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The value and success of a well-fitting and anatomically correct prosthesis are compromised if the color does not match the adjoining tissue. Color and color science are reviewed to help develop a simplified acrylic resin shade guide to aid in fabricating acrylic resin facial prostheses. This guide will help the clinician obtain a good intrinsic shade and minimize extrinsic coloration.
Prosthetic rehabilitation is essential for maintaining postoperative oral function after maxillary reconstruction. However, the maxillary prosthesis becomes unstable in some patients because of extensive palatomaxillary resection and drooping of the transferred flap. In such patients, maintaining sufficient oral function is difficult, especially if the patient is edentulous. To achieve prosthetic retention, the authors performed microvascular maxillary reconstruction with a slit-shaped fenestration in the midline of the hard palate. Maxillary defects after subtotal or total maxillectomy were reconstructed with rectus abdominis musculocutaneous flaps in five patients. Defects of the nasal lining and palate were reconstructed with the single cutaneous portion of the flap, and a slit-shaped fenestration was left between the cutaneous portion of the flap and the edge of the remaining hard palate. Postoperatively, patients were fitted with maxillary prostheses that had a flat projection for the palatal fenestration. In all patients, the prosthesis was stable enough for mastication and prevented nasal regurgitation. Speech function was rated as excellent on Hirose's scoring system for Japanese speech ability. The authors believe that their method of palatomaxillary reconstruction is both simple and reliable.
A survey was conducted to evaluate patient reactions to facial prostheses that were provided to 143 patients in the past 7 years at Roswell Park Memorial Institute. Of the 76 patients who responded, 38 patients were wearing their prostheses and 38 patients were not wearing their prostheses. Reasons cited by the patients for not using their prosthesis included lack of retention, additional surgery, discomfort, and irritation. Most of the prostheses were prepared in silicone rubber with color characterization accomplished by the tattooing method. More than 69% of the prostheses were remade within a year because of rapid changes in the defect, prosthesis material, or prosthesis color. The study revealed the need for improvement in materials, adhesive techniques, and the psychological orientation of the patient. This project was conducted at a teaching and research institute. No fees for the patients were required. Therefore our data might differ from that collected from a private practice or clinic.
Patients with complete avulsion of the palate may require extensive surgical and prosthodontic rehabilitation. The prosthesis should replace not only missing teeth but also lost soft tissues and bone, including the hard palate, residual alveolar ridges, and in some situations, the soft palate. This clinical report describes the prosthetic rehabilitation, after appropriate surgical options had been exhausted, of a patient with bilateral traumatic avulsion of the maxilla.
A survey of experience treating patients with extraoral implants for facial prosthesis retention in 13 United States centers and in Sweden has been completed. Patients who have not received radiation for elimination of malignant disease can be treated with reasonably good expectations for long-term success. Reported success rates indicate that patients who have received radiation should be selected carefully and treated with caution, since overall success rates in this category are disappointingly low.
This study reports on forces generated by magnets to retain facial prostheses. The retention force was measured in cylindrical magnetic inserts and in telescope magnetic inserts. The forces between insert and secondary magnets were measured at different angles. The mean force in the axial direction was 1.8 N. The force decreased as the angle between force direction and insert-axis increased. The results will help clinicians to insert implants in an optimal position when using them to retain facial prostheses.
Reconstruction of large defects of the frontal bone and bony orbit may be required following trauma or ablative tumor surgery. Autogenous bone or alloplastic implants used alone may prove inadequate due to difficulties obtaining symmetric contours with bone and lack of strength and resistance to infection with alloplastic materials. These problems can be overcome with the combined use of a prefabricated Dacron polyurethane mesh prosthesis (Osteo-Mesh, Xomed, Inc.) to establish contour of the forehead and superciliary ridges, and underlying split-rib grafts to protect the brain and isolate the paranasal sinuses. This technique is not indicated for small frontal defects, but it should be considered for use by the head and neck surgeon who is faced with the challenge of reconstructing a major fronto-orbital defect.
Conventional maxillary prostheses were fabricated for more than 200 cases of postoperative maxillary defect. The maxillary prosthetics could be combined at any time in the course of primary tumor treatment by taking care to start early, fabricating quickly and lightening the prosthesis weight. Of these 200 cases, 104 who had visited during the one year period of 1992, were sent questionnaires for the evaluation of maxillary prosthesis. The questionnaires were composed of subjective and objective evaluations of speech, swallowing, eating and the feeling and duration of usage. Of 98 answers obtained, 94 valid answers were converted into points and analyzed in combination with the classifications of maxillary defect, stroke of mouth opening and the number of residual teeth. As the sizes of maxillary and soft palate defects increased, each point on the evaluations of speech, swallowing, eating, and feeling decreased, except the duration of usage in one day. The stroke of the mouth opening and the number of residual teeth were related to the abilities to swallow and eat. The analysis in this study revealed that early prosthesis fabrication served to enhance the quality of life. The patients, however, took a long time to become skilled in using the prosthesis. To obtain better prosthesis function, it is important (1) to avoid soft palate defects, (2) to minimize gingival and hard palate defects, (3) to make the mouth opening more than 20mm, and (4) to preserve the teeth material as much as possible. On the basis of these results, the author concludes that maxillary prosthetics designed according to our concept greatly enhance the quality of life of patients with postoperative maxillary defects.
In past years, characterization of extraoral prosthetics had to be performed through time-consuming techniques. As technology and materials have improved, so has the realistic appearance of today's prostheses. The device used in this article simulates a sewing machine effect that allows placement of up to 14 half-inch hairs in less than 30 seconds. These hairs can be shaped and contoured to simulate realistic hair strands (Figs. 9 and 10). By use of such a device, gluing, painting, and matting of hair have become techniques of the past.
If maximal preservation of appearance and function are to be achieved for the maxillectomy patient, preoperative dental impressions should be obtained, and clear communication should be established between the surgeon and the prosthodontist. The immediate surgical splint, which can be used for edentulous as well as dentulous patients, provides numerous advantages for the patient and the surgeon. Surgical procedures that enhance the fit and comfort of a prosthesis include (1) making the mucosal incision 0.5 cm lateral to the bony cut, (2) extracting the first tooth on the resected side before making the bony cut, (3) preserving the premaxillary segment, (4) creating a skin-graft mucosal-scar band, (5) removing the entire velum when the surgical procedure requires resection of more than one-half of the velum, and (6) evaluating the possible removal of the coronoid process.
Presentation of two cases of open orbital roof fracture with destruction of all the orbital roof extending from the fronto-maxillo region to the spina orbitalis. After a first emergency neurosurgical treatment, a cast of the excised soiled bone fragment was taken and identical replica was made from methylmethacrylate. In a second surgical procedure, the resine mould was set in place by endocranicl approach, and was fastened firmly to the surrounding bone with wire sutures. In such types of defects cranioplasty and orbitoplasty are mandatory.
The in vitro physical properties of two types of polydimethyl siloxane, MDX 4-4210 and a new material A-2186, were compared. The properties that were investigated in this study were tensile strength, elongation, tear strength, and surface hardness. The properties tested were selected because of their clinical significance for fabricating a facial prosthesis. According to the results obtained in this investigation, the new material, A-2186, had greater tear resistance, tensile strength, and a larger percentage of elongation. A-2186 material, also proved to be softer at the surface than the MDX 4-4210. This combination of physical properties makes this material, A-2186, a better choice than the traditional MDX 4-4210 for the fabrication of facial prostheses.
A review of the polyurethane elastomers used for facial prostheses has been presented. A description of the casting technique was given. The materials require accuracy and care in handling to insure the successful casting of a prosthesis. They seem to simulate the characteristics of the facial tissues and are more durable and comfortable than previously used materials. Over 300 patients have been exposed to or treated with these materials without evidencing significant adverse tissue reaction. In spite of the improvements that these materials present over previous ones (PVC and silicones), much work is still required to understand their behavior and their physical and mechanical characteristics and to compensate for the metameric phenomenon.
The authors stress upon the various functional, physiological and cosmetic disorders in patients with frontal continuat resection of the lower jaw. Their experience in the treatment of eight patients with frontal resection reveals the advantages of the two-part prosthetic constructions, consisting of one fixed part blocking the teeth and one removable part replacing the defect. In all cases with big bone defects in the frontal region of the lower jaw the authors recommend removable partial denture with intracornal channel-shoulder-pin-attachement, being with high functional, medicobiological and aesthetic indices.
A computer-aided designing and manufacturing (CAD/CAM) technique for clinical fabrication of facial prostheses was developed. Laser surface scanning was applied to acquire three-dimensional imaging data of the patient's facial defect. The three-dimensional imaging data was then transferred to a CAD/CAM interactive program for image processing, which then mathematically designed and produced a model for fabrication of the facial prosthesis. This CAD/CAM technique has the potential to simplify the procedure and decrease the laboratory work required compared to that required for the conventional plaster-cast method. This new technique also provides a novel approach to the fabrication of prostheses for the reconstruction of facial defects. Two alternative three-dimensional modeling processes, laser lithographic modeling and numerically controlled milling modeling, were integrated in this study. The possibilities and current limitations of the techniques are also discussed.
Large acquired defects with undercuts can be restored with sectional prostheses. Sections of the prosthesis can be connected with small Sm-Co magnet pairs. The advantages of Sm-Co magnets are that (1) sections of prostheses can be connected by magnets less than 1 cm in size, (2) they can be embedded in thin sections of acrylic resin, (3) they are easy to place, (4) insertion is easy (magnetic attraction enhances), (5) hollow obturators can be used, and (6) tissue undercuts can be used for additional retention of prostheses.
This retrospective study evaluated the use of percutaneous craniofacial implants for the prosthetic rehabilitation of patients with a history of orbital exenteration and irradiation for oncologic tumors of the head and neck. A total of 24 implants were placed in six patients. All implants were determined to be osseointegrated at the time of uncovering. Three implants were subsequently resubmerged beneath the soft tissue because of positional interferences with prosthesis fabrication. The remaining 21 implants were ultimately used to retain six orbital prostheses. Two implants failed to maintain osseointegration during the follow-up period and were subsequently removed without complications. This represents an overall integration success rate of 90.5% over a mean follow-up period of 32.8 months (range = 11 to 68 months). The significance of these findings and their relationship to comparable reports in the literature are discussed.
This pilot research aims to identify and assess suitable technologies that may be used to capture, create, and produce fine textures and wrinkles that may be incorporated into computer aided prosthesis design and production techniques. A range of suitable technologies is identified and two methods that may be used in different prosthetic rehabilitation situations are assessed: the creation of three-dimensional relief in a computer aided design environment and the capture of facial anatomy and texture using fringe-projection surface scanning. Patterns were produced using the suitable rapid prototyping processes identified, and these were assessed by a qualified and experienced prosthetist. The suitability of the technologies is commented upon, limitations discussed, and future directions identified.