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.     

CAD/CAM联合游离腓骨肌皮瓣修复双侧下颌骨大范围骨缺损

目的:探讨恢复双侧下颌骨大范围骨缺损的解剖外形、重建患者咬合功能的有效方法。方法:对病变累及双侧下颌骨、需进行(或已进行)节段性骨切除术的15例患者行术前CT扫描,提取扫描数据,采用CAD/CAM快速原型技术行数字化颅颌面骨三维重建和下颌骨实体模型打印。在实体模型上设计截骨区间和钛网外形,数控成型机冲压钛网,使预成钛网与缺损区下颌骨外形完全一致。切取腓骨肌皮瓣,血管化游离移植联合预成钛网植入完成下颌骨缺损的修复重建。结果:15例患者腓骨肌皮瓣全部存活,创口愈合良好,下颌骨解剖外形包括自然弧度、曲率和高度恢复满意,同期修复者手术前后容貌无明显变化。结论:CAD/CAM快速原型技术联合游离腓骨肌皮瓣移植修复双侧下颌骨大范围节段性骨缺损,不仅可以最大限度地重建下颌骨的自然外形,维持患者容貌,也为种植体植入及咬合功能重建创造了良好条件。     

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.     

One-stage microvascular mandible reconstruction and alloplastic TMJ prosthesis

Severely deformed or absent temporomandibular joints (TMJ) benefit from total alloplastic joint replacement and large mandibular defects from revascularized free tissue transfer for reconstruction. However no cases of their combined one-stage placement with outcomes can be found in the literature. We present two cases with different indications and reconstruction.The first patient required mandibular body and ascending ramus reconstruction after previous sarcoma resection. This was with a condyle-bearing reconstruction plate which resulted in significant dysfunction, leaving the patient unable to open her mouth. A one-stage vascularized iliac crest free flap and alloplastic TMJ prosthesis was used to reconstruct the mandible. Subsequently, metal removal, soft tissue augmentation by lipotransfer and dental implant placement were performed. At 63 months follow-up patient was pain-free, with mouth opening, protrusion and lateral excursion back to normal.The second patient required mandibular body, ascending ramus and joint reconstruction, performed by transoral vascularized fibula free flap with temporal vessel anastomosis. The traumatic deep bite and posterior facial height were corrected, additional submandibular scars avoided by transoral placement of the fibula transplant and a miniaturized TMJ prosthesis along with the vascularised free flap with 28 months follow-up.A miniaturized TMJ prosthesis may become placed transorally for reconstruction of the TMJ, together with a vascularized free flap for mandibular reconstruction and promises good long-term stability with normal function above all for protrusion and lateral excursion.     

CAD／CAM导板在上颌后牙种植修复中的临床应用研究

目的：评价基于临床CT数据的计算机辅助设计和制造（computer aided design／computer aided manufacture,CAD／CAM）导板在上颌后牙种植修复中的定位精度。方法：通过对16例患者上颌骨进行CT扫描,基于CT数据设计和制作黏膜支持式CAD／CAM种植导板,并在种植导板辅助下于缺牙区不翻瓣植入20枚柱状软组织水平种植体,再次行CT扫描,采用点对点配准技术实现扫描前后的CT三维重建模型配准,测量实际种植体位最与虚拟放置种植体位置问的偏离值。结果：在CAD／CAM种植导板辅助下,20枚种植体平均头部偏差量为1．19mm±0．02mm,颊舌向和近远中向以及胎龈向偏离值分别为0．53mm±0．04mm、0．42mm±0．03mm和0．30mm＋0．04mm。尾部偏差量为1．03mm±0．06mm,角度偏差量为0．73°±0．64°。经统计学检验,种植体头部偏离值在颊舌向、胎龈向的偏离值无统计学差异（P〉0．05）;而在近远中向的偏离值较其他2个方向略大,其差异有统计学意义（P〈0．05）。但是,种植体头部偏离值分别在颓舌向、近远中向、胎龈向偏离值都无统计学差异（P〉0．05）。结论：在CAD／CAM导板辅助下,上颌后牙区植入种植体精度较高;种植导板对种植体植入后的整体角度偏离影响较为明显;并且在三维方向上种植体头部在近远中方向的偏离对整体头部的偏离影响较大。     

Optimal restoration of dental esthetics and function with advanced implant-supported prostheses: a clinical report

For more than 25 years, computer-aided design and computer-aided manufacturing (CAD/CAM) technology has been used in implant restorative dentistry. Today this technology offers a means of milling titanium frameworks that fit dental implants accurately. This report presents a restoratively driven protocol employing advanced implant restorative and surgical techniques. Treatment of a patient with advanced periodontitis with extensive loss of hard and soft tissues is presented. After extraction of the patient's remaining hopeless teeth, dental implants were placed, along with interim, fixed-margin abutments and abutment protection caps. Two days later, acrylic resin fixed-interim prostheses restored the patient's esthetics and partial masticatory function. After implant osseointegration, maxillary, and mandibular frameworks for definitive prostheses were milled from Ti alloy, using one specific CAD/CAM technology. The benefits of this technology are also discussed.     

颌骨与牙列同日重建的最新进展与实践

微血管化骨组织移植是颌骨肿瘤切除后颌骨重建的一个重要里程碑.传统游离骨肌皮瓣移植虽然即刻重建了颌骨,但需要6～18个月后才能完成牙列修复.牙列缺损严重影响了患者的生活质量,并给患者造成较大的心理负担.随着"4P"医学时代的到来,对于手术的可预测性和个体化提出了更高的要求.颌骨与牙列同日重建(jaw-in-a-day)是...     

Severe osteomyelitis following immediate placement of a dental implant

Risk factors and complications in immediate implant placement are widely discussed. The present report describes a case of severe osteomyelitis as a serious complication after the immediate placement of a dental implant into an extraction socket of a 61-year-old woman. The course leads from initial treatment of recurrent perimandibular abscesses with surgical drainage and high-dose intravenous antibiotics to a refractory osteomyelitis. Hemimandibulectomy and partial mandibular reconstruction with a free fibular flap followed.     

Continuity defects of the mandible: Comparison of three techniques for osseous reconstruction and their impact on implant loading

Computer-aided design/manufacturing (CAD/CAM) is now widely used, but whether it can help to overcome complications in mandibular reconstruction and accelerate dental implantation is still a matter for debate. Therefore, we aimed to evaluate the benefits of this technique using vascularized iliac crest or fibula flaps in mandibular reconstruction, with respect to the time between reconstruction and implantation, and the ratio of planned to inserted implants. We reviewed retrospectively the records of 54 patients who underwent mandibular reconstructions between 2012 and 2016, and included in our study the last 10 cases representing each of the following groups: iliac crest flap with CAD/CAM (Group 1); fibula flap with CAD/CAM (Group 2); and fibula flap without CAD/CAM (Group 3). Groups 1 (p = 0.045) and 2 (p = 0.034) showed significantly shorter delays when compared with Group 3. Significant differences in average counts of implants placed were also found between Group 1 and Groups 2 (p = 0.04) and 3 (p = 0.019). The ratio of planned to placed implants was highest in Group 1. The observed differences between Group 1 and Groups 2 (p = 0.04) and 3 (p = 0.019) were significant. Our results indicate an accelerating effect of CAD/CAM on graft consolidation and dental rehabilitation.     

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.     

Complication rates and clinical outcomes of osseous free flaps: a retrospective comparison of CAD/CAM versus conventional fixation in 128 patients

Studies evaluating plate-related complications in patient-specific versus conventional fixation systems in free flap surgery are lacking. This was a retrospective study of 128 osseous free flaps with a minimum follow-up of 12 months. Wound healing disorders, plate exposure, fixation failure, and subtotal osseous union were recorded and evaluated statistically by univariate and regression analysis. Complication rates were as follows: wound healing disorders 33.6% (computer-aided design and computer-aided manufacturing (CAD/CAM) vs. conventional: 35.1% vs. 33.0%); plate exposure 21.9% (29.7% vs. 18.7%); fixation failure 7.0% (8.1% vs. 6.6%); subtotal osseous union 36.7% (45.9% vs. 33.0%). Radiotherapy (P < 0.001) and more than two segments (P = 0.026) were independent variables for the overall complication rate and were negatively correlated with the dental implantation rate. The time between diagnosis and ablative surgery was increased by 11.0 days in the CAD/CAM group (34.2 ± 16.2 days vs. 23.2 ± 12.0 days; P = 0.002). Rates of dental rehabilitation were not significantly different (35.1% vs. 44.0%, P = 0.358). On average, 3.2 ± 1.7 dental implants were placed into flap segments. Plate-related complications were increased with radiotherapy and multisegment flaps. There was a non-significant trend towards increased complications with patient-specific plates in comparison to conventional reconstruction plates.     

Surgical planning and prosthesis construction using computer technology and medical imaging for immediate loading of implants in the pterygomaxillary region

This report describes a protocol that uses computerized tomography (CT), computer-aided design/computer-assisted manufacture (CAD/CAM) technology, and the Internet to plan placement of anterior and posterior dental implants and construct a precise surgical template and definitive prosthesis, which is connected at the time of implant placement. This procedure drastically reduces surgical treatment time and the recovery period. Patients with an edentulous arch had a denture with radiopaque markers constructed for CT scans of the appropriate jaw. The CT images, with acquisition slices of 0.5 mm, were transferred into a three-dimensional image-based program for planning and strategic placement of dental implants. After implants were virtually placed on the computer, the surgical treatment plan was sent to a manufacturing facility for construction of a surgical template and the prosthesis, Special surgical guide components were also manufactured for placement of implants in the pterygomaxillary region. The manufactured surgical components, surgical template, and definitive prosthesis were then delivered to the clinical site. Implant placement surgery was performed using the surgical template, without a flap, and the prosthesis was delivered, achieving immediate functional loading. Minor occlusal adjustments were made. The total surgical treatment time required was less than 60 minutes. Postoperative symptoms, such as pain, swelling, and inflammation, were minimal. Identification of the bone in relationship to the tooth position via three-dimensional CT prior to surgery allows precise placement of implants. CAD/CAM technology using the three-dimensional images allows for fabrication of the surgical guide and final prosthesis. This is a significant advancement in implant dentistry and prosthodontics.     

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。     

Minimally-invasive, full-mouth rehabilitation using an Er,Cr:YSGG laser and CAD/CAM technology.

The use of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers and CAD/CAM technology in dentistry is becoming more accepted and prevalent. Using these two technologies together, full-mouth dental reconstruction was attempted to evaluate their effectiveness. The authors prepared all remaining maxillary and mandibular teeth without the use of a dental drill or an anesthetic; fabrication and insertion of the 28 all-ceramic CAD/CAM restorations were completed in two appointments. When used appropriately, practitioners can combine Er,Cr:YSGG losers and CAD/CAM technology to deliver a quality permanent restorative product for their patients.     

The use of CAD/CAM in dentistry

Computer-aided design (CAD) and computer-aided manufacturing (CAM) have become an increasingly popular part of dentistry over the past 25 years. The technology, which is used in both the dental laboratory and the dental office, can be applied to inlays, onlays, veneers, crowns, fixed partial dentures, implant abutments, and even full-mouth reconstruction. This article discusses the history of CAD/CAM in dentistry and gives an overview of how it works. It also provides information on the advantages and disadvantages, describes the main products available, discusses how to incorporate the new technology into your practice, and addresses future applications.     

Two new clinical/laboratory protocols for CAD/CAM implant restorations

BACKGROUND: Conventional casting technology has some disadvantages for dental laboratory technicians and restorative dentists, including porosity of restorations, miscasting and inaccuracy. It also is labor-intensive. Computer-aided design/computer-aided manufacturing (CAD/CAM) technology was developed in the late 1980s for dentistry, and it significantly reduced and/or eliminated problems associated with dental castings. The purpose of this article is to give readers an overview of the use of CAD/CAM technology for dental implants and illustrate two clinical protocols for that use. CLINICAL IMPLICATIONS: The CAD/CAM technology described in this article can reduce restorative dentists' chairside time associated with implant treatment in both edentulous and partially edentulous patients, can decrease costs without sacrificing accuracy or biocompatibility for both clinicians and dental laboratory technicians, and is available to dental laboratories without the capital expenses associated with purchasing new technology.     

Treatment of an Edentulous Patient with CAD/CAM Technology: A Clinical Report

CAD/CAM (computer-aided design/computer-aided manufacturing) technology with large-scale industrial applications has been developed and used over the last 3 decades. Implant Innovations, Inc. (Palm Beach Gardens, FL), has recently introduced a version of this technology for use in implant restorative dentistry. Different software programs were written to design and machine individual implant abutments and bar-type frameworks. This report provides a literature review of CAD/CAM technology in dentistry and describes the treatment of one edentulous patient restored with individual implant abutments and conventional cemented fixed partial dentures in the edentulous maxilla and a fixed, screw-retained prosthesis that replaced the missing mandibular teeth. The abutments were made using The Encode Restorative System; the mandibular framework was made with a CAM StructSURE Precision Milled Bar. The benefits and limitations of this technology are also discussed. Additional clinical and laboratory studies are needed to further validate this technology.     

Vertical distraction osteogenesis of fibula transplant for mandibular reconstruction: a case report

Bone continuity defects in the mandible are caused by tumor surgery, trauma, infection, or osteoradionecrosis. Today, reconstruction of long-span mandibular defects with a free fibular flap is a routine procedure. However the bone height of the mandible after reconstruction is about half that of the dentulous mandible. Therefore, the deficiency in bone height makes implant placement impractical. In our case, because it was necessary to restore the mandibular height, a vertical distraction osteogenesis was performed on the grafted mandible of the patient who was referred to our clinic with a reconstructed mandible owing to a gunshot injury. As a result, the vertical discrepancy between the fibula and the native hemimandible of the patient was corrected. And the placement of dental implants was performed without any complications. In conclusion, we believe that the vertical distraction osteogenesis of free vascularized fibula flaps is a reliable technique that optimizes implant positioning for ideal prosthetic rehabilitation.     

犬下颌骨节段性缺损的个体化再生修复实验研究

目的:通过实验观察犬下颌骨节段性缺损个体化再生修复的效果,为计算机辅助个体化再生修复下颌骨缺损的技术和方法向临床过渡提供依据。方法:利用计算机辅助设计/制作、快速原型技术等设计制作实验动物下颌骨个体化三维中空钛网修复体,再将其与β-磷酸三钙和松质骨髓植入联合应用于犬下颌骨节段性缺损的修复,通过X线片、大体标本和组织学切片对下颌骨节段性缺损的个体化再生修复效果进行观察。结果:犬下颌骨解剖形态恢复十分理想,组织学和X线摄影观察显示钛网内具有新骨形成,新生骨在3个月时已十分明显和成熟。结论:将计算机辅助技术与骨再生材料联合应用,可望通过骨再生途径实现下颌骨节段性缺损的个体化修复重建。     

Maxillary implant-supported bar overdenture and mandibular implant-retained fixed denture using CAD/CAM technology and 3-D design software: a clinical report

The implant-supported bar overdenture and the implant-retained fixed complete denture are appropriate treatment choices for patients with inadequate bone volume in the posterior maxilla and mandible, respectively. Computer-aided design/computer-aided manufacturing (CAD/CAM) technology has broadened the scope and application of those treatment options, allowing for prosthodontically-driven implant placement and ideal substructure design for optimal esthetics and biomechanics. This report describes the fabrication of a maxillary implant-supported milled titanium bar with attachments and an overdenture, and a mandibular implant-retained fixed complete denture with milled titanium substructure.