Advanced Three-Dimensional Technologies in Craniofacial Reconstruction.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Describe the evolution of three-dimensional computer-aided reconstruction and its current applications in craniofacial surgery. 2. Recapitulate virtual surgical planning, or computer-assisted surgical simulation, workflow in craniofacial surgery. 3. Summarize the principles of computer-aided design techniques, such as mirror-imaging and postoperative verification of results. 4. Report the capabilities of computer-aided manufacturing, such as rapid prototyping of three-dimensional models and patient-specific custom implants. 5. Evaluate the advantages and disadvantages of using three-dimensional technology in craniofacial surgery. 6. Critique evidence on advanced three-dimensional technology in craniofacial surgery and identify opportunities for future investigation. SUMMARY: Increasingly used in craniofacial surgery, virtual surgical planning is applied to analyze and simulate surgical interventions. Computer-aided design and manufacturing generates models, cutting guides, and custom implants for use in craniofacial surgery. Three-dimensional computer-aided reconstruction may improve results, increase safety, enhance efficiency, augment surgical education, and aid surgeons' ability to execute complex craniofacial operations. Subtopics include image analysis, surgical planning, virtual simulation, custom guides, model or implant generation, and verification of results. Clinical settings for the use of modern three-dimensional technologies include acquired and congenital conditions in both the acute and the elective settings. The aim of these techniques is to achieve superior functional and aesthetic outcomes compared to conventional surgery. Surgeons should understand this evolving technology, its indications, limitations, and future direction to use it optimally for patient care. This article summarizes advanced three-dimensional techniques in craniofacial surgery with cases highlighting clinical concepts.

Bone Reconstruction Planning Using Computer Technology for Surgical Management of Severe Maxillomandibular Atrophy.

Digital imaging technology and refined software programs have significantly improved a clinician's ability to assess and evaluate anatomic structures and quantify both defect size and required graft volume. This article summarizes the computed tomography-based technology used in these applications to illustrate their current use as exemplified by computer-assisted planning and treatment of severe maxillofacial atrophy treated using both interpositional and mesh-onlay grafting methodology.

The paradigm shift for drug delivery systems for oral and maxillofacial implants.

Along with the development of nanotechnological strategies for biomaterials associated with the prevention of infections, a myriad of clinically unproven techniques have been described to date. In this work, the aim was to perform a critical analysis of the literature available concerning antibacterial biomaterials for oral implantology and to provide a practical derivation for such a purpose. As anti-adhesive strategies may affect osseointegration, they should no longer be recommended for inclusion in this class of biomaterials, despite promising results in biomedical engineering for other, non-bone load bearing organs. Targeted, antibacterial drug delivery is most likely desirable in the case of intraosseous implants. Interfering factors such as the oral cavity environment, saliva, the bacterial microbiome, as well as, the characteristics of the alveolar mucosa and peri-implant space must be taken into account when calculating the local pharmacokinetics for antibacterial coatings. Effective release is crucial for tailoring antibacterial implant longevity providing minimal inhibitory concentration (MIC) for the desired amount of time, which for oral implants, should be at least the cumulative time for the osseointegration period and functional loading period within the tissues. These parameters may differ between the implant type and its anatomical site. Also, the functional drug concentration in the peri-implant space should be calculated as the amount of the drug released from the implant surface including the concentration of the drug inactivated by biological fluids of the peri-implant space or saliva flow throughout the effective release time.

Adjuvant therapy for intra oral surgical oncological defect with ancillary prosthesis: A literature review.

The role of a maxillofacial prosthodontist in the treatment of facial defects cannot be underestimated. A multidisciplinary approach is required during the rehabilitation procedure to bring out effective results. Ancillary maxillofacial prostheses limit the patient's disability and improve function. These prostheses are inevitable in restoring the function, esthetics, general, and psychological health of the patients. This article reviews the various ancillary-maxillofacial prostheses and throws light on their historical development.

A Simple Technique for Placing Extraoral Implants at an Optimal Position in Orbital Defects.

Translucent acrylic templates have been used to indicate implant positions for implant-retained extraoral prostheses; however, this procedure can be challenging, as the acrylic templates have to be positioned onto reflected skin flaps. The fabrication of an acrylic-based colorless template or duplicating an existing prosthesis can facilitate the location of extraoral implants. Spots can be created on templates to indicate the optimal position of the implants. Afterward, punching the skin to the bone with a very thick sharp needle or a small sharp bur will mark the desired implant position on the bone before reflecting the skin.

Use of a three-dimensional custom-made porous titanium prosthesis for mandibular body reconstruction.

The progress made in recent years in the field of head and neck bone reconstruction is directly related to technological advancements made in computer-aided design and manufacturing (CAD/CAM) and three-dimensional printing in particular. Today these technologies are mainly used in mandibular reconstruction to manufacture aids for harvesting and shaping bone flaps. However problems remain when addressing patients with a contraindication to microsurgery who need extensive bone reconstruction. For these patients who cannot benefit from vascularized bone grafts, surgeons have to find alternative solutions aimed at maintaining best function and aesthetics. The goal of this article is to present an original method for mandibular body replacement with custom-made porous titanium prostheses in patients ineligible for a bone free flap. This solution has been used for two patients with an intraoral approach, resulting in no visible scars, with simple postoperative care of a short duration. This innovative solution represents an additional option for the treatment of complex mandibular reconstructions.

Reconstruction of midface defect from idiopathic destructive process using Medpor implant.

IMPORTANCE: Reconstruction of the midface remains a challenging task for even the most experienced surgeon, with a host of reconstructive options including free tissue transfer, allografts, or prosthetic implants. Presented here is a case of idiopathic bony destruction of the right midface in a 19year old female, creating a unique defect requiring repair. OBJECTIVE: Demonstrate a unique case of severe maxillary degeneration and discuss the associated reconstructive challenges and final repair with a prosthetic implant. DESIGN: Case report. RESULTS: The patient presented with a 7month history of an idiopathic progressive deformity of the right cheek. Computed tomography of the paranasal sinuses revealed extensive bone loss of the right midface and orbit. The patient underwent facial reconstruction using a customized Medpor (Stryker Corp, Kalamazoo, MI) implant. At 6month follow-up the patient and physician were both pleased with the patient's overall appearance. The patient did have some residual lower lid retraction present as well as some lateral pull at the lateral canthus outward from the orbit itself. CONCLUSIONS: Preoperative planning for midface reconstruction requires a deep understanding of the aesthetic, functional, and supportive roles this structure holds. Computer assistance allows the creation of custom made implants, providing the reconstructive surgeon with innovative options for reconstruction with minimal morbidity to the patient. As the technology around the design and creation of the custom implants continues to improve, the role of computer assistance in reconstruction will become more prominent.

Biocompatibility of primers and an adhesive used for implant-retained maxillofacial prostheses: An in vitro analysis.

STATEMENT OF PROBLEM: Implant-retained maxillofacial prostheses should be biocompatible, regardless of the primers and adhesives used to bond the acrylic resin and facial silicone. The authors are unaware of any study evaluating the influence of these primers and adhesives on the biocompatibility of maxillofacial prostheses. PURPOSE: The purpose of this in vitro study was to evaluate the cytotoxic effect of primers and an adhesive used to bond acrylic resin and facial silicone during the fabrication of implant-retained maxillofacial prostheses. MATERIAL AND METHODS: Twenty-eight circular specimens made of resin and silicone were fabricated, either bonded or nonbonded with primer and adhesive. The specimens were divided into 7 groups: resin; silicone; resin+silastic medical adhesive type A+silicone; resin+DC 1205 primer silicone; resin+Sofreliner primer+silicone; resin+DC 1205 primer+silastic medical adhesive type A+silicone; and resin+Sofreliner primer+silastic medical adhesive type A+silicone. Eluates of the materials tested were prepared by setting 4 specimens of each experimental group in Falcon tubes with medium and incubating at 37°C for 24 hours. The eluate cytotoxicity was evaluated by an assay of survival/proliferation ((3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide [MTT] test) in cultures of human keratinocytes. The levels of IL1, IL6, TNFα, and the chemokine MIP-1α were evaluated by enzyme-linked immunosorbent assay. The mRNA expressions for MMP-9, TGF-ß, and collagen type IV were analyzed by the real time polymerase chain reaction. Data were submitted to analysis of variance with Bonferroni post hoc tests (α=.05). RESULTS: An increased cell proliferation was observed for the RAS group, with statistically significant differences (P<.001) compared with the unstimulated group. The RDCpS group showed the highest IL6 concentration values (P<.001). No significant statistical difference was found in the relative quantification of mRNA for collagen type IV, MMP9, or TGFß between the groups (P>.05). CONCLUSIONS: The RAS group showed the highest cell proliferation percentage, while the RDCpS group exhibited the highest IL6 concentration values. No detectable levels of IL1ß, TNF α, or CCL3/MIP1α were observed. The tested materials showed no toxic effects on the HaCaT cell line.

Palatal and lingual augmentation prosthesis for patients with dysphagia and functional problems: A clinical report.

This clinical report describes the treatment of a patient with insufficient tongue movement due to bilateral hypoglossal nerve palsy. A palatal augmentation prosthesis and a mandibular intraoral prosthesis (lingual augmentation prosthesis) were provided for this patient to address his functional dysphagia problems. These problems included insufficient oral to pharynx bolus transportation and displacement of the tongue to the right posterior. The 2 prostheses improved these 2 problems and also the head extension posture during swallowing. After insertion of the 2 prostheses, the patient could transport the bolus actively from the oral cavity to the pharynx.

Percutaneous implant retention of a nasal prosthesis.

This report describes an approach to the simultaneous retention of a nasal prosthesis and an intraoral prosthesis for a patient who had undergone a total rhinectomy with resection of the upper lip and premaxilla. At the time of the nasal resection, 2 dental implants were placed adjacent to the resection margins in the first premolar positions. These were used to anchor an intraoral, milled titanium bar and overdenture to replace the missing anterior teeth and provide support for the upper lip, which had been reconstructed with a vascularized radial forearm free-flap. The titanium bar also incorporated a connection for a tissue-penetrating percutaneous nasal extension, which pierced the radial forearm flap near the junction with the hard palate. Magnetic attachments screwed to the nasal extension retained a nasal prosthesis. The predictable and straightforward implementation of this novel concept with digital design and manufacture of the titanium components and guided placement of the nasal extension was made possible with software planning.

Solid Implants in Facial Plastic Surgery: Potential Complications and How to Prevent Them.

Allogenic implants are an effective alternative to autologous grafts in the reconstruction of facial defects. These implants are used to reconstruct a variety of bony and soft-tissue defects, including the frontal and temporal regions; internal orbit; infraorbital rim; malar, paranasal, and nasal regions; mandible; and chin. In comparison to their autologous counterparts, alloplastic materials are more readily available, lack donor-site morbidity, decrease surgical time and cost, and still have relatively good postoperative tissue tolerance. However, these implants are not without their own spectrum of complications. Common solid implant materials include silicone, GoreTex (expanded polytetrafluorethylene; W. L. Gore & Associates Inc., Flagstaff, AZ), MedPor (high-density porous polyethylene; Porex Industries, Fairburn, GA), and Mersilene mesh (nonresorbable polyester fiber; Ethicon, Somerville, NJ). Each of these materials poses certain complication risks based on their surface contour (smooth vs. porous), pliability, and reactivity with surrounding tissue. In addition, certain implant locations within the head and neck are at risk for different postoperative complications. Although there are no evidence-based guidelines for implant reconstruction to help avoid common complications, there are several principles and techniques that are commonly employed by surgeons to help reduce complication rates. These include careful patient selection, proper choice of operative procedure, infection control practices (including pre/intraoperative systemic antibiotics, meticulous aseptic technique, impregnation/soaking of implant in antibiotic, irrigation of implant pocket with antibiotic, careful closure of tissue layers, and postoperative oral antibiotics), preoperative implant shaping, choice of surgical approach, and intraoperative surgical techniques. Larger, controlled trials are needed to confirm the efficacy of the aforementioned techniques in the reduction of postoperative complications.

Hydroxyapatite/Collagen Composite Is a Reliable Material for Malar Augmentation.

PURPOSE: To evaluate the long-term results of cheekbone augmentation using porous hydroxyapatite granules mixed with microfibrillar collagen in a large group of patients. MATERIALS AND METHODS: Four hundred thirty patients who underwent zygomatic augmentation and intermaxillary osteotomy were evaluated clinically, radiologically, and histologically. RESULTS: Complications were found in 13 patients (1.56%). There were no relevant radiologic differences in prosthesis volume after 1 month (T1) or after 24 months (T2) in any patient; there were no clinically relevant differences in 110 patients after 36 months. At T1, the prosthesis had a granular structure and the granules had not migrated; at T2, the prosthesis was staunchly adhering to the underlying bone. Over time, the radiopacity of the material increased. Histologic results of 19 biopsy specimens obtained from 8 patients 2 years after the procedure showed prominent ossification with low inflammation, confirming new bone formation over time. According to the visual analog scale, the patients were generally satisfied with the aspects that were considered. CONCLUSION: Hydroxyapatite and collagen composite used during malarplasty produced a successful outcome. Its main drawback is a learning curve that is longer than for more frequently used implantable biomaterials.

An Adverse Implication of Radiation Therapy for Implant-Retained Maxillofacial Prostheses.

We report the 19-year postoperative course of a patient whose maxillary defect was reconstructed with maxillofacial implant-retained facial prostheses. The patient received 60 Gy of radiation therapy. Adjunctive hyperbaric oxygen therapy was administered and four 4.0-mm long maxillofacial implants were inserted. Four years and 6 months after insertion surgery, two of the four implants were lost and the others showed bone regression in the surrounding bone. All implants were replaced with Epitec System maxillofacial implants placed in non-irradiated bone. Eleven years and 6 months after replacement, the Epitec System has been maintaining good and firm osseointegration. Appropriate selection of implant sites and no history of radiation therapy are keys to successful implant reconstruction. However, adjunctive hyperbaric oxygen therapy is believed to be effective, osseointegrated implant should be inserted at a point appropriately distant from an irradiated lesion.

Anatomical reproducibility through 3D printing in cranio-maxillo-facial defects / Reproducibilidad anatómica a través de impresión 3d en defectos cranio-maxilo-faciales

The planning and 3D reconstruction in craniofacial defects based on anatomical principles of symmetry and passive adaptation has evolved radically the past few years. This article recounts the possibility to develop personalized and extensive craniofacial implants. We present a case of a patient with a 10-year trauma sequel evolution; the patient lost the right frontal bone, supraorbital wall and part of the temporal fossa. From the computerized tomography, and by using Materialise software (3-Matic and Mimics). Subsequently, the printing was performed using the virtual planning with a laser printer in titanium where the piece was elaborated with the determined specifications in the planning; surgery was performed without complications in which the implant was placed via a coronal approach, which did not require any type of adaptation. After a two-year follow-up we observed a correct position, symmetry, absence of infection or any other alteration. It is concluded that the planning and 3D printing are suitable to perform craniofacial reconstructions with a low morbidity, shorter surgical time, and with an adequate facial symmetry and aesthetic return.

La planificación y reconstrucción 3D en defectos craneofaciales se basa en principios anatómicos de simetría y pasividad en la adaptación, evolucionando rápidamente en los últimos años. El presente articulo presenta la posibilidad de rehabilitación de un paciente con trauma importante gracias a un implante craneofacial extenso. Se presenta el caso de un sujeto con evolución de 10 años de una secuela de trauma, donde perdió el hueso frontal, pared supraorbitaria y parte de la fosa temporal. A partir de una tomografía computadorizada, utilizando un software de planificación Materialise (3-Matic and Mimics) se construyó un modelo virtual a través de un implante de pieza única para cubrir íntegramente el defecto; se planificó la posición junto a la cantidad y longitud de tornillos a utilizar. A continuación se realizó la impresión de la pieza mediante una impresora laser de titanio donde la pieza fue construida según las especificaciones de la planificación; la cirugía fue realizada sin complicaciones en el cual el implante fue instalado a través de un acceso coronal sin necesidad de ningún tipo de adaptación. Después de dos años de seguimiento se observa una posición correcta, simétrica y en ausencia de infecciones u otro tipo de alteración. Se concluye que la planificación e impresión 3D es viable de realizar en reconstrucción craneofacial con baja morbilidad, disminución del tiempo quirúrgico, obteniendo una adecuada simetría y estética facial.

The use of a computed tomographic application for mobile devices in the diagnosis of oral and maxillofacial surgery.

The aim of the current technical report was to introduce a computed tomographic (CT) application for mobile devices as a diagnostic tool for analyzing CT images. An iPad and an iPhone (Apple, Cuppertino, CA) were used to navigate through multiplanar reconstructions of cone beam CT scans, using an application derived from the OsiriX CT software. Tools and advantages of this method were recorded. In addition, images rendered in the iPad were manipulated during dental implant placement and grafting procedures to follow up and confirm the implant digital planning in real time. The study population consisted of 10 patients. In all cases, it was possible to use image manipulation tools, such as changing contrast and brightness, zooming, rotating, panning, performing both linear and area measurements, and analyzing gray-scale values of a region of interest. Furthermore, it was possible to use the OsiriX application in the dental clinic where the study was conducted, to follow-up the analyzed implant placement and grafting procedures at the chairside. The current findings suggest that technological and practical methods to visualize radiographic images are invaluable resources to improve training, teaching, networking, and the performance of real-time follow-up of oral and maxillofacial surgical procedures. This article discusses the advantages and disadvantages of introducing this new technology in the clinical routine.