血管化腓骨重建下颌骨后用腓骨残端游离移植及牙种植的可行性研究

目的: 探讨利用残余腓骨增加下颌骨缺损腓骨重建患者垂直骨高度的临床效果。方法: 选择12例下颌骨缺损血管化腓骨重建后拟行种植牙修复的患者,利用腿部残余腓骨段进行垂直骨增量,同期或延期植入种植体并最终完成牙列修复,对术后骨吸收情况和种植体稳定性、存留率等数据采用SPSS 19.0软件包进行统计分析。结果: 术后6个月,近中骨块和远中骨块的吸收量分别为（0.94±0.18）mm和（0.89±0.15）mm;术后12个月,吸收量分别为（1.16±0.21）mm和（1.07±0.17）mm。种植体植入6个月和12个月后,ISQ值分别为（67.25±6.43）和（71.08±4.89）;边缘骨吸收量在植入术后6个月和12个月分别为（0.65±0.12）mm和（0.76±0.18）mm。术后1年种植体存留率为87.1%。结论: 非血管化腓骨具有可靠的抗吸收能力,在下颌骨缺损重建术后垂直骨高度不足的情况下,可为种植体植入提供充足骨量,并维持长期稳定性和存留率。     

Reconstruction of maxillary and mandibular defects using prefabricated microvascular fibular grafts and osseointegrated dental implants -- a prospective study

The fibular flap can be used for a variety of indications. Recently, the treatment of four patients with severely atrophied upper jaws using a method to prefabricate the vascularized fibular graft has been published. This technique consists of a two-stage operation procedure that allows simultaneous prosthodontic rehabilitation and immediate placement of dental implants. In this paper eight patients with 29 ITI implants (Straumann AG, Waldenburg, Switzerland) who had reconstruction of either the upper or lower jaw are presented. The aim of the study was (i) to evaluate the behavior of the newly formed soft tissue around implants inserted in the fibula by applying periodontal parameters, (ii) to monitor prospectively the integration of the implants in the fibular graft, and (iii) to assess the osseous integration of the fibular graft used for reconstruction of the upper or lower jaw. Two implants failed during the observation time because of avascular bone at the distal end of the fibular graft. Stabilization of the graft, however, was never compromised. Due to the prefabrication firmly attached gingiva-like soft tissue could be provided preventing periimplant soft tissue inflammation and facilitating oral hygiene. After 1 year of observation the mean attachment level was similar to implants placed in original bone whereas vertical bone loss measured radiographically was lower in the present study. This may indicate that the remodeling of a bicortical bone requires a longer period of time compared with the bone of the alveolar crest. The prospective 1-year results are promising but long-term evaluation of periodontal and radiological parameters are required.     

非血管化游离骨移植同期种植骨活力的实验研究

目的观察非血管化骨移植同期种植的骨块在不同离体时间点植入体内后细胞活力及成骨情况.方法拔除狗前磨牙,口腔粘膜完全愈合后,截除长度3 cm的无牙下颌骨段,取不带血管和软组织的髂骨全层,植入直径2 mm带自攻螺纹的纯钛种植体2～3枚,分别在离体60、120分钟内植入下颌缺损区.术后4、8周取出植骨块,观察游离移植的非血管化骨块内细胞活力和新骨形成情况.结果非血管化游离骨移植同期种植恢复了下颌骨节段性缺损的连续性.游离骨块在离体60分钟植入体内4～8周为活骨块,可见到大量成活的骨细胞,并有数量不等的新骨形成.离体120分钟的游离骨块植入体内后4～8周为死骨块,其中未见成活骨细胞,部分骨块中见到破骨细胞.结论在以狗为对象的实验中,非血管化游离髂骨块移植同期种植可以修复长度3cm的下颌骨节段性缺损,植入体内骨块能否成活与其离体时间有关.     

Placement of endosteal implants combined with chin bone onlay graft for dental reconstruction in patients with grafted alveolar clefts

Endosteal implants were inserted into grafted alveoli after particulate cancellous bone and marrow grafting in seven patients with cleft lip or palate in conjunction with simultaneous chin bone onlay grafting. In these patients, the alveolar bone height of the bony bridge was insufficient when evaluated by both computed tomographic and periapical radiographic images. The age at first implant surgery ranged from 14 to 28 years. Although four of the seven patients had an uneventful course, three had wound dehiscence, and in all but one of them the exposed chin bone underwent partial or total necrosis. Ultimately all seven implants integrated into the bone, and the alveolar bone height was increased in all but one patient. The results indicate that chin bone onlay grafting with simultaneous implant insertion is useful in patients with cleft lip or palate with insufficient alveolar bone height.     

Comparative finite element analysis of mandibular posterior single zirconia and titanium implants: a 3-dimensional finite element analysis

PURPOSEZirconia has exceptional biocompatibility and good mechanical properties in clinical situations. However, finite element analysis (FEA) studies on the biomechanical stability of two-piece zirconia implant systems are limited. Therefore, the aim of this study was to compare the biomechanical properties of the two-piece zirconia and titanium implants using FEA.MATERIALS AND METHODSTwo groups of finite element (FE) models, the zirconia (Zircon) and titanium (Titan) models, were generated for the exam. Oblique (175 N) and vertical (175 N) loads were applied to the FE model generated for FEA simulation, and the stress levels and distributions were investigated.RESULTSIn oblique loading, von Mises stress values were the highest in the abutment of the Zircon model. The von Mises stress values of the Titan model for the abutment screw and implant fixture were slightly higher than those of the Zircon model. Minimum principal stress in the cortical bone was higher in the Titan model than Zircon model under oblique and vertical loading. Under both vertical and oblique loads, stress concentrations in the implant components and bone occurred in the same area. Because the material itself has high stiffness and elastic modulus, the Zircon model exhibited a higher von Mises stress value in the abutments than the Titan model, but at a level lower than the fracture strength of the material.CONCLUSIONOwing to the good esthetics and stress controllability of the Zircon model, it can be considered for clinical use.     

Efficiency of occlusal and interproximal adjustments in CAD-CAM manufactured single implant crowns - cast-free vs 3D printed cast-based

PURPOSEThe aim of this study was to evaluate the efficiency of occlusal and interproximal adjustments of single implant crowns (SIC), comparing a digital cast-free approach (CF) and a protocol using 3D printed casts (PC).MATERIALS AND METHODSA titanium implant was inserted at position of lower right first molar in a typodont. The implant position was scanned using an intraoral scanner and SICs were fabricated accordingly. Ten crowns (CF; n = 10) were subject to a digital cast-free workflow without any labside occlusal and interproximal modifications. Ten other identical crowns (PC) were adjusted to 3D printed casts before delivery. All crowns were then adapted to the testing model, simulating chair-side adjustments during clinical placement. Adjustment time, quantity of adjustments, and contact relationship were assessed. Data were analyzed using SPSS software (P < .05).RESULTSMedian and interquartile range (IQR) of clinical adjustment time was 02:44 (IQR 00:45) minutes in group CF and 01:46 (IQR 00:21) minutes in group PC. Laboratory and clinical adjustment time in group PC was 04:25 (IQR 00:59) minutes in total. Mean and standard deviation (±SD) of root mean squared error (RMSE) of quantity of clinical adjustments was 45 ± 7 µm in group CF and 34 ± 6 µm in group PC. RMSE of total adjustments was 61 ± 11 µm in group PC. Quality of occlusal contacts was better in group CF.CONCLUSIONTime effort for clinical adjustments was higher in the cast-free protocol, whereas quantity of modifications was lower, and the occlusal contact relationship was found more favourable.     

Computed tomography-guided implant surgery for dental rehabilitation in mandible reconstructed with a fibular free flap: description of the technique

The fibular free flap, with or without a cutaneous component, is the gold standard for reconstructing mandibular defects. Dental prosthetic rehabilitation is possible this way, even if the prosthesis-based implant is still a challenge because of the many anatomical and prosthetic problems. We think that complications can be overcome or reduced by adopting the new methods of computed tomography (CT)-assisted implant surgery (NobelGuide, Nobel Biocare AB, Goteborg, Sweden). Here we describe the possibility of using CT-guided implant surgery with a flapless approach and immediate loading in mandibles reconstructed with fibular free flaps.     

位点保存术及种植联合游离龈移植术修复牙周炎患者后牙缺失1例报告

固定桥修复是临床常见的修复方式之一,外形美观、咀嚼效率高。然而固定桥修复不利于患者自我清洁,菌斑控制不佳时可加速基牙牙周炎进展,联冠修复往往掩盖病情,不利于基牙疾病的早期发现。缺牙区常伴有牙槽骨高度、宽度减少,角化龈消失等软硬组织缺陷。随着种植技术的发展,种植修复已成为牙列缺损的首选修复方法。本文展示1例牙周炎患者拆除不良固定桥修复体后位点保存术及种植联合膜龈手术修复后牙缺失的治疗过程,种植后游离龈移植增加种植体周围角化龈宽度,改善功能及美观,术后1年效果稳定。现报道如下。     

Osseointegration of 3D-printed titanium implants with surface and structure modifications

BackgroundThe purpose of this study was to establish a mechanical and histological basis for the development of biocompatible maxillofacial reconstruction implants by combining 3D-printed porous titanium structures and surface treatment. Improved osseointegration of 3D-printed titanium implants for reconstruction of maxillofacial segmental bone defect could be advantageous in not only quick osseointegration into the bone tissue but also in stabilizing the reconstruction.MethodsVarious macro-mesh titanium scaffolds were fabricated by 3D-printing. Human mesenchymal stem cells were used for cell attachment and proliferation assays. Osteogenic differentiation was confirmed by quantitative polymerase chain reaction analysis. The osseointegration rate was measured using micro computed tomography imaging and histological analysis.ResultsIn three dimensional-printed scaffold, globular microparticle shape was observed regardless of structure or surface modification. Cell attachment and proliferation rates increased according to the internal mesh structure and surface modification. However, osteogenic differentiation in vitro and osseointegration in vivo revealed that non-mesh structure/non-surface modified scaffolds showed the most appropriate treatment effect.Conclusion3D-printed solid structure is the most suitable option for maxillofacial reconstruction. Various mesh structures reduced osteogenesis of the mesenchymal stem cells and osseointegration compared with that by the solid structure. Surface modification by microarc oxidation induced cell proliferation and increased the expression of some osteogenic genes partially; however, most of the markers revealed that the non-anodized solid scaffold was the most suitable for maxillofacial reconstruction.     

游离端缺失牙周炎患者通过种植修复联合游离龈移植术恢复口腔功能1例

随着软硬组织增量技术的不断发展,种植修复适应证越来越广。Ⅳ期牙周炎患者由于失牙数多和软硬组织破坏,在进行种植修复时,需要临床医生全面考量,对软硬组织量充分评估,以实现种植后植体周健康。本文报道1例Ⅳ期C级牙周炎患者上下颌游离端缺失,通过牙周系统治疗、种植修复以及游离龈移植术恢复患者口腔功能,达到良好的临床效果。     

Long-term outcomes of implant-based dental rehabilitation in head and neck cancer patients after reconstruction with the free vascularized fibula flap

The study aimed at evaluating, comprehensively, implant-based dental rehabilitation in head and neck cancer patients after maxillofacial reconstruction with a vascularized free fibula flap (FFF).Data were obtained by retrospectively reviewing the medical records of patients treated in Amsterdam UMC-VU Medical Center. Dental implant survival and implant success according to the Albrektsson criteria were analyzed. Additionally, prosthetic-related outcomes were studied, with a focus on functional dental rehabilitation.In total, 161 implants were placed in FFFs, with a mean follow-up of 4.9 years (range 0.2–23.4). Implant survival was 55.3% in irradiated FFFs and 96% in non-irradiated FFFs. Significant predictors for implant failure were tobacco use and irradiation of the FFF. Implant success was 40.4% in irradiated FFFs and 61.4% in non-irradiated FFFs, mainly due to implant failure and non-functional implants. Implant-based dental rehabilitation was started 45 times in 42 patients, out of 161 FFF reconstructions (27.9%). Thirty-seven patients completed the dental rehabilitation, 29 of whom achieved functional rehabilitation. Irradiation of the FFF negatively influenced attainment of functional rehabilitation. For patients with functional rehabilitation, the body mass index varied at different timepoints: FFF reconstruction, 24.6; dental implantation 23.5; and after placing dental prosthesis, 23.9.Functional implant-based dental rehabilitation, if started, can be achieved in the majority of head and neck cancer patients after FFF reconstruction. Actively smoking patients with an irradiated FFF should be clearly informed about the increased risk for implant and prosthetic treatment failure.     

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.     

Combination of biomechanical evaluation and accurate placement of dental implants: a new concept of virtual surgery in maxillary and mandibular functional reconstruction

Biomechanics are crucial for bony regeneration and survival of implants in functional maxillary and mandibular reconstructions. However, we know of no study that has included an analysis of biomechanics to guide the optimal position of a fibular graft in virtual surgery. This study was designed to evaluate the combination of biomechanics and accurate placement of implants for virtual surgery in reconstruction of the jaw using fibular grafts. Thirty-one patients had maxillary or mandibular reconstruction with vascularised fibular grafts and the immediate placement of dental implants. Virtual studies were made preoperatively to evaluate the biomechanics and to assess the position of the fibular grafts with minimal distribution of stress. All operations proceeded accurately and with no complications with a mean (range) of 14 (6-20) months’ follow-up. According to the individual biomechanical evaluations, the optimal position for the fibular graft is probably the middle of the mandibular body or below the bottom of the maxillary sinus. The combination of biomechanical evaluation and accurate placement of dental implants is a new concept that could achieve good biomechanical positioning of fibular grafts in the jaw and a desirable level of accuracy for functional reconstruction.     

Assessment of quality of life and sociocultural aspects in patients with ameloblastoma after immediate mandibular reconstruction with a fibular free flap

Our aim was to evaluate the quality of life (QoL) in patients with ameloblastoma who had been treated by immediate mandibular reconstruction with a fibular free flap, and to analyse the association between QoL and their sociocultural and medical characteristics. We assessed the QoL outcomes of 33/45 patients using the University of Washington quality of life (UW-QoL) questionnaire and the 14-item Oral Health Impact Profile (OHIP-14). Thirty-three of the 45 questionnaires were returned (73%). In the UW-QoL the best-scoring domain was “shoulder”, whereas the lowest scores were for “chewing” and “activity”. In the OHIP-14 the lowest-scoring domain was “handicap”, followed by “social disability” and “psychological discomfort”. Mandibular reconstruction with a fibular free flap significantly influenced the patients’ QoL and oral function. Their sociocultural data showed that most patients had a fairly low level of education.     

腓骨肌皮瓣修复6岁儿童创伤性口腔颌面部缺损：1例报告及文献复习

临床上造成口腔颌面部缺损的原因主要有肿瘤、瘢痕切除和创伤等,但很少有切割伤导致口腔颌面部软、硬组织大面积缺损的报道,儿童更为罕见,在治疗上具有极大的难度与挑战。本文报告1例制备游离血管化腓骨肌瓣带有巨大皮岛修复重建6岁儿童口腔颌面部软、硬组织重度缺损的病例,并对相关文献进行复习。