Digital fabrication of custom tracheostomy appliances: A clinical report.

The use of rapid prototyping technology has revolutionized the fabrication of intraoral prostheses. With the advancement of digital technology, its applications have expanded to extraoral prostheses and appliances to replace a variety of head and neck defects. The following clinical report illustrates the use of a new technique that allows the digital replication and recontouring of a stock tracheostomy tube to improve patient fit, comfort, and esthetics.

Gradated silicone shade guide utilized for shade matching extraoral prostheses.

Shade matching of extraoral prostheses is completed by mixing pigments and rayon flocking into medical-grade silicone and using a carrier to evaluate the color match. This process does not account for how material thickness affects the appearance of the silicone. This clinical case report discusses an innovative way to match the patient's skin tone using a digitally designed gradated silicone carrier and how this device allows for the assessment of shade from the thin marginal edge to 5 mm thickness.

[Modern methods of adhesive fixation of facial epitheses]. / Sovremennye metody adgezivnoi fiksatsii epitezov litsa.

This review presents an analysis of domestic and foreign literature on the issues of fixation of facial epitheses and combined maxillofacial prostheses, such as the use of craniofacial implants installed in the zygomatic bone, brow arches, orbital walls, mastoid process of the temporal bone with beam or magnetic beam fixation systems. The advantages and disadvantages of such fastening systems are described. The analysis and systematization of available data on medical adhesive compositions that can be used in maxillofacial prosthetics to hold facial epitheses has been carried out. Much attention is paid to the chemical composition of pressure-sensitive adhesives, water-based and silicone-based. Examples of such compositions are given. The physicochemical properties of medical adhesive systems that cause adhesive-cohesive interaction are described. This review presents the results of comparative studies to assess the fixing properties of various adhesives, as well as to study the formation of biofilm on the surfaces of prostheses and skin when using different adhesives.

Preliminary impression for maxillary defect: A two-step technique.

Preliminary impressions must record the periphery and height of maxillary defects to allow for an eventual extension of the master impression tray. These impressions are usually made with irreversible hydrocolloid. Carrying the impression material into the defect can be complex, especially in the case of a limited oral opening. Moreover, the patient can be harmed during the removal procedure, and material may be stuck in anatomical structures. The technique presented in this article avoids these issues in any maxillary defect with a two-step preliminary impression. An elastomeric material ball is first placed in the defect until full setting. Then, this "obturator bulb" is removed and eventually relined until it is retentive. Retentions are designed on the oral side of the bulb and the bulb is placed back into the defect. Finally, an alginate over-impression of the maxillary is made. The alginate is removed after full setting, and the obturator can be reassembled on the maxillary impression to provide a full recording of the maxillary. This protocol can safely be used for defects of any size, despite eventual limitations in oral opening.

Prevalence of Possible Dementia in Patients with Maxillofacial Defects and Difficulty of Inserting Obturator in Maxillectomy Patients: Toward Better Provision of Supportive Care.

As society ages, it is important to understand the prevalence of dementia and the difficulties of inserting prostheses in patients with maxillofacial defects in order to clarify issues in supportive care. We screened 183 patients for dementia using the revised Hasegawa's dementia scale (HDS-R) at the Clinic for Maxillofacial prosthetics, Tokyo Medical and Dental University, and investigated age and sex differences in HDS-R score. We asked 47 of the 183 participants about the difficulty of inserting a maxillofacial obturator prosthesis and collected subjective comments, information about the prosthesis, and data from five assessments. Multiple regression analysis was used to reveal factors associated with insertion difficulty. Overall, 8.7% of the participants were judged to have possible dementia. Men were more likely than women to have possible dementia, and the risk increased with age. Of the 47 participants, 26 reported difficulty inserting their prosthesis, 12 of whom attributed it to their oral defect. Fourteen patients advised following doctor's instructions to practice insertion in order to become accustomed to it. A lower HDS-R score had a significant impact on insertion difficulty. Cognitive function and difficulty inserting maxillary obturator prostheses should be considered in the provision of continuous supportive care to patients with maxillary defects.

Somatoprótesis y Estallido Social Chileno 2019

Durante el Estallido Social en Chile 2019, la Odontología tomó un rol protagónico que nadie esperaba: La rehabilitación protésica de las víctimas de trauma ocular. Estos eventos dejaron al desnudo importantes fragilidades del sistema de salud Chileno.

During the social unrest in Chile in 2019, dentistry took a protagonist role that no one foresaw: The prosthetic rehabilitation of the ocular trauma victims. These events revealed important flaws on the Chilean Health system.

Psychosocial distress and psychological adjustment in patients with ocular loss: a framework analysis.

BACKGROUND: Patients with ocular loss tend to have physical and psychosocial difficulties. Maxillofacial prosthetic specialists involved in the treatment should be trained with competence to manage psychological complications. However, due to the multifactorial origin of the psychosocial distress, designing such training activities can be challenging. This research aimed to construct a conceptual framework illustrating the effects of ocular loss on patients' physical and psychosocial well-being and their coping strategies, to propose the learning content of training sessions. METHODS: A semi-structured interview and a topic guide were employed to explore the perceptions from patients who were receiving their first custom ocular prosthesis, fabricated by maxillofacial prosthodontists. The participants were selected using a purposeful sampling up until data saturation. The data were analyzed using framework analysis. RESULTS: Twelve patients participated in this research. Four main themes emerged from the data analysis: (1) Impact of ocular loss, (2) Factors influencing psychosocial distress, (3) Psychological adjustment, and (4) Expected treatment outcomes. Each theme appeared to have influence on the other, rather than presenting itself independently. Although patients with ocular loss experienced both physical and psychosocial difficulties, psychological distress was greatly influenced by self-perceived disfigurement, etiology, and social status. Therefore, they needed to develop their coping strategies including rehabilitation with ocular prosthesis. CONCLUSION: Various forms of psychological adjustments were necessary in these patients with ocular loss to resume their daily lives. The specialist involved in the treatment should also partake in patients' psychological adjustment and should be competent in psychological management skills, such as supporting patients to meet their expectations.

[Professor V.A. Dunaevsky (on the occasion of the 100th anniversary)]. / Professor V.A. Dunaevskii (k 100-letiyu so dnya rozhdeniya).

The purpose of the work is to highlight the scientific, clinical, pedagogical and social activities of the famous dentist, participant of the Great Patriotic War, Doctor of Medical Sciences, Professor Vladimir Arsenievich Dunaevsky in connection with the 100th anniversary of his birth, and also to note the peculiarities of his personality, character and merits in the organization dental care to the population.

Accuracy of capturing nasal, orbital, and auricular defects with extra- and intraoral optical scanners and smartphone: An in vitro study.

OBJECTIVES: This in vitro study compares the scanning accuracy of various stationary and portable as well as extra- and intraoral devices for capturing oncological defects. METHODS: A 3D-printed model of a nasal, orbital, and auricular defect, as well as one of an intact auricle, were digitalized (n = 7 per device) with a stationary optical scanner (Pritiface), a portable extraoral optical scanner (Artec Space Spider), two intraoral scanners (Trios 4 and Primescan), and a smartphone (iPhone 11 Pro). For the reference data, the defect models were digitalized using a laboratory scanner (D2000). For quantitative analysis, the root mean square error value for trueness and precision and mean deviations in millimeters were obtained for each defect type. The data were statistically analyzed using two-way ANOVA and Tukey multiple comparison test. For qualitative analysis, a colorimetric map was generated to display the deviation within the defect area and adjacent tissue. RESULTS: Statistically significant interactions were found in the trueness and precision for defect and scanner type. CONCLUSION: The Primescan and Artec Space Spider scanners showed the highest accuracy for most defect types. Primescan and Trios 4 failed to capture the orbital defect. The iPhone 11 Pro showed clinically acceptable trueness but inferior precision. CLINICAL SIGNIFICANCE: The scanning devices may demonstrate varying accuracy, depending on the defect type. A portable extraoral optical scanner is an universal tool for the digitization of oncological defects. Alternatively, an intraoral scanner may be employed in maxillofacial prosthetics with some restrictions. Utilizing a smartphone in maxillofacial rehabilitation should be considered with caution, because it provides inconsistent accuracy.

Binder Jetting of Custom Silicone Powder for Direct Three-Dimensional Printing of Maxillofacial Prostheses.

Recent advances in digital workflow have transformed clinician's ability to offer patient-specific devices for medical and dental applications. However, the digital workflow of patient-specific maxillofacial prostheses (MFP) remains incomplete, and several steps in the manufacturing process are still labor-intensive and are costly in both time and resources. Despite the high demand for direct digital MFP manufacturing, three-dimensional (3D) printing of colored silicone MFP is limited by the processing routes of medical-grade silicones and biocompatible elastomers. In this study, a binder jetting 3D printing process with polyvinyl butyral (PVB)-coated silicone powder was developed for direct 3D printing of MFP. Nanosilica-treated silicone powder was spray dried with PVB by controlling the Ohnesorge number and processing parameters. After printing, the interconnected pores were infused with silicone and hexamethyldisiloxane (HMDS) by pressure-vacuum sequential infiltration to produce the final parts. Particle size, coating composition, surface treatment, and infusion conditions influenced the mechanical properties of the 3D-printed preform, and of the final infiltrated structure. In addition to demonstrating the feasibility of using silicone powder-based 3D printing for MFP, these results can be used to inform the modifications required to accommodate the manufacturing of other biocompatible elastomeric materials.

Post-residency fellowship training in Maxillofacial Prosthetics is needed in Pakistan.

OBJECTIVE: To determine the spectrum of maxillofacial prosthetics services in Pakistan, to explore the need of a relevant fellowship training programme in the country, and to determine whether they contribute to tumour board of head and neck oncology. METHODS: The cross-sectional online survey was conducted from March to June 2020 and comprised all prosthodontists registered on the portal of the Pakistan Prosthodontics Association. Using Google Forms, the survey questionnaire was sent via email. The survey form was self-generated. Data was analysed using SPSS 23. RESULTS: Of the 84 prosthodontists approached, 44(52.4%) responded. The overall median age was 39 years (range: 30-60 years), and 34(77.3%) subjects were males. Overall, 19(43.2%) subjects were from Punjab, 14(31.8%) Sindh, 6(13.6%) Khyber Pakhtunkhwa, and 5(11.4%) Islamabad. None of the participants had received any formal accredited training in maxillofacial prosthetics. Although 37(84.1%) respondents reported providing maxillofacial prosthetics services to their patients as they had learnt it during their prosthodontics residency. Only 3(6.8%) respondents were contributing to head and neck tumour board. An overwhelming majority 42(95.5%) stressed the need of structured training programmes in maxillofacial prosthetics. CONCLUSIONS: There is no accredited maxillofacial prosthetics training centre and an obvious lack of prosthodontists with formal training in the professional area. The participation of prosthodontists in the head and neck tumour board was negligible.

Optimization of Prosthodontic Computer-Aided Designed Models: A Virtual Evaluation of Mesh Quality Reduction Using Open Source Software.

PURPOSE: Mesh optimization reduces the texture quality of 3D models in order to reduce storage file size and computational load on a personal computer. This study aims to explore mesh optimization using open source (free) software in the context of prosthodontic application. MATERIALS AND METHODS: An auricular prosthesis, a complete denture, and anterior and posterior crowns were constructed using conventional methods and laser scanned to create computerized 3D meshes. The meshes were optimized independently by four computer-aided design software (Meshmixer, Meshlab, Blender, and SculptGL) to 100%, 90%, 75%, 50%, and 25% levels of original file size. Upon optimization, the following parameters were virtually evaluated and compared; mesh vertices, file size, mesh surface area (SA), mesh volume (V), interpoint discrepancies (geometric similarity based on virtual point overlapping), and spatial similarity (volumetric similarity based on shape overlapping). The influence of software and optimization on surface area and volume of each prosthesis was evaluated independently using multiple linear regression. RESULTS: There were clear observable differences in vertices, file size, surface area, and volume. The choice of software significantly influenced the overall virtual parameters of auricular prosthesis [SA: F(4,15) = 12.93, R2 = 0.67, p < 0.001. V: F(4,15) = 9.33, R2 = 0.64, p < 0.001] and complete denture [SA: F(4,15) = 10.81, R2 = 0.67, p < 0.001. V: F(4,15) = 3.50, R2 = 0.34, p = 0.030] across optimization levels. Interpoint discrepancies were however limited to <0.1mm and volumetric similarity was >97%. CONCLUSION: Open-source mesh optimization of smaller dental prostheses in this study produced minimal loss of geometric and volumetric details. SculptGL models were most influenced by the amount of optimization performed.

Technical Protocol for Presenting Maxillofacial Prosthetics Concepts to Dental Students using Interactive 3D Virtual Models within a Portable Document Format.

An appropriate presentation of maxillofacial defects and their prosthetic rehabilitation concepts using traditional two-dimensional educational materials is challenging for dental students and prosthodontics residents. This technique article introduces a simple approach to visualize and communicate three-dimensional (3D) virtual models embedded into a portable document format (PDF) file for presenting maxillofacial prosthetics concepts and enhancing students' spatial ability when learning maxillofacial prosthetics. MeVisLab software was used to combine various maxillofacial models and save them as a single 3D model. Adobe Acrobat Pro DC software was used to import the 3D model and create interactive visualization PDF documents. Adobe reader software was then used to visualize the content of the PDF documents. This approach allows educators to develop PDF files with multiple 3D models for teaching maxillofacial prosthetics concepts and communicate them with their students. Students can simply open the PDF file, activate the 3D mode, and interactively manipulate the 3D models to enhance their spatial ability for learning maxillofacial prosthetics.

Designing 3D prosthetic templates for maxillofacial defect rehabilitation: A comparative analysis of different virtual workflows.

OBJECTIVE: To design and compare the outcome of commercial (CS) and open source (OS) software-based 3D prosthetic templates for rehabilitation of maxillofacial defects using a low powered personal computer setup. METHOD: Medical image data for five types of defects were selected, segmented, converted and decimated to 3D polygon models on a personal computer. The models were transferred to a computer aided design (CAD) software which aided in designing the prosthesis according to the virtual models. Two templates were designed for each defect, one by an OS (free) system and one by CS. The parameters for analyses were the virtual volume, Dice similarity coefficient (DSC) and Hausdorff's distance (HD) and were executed by the OS point cloud comparison tool. RESULT: There was no significant difference (p > 0.05) between CS and OS when comparing the volume of the template outputs. While HD was within 0.05-4.33 mm, evaluation of the percentage similarity and spatial overlap following the DSC showed an average similarity of 67.7% between the two groups. The highest similarity was with orbito-facial prostheses (88.5%) and the lowest with facial plate prosthetics (28.7%). CONCLUSION: Although CS and OS pipelines are capable of producing templates which are aesthetically and volumetrically similar, there are slight comparative discrepancies in the landmark position and spatial overlap. This is dependent on the software, associated commands and experienced decision-making. CAD-based templates can be planned on current personal computers following appropriate decimation.

Comprehensive prosthetic rehabilitation of a case of the orofacial digital syndrome.

Maxillofacial defects can result from trauma, treatment of neoplasm, or congenital malformations. Many a time due to the size, location of the defect, or because of the patient's medical condition, surgical reconstruction may not be possible. In these cases, rehabilitation is indicated with the help of a maxillofacial prosthesis. Orofacial digital syndrome (OFDS) is a congenital anomaly that affects the development of the mouth, face, and digits. Such abnormalities or defects compromise form, function, esthetics, and social acceptance and deeply affect the psychological status of an individual. This report describes the comprehensive prosthetic rehabilitation of a case of OFDS with bilateral cleft lip and palate as well as syndactyly and brachydactyly of the foot. The individual was rehabilitated with a definitive obturator and a custom-made foot prosthesis using room-temperature-vulcanizing silicone. The prosthetic rehabilitation significantly improved esthetics, phonetics, and function as well as social and psychological status of the patient.

[Features of dental rehabilitation of elderly patients after treatment of maxillofacial neoplasm.]

The purpose of this study is a comparative analysis of the effectiveness of the use of dental trays-transformers for the manufacture of prosthetic designs for elderly patients with acquired microstomia. Was conducted a clinical study of 12 hemimaxillectomy patients from 60 to 72 years. The 1st group included 6 patients with acquired microstomia, impressions of the jaws were obtained with dental trays-transformers. The 2nd group includes 6 patients who have less traumatic oral opening, they were removed with standard dental trays. The group of clinical control consisted of 6 patients with partial absence of maxillary teeth, who needed to prosthetic dentistry. The results of the study indicate the effectiveness of the use of trays-transformers to impressions of the jaw in elderly patients with restricted oral opening, as well as in patients with normal oral opening. Optimization of the stages of obturator prostheses allows to provide qualitative prosthetic care of patients with malignant neoplasms of the oropharyngeal region, which has a positive effect on the quality of life of elderly patients with acquired defects of the oropharyngeal region.

Custom Nasal Septum Prosthesis Fabricated from a 3D-Printed Working Model: A Clinical Report.

This clinical report describes the treatment of a 47-year-old female patient with a nasal septum perforation. The treatment used a 2-piece magnetic custom prosthesis fabricated from a 3D-printed model. By using an existing medical CT scan to generate the printed working model, the number of clinical appointments was reduced. The workflow expanded the purpose of the radiologic images from simply diagnostic to include the prosthetic aspect of treatment.

Suitability of a Mobile Phone Colorimeter Application for Use as an Objective Aid when Matching Skin Color during the Fabrication of a Maxillofacial Prosthesis.

PURPOSE: Color matching a facial prosthesis to human skin is very challenging. Colorimeters aid this process by adding objectivity to what is an otherwise subjective procedure. Mobile phone colorimeter applications offer a less expensive and widely available alternative to dedicated colorimeter devices for color measurement. There is a lack of evidence in the literature regarding the suitability of mobile phone colorimeter applications for the development of silicone shades for facial prosthetics. The purpose of this study is to determine the suitability of a mobile phone colorimeter application for matching natural skin colors during the fabrication of maxillofacial prostheses. MATERIALS AND METHODS: Ten pigmented maxillofacial silicone elastomer swatches were fabricated to mimic a range of human skin tones. Color measurements of these swatches were recorded using a test instrument-the mobile phone colorimeter application (RGB Colorimeter) and a reference instrument-the commercially available skin color measurement device e-skin spectrocolorimeter. Comparisons in trueness and precision of the color measurements were made using previously described methods. Data analysis was performed on the recorded results for each of the parameters at three distances (25, 30, and 35 mm) of the test instrument from the target against both a black and a white background. RESULTS: The trueness of the mobile phone colorimeter application relative to the colorimeter device varied depending on the distance from the target and the background color. The relative trueness of the color difference measurements fell just within the documented upper threshold of acceptable limits of color difference (∆E 3.0 - 4.4). The calculated precision of the CIE L*a*b* and ∆E measurements of the mobile phone colorimeter application was good, with the latter being well within the documented acceptable limits. CONCLUSIONS: A mobile phone colorimeter application would be a suitable aid in objectifying the process of color matching a silicone maxillofacial prosthesis. Further investigation into image calibration to improve trueness and the control of variables such as background noise, uniformity of illumination, and measuring distance is required.

Virtual Surgical Planning Computer-aided Design-guided Osteocutaneous Fibular Free Flap for Craniofacial Reconstruction: A Novel Surgical Approach.

Advancements and increased availability of radiological services have revolutionised our approach to oncological and reconstructive surgical practice. With an increasing demand for accuracy in diagnosis and improved oncological outcome, the requirement for precise application of radiological tools and the exploration of novel software has developed. This has led to the evaluation of modern technologies such as computer-aided design to enhance reconstructive surgery. Mandibular reconstruction following oncological resection using an osteocutaneous fibular free flap is now considered to be the gold standard reconstructive surgical approach, as this approach provides more satisfactory outcomes for both patients and reconstructive surgeons. Recent years have seen Irish reconstructive surgeons introduce computer-aided design pre-operative planning to operating theatres as means of improving cosmetic, functional and oncological outcome, yet the detailed, complex planning required pre-operatively is not well described. Herein, the purpose of this article was to demonstrate the precision and accuracy of virtual surgical planning computer-aided design (VSP-CAD) as a modern surgical approach to craniofacial reconstruction following surgical resection of an American Joint Committee on Cancer stage 4 oral carcinoma.