Bone volume change following vascularized free bone flap reconstruction of the mandible

BackgroundBone volume changes following vascularized bone flaps and possible confounding factors over time are described in the literature with some controversy. The purpose of this study was to evaluate the bone volume behavior of two frequently used free flaps.Materials and methodsComputed tomography (CT) scans were examined with regard to bone volume using the software program ITK-SNAP for all patients who required mandibular reconstruction with a free fibula flap (FFF, conventionally vs assisted by computer-aided design/computer-aided manufacturing (CAD/CAM)) or iliac crest flap (DCIA) following mandibular resection because of benign or malign processes, between August 2010 and August 2015. Clinical data, complication rates, and CT scans were analyzed retrospectively. Additionally, complication rates (microvascular revision, flap loss, postoperative fistula or dehiscence, and postoperative bone exposure) were compared within early (≤30 days), late (31st–100th day), and overall (≤100th day) postoperative time intervals.Results113 cases, comprizing 89 FFF and 24 DCIA cases, were included. FFF showed superior bone volume behavior over the DCIA flap. Multivariable regression models assessed the relationships between the following and bone volume behavior: interval between operation and CT scan (p < 0.683), age (p = 0.004), gender (p = 0.006), BMI (p = 0.400), adjuvant radiation therapy (p = 0.334), reconstruction with DCIA flap (p < 0.0001), number of segments (p = 0.02), and incidence of dental implant insertion (p = 0.45).ConclusionsThe bone volume of FFFs remains stable. DCIA flaps show a higher bone volume reduction, but the postoperative course might be associated with fewer complications. Time interval between operation and CT scan, age, gender, reconstruction with DCIA flap, and number of fibula segments contributed significantly to bone volume behavior.     

两种血管化游离骨肌瓣移植修复下颌骨缺损临床分析

目的:评价血管化游离髂骨肌瓣和腓骨肌瓣移植修复下颌骨缺损的临床效果,比较两种修复方法的优缺点。方法:对44例血管化髂骨肌瓣和腓骨肌瓣移植修复下颌骨缺损的病例进行回顾性研究,分析两种骨肌瓣修复后对患者面部外形与口腔功能的影响,对比供受区并发症的差异。结果:20例髂骨肌瓣,24例腓骨肌瓣均成活;二者在恢复面部外形与口腔功能上无明显差异,在移植骨长度上,两者有明显不同。结论:血管化游离髂骨肌瓣与腓骨肌瓣作为下颌骨缺损修复的常用方法,可以满足不同类型下颌骨缺损修复的需要,但根据两种骨肌瓣的特点,对于缺损长度低于8 cm,可优先考虑髂骨瓣,而缺损范围大于8 cm的可选腓骨瓣。     

Comparison of outcome of microvascular bony head and neck reconstructions using the fibular free flap and the iliac crest flap

Several microvascular free flaps are available for reconstruction of the osseous components after resections for head and neck cancer. We have prospectively evaluated patients treated by bony microsurgical reconstruction to identify predictors of adverse outcomes for delayed wound healing and failure of free flaps. All patients from July 2007 to June 2011 who had reconstructions with microvascular fibular or iliac crest flaps immediately after resection of the tumour were evaluated. There were a total of 156 bony free flaps: 120 (77%) fibular and 36 (23%) iliac crest flaps. A total of 133 (85%) were successful. Delayed wound healing was more common with the iliac crest flap (p = 0.01) at the intraoral site (p = 0.04). Significantly more iliac crest free flaps failed (p = 0.02). Anastomosis to the facial artery (p = 0.05) and facial vein (p = 0.04), and duration of overall operating time were associated with a significantly higher risk of failure of the flap. Patients with cancer of the head and neck who require microsurgical bony reconstruction are at increased risk of postoperative complications. Significantly more complications were found with the iliac crest flap, whereas the fibular flap was associated with a significantly longer operating time.     

Non-vascularised iliac crest bone graft for immediate reconstruction of lateral mandibular defect

Introduction

Mandibular defect reconstruction is extremely important to achieving an improved quality of life of patients as this bony defect influences facial harmony and aesthetics. Reconstruction of mandibular defects at our centre comprises use of reconstruction plate, non-vascularised anterior iliac crest graft and vascularised fibula flap. Despite the large mandibular defect recorded in our developing environment, non-vascularised iliac crest graft continues to play a role in its exclusive use for lateral mandibular defects. The aim of this study was to analyse the role, complications and outcomes of the use of non-vascularised iliac crest graft for mandibular reconstruction in a free flap-enabled centre.

Patients and method

This was a retrospective case cohort from study institution’s records of mandibular reconstruction following mandibular surgery for benign tumours. Eligibility for study inclusion comprised case cohort with head and neck diseases requiring mandibular surgery and reconstruction with either reconstruction plate, non-vascularised iliac crest graft or vascularised fibula flap.

Results

A total of 18 subjects underwent iliac crest grafting. Of the 18 subjects with iliac crest graft, 7 (39 %) were females while 11 (61 %) were males. Ten of the 18 subjects with iliac crest grafting were diagnosed with ameloblastomas. Six (33.3 %) subjects had class H (Jewer’s classification) mandibular defect. The average graft length was 5.4 cm and height was 2.3 cm. Three cases experienced graft site complications of which two grafts were lost. All 18 cases experienced good to acceptable clinical outcomes. Predictors of graft outcome were not statistically significant.

Conclusion

Despite our small sample size, it is suggestible that non-vascularised iliac crest graft be considered for lateral mandibular defect reconstruction, considering the reduced graft failure rate and satisfactory clinical outcomes from this study.

     

腓骨瓣及CAD/CAM技术在重建下颌骨缺损中的应用

目的　探讨应用腓骨瓣及CAD/CAM技术修复大面积下颌骨缺损的经验。方法　根据16例患者下颌骨缺损的部位和特征,通过螺旋CT扫描获取缺损区的数据,在软件中应用CAD/CAM技术模拟下颌骨切除及重建手术,利用快速成型机加工制作出实物模型,依据模型对腓骨进行塑形、钛板重建,恢复下颌骨的形态和功能。结果　CAD/CAM技术的应用使术中截骨、腓骨塑形、定位速度明显加快;术后患者面部外形基本对称,影像学检查显示下颌骨缺损区的重建形态及固位良好;无严重并发症。结论　腓骨瓣联合CAD/CAM技术重建下颌骨缺损,能够明显缩短手术时间,提高手术质量,保证手术效果,是值得推广的重建下颌骨缺损的理想方法。     

A comparison of vascularized fibular flap and iliac crest flap for mandibular reconstruction

Segmental mandibular defects, which are caused either by ablative surgery or trauma, are usually accompanied by different degrees of skin, soft tissue or mucosa losses. The reconstruction of such defects requires complicated surgical procedures.An ideal mandibular reconstruction method must support the insertion osseointegrated dental implants which is necessary for total oral rehabilitation. The soft tissue defect should also be reconstructed if it accompanies the bony defect. We performed 37 mandibular reconstructions using either vascularized iliac crest flap or fibula flap. Sixteen of 24 patients who underwent mandibular reconstruction using iliac crest flap, and 3 of 13 patients who has been reconstructed with fibula flaps, had mandibular defects involving skin and/or mucosa. Both techniques were compared regarding patients records such as hospital stay, operation time, defect size, etiopathogenesis, skin paddle, blood transfusion, and complication rates. Self-assessment questionnaires were also used to evaluate aesthetic and functional results.When 2 different mandibular reconstruction techniques are compared regarding patient records, the complication rate of fibula flap was less than the iliac crest flap. Functional and aesthetic results also showed that oral continence, social activities, and facial appearance rates of fibula flap were superior to iliac crest flap. Lower complication rates of fibula flap group may be associated with patients' higher satisfaction rate.Both flaps are commonly used in mandibular reconstruction, however, many parameters including defect localization, defect size, presence of soft tissue defect should be considered.     

CAD/CAM and conventional reconstruction of the mandibular condyle by fibula free flap: a clinical and radiological evaluation

The aim of this study was to analyse the radiological and clinical outcomes of condylar reconstruction by fibula free flap (FFF), comparing conventional freehand and CAD/CAM techniques. Fifteen patients (nine CAD/CAM, six freehand) who underwent condylar reconstruction with a FFF were reviewed retrospectively regarding pre- and postoperative computed tomography/cone beam computed tomography scans and clinical function. After surgery, all patients were free of temporomandibular joint pain. Mean postoperative mouth opening was 30.80 mm, with no significant difference between the freehand and CAD/CAM groups. In all patients, laterotrusion was decreased to the contralateral side (P = 0.002), with no difference between freehand and CAD/CAM, while the axis of mouth opening deviated to the side of surgery (P < 0.001). All patients showed significant radiological deviation of the fibular neocondyle in the laterocaudal direction (lateral: P = 0.015; caudal: P = 0.001), independent of the technique. In conclusion, reconstruction of the mandibular condyle by FFF provided favourable functional results in terms of mouth opening, reduction of pain, and mandibular excursions. Radiological deviation of the neocondyle and deviation of laterotrusion and mouth opening did not impair clinical function. CAD/CAM planning facilitated surgery, decreased the surgery time, and improved the fit of the neocondyle in the fossa.     

Mandibular reconstruction with free fibula flaps in the elderly: a retrospective evaluation

The purpose of this study was to evaluate surgical outcomes in elderly patients who had undergone free fibula flap transfer for malignant head and neck tumours. A retrospective chart review was performed to identify patients who had undergone free fibula flap transfer for mandibular reconstruction after malignant tumour resection at Jichi Medical University Hospital between May 2009 and April 2015. Enrolled patients were divided into an elderly group (≥80 years old) and a younger group (<80 years old). Seventeen patients met the inclusion criteria and were included in the elderly group. Age at surgery ranged from 80 to 92 years. Thirteen patients (76.5%) experienced postoperative complications. Surgical site complications occurred in seven patients. The success rate of free fibula flap transfer was 100%. Systemic complications occurred in nine patients, most commonly delirium (n = 6). No perioperative mortality was encountered. The overall 1-year survival rate was 94.1% (16/17). No patient reported gait disturbance as a donor site complication or any other major complication. The incidence of postoperative complications did not differ significantly between the elderly and younger groups. Almost no difference in postoperative course was seen between the groups. Elderly patients appear to tolerate free fibula flap reconstruction just as well as younger patients.     

Patient-centred outcomes and dental implant placement in computer-aided free flap mandibular reconstruction: a systematic review and meta-analysis

Computerised surgical planning (CSP) and computer-aided design and manufacturing (CAD/CAM) have been demonstrated to increase surgical accuracy and reduce operative time in free flap mandibular reconstruction, but evidence is lacking as to their impact on patient-centred outcomes. Implant-supported dental prostheses, however, have been associated with improved quality of life outcomes following free flap mandibular reconstruction. We aim to review reported patient-centred outcomes in mandibular reconstruction with CSP and CAD/CAM and determine whether use of these technologies is associated with higher rates of dental implant placement following free flap mandibular reconstruction. On December 20, 2020, a systematic review and meta-analysis were conducted according to PRISMA guidelines for studies reporting quality of life, functional outcomes, and rates of dental implant placement in computer-aided free flap mandibular reconstruction. A random-effects meta-analysis was performed to compare dental implant placement rates between surgeries using CSP and those using conventional freehand techniques. A total of 767 articles were screened. Nine articles reporting patient-centred outcomes and 16 articles reporting dental implant outcomes were reviewed. Of those reporting dental implant outcomes, five articles, representing a total of 302 cases, were included in the meta-analysis. Use of CSP was associated with a significant increase in the likelihood of dental implant placement, with an odds ratio of 2.70 (95% CI 1.52 to 4.79, p = 0.0007). Standardised reporting methods and controlled studies are needed to further investigate the impact of CSP and CAD/CAM technologies on functional outcomes and patient-reported quality of life in free flap mandibular reconstruction. Use of CSP and CAD/CAM technologies is associated with higher rates of dental implant placement in patients undergoing free flap mandibular reconstruction when compared to conventional freehand techniques.     

Application of computer-aided designed/computer-aided manufactured techniques in reconstructing maxillofacial bony structures

Background

Today, virtually planned surgery and computer-aided designed/computer-aided manufactured (CAD/CAM) tools to reconstruct bony structures are being increasingly applied to maxillofacial surgery. However, the criteria for or against the usage of the CAD/CAM technique are disputable, since no evidence-based studies are available. Theoretically, the CAD/CAM technique should be applied to complex cases. In this case report, we present our experiences and discuss the criteria for application.

Case report

Three cases are reported in which subjects received an osseous reconstruction using CAD/CAM techniques. In the first case, resection of the mandibular body and ramus was carried out, and reconstruction with a vascularised iliac bone transplant was performed. During surgery, a repositioning of the ipsilateral condyle was necessary. The second case comprised a wide mandibular reconstruction together with a repositioning of the condyles and the soft tissue chin using a two-segment osteomyocutaneous fibula flap. In the third case, a two-flap technique consisting of a double-barrelled osseous fibula flap and a radial forearm flap was applied to cover a wide palatine defect.

Conclusion

Our experience suggests that the CAD/CAM technique provides an accurate and useful treatment not only in complex cases, but also in simpler ones, to achieve an anatomically correct shape of the bone transplant and to reposition adjacent structures.     

Comparison of the complications of mandibular reconstruction using fibula versus iliac crest flaps: an updated systematic review and meta-analysis

The aim of this study was to review and compare the complications of mandibular reconstruction using the fibula or iliac crest flap. PubMed, Embase, and the Cochrane Library were systematically searched for available papers published up to May 2020. The primary outcomes were the number of failures, the number of patients with major donor site complications, and the number of patients with recipient site complications. Eighteen studies involving 942 patients were included (one randomized controlled trial, 12 cohort studies, and five case series). There was no difference between the fibula flap and the iliac crest flap regarding the odds ratio of failure (P = 0.563), donor site complications (P = 0.756), or recipient site complications (P = 0.452). There was no difference in the dental outcomes between the two flaps (P = 0.296). The sensitivity analyses suggest that the meta-analyses were robust. There was no publication bias. This meta-analysis suggests no difference between the fibula flap and the iliac crest flap regarding the odds ratios of failure, donor site complications, recipient site complications, and dental outcomes. The recent development of computer-aided design, 3D printing, and other technologies could optimize the surgical design, improve the success rate of the surgery, and reduce complications. Nevertheless, all non-randomized studies will be at a relatively high risk of bias. Therefore, caution should be exercised when interpreting the results of the analyses.     

Virtual planning,simultaneous dental implantation and CAD/CAM plate fixation: a paradigm change in maxillofacial reconstruction

Prosthetic rehabilitation in patients undergoing reconstructive surgery using vascularized free flaps is challenging, and functional rehabilitation of the patient with a fixed prosthesis is rare. Virtually planned maxillofacial reconstruction including simultaneous dental implantation according to the prosthodontic ideal position of the implants could further enhance dental rehabilitation. The data of 21 patients undergoing fibula free flap reconstructive surgery with CAD/CAM patient-specific reconstruction plates during the years 2015–2018 were analysed, including the applicability of the virtual plan, flap survival, duration of surgery, ischemia time, simultaneous dental implantation, implant exposure, and postoperative complications. The virtual plan could be translated to surgery in all cases. In total, 76 dental implants were simultaneously placed during primary reconstruction in the 21 patients. For 38.1% of these patients, the implants could be uncovered in secondary surgery; the mean duration until exposure was 7.6 months. The implant survival rate was 97.4% (74/76). Wound infection requiring a secondary intervention occurred in 23.8% of patients during follow-up. Virtually planned reconstruction with a fibula free flap, simultaneous dental implantation, and CAD/CAM plates allows early and functional dental rehabilitation. A dental workflow should be integrated into the virtual planning, and prosthetically favourable implant positions should determine the position of the fibula segments.     

Accuracy of CAD/CAM mandibular reconstruction: A three-dimensional,fully virtual outcome evaluation method

Purpose

Computer-aided design/computer-aided manufacturing (CAD/CAM) methods for mandibular reconstruction have improved both functional and morphological results. We evaluated the accuracy of the CAD/CAM method for mandibular reconstruction and assessed the quantitative and qualitative reproducibility of virtual preoperative planning.

颧种植体在上颌骨缺损重建中的应用探讨

目的：评价颧种植体结合血管化骨瓣修复上颌骨缺损的效果。方法：对4例上颌骨切除术后缺损患者,利用三维CT数据,借助CAD／CAM系统制作1：1大小的解剖模型,术前测量相关参数并制作精确种植模板。术中采用血管化骨肌皮瓣和骨结合牙种植体修复上颌骨缺损,利用上颌骨和颧骨的测量数据．结合定位模板共植入6枚颧种植体和7枚牙种植体,颧种植体结合血管化骨瓣重建上颌骨的形态和功能。结果：利用血管化骨瓣重建4例患者的上颌牙弓形态,使面中1／3得以恢复：在术前设计和术中植入6枚颧种植体和7枚常规种植体时．应用解剖学模型和外科模板,使种植体精确定位。结论：上颌骨术后缺损,可采用颧种植体重建颧上颌支柱,恢复面中1／3的形态：使用血管化骨瓣结合颧种植体,提高了上颌骨缺损修复的效果;颧上颌支柱的恢复,使he的稳定得到了保证．从而有利于美观和功能的恢复。     

Complications and loss of free flaps after reconstructions for oral cancer

The aim of this retrospective study was to analyse the incidence of complications and loss of flaps after primary reconstructions for oral cancer in 191 patients at our hospital over the five years 2005–2010. The patients’ clinical and personal details, characteristics of the tumours, types of microvascular flap, complications, and outcomes were recorded. The soft tissue flaps used most often were the fasciocutaneous radial forearm free flap (RFFF) (n = 86, 45%) and the anterolateral thigh free flap (ALTFF) (n = 48, 25%) while the most commonly used osseous flap was the deep circumflex iliac artery flap (DCIA) (n = 25, 13%). There were postoperative complications that required intervention in a quarter of the patients, most often in the age group 41–50 years (p = 0.018). Older age was not associated with the development of complications. The overall survival of all free flaps was 181/191 (95%), and the only significant individual predictor of loss of a flap was reconstruction with a DCIA (p = 0.016), five of the 25 of which were lost. We conclude therefore that DCIA free flaps are associated with an increased risk of failure; the method of osseous reconstruction for maxillofacial reconstruction should be selected carefully; and carefully chosen older patients do not seem to be at increased risk of morbidity.     

带血管蒂腓骨组织瓣游离移植修复下颌骨缺损的临床研究

目的:评价带血管蒂腓骨组织瓣游离移植修复下颌骨缺损的临床应用价值。方法:对25例患者用腓骨瓣游离移植修复下颌骨缺损。手术采取血管吻合、坚固内固定方法恢复下颌骨形态及完整性。其中22例患者为单纯腓骨瓣移植,3例患者为携带肌皮瓣或皮瓣的腓骨瓣移植,3例患者还同期植入种植体共5枚。结果:25例患者平均随访917个月,成功率为96%。3个患者的5枚种植体均达到良好的骨整合效果,并已行上部义齿的修复。62% 的患者可正常进食,余38%的患者可进软食。96%的患者面部外形的恢复达满意或较为满意。所有患者均能正常行走,无1例出现踝关节不稳定。结论:带血管蒂的游离腓骨组织瓣具有众多其它自体骨组织瓣不可比拟的优点, 是下颌骨缺损修复重建的最佳方法之一。     

Iliac flap versus fibula flap in mandibular reconstruction

The mandible is one of the important parts of the body in terms of facial appearance and function. Vascularized free bone grafts have become the criterion standard in mandible reconstruction. With flap survival rates not too much distant to 100%, the focus is now on function and aesthetics. With the various free-flap options now available, reconstruction of the mandibular defect has achieved significant improvement in both functional and aesthetic results. However, few studies have compared the results of these options. The fibula is defined as the most popular flap in mandibular reconstruction, and only in few papers iliac flaps are preferred. However, quality of life and effectiveness data are not available to support this choice. Not any previous study prospectively compared these 2 flaps. Short- and long-term results of an outcome-research study were prospectively compared in microvascular mandibular reconstruction with fibular flap and iliac crest flaps. Mean functional and quality-of-life scores were higher following iliac crest reconstructions. Fibular flap was the flap of choice in total/subtotal mandibulectomy, but it does not appear preferable in hemimandibulectomy and/or in cases of segmental mandibulectomy, if compared with the iliac crest.     

Interface of unloaded titanium implants in the iliac crest, fibula, and scapula: a histomorphometric and biomechanical study in the pig

PURPOSE: Prefabrication of free vascularized fibular flaps is a 2-stage procedure for the reconstruction of maxillary and mandibular defects. The delay between prefabrication and flap transfer is 6 weeks and depends on biomechanical stability and osseointegration of the implants. The purpose of this animal study was to evaluate implant stability by measuring the removal torque values (RTVs) at 3, 6, and 12 weeks and to compare the results with interface strength of the bone-implant surface in the fibula, the scapula, and the iliac crest under unloaded conditions. MATERIALS AND METHODS: ITI implants (n = 108) with a sandblasted and acid-etched surface were placed in the fibula, the scapula, and the iliac crest of 6 Yorkshire pigs. Biomechanical, histologic, and histomorphometric results were collected at 3, 6, and 12 weeks, respectively. RESULTS: Bicortical anchored 8-mm implants in the fibula (63.7 to 101.8 Ncm) showed RTVs similar to those of monocortical anchored 12-mm implants in the scapula (62.3 to 99.7 Ncm). The RTVs of monocortical anchored 8-mm and 10-mm implants in the iliac crest (19.1 to 44.3 Ncm) and the scapula (27.2 to 55.3 Ncm) were significantly lower. The bone-to-implant contact in the fibula at 3, 6, and 12 weeks (35.2%, 44.4%, and 46.8%, respectively) was similar to that in the iliac crest (24.2%, 44.2%, and 52.5%, respectively), but significantly lower than in the scapula (63.7%, 73.8%, and 74.2%, respectively). DISCUSSION AND CONCLUSION: Bicortical anchorage determined implant stability in the fibula, whereas interfacial strength seemed to define stability in the scapula. The quality and type of bone determined the bone's response in terms of biomechanical press fit or biologic interface strength.     

Oromandibular reconstruction using microvascularized bone flap: report of 1038 cases from a single institution

This retrospective study was performed to review 1038 patients who underwent mandibular reconstruction with free vascularized bone flaps at a single institution between 2006 and 2017. Of these patients, 827 (79.67%) had fibula flaps, 197 (18.98%) had deep circumflex iliac artery perforator (DCIA) flaps, and 11 (1.06%) had scapula bone flaps. The most common pathological diagnosis was ameloblastoma (n = 366, 35.26%), followed by squamous cell carcinoma (n = 278, 26.78%) and osteoradionecrosis (n = 152, 14.64%). Fifty-seven patients (5.49%) had major complications requiring surgical intervention and one patient died of a pulmonary embolism. Venous crisis was the most frequent major complication (n = 20, 1.93%), followed by haematoma (n = 17, 1.64%) and flap necrosis (n = 14, 1.35%). One-stage mandibular reconstruction was preferred whenever possible, as this generally decreases the financial and hospitalization burden. The four-segment method of jaw reconstruction appeared to achieve good aesthetic appearance results in Asian patients and this was not associated with a higher risk of segment ischemia compared with the three-segment method.     

Early bone resorption of free microvascular reanastomized bone grafts for mandibular reconstruction – A comparison of iliac crest and fibula grafts

ObjectivesPatients with continuous bone defects of the mandible after ablative tumor surgery need bony reconstruction for proper function and aesthetics. Free microvascular reanastomized bone grafts provide a clinically proven option for such patients, yet the optimal source of donor tissue has not yet been established. The aim of this study was to evaluate and compare the bone volume stability of vascularized bone grafts, particularly in the early highly resorptive phase, from the iliac crest (DCIA) and the fibula and to assess the implantologic rehabilitations.Materials and methodsThirty-six patients with mandibular continuity defects due to tumor resection were reconstructed by the use of vascularized bone grafts; 21 patients received DCIA flaps and 15 patients received a composite free fibular flap, depending on the size and location of the defect. Bone resorption was assessed using digital panographs. Radiographs were taken immediately after bone reconstruction, 6 months postoperatively, prior to implant surgery, and at prosthetic loading.ResultsAfter a mean observation period of 6 months, vertical bone resorption was 6.79% for the patients of the iliac crest group (DCIA), 10.20% after 11 months, and 12.58% after 17 months. Fibular grafts showed a bone resorption of 5.30% after a mean observation time of 6 months, 8.26% after 11 months, and 16.95% after 17 months. Eighteen patients received 71 implants for implant-retained dental reconstructions.ConclusionsMicrovascular reanastomized bone grafts represent a reliable treatment option for reconstruction in cases of large defects of the mandible, with low graft resorption in the early healing phase. Additionally, the compared grafts provide sufficient bone volume to permit implant rehabilitation.