应用螺旋CT与快速成型技术制作义耳

目的：探讨应川螺旋CT与快速成型技术制作义耳。方法：采用多排螺旋CT对一名因外伤导致右耳全缺损患者扫描，对耳廓进行三维重建。在Magics RP软件巾实现镜像、定位、布尔运算获得缺损区耳廓三维实体数据，应用Freeform自由造型软件对耳模型修整，使之与病人缺损区组织面完美贴合，肝转化为STL文件。应用LOM法制作缺损区耳廓阳模。最后用医用砘胶翻制耳廓硅胶阳模。结果：完成耳廓软组织的三维重建，获得了缺损区耳廓的三维实体数据，最后制作的义耳与组织面完美贴合，外形精度高，个性化程度高。结论：应川螺旋CT与快速成型技术制作义耳是一种切实可行的方法。     

Prosthodontic rehabilitation of a patient with bilateral auricular deformity

Maxillofacial prosthodontics is an art and science which provides life like appearance to the person with facial deformity. Maxillofacial prosthetic rehabilitation for acquired defects has become more complex and sophisticated with advancement in techniques and materials. This case report describes the clinical and laboratory procedure for fabricating an auricular prosthesis for a patient with trauma related bilateral auricular deformity. Ear prosthesis was fabricated in two parts taking retention from external auditory canal.     

Design and fabrication of auricular prostheses by CAD/CAM system

PURPOSE: The purpose of this report is to describe a new technique for fabricating auricular prostheses by a computer-aided design/manufacturing (CAD/CAM) system. MATERIALS AND METHODS: A spiral CT was performed on a patient who had a right ear defect resulting from an accident. A 3-D image was reconstructed with the CT data. Through image ware, the image of the normal ear was extracted, mirrored, and Boolean operated with the image of the deformed side of the face. It was well modified and smoothed in the FreeForm model system so that it could precisely adapt to the deficient side of the face. A paper model ear was manufactured by rapid prototyping from the digitized data. Finally, silicone was poured into a silicone mold from the paper ear to create a silicone auricular prosthesis. RESULTS: The dimension, shape, and anatomic contour of the auricular prosthesis were quite similar to those of the normal ear and precisely matched the deformed area. CONCLUSION: The CAD/CAM system for creating auricular prostheses appears to be a practical technique.     

Maxillofacial Prosthetic Management of an Auricular Defect for a Young Patient With Hemifacial Microsomia: A Clinical Report

Facial anomalies in hemifacial microsomia patients may have significant psychosocial impact even from a very young age. The management and fabrication of an auricular prosthesis replacement supported by endosseous craniofacial implants for a young patient with Goldenhar-Gorlin Syndrome has been reported. It is beneficial for the defects of a hemifacial microsomia patient to be managed as early as possible, consistent with the patient's ability to manage the prosthesis.     

Modified technique for retaining silicone auricular prosthesis: a case report

Prosthetic rehabilitation of auricular defects can be a demanding procedure due to a broad variety of clinical presentations and a wide array of treatment options. The retention of auricular prostheses is a major factor influencing the successful outcome of rehabilitative treatment following cancer surgery or trauma. Auricular prostheses have been retained by methods including implants, adhesives and spectacle frames but the choice of repair ultimately depends on patient factors, amount of soft tissue loss, and location of the auricular defect. This article describes a newer technique of using resin template for silicone auricular prosthesis, for better retention and orientation. Moreover it is cost effective and aesthetically acceptable for patients who decline or need to postpone implant retained prosthesis reconstruction.     

Assisted retention of a hearing device in an implant-retained auricular prosthesis.

The use of bone-anchored hearing aids is not possible for all patients who wear an implant-retained auricular prosthesis. For some patients, the external ear canal cannot be occluded with a conventional hearing device. Currently manufactured hearing aids may not readily fit the contours of an implant-retained auricular prosthesis. This article describes a technique that allows a modular hearing aid device to be inserted into a custom "sleeve." With this device, the patient can take advantage of binaural cues.     

Esthetic removable partial denture design in replacing maxillary anterior teeth

Prosthodontic rehabilitation of missing maxillary anterior teeth requires special consideration to restore function and esthetics. This case report describes the prosthodontic management of a patient who lost three maxillary incisors due to a motor vehicle accident. A rotational path removable partial denture was constructed, for which a proximal undercut was created by means of a composite buildup to provide the retention for the prosthesis.     

Multidisciplinary treatment for an implant retained auricular prosthesis rehabilitation.

Retention of a facial prosthesis is the most important factor in creating a useful prosthesis for the patient. This paper presents a detailed case study of an auricular defect that was rehabilitated using two types of prosthetic retention: adhesive and osseointegration. We present the patient selection criteria, the surgical considerations prior to implant placement, retention component selection, prosthetic fabrication techniques and patient management after prosthetic delivery. The osseointegrated prosthesis made a large improvement in the patient's quality of life.     

Simulation of tissue-prosthesis margin interface by using surface scanning and digital design for auricular prostheses

Statement of problemOne of the most challenging aspects of auricular prosthesis design and fabrication is ensuring that the prosthesis fits the patient through a range of head and facial movements. Techniques used in conventional prosthetic treatment pathways account for issues of prosthesis fit, but this challenge has not been fully addressed in emerging treatment pathways that use digital technology.PurposeThe purpose of this clinical study was to develop and evaluate a digital workflow by using surface scan data and incorporating the simulation of tissue movement into the design of auricular prostheses that fit the participant through a range of facial movements. An iterative design process was used to develop a design workflow through a sequential case series of participants with auricular prostheses.Material and methodsScan data were acquired from a case series of 5 participants with existing implant-retained auricular prostheses. An iterative design process was used to digitally design auricular prostheses that fit the participants through a range of jaw and facial movements. The fit, shape, and retention of the digitally designed and conventionally made prostheses were assessed and compared. Design considerations were identified and documented through the iterative design process.ResultsA final design workflow was iteratively developed based on the 5 participants. The shapes of the digitally designed prostheses were well matched to nontreatment anatomy overall. Prosthesis fit was variable: Some digitally designed prostheses fit the participant intimately through a range of movements, and others experienced significant gaps between the margins and the tissues.ConclusionsAn iterative design process provided a method of working toward quality improvement. Although the final design workflow provides a generally successful method of manipulating scan data in the design of auricular prostheses, the prosthesis fit at the anterior margin during facial movements remains variable and requires further development to achieve a consistently acceptable solution.     

Hair band retained prosthetic reconstruction of bilaterally missing ears: A case of congenital atresia of external auditory canals and pinna

IntroductionAuricular defects present reconstructive challenges, especially if they are bilateral. Surgical reconstruction provides effective results for defects; however for some patients surgical intervention is contraindicated. This case report describes an easy clinical technique to rehabilitate a patient with auricular defects. The prime purpose of this treatment rendered was to restore the lost auricular structure to the patient's satisfaction in an elegant, comfortable and cost effective manner.PatientA thirteen year old female patient, who had bilaterally missing ears, was referred with a chief complaint of discomfort caused due to her existing hair band prosthesis and unsatisfactory esthetics. There was constant formation of ulcers at the site where the prosthesis came in contact with the skin. Considering the patient's age, ease of use and economic status, hair band retained ear prosthesis was selected. Silicone ear prostheses were fabricated on acrylic substructure to ensure fit, esthetics. Beneath the acrylic plates, a thin layer of soft silicone material was attached. The ear prostheses of both sides were connected with a metal hair band to retain.DiscussionThe newly fabricated prosthesis overcame the limitations of the existing one. The patient and her parents were satisfied with the results.ConclusionThe hair band retained silicone ear prosthesis is esthetic, economical and easy to use as a facial prosthesis. The addition of soft liner provided a cushion-like effect, thus reducing the formation of any ulcers due to pressure.     

Alternative retention for an implant-retained auricular prosthesis

The introduction of intraoral endosseous implants was inevitably followed by their external use in maxillofacial prosthodontics. Bar and clip attachments provide satisfactory retention for auricular prostheses, although the bar may inhibit patient hygiene by limiting access to the defect area. A simple clinical and laboratory technique to enhance the retention of an implant-retained auricular prosthesis is described, with custom-made stud attachments used for retention. Improved access for hygiene is provided. A clinical case is presented.     

Facilitation of facial prosthesis placement with tattoo markers: a clinical report

Proper repeatable alignment of an adhesive-retained auricular prosthesis may be a difficult challenge. Usually anatomical undercuts, tissue remnants, and scars are used as references to secure a facial prosthesis and provide retention and stability. Repeated application may be hindered when none of these references is present. This clinical report describes a method of using tattoo marks as references to repeatably align the facial prosthesis of a patient with a skin flap reconstruction.     

Prosthodontic rehabilitation after traumatic tooth and bone loss: a clinical report

Traumatic injuries from motor vehicle accidents may cause anatomic deficiencies in soft and hard tissues. Successful treatment of patients with such deficiencies may include preprosthetic surgery using osseointegrated implants to increase prosthesis retention and stability. This article describes the treatment of a motor vehicle accident victim whose anterior teeth and supporting tissues were lost.     

Applications of rapid prototyping technology in maxillofacial prosthetics

PURPOSE: The purpose of this study was to compare the accuracy, required time, and potential advantages of rapid prototyping technology with traditional methods in the manufacture of wax patterns for two facial prostheses. MATERIALS AND METHODS: Two clinical situations were investigated: the production of an auricular prosthesis and the duplication of an existing maxillary prosthesis, using a conventional and a rapid prototyping method for each. Conventional wax patterns were created from impressions taken of a patient's remaining ear and an oral prosthesis. For the rapid prototyping method, a cast of the ear and the original maxillary prosthesis were scanned, and rapid prototyping was used to construct the wax patterns. For the auricular prosthesis, both patterns were refined clinically and then flasked and processed in silicone using routine procedures. Twenty-six independent observers evaluated these patterns by comparing them to the cast of the patient's remaining ear. For the duplication procedure, both wax patterns were scanned and compared to scans of the original prosthesis by generating color error maps to highlight volumetric changes. RESULTS: There was a significant difference in opinions for the two auricular prostheses with regard to shape and esthetic appeal, where the hand-carved prosthesis was found to be of poorer quality. The color error maps showed higher errors with the conventional duplication process compared with the rapid prototyping method. CONCLUSION: The main advantage of rapid prototyping is the ability to produce physical models using digital methods instead of traditional impression techniques. The disadvantage of equipment costs could be overcome by establishing a centralized service.     

耳廓三维图像数据库的应用研究

目的：探索一种新的耳腰复体制作方法。方法：将耳廓三维图像数据库中的三维模型,在surfacer 10．0软件平台上数据处理为CAD模型;并在此基础上,根据预修改内容设计标准,局部修改调整耳廓三维图像数据库中三维模型形态,建立预修改模型库和一种模拟的CAD功能。在Magics RP5．41软件平台上完成耳廓三维模型按一定比例放大、缩小及镜像处理。运用快速成型技术完成最终三维模型向实体模型的转化过程,制作耳腰复体模型。结果：建立了一个耳廓三维图像数据库应用系统。结论：探索了一种新的,更加方便的制作耳腰复体的方法。     

Bilateral implant-retained auricular prosthesis for a patient with congenitally missing ears. A clinical report

Microtia is a major congenital anomaly of the external ear. It includes a spectrum of deformities from a grossly normal but small ear to the absence of the entire external ear. These deformities account for three in every 10,000 births, with bilaterally missing ears seen in fewer than 10% of all cases. Congenital abnormalities of the ear are unlikely to result in the complete absence of the ears, but the patient presented in this article had bilateral congenitally missing ears. There was loss of anatomic landmarks and alteration of normal bony architecture. Minimal tissue was available for retention; therefore, conventional techniques could not be used for achieving retention. A two-implant-supported auricular prosthesis was planned, but the patient was found to have deficient bone in the implant site. Hence the implants were placed posterior to these sites, and the superstructure was modified to accommodate for this change in position of the implant to ensure the esthetic positioning of the prosthesis.     

Self retentive partial silicone auricular prosthesis: a case report

An auricular prosthesis may be required for a number of conditions including congenital abnormalities, malignancy and trauma, which result in disfigurement of the pinna. Whatever the cause of the absence of the pinna, it is a significant loss of a prominent part of the face for the person involved. This article describes a simple and cost effective technique for retention of a silicone partial auricular prosthesis. A Fish-bone shaped substructure (FSS) designed and fabricated using orthodontic wire and autopolymerizing acrylic resin, was embedded into the silicone elastomer of a self-retentive silicone prosthesis. The prosthesis is designed to overcome the disadvantages associated with traditionally fabricated prostheses; namely poor structural strength, inadequate retention, poor adaptation and durability over time.     

Prefabricated Stock Trays for Impression of Auricular Region

The conventional methods of impression making for maxillofacial defects are cumbersome and time consuming for both patient and operator. This study focuses upon standardizing and simplifying the impression making methodology for auricular prosthesis with the help of prefabricated stock trays for auricular region. The stock trays were designed on positive replicas of anatomical structures, broadly divided into long and narrow, short and broad and long and broad ear. For each stock tray, impressions of auricle, of patients of different morphology were made with plastic funnels of different shape and size ensuring at least 6 mm of space between the anatomical part and inner surface of funnel and master cast was obtained. Subsequent adaptation of wax was done and fabrications of stock stainless steel trays were done. A standardized stock tray for making of auricular impressions was developed. From this innovative technical procedure it is possible to get an accurate impression of auricular defects now by the use of prefabricated stock trays rather than the cumbersome conventional method.     

Planning implant positions for an auricular prosthesis with digital data

The esthetic result of an auricular prosthesis is influenced by the position of the prosthesis incorporating the implants. The entire surface of the patient's head is captured by means of a conventional computed tomography (CT). The digital data are used to mirror the contralateral unimpaired ear for restoration of the impaired side. The virtual ear is integrated into a template covering the auricular defect and indexed to the nasal area with computer-aided technology (CAD/CAM). This virtual template is converted into an acrylic resin template. With that the surgeon and the anaplastologist should determine the optimal implant position of the auricular prosthesis.     

Prosthodontic management of maxillofacial cases: a case series

Maxillofacial prosthetics is an important and recognized sub‐discipline of prosthodontics that forms a key component of postgraduate training programmes. General dentists have a role to play in the management of maxillofacial defect patients even though treatment usually requires a multidisciplinary approach in an institutional environment. Maxillofacial prosthetic cases frequently present with complex histories but simple patient goals. The conservatively managed implant‐retained auricular prosthesis, speech aid prosthesis and orbital prosthesis cases described in this report were completed in a postgraduate clinical residency program and highlight the intrinsic complexities, challenges and ultimately satisfaction related to cases of this nature.