADO performed on reconstructed mandible allows appropriate dental implant rehabilitation, achieving good esthetics and occlusal outcomes.

LONG-TERM OUTCOMES OF DIFFERENT RECONSTRUCTION OPTIONS USING AUTOGENOUS BONE GRAFT FOR MANDIBULAR RECONSTRUCTION: A RETROSPECTIVE COMPARATIVE STUDY

Background: Several recent studies have attempted to document VBG and NVBG following mandibular reconstruction, mainly the advantages and disadvantages, but very few have specifically evaluated the differences in large parameters including both radiographic and functional aspects for long-term follow-up. However, the object of this study is to compare between two different methods of reconstruction in mandibular defects and to determine the outcomes of different reconstruction options using autogenous vascularized and nonvascularized bone grafts for mandibular reconstruction. Patients and Methods: a total of 39 patients, 22 (56.4%) females and 17 (43.6%) males, with a mean age of 36.41 years at the time of presentation (age ranged for 48 years). Study was performed in two stages at the Department of Head and Neck Surgery - Oral and Maxillofacial oncology. In the First stage (N=39), bone-density, bone resorption, and bone graft failure were examined radiographically on panorex and CBCT. The second stage included functional evaluation (physical examination and questionnaire) based on pain, infection, speech and recurrence. Both groups were followed-up for at least 1month, 6 months and 1 year. Results:the results show significant difference in Pain after one month (p=0.032), radiodensity (p=0.05), bone graft resorption (p=0.03) for 1 year follow-up in favor of the VBG group compared to the NVBG group, there was no statistical difference in bone graft failure, infection, speech and recurrence between the two groups. Conclusion: Vascularized bone graft is the method of choice, especially in extensive malignant defects. On the other hand, novascularized bone graft (81.2% success rate) is a suitable complementary flap for mandible reconstruction mainly in benign and healthy patients. For future studies, large sample size with long-term follow-up more than 1 year will be required to validate our study.

Long-Term Effect of Honeycomb β-Tricalcium Phosphate on Zygomatic Bone Regeneration in Rats

In recent years, artificial bones with high biocompatibility have been developed for hard tissue reconstruction. However, current bone replacement methods are inadequate for large defects, causing infection, exposure, and damage. We have developed a new honeycomb β-tricalcium phosphate (TCP) material, which achieved good bone regeneration after implantation in a rat complete zygomatic bone defect. In this study, we further investigated the ability of honeycomb β- TCP for remodeling after bone regeneration as a long-term result. Bone morphogenic protein (BMP)-2-free honeycomb β-TCP (TCP group) and honeycomb β-TCP with BMP-2 (BMP group) were implanted in the zygomatic bone of rats. Micro-computed tomography was performed to track the zygomatic bone morphology, and specimens were histologically examined for osteogenesis and remodeling. In the TCP group, no bone formation was observed at 1 month, but it was observed at 6 months. Bone formation was observed in the BMP group at 1 month, and β-TCP absorption reproducing the zygomatic bone morphology was observed at 6 months. This honeycomb β-TCP with BMP-2 may provide appropriate remodeling that reproduces good bone formation in the early stage and good morphology in the long term, offering an alternative bone reconstruction material to vascularized bone grafts.

Complication of osteo reconstruction by utilizing free vascularized fibular bone graft

The success of free vascularized fibular bone graft (FVFBG) has accelerated the osteo reconstruction which results from trauma, resection of a tumor or an infectious bone segment, or correction of congenital deformity. But the complication behind should not be overlooked. The failure could necessitate a second surgery, which prolong the rehabilitation period and produce further health cost. Worst, the patients may suffer a permanent impaired ankle function, or a sustained morpho-functional loss on reconstructive area which are hard to save. To provide an overview of the complication related to reconstruction by FVFBG, a narrative review is conducted to identify the complications including their types and rates, the contributing factors, the approaches to measure and the techniques to avoid. Methodologically, by quick research on Pubmed and abstract reading of reviews, we characterize five reconstructive areas where FVFBG were most frequently applied: extremities, mandible, spine, osteonecrosis of femoral head, and penile. Following, the complications on different reconstructive areas are retrieved, studied and presented in five (or more specifically, six) separate sections. By the way, meaningful difference between FVFBG and other bone flap was presented in a few words if necessary. Donor-site morbidities were studied and summarized as a whole. In these literatures, the evidences documented on limb and mandibular reconstruction have the fullest detail, followed by the spine and lastly the penile. In conclusion, FVFBG, though a mature technique, needs further deep and comprehensive study and maybe device-based assistance to achieve better reconstructive effect and minimize donor-site damage.

Free fibula flap for reconstruction of the severely atrophic mandible: a retrospective study

The purpose of this retrospective study was to assess the feasibility of using a free fibula flap (FFF) for reconstruction of the alveolar region of the severely atrophic mandible, by determining bone stability after dental implant insertion and prosthetic rehabilitation in a series of eight female patients aged 36-65 years. Dental implant insertion was performed 3-4 months after reconstruction. Prosthetic loading was performed 3-4 months after implant insertion. The height of the reconstructed mandible after surgery was 21.20±1.87mm, with an increase of 8.80±1.71mm from the preoperative height. The height of the FFF immediately after reconstruction was 11.24±1.10mm; this showed a vertical loss of 0.99±0.52mm (8.79%) and maintenance of 91.21% of the initial height at a mean 14 months post-reconstruction. Applying the Wical and Swoope formula to estimate the original mandibular body height, it was found that the difference between this calculated height (21.17±3.76mm) and the reconstructed height (21.20±1.87mm) was only 0.03±3.17mm (0.14%). An overall insignificant decrease of 0.46±1.14 cm³ in FFF volume had occurred at 3-4 months after dental implant functional loading, while in two cases an increase in volume was found (1.22cm³ and 1.71cm³). The good and stable results obtained show that the FFF may be used to reconstruct the whole mandibular alveolar region, with the best possible outcomes.

Correction of malocclusion using sliding fibula osteotomy with sagittal split ramus osteotomy after mandible reconstruction

Background

Fibula free flap mandible reconstruction is the standard procedure after wide resection of the mandible. Establishment and maintenance of normal occlusion are important in mandible reconstruction both intraoperatively and after surgery. However, scar formation on the surgical site can cause severe fibrosis and atrophy of soft tissue in the head and neck region.

Case presentation

Here, we report a case of severe soft tissue atrophy that appeared along with scar formation after mandibular reconstruction through the fibular free flap procedure. This led to normal occlusion collapse after it was established, and the midline of the mandible became severely deviated to the affected side that was replaced with the fibula free flap, leading to facial asymmetry. We corrected the malocclusion with a secondary operation: a sagittal split ramus osteotomy on the unaffected side and a sliding osteotomy on the previous fibula graft. After a healing time of 3 months, implants were placed on the fibula graft for additional occlusal stability.

Conclusion

We report satisfactory results from the correction of malocclusion after fibula reconstruction using sliding fibula osteotomy and sagittal split ramus osteotomy. The midline of the mandible returned to its original position and the degree of facial asymmetry was reduced. The implants reduced difficulties that the patient experienced with masticatory function.

Association between condylar position changes and functional outcomes after condylar reconstruction by free fibular flap

OBJECTIVES

Stable and appropriate condyle positioning is necessary for maintaining temporomandibular joint function. It is unclear if this position remains stable in patients after free fibular flap (FFF) condylar reconstruction. We investigated whether condylar position deviated after reconstruction, and whether this affected functional recovery.

MATERIALS AND METHODS

We retrospectively reviewed 43 patients who underwent conventional FFF condylar reconstruction, and 5 patients who underwent reconstruction by computer-assisted three-dimensional (3D) printing methods. Three-dimensional models were built from cone-beam computed tomography images obtained immediately postoperatively and 1-year postoperatively. The glenoid fossa and fibular condyle centers were used to measure the fibular condyle position in the models. Clinical examination indices, including maximum mouth opening (MMO), pain during chewing/mouth opening, and patient satisfaction with mastication and 1-year outcomes were assessed.

RESULTS

Fibular condyle position changed significantly over 1 year in both groups (P < 0.05). Clinical examination at 1 year after the surgery showed that in the conventional group, the MMO range was ≥ 35 mm in 76.7% of patients and < 35 mm in 23.3% of patients; 4.7% experienced pain during chewing/mouth opening, and 7% were dissatisfied with treatment outcomes. In the 3D printing group, all patients had an MMO range exceeding 35 mm, none had pain, and all were satisfied with functional outcomes.

CONCLUSIONS

The position of the fibular condyle deviates after reconstructive surgery, but it is unlikely to affect functional recovery.

CLINICAL RELEVANCE

These findings can form the basis for evaluation of functional outcomes of patients who have previously undergone condylar reconstruction by FFF.

Biomechanical Analysis of Various Reconstructive Methods for the Mandibular Body and Ramus Defect Using a Free Vascularized Fibula Flap

Several different methods exist for reconstructing the mandibular body and ramus defect with the use of a free vascularized fibula flap, but none have adequately addressed the long-term mechanical stability and osseointegration. The aim of this study is to compare the biomechanics of different surgical methods and to investigate the best approach for reconstructing the mandibular body and ramus defect. Five finite element models based on different reconstructive methods were simulated. Stress, strain, and displacement of connective bone sections were calculated for five models and compared. The models were printed using a 3D printer, and stiffness was measured using an electromechanical universal testing machine. The postoperative follow-up cone beam computed tomography (CBCT) was taken at different time points to analyze bone mineral density of connective bone sections. The results showed that the “double up” (DU) model was the most efficient for reconstructing a mandibular body and ramus defect by comparing the mechanical distribution of three sections under vertical and inclined loading conditions of 100 N. The stiffness detection showed that stiffness in the DU and “double down” (DD) models was higher compared with the “single up” (SU), “single down” (SD), and “distraction osteogenesis” (DO) models. We used the DU model for the surgery, and postoperative follow-up CBCT showed that bone mineral density of each fibular connective section increased gradually with time, plateauing at 12 weeks. We conclude that a free vascularized fibula flap of the DU type was the best approach for the reconstruction of the mandibular body and ramus defect. Preoperative finite element analysis and stiffness testing were shown to be very useful for maxillofacial reconstruction.

Prosthetic design related to peri-implant bone resorption in microvascular free fibular flap among patients with oral cancer: A retrospective clinical study

STATEMENT OF PROBLEM

Prosthetic rehabilitation is challenging after tumor excision in patients with oral cancer. Prosthetic parameters may be compromised because of the physical limitations of the oral cavity. Although microvascular free fibular flaps are a common treatment modality for mandibular reconstruction and allow the placement of dental implants, fibular resorption under long-term functional loading is still a controversial issue. Research focusing on how prosthetic design affects fibular resorption around dental implants in an oral cancer population is lacking.

PURPOSE

The purpose of this retrospective clinical study was to correlate the success of implant-supported prostheses in microvascular free fibular flaps with occlusal force and fibular resorption around the implants 7 years after functional loading.

MATERIAL AND METHODS

The T-Scan III was used to measure occlusal force in 13 participants with oral cancer. Forty-seven successful endosseous dental implants (Biomet 3i) under functional loading in the participants from 2010 to 2017 were analyzed retrospectively. Prosthetic design including fibular length, rehabilitated arch length, and crown-to-implant ratios was estimated from panoramic radiographs. The intergonial distance was used to calibrate the panoramic radiographs to enhance accuracy. To compensate for panoramic distortion, all parameters were represented as a ratio such as fibular length/mandibular width; implant-supported prosthesis length/mandibular dental arch length; implant-supported prosthesis length/maxillary dental arch length; and mandibular dental arch length/maxillary dental arch length. A generalized estimating equation was used for longitudinal analysis to estimate the impact of variables on fibular resorption around the implants.

RESULTS

Increased length of the implant-supported prostheses compared with maxillary and mandibular dental arch length significantly impaired the maximal occlusal force (P=.045 and P=.029). The crown-to-implant ratios in the fibular flaps were not correlated with fibular resorption around the implants under long-term functional occlusion (P>.05). The increased ratio of the implant-rehabilitated mandibular to maxillary dental arch length showed a statistically significant tendency to reduce fibular resorption around the implants (P=.007).

CONCLUSIONS

Crown-to-implant ratios were not significantly correlated with maximal occlusal force or fibular resorption around dental implants. Increasing the length of the reconstructed mandibular implant-supported prosthesis in the fibular flap will reduce occlusal force. The rehabilitated mandibular dental length should be as long as the maxillary arch for optimum occlusal stress distribution to maintain the peri-implant fibula bone level.

Metal trabecular bone reconstruction system better improves clinical efficacy and biomechanical repair of osteonecrosis of the femoral head than free vascularized fibular graft: A case-control study

In this study, we aim to compare and analyze the biomechanical repair and clinical efficacy of osteonecrosis of the femoral head (ONFH) with the use of metal trabecular bone reconstruction system and free vascularized fibular graft. The study enrolled 66 adult patients from medical records of nontraumatic ARCO 2A-3B stage ONFH. A simple ONFH model without surgical treatment was established in 13 cases, 29 cases were treated with metal trabecular bone reconstruction system, and 24 cases were treated with free vascularized fibular graft. Computer-recognized and extracted femur outlines were imported, and three-dimensional reconstructions were performed. The stress concentration and stress peak value were analyzed, and the Harris score, visual analog scale pain score, and operation status of the above patients were compared. Finally, quality of life assessment was performed using SF-36 scale. Metal trabecular bone reconstruction system provided less operation time, blood loss, and the total length of postoperative hospital stay than free vascularized fibular graft. Metal trabecular bone reconstruction system promoted bone reconstruction, increased bone mineral density and Harris score. The total clinical effective rate of young patients (20-40 years) was higher than that of older patients (41-60 years). Metal trabecular bone reconstruction system provided higher physical component summary, mental component summary, and role/social component summary than free vascularized fibular graft. This study demonstrates that both metal trabecular bone reconstruction system and free vascularized fibular graft can prevent or delay the progression of ONFH, while metal trabecular bone reconstruction system is a better choice because of better short-term clinical efficacy.

Osseous Changes Over Time in Free Fibular Flap Reconstruction

OBJECTIVES/HYPOTHESIS

Evaluate bone resorption in free fibular grafts and document resorption behavior as compared to dentulous and edentulous autochthonous mandibular bone.

STUDY DESIGN

Retrospective Chart review.

METHODS

Postoperative computed tomography images were used to evaluate fibular graft resorption rates and corresponding sites of the dentulous or edentulous mandible. Bone height, width, and cortical thickness were measured.

RESULTS

Eighteen patients underwent fibula free flap reconstruction following resection of a primary head and neck cancer. Mandibular defects were classified using Jewer's classification. The average interval loss of osseous height was 0.23 ± 0.09 mm/yr for fibula flap, 0.55 ± 0.13 mm/yr for dentulous native mandible, and 0.98 ± 0.41 mm/yr in edentulous native mandible. Change in osseous width was 0.19 ± 0.08 mm/yr, 0.55 ± 0.33 mm/yr, and 0.73 ± 0.15 mm/yr, respectively. Rate of superior cortical resorption was 0.33 ± 0.34 mm/yr, 0.35 ± 0.13 mm/yr, and 0.53 ± 0.11 mm/yr in fibula flap, dentulous, and edentulous mandible, respectively. Inferior cortical resorption rates were quantified as 0.30 ± 0.11 mm/yr, 0.35 ± 0.08 mm/yr, and 0.51 ± 0.08 mm/yr.

CONCLUSIONS

Fibula free flap reconstruction of the mandible provides excellent functional results and allows for stable outcomes. Bone resorption is significantly lower in fibular graft compared with both edentulous and dentulous mandible. Edentulous bone displays significantly increased rates of atrophy in comparison to the dentulous mandible. This may have implications with regard to long-term viability of both the fibular flap and native mandible. The role of dental restoration on overall osseous stability warrants further research.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:1113-1116, 2019.

Evaluation of postoperative changes in vascularized iliac bone grafts used for mandibular reconstruction

Vascularized iliac bone grafts are used for mandibular reconstruction, but the factors affecting graft maintenance are unknown. This study explored the postsurgical changes in vascularized iliac bone grafts in patients who had undergone mandibular reconstruction after segmental resection. The study involved 24 patients (16 men and eight women) with oral tumours or osteoradionecrosis. Thirteen patients required bare bone grafting (BBG) and 11 patients required reconstruction with soft tissue coverage (six with a skin paddle and five with direct closure). The bone graft maintenance rate (with regard to the height of the centre of the graft) was calculated immediately after surgery and at 3, 6, 12, 24, and 36months after surgery. The maintenance rate was significantly lower in the BBG group than in the soft tissue coverage group at 3, 6, 12, 24, and 36months, and in those who were fitted with dentures compared to those who were not at 6, 12, 24, and 36months. Local infection also influenced the maintenance rate, but not significantly so. These findings indicate that the reconstruction technique and denture use can affect the bone graft maintenance rate after mandibular reconstruction with vascularized iliac bone grafts.