Endoscopically assisted fixation of the custom-made total temporomandibular joint prosthesis in TMJ Yang’s system through a modified preauricular approach

This article describes the experience with the endoscopically assisted fixation of the customized total temporomandibular joint (TMJ) prosthesis in TMJ Yang’s system only through a modified preauricular approach. Twenty patients (23 joints) treated with the custom-made total TMJ prosthesis were retrospectively recruited. An endoscopically assisted technique was used through a modified preauricular approach to fix the mandibular component for all these patients. These reconstructions were evaluated by surgical records, clinical examinations, and radiographic observations. All patients had successful fixation of the prosthesis. No patient had permanent weakness of the facial nerve and malocclusion or any other severe complications. The mean operative time was 111 min per joint (range, 85–133 min). The average surgical bleeding was 195 ml per side. The mean follow-up period was 16.2 months (range, 5–32 months). The mean scores were 8.3 for surgical satisfaction and 9.2 for scar healing evaluation. All patients experienced positive clinical outcomes, with a mean 75.2% reduction in pain and 53.7% increase in mouth opening with significant differences (P < 0.05). The endoscopically assisted TMJ reconstruction with the customized prosthesis in TMJ Yang’s system through the modified preauricular approach could produce good aesthetic and functional results.     

Prosthetic rehabilitation in post-oncological patients: Report of two cases

Prosthetic rehabilitation in post-oncologic patients after bone reconstruction are not substantially different than those of patients affected by severe atrophia of upper or lower jaw after bone reconstruction.Aim of this paper is to evaluate the possibilities of prosthetic rehabilitation on these patients and to present our method. Prosthesis-based oral rehabilitation of such tumor cases rapresents a challenge.The report analyses two cases of patients who underwent ablative oral surgery. Both have received a fibula free vascularised flap. The first was rehabilitated with a removable prosthesis fixed on the residual teeth, while the second with an implant supported prosthesis.In case of carcinoma resection of the oral mucosa, the removable prosthesis guarantees a simplification in dental care operations. On the other hand, irradiated mucosa is frequentely unable to tolerate the friction created by the acrylic base. However, the fixed prosthesis can limit the view during follow-up controls.In our school, according to all exposed reasons, we consider the implant supported overdenture prosthesis to be the best choice for those patients.     

计算机辅助设计与制作技术在下颌骨缺损个体化钛赝复体修复中的应用

目的 探讨计算机辅助设计与制作(CAD-CAM)在下颌骨缺损赝复体设计、制作及临床中的应用.方法 下颌骨升支及下颌角肿瘤患者6例术前行螺旋CT扫描,利用CAD-CAM在三维虚拟模型上进行模型外科设计,三维虚拟模型上调整下颌骨赝复体的位置、大小和形状.在达到最佳设计要求后,通过与电脑相连的精雕机直接将医用钛合金切削成钛赝复体,设计并制成与患者下颌骨缺损区正常外形相同的个体化钛赝复体,术中根据术前设计切除下颌骨病变区骨组织,植入个体化钛赝复体.结果 6例术中显示下颌骨钛赝复体与下颌骨缺损区吻合程度一致.术后随访9～38个月.X线片显示钛赝复体与下颌骨贴合良好,重建的下颌骨形态对称良好.术后患者面部外形恢复正常,咬合关系及张口度恢复良好.结论 CAD-CAM为下颌骨病变的术前手术设计、钛修复赝复体的个体化设计制作提供了精确的模拟及快速制作过程,简化了以往钛金属赝复体需要翻模铸造或快速原型法(rapid prototyping,RP)实体模型的制作流程,提高了手术的精确性,术后患者功能恢复良好.对于下颌骨升支及角部的缺损,钛金属赝复体不失为一种良好的修复重建方法.

Abstract：

Objective To investigate the application of computer aided design-computer aided manufacture(CAD-CAM)technique in the reconstruction of mandible defect with individual titanium prosthesis. Methods Six patients with large mandibular ramus and angle tumor were spiral CT scanned preoperatively, and the CAD-CAM was used to design and make individual titanium prosthesis for reconstructing the mandibular defects after resection of the tumor. The prosthesis were assembled during operation. Postoperative follow-up period was 9-38 months.Results The design and manufacture of titanium prosthesis by use of CAD-CAM technique was convenient and the prosthesis fitted the defects very well.The outline of the face,the occlusion and function were restored. After 9-38 months of follow-up, the mandibular symmetry was good.Conclusions The application of CAD-CAM provided accurate simulation and fast manufacturing process for the titanium prosthesis in the repair of mandibular defect.     

Indications for reconstruction of mucosal defects in oropharyngeal cancer using a supraclavicular island flap

The use of the supraclavicular island flap (SCIF) for the reconstruction of facial and neck skin defects is increasing. The value of this fasciocutaneous flap as a reconstructive modality for oropharyngeal defects in cancer patients is unclear. In the present study, a SCIF was used for reconstruction of mucosal defects following resection of the tumour in a group of four patients with T2 squamous cell carcinoma of the oropharynx and a clinical N0 neck. Reconstruction was performed following transoral tumour resection and selective neck dissection at levels I–III in the same session. Intraoperative and postoperative complications were analyzed, and functional and aesthetic results for the neck and shoulder region were evaluated in follow-up examinations. In addition, sensation to the flap was evaluated. No flap failures were observed. Only minor surgical complications were evident, which did not cause any relevant functional or aesthetic impairments. Sensation to the flap was observed in all cases. The SCIF appears to be a good and time-saving alternative to free flaps for oropharyngeal reconstruction following oncological resection in selected patients.     

计算机辅助导航技术在上颌骨肿瘤切除及缺损重建中的应用

目的：探讨计算机辅助导航技术在上颌骨肿瘤切除及同期重建中的应用。方法：选择进行上颌骨肿瘤切除及同期重建的患者5例．其中骨肉瘤1例．骨化纤维瘤4例。定位钉植入后拍摄颌面部CT,进行术前设计及模拟,确定肿瘤切除范围、截骨部位及重建外形。导航辅助下进行肿瘤切除及同期重建。术后随访,CT复查,与术前设计图像融合,进行手术精确度及导航误差评价。结果：经术前设计及术中导航定位,所有患者顺利完成肿瘤切除及同期重建术。4例患者进行了假体植入．1例患者进行血管化腓骨移植上颌骨重建术．术中实现了手术器械的实时定位．术者能够明确其与解剖结构的位置关系,精确度高．系统误差小于1mm。术后CT检查示截骨部位、切除范同、重建外形与术前设计基本一致。5例患者术后愈合良好,无严重并发症,面部对称。随访1-3a,肿瘤无复发。结论：计算机辅助导航外科可以实现术前设计、手术模拟及术后预测,有助于上颌骨肿瘤切除范围的确定、缺损重建,面部对称性的恢复．是一种有效的颌面部手术辅助方法．     

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.     

Outcome of partial mandibular reconstruction with fibula grafts and implant-supported prostheses

This study sought to evaluate the outcome of patients treated with fibula grafts for partial mandibular reconstruction and implant-supported prosthesis at a Danish university hospital. Patient inclusion criteria were: partial mandibular resection, reconstruction with a fibula graft, and treatment during the period 1998–2011. Patients with incomplete medical records were excluded. Thirty-six patients were included, of whom 16 were treated with an implant-supported prosthesis. Relevant presurgical, intraoperative, and postoperative parameters were registered. The fibula graft survival rate at the last follow-up (mean follow-up 22 months, range 0–89 months) was 97%. Half of the patients experienced non-severe complications such as loosening of osteosynthesis material, fistulae, and graft exposure. One of 37 fibula grafts in the 36 patients was removed due to infection. The implant survival rate was 96%; three of 67 implants were lost due to infection. Eight implants were not included in the prosthetic rehabilitation. Fibula graft surgery for mandibular reconstruction was found to be a reliable treatment modality with a high survival rate. Rehabilitation with implant-supported prostheses was characterized by high survival rates and few complications. The results obtained are comparable to those of previous studies.     

Total temporomandibular joint reconstruction with a Delrin titanium implant.

Numerous alloplastic materials have been used for partial or total reconstruction of the temporomandibular joint in patients with fibrous or bony ankylosis, severe degenerative joint disease, or traumatic deformity, and for reconstruction following tumor resection and corrective surgery following multiple arthroplasties. We have had initial success with the use of a polyoxymethylene (Delrin) condylar head affixed to a pure titanium mesh for these reconstructive procedures. This versatile prosthesis does not require use of a separate glenoid fossa prosthesis. The surgical technique, as well as a historical perspective on alloplastic total joint prostheses used to date, is described in several patients.     

Secondary reconstruction of the mandible with an aluminum oxide prosthesis

A case is presented where secondary mandibular reconstruction with an aluminum oxide ceramic prosthesis was performed for a patient who had had an earlier hemimandibulectomy and primary bone graft for management of an ameloblastoma. Various factors that were considered in the construction of the prosthesis and problems encountered during operation are discussed. Although the prosthesis was found to be quite useful for the restoration of facial contour, the results of a long-term follow-up are needed to obtain a final evaluation of the reconstruction.     

Missing facial parts computed by a morphable model and transferred directly to a polyamide laser-sintered prosthesis: an innovation study

Mirroring of missing facial parts and rapid prototyping of templates have become widely used in the manufacture of prostheses. However, mirroring is not applicable for central facial defects, and the manufacture of a template still requires labour-intensive transformation into the final facial prosthesis. We have explored innovative techniques to meet these remaining challenges. We used a morphable model of a face for the reconstruction of missing facial parts that did not have mirror images, and skin-coloured polyamide laser sintering for direct manufacture of the prosthesis. From the knowledge gleaned from a data set of 200 coloured, three-dimensional scans, we generated a missing nose that was statistically compatible with the remaining parts of the patient's face. The planned prosthesis was manufactured directly from biocompatible skin-coloured polyamide powder by selective laser sintering, and the prosthesis planning system produced a normal-looking reconstruction. The polyamide will need adjustable colouring, and we must be able to combine it with a self-curing resin to fulfil the requirements of realistic permanent use.     

Our experiences with a removable partial prosthesis as a preventive therapeutic device]

On the basis fo follow-up examinations, the author points to essential features on which the preventive action of the cast removable partial prosthesis depends. Frequently encountered periodontal diseases are caused by clasps and covering components of the denture base. Traumatic occlusions occur independently of the duration of wear, which is indicative of the dentist's inadquate attention. Metaphylaxis associated with adjustment of the prosthesis to the changing masticatory organ is the main prerequisite for long-term success.     

Magnet retained intraoral-extra oral combination prosthesis: a case report

Facial prosthesis is generally considered over surgical reconstruction to restore function and appearance in patients with facial defects that resulted from cancer resection. Retention of the prosthesis is challenging due to its size and weight. Retention can be achieved by using medical grade adhesives, resilient attachments, clips and osseointegrated implants. It can also be connected to obturator by magnets. This clinical report highlights the rehabilitation of a lateral midfacial defect with a two piece prosthesis that included an extra oral facial prosthesis and an intraoral obturator with the use of magnets.     

Delayed mandibular reconstruction following removal of a mesenchymal chondrosarcoma. Report of a case

An unusual case of mesenchymal chondrosarcoma is presented. Initially seen when the patient was 8 years old, the lesion was repeatedly biopsied and curetted with a diagnosis of odontogenic fibroma. In 1971 a diagnosis of osteosarcoma of the chondroblastic type was made. At that time, the patient underwent a partial mandibulectomy with immediate graft. The patient did well until 1981, when a recurrence of the lesion was noted. The microscopic diagnosis at this time was mesenchymal chondrosarcoma. The treatment of this lesion as a staged procedure with initial resection of the mandible and placement of a silicone rubber mandibular prosthesis is discussed. The second stage of the procedure was definitive mandibular reconstruction, with an allogeneic mandible as a crib for autologous particulate cancellous bone from the iliac crest. Although the prognosis of mesenchymal chondrosarcoma is usually grave, this case is unusual because of its long history of multiple procedures performed prior to the definitive treatment of the lesion 14 years after its discovery. Two-year follow-up since the definitive mandibular reconstruction shows adequate range of motion, excellent healing, and no recurrence.     

Navigation-guided en bloc resection and defect reconstruction of craniomaxillary bony tumours

The aim of this study was to evaluate the validity of navigation-guided en bloc tumour resection and defect reconstruction in the treatment of craniomaxillary bony tumours. Three patients with ossifying fibroma and two patients with fibrous dysplasia were enrolled in this study. After preoperative planning and three-dimensional simulation, the osteotomy lines for resection were delineated and the normal anatomic structures for defect reconstruction were ascertained. With the guidance of an Accu-Navi navigation system, an en bloc tumour resection and simultaneous defect rehabilitation were performed. The system provided continuously updated information on the position and movement of surgical instruments in the operating field in relation to the preoperative imaging data set. The system error measured by the computer did not exceed 1 mm. The osteotomy lines and reconstruction contour were checked by postoperative computed tomography, and good matching with the preoperative planning was achieved. Patients showed no signs of tumour recurrence or prosthesis infection during follow-up (range 12–35 months). Image-guided navigation makes radical bone tumour resection more reliable by implementing preoperative planning, showing the determined safety margins, preserving vital structures and guiding reconstruction.     

少汗型外胚层发育不全患者咬合重建1例

少汗型外胚层发育不全（HED）患者常伴有颌间距离丧失、牙槽骨发育不良以及先天缺牙等,修复治疗较难。本文报道1例20岁的HED患者,为其设计上颌固定、下颌套筒冠义齿修复进行咬合重建。1年后复查,患者的义齿使用良好,咬合功能恢复正常。     

Customized skull base–temporomandibular joint combined prosthesis with 3D-printing fabrication for craniomaxillofacial reconstruction: a preliminary study

Temporomandibular joint (TMJ) lesions, when large and extensive, will often involve skull base destruction and result in extensive resections, requiring a challenging reconstruction. This study introduces a special type of craniomaxillofacial prosthesis for massive combined skull base–TMJ lesions. Patients who presented with combined skull base–TMJ lesions were recruited. Enhanced computed tomography (CT) data were obtained for all patients and transformed into three-dimensional (3D) reconstruction models. The combined skull base–TMJ prosthesis was designed and fabricated with a customized principle by 3D-printing technology. Clinical follow-up and radiographic evaluations were performed to assess the feasibility of the combined prosthesis in clinical application. A series of five consecutive patients were included in this study. No severe complications occurred after surgery. Based on a mean follow-up period of 13.8 months, the preliminary results suggest that the combined prosthesis has a positive impact on clinical outcomes: there was a mean 75.0% reduction in pain, 55.6% improvement in diet, 54.5% improvement in mandibular function, and 33.6% increase in mouth opening, with significant differences when compared with the preoperative state (all P < 0.05). This study suggests that the combined prosthesis represents a safe and reliable implantable reconstruction method for combined skull base–TMJ lesions.     

Oral rehabilitation of a 12-year-old patient diagnosed with a central giant cell granuloma using a fibula graft and an implant-supported prosthesis: a clinical report

This clinical report describes the oral rehabilitation of a 12-year-old boy with a central giant cell granuloma of the mandible. He underwent en bloc resection of a central giant cell granuloma, free vascularized fibula reconstruction, implant placement, and prosthesis fabrication. The multidisciplinary approach successfully restored function and esthetics. Considerations regarding the extensive surgical and prosthetic rehabilitation of a young adult with remaining growth are discussed.     

Novel approach to the study of jaw kinematics in an alloplastic TMJ reconstruction

Total alloplastic temporomandibular joint (TMJ) reconstruction is a reliable treatment modality in patients with severely diseased TMJ with good clinical behaviour. TMJ mandibular function after alloplastic reconstruction has scarcely been analysed as a biomechanical parameter and investigation has generally been limited to interincisal measurements without deeper insight into joint kinematics. Dynamic stereometry to assess condylar movements relative to the fossa was performed at the 5 year follow-up of a patient who underwent condylar resection of the right TMJ followed by total alloplastic joint reconstruction to treat pigmented villonodular synovitis. The patient could achieve wide mouth opening, but overall mandibular kinematics showed a strong deviation towards the prosthetic side due to the lack of mandibular translation caused by the absence of the lateral pterygoid attachment. Possible overloading of the joint contralateral to the TMJ prosthesis might be prevented by optimizing replacement joint design.     

Speech intelligibility following maxillectomy with and without a prosthesis: an analysis of 54 cases

To statistically evaluate the factors that influenced speech following maxillectomy, the speech intelligibility (SI) in 54 patients was measured with and without a prosthesis. The mean SI score without a prosthesis in all patients was 35.7 ± 22.7% and that with a prosthesis was 84.9 ± 12.7%. The results of the postmaxillectomy SI statistical analysis revealed that an oro–nasal communication was one of the factors that influenced SI without a prosthesis. The resection of the anterior portion of the soft palate was one of the factors that influenced SI with a prosthesis, which suggested that for some of these patients we should consider specific surgical treatment, aimed at the reconstruction in the deep defect extending to the intratemporal fossa. A new classification of maxillary defects has been proposed which will help to predict the grade of postmaxillectomy speech disorder following surgery.     

颅底—颞下颌关节区骨巨细胞病变的切除及修复

目的：探讨发生于颅底—颞下颌关节区的骨巨细胞病变的手术切除特点及修复原则。方法：1994年3月～2007年7月共手术治疗颅底—颞下颌关节区骨巨细胞病变18例,12例行颅颌联合手术。15例病变全部切除,3例近全切除,仅1例切除部分硬脑膜并修补。对于术后缺损,17例用邻近带蒂组织瓣如颞肌系统瓣、胸锁乳突肌瓣修复,1例用游离背阔肌肌皮瓣修复;4例用钛板重建颧弓,6例用钛网重建颅底,2例分别用人工关节和游离髂骨重建颞下颌关节。3例近全切除者加用术后放疗。结果：除1例术后第3天发生脑脊液漏,经保守治疗康复,其余无并发症。所有18例术后外形基本对称,术前各种症状明显改善。16例在随访期间（6个月～10a）未出现复发,2例失访。结论：对发生于颅底-颞下颌关节区的骨巨细胞病变,应力求根治性切除,硬脑膜缺损应予修补。用邻近的带蒂组织瓣修复软组织缺损,钛板或钛网修复骨组织缺损,可获得满意的外形,较大的缺损可用游离组织瓣修复。