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Purpose: This study investigated the use of digital technology in maxillofacial prosthetics among practitioners involved in maxillofacial prosthetic rehabilitation in Japan. Materials and Methods: A self-administered survey questionnaire with 24 closed-ended and multiple choice questions was used. A total of 300 questionnaires were distributed at the 32nd meeting of the Japanese Academy of Maxillofacial Prosthetics that was held in Tokyo, Japan in June 2015. The survey questionnaire was distributed in a pack that included an introduction letter explaining the research aims, objectives, and informed consent. The data obtained were analyzed by descriptive statistical methods and reported as frequency and range. Results: In total, 105 respondents (77 men (73.4%), 28 women (26.6%); median age, 40 years; age range 21-66 years) completed the questionnaire (response rate, 35%). The majority of respondents were dentists (75.2%), followed by dental technicians (21.9%). The median duration of work experience for the respondents in their specialty was 14 years, and 97% of respondents had interested and adopted digital technologies in maxillofacial prosthetics. Digital technologies were used significantly in patient and practice management, diagnostic, and patient’s defect visualization (p < 0.001) but insignificant in treatment planning (p = 0.917). In contrast, there were significant increases in non-use of digital technologies in prosthesis design, prosthesis manufacturing, and patient and prosthesis evaluation (p < 0.001). Conclusion: Japanese dental practitioners are interested and willing to use digital technology in maxillofacial prosthetics. Most respondents use some or a substantial number of digital technologies in clinical practice. (Int J Maxillofac Prosthetics 2021;4:25-36)

Purpose: Surgical obturators improve patients’ quality of life after maxillectomy by maintaining oral functions. As digital workflows are commonly used for planning maxillofacial surgeries and prostheses, the hypothesis of this study was that the fabrication of the immediate surgical obturator could benefit from the currently available open-source software. The aim of this study was to develop a protocol for fabricating before the surgery a prefabricated, personalized, and lightweight immediate surgical obturator with open-source software and limited amount of relining material. Materials and methods: The protocol steps consisted of digital simulation of maxillectomy defect based on CBCT segmentation of cadavers’ heads according to the surgical planning. Design of immediate surgical obturator by boolean subtraction tools using open-source software, scaling down the final designed immediate surgical obturator to 90%, and then 3D-printing it layer by layer in biocompatible resin to be relined and fitted intraorally after surgery. Results: The developed protocol was successfully achieved. Maxillectomy defect interest areas were successfully segmented using open-source software. Immediate surgical obturator was also successfully designed and 3D printed using biocompatible resin materials. The immediate surgical obturator was thus adapted to the defect with limited amount of relining material. Conclusions: This innovative method could give the patient an opportunity to benefit from a personalized, biocompatible and lightweight immediate surgical obturator. (Int J Maxillofac Prosthetics 2021;4:18-24)

This study aimed to evaluate the stability of the surface of the maxillary teeth and mucosa in cleft lip and palate (CLP) patients with a maxilla defect or tissue deficiency according to the duration of observation and cleft type.Pairs of maxillary casts taken from 18 patients at different time points after prosthodontic treatment were investigated in this study. All 36 casts were scanned with an intraoral scanner, and the acquired images were saved in standard tesselation language (STL) files. The two STL files for each patient were then superimposed using three-dimensional (3D) evaluation software, with 3D deviations shown as a color map. Areas with a 3D deviation within ±0.100 mm were defined as stable. The influence of cleft type and duration of observation on the ratio of stable areas to the entire maxillary surface comprising the teeth and mucosa was investigated using multiple regression analysis. Statistical significance was set at p0.05.Multiple regression analysis showed that the duration of observation was significantly associated with the stable area ratio (B = -23.463, P.001), whereas cleft type was not (β = 0.13, P = 0.301).The maxillary teeth and mucosa of CLP patients changed over time, with stable areas showing a negative correlation with the observation period. However, the stability of the dental arch was not significantly affected by the cleft type. 3D analysis of the casts of CLP patients allowed for measurements and to accurately assess relapse of the maxillary arch after prosthetic treatment.

Purpose To introduce an augmented reality (AR) application for students, patients, and practitioners to use to visualize a maxillectomy defect, the associated obturator prosthesis, and the eventual effects on the patient's facial appearance. Materials and methods Various 3D virtual models related to maxillectomy defects and their prosthetic rehabilitations were used to illustrate the handheld AR application. The AR "scene" was created using Vuforia and Unity3D software. Within this scene, 3D virtual models were linked to the target image by detecting a symbol track marker. The final file was saved as an installable application and exported for Android smart devices. Results The target image containing the maxillectomy defect and the prosthetic rehabilitation were successfully visualized interactively in 3D mode using the handheld AR maxillofacial prosthetic application. Conclusion An AR application for visualizing maxillofacial prosthetic data could interestingly be developed as a pedagogic tool to explain prosthetic treatments.

Purpose To assess the feasibility of using an intraoral scanner for data acquisition of maxillectomy defects. Materials and methods In 10 patients who had undergone a maxillectomy, the maxillectomy defects in dentate and edentulous maxillary arches were intraorally scanned. Intraoral photographs were also taken using a digital camera for comparison. Results Adequate scanning was achieved for the nondefect side of the maxilla and for residual teeth. In some cases, it was impossible to scan the maxillectomy defect, especially the deep sites. Conclusion Improved intraoral scanning technology will increase the feasibility of its use in maxillofacial prosthetics.

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.

This report describes prosthetic rehabilitation of a patient with dry mouth due to a complex maxillofacial defect. The patient had undergone 5 surgical operations because of repeated recurrence pleomorphic adenoma, which resulted in partial maxillectomy followed by total maxillectomy, and finally orbital resection. The patient was left with oral, nasal, and orbital communication. Rehabilitation with a silicone facial cover was planned because the patient’s chief complaint was mouth dryness during sleep, and air leakage through the defects was considered a cause of this dryness. Furthermore, the patient was reluctant to use a conventional prosthesis for the time being. A silicone facial cover was fabricated. The patient's speech and sleep quality were evaluated with and without the cover, and the patient’s oral dryness was found to improve with use of the cover. Use of a silicone facial cover instead of a conventional prosthesis gave a satisfactory result, and is one option for preventing mouth dryness in a patient with multiple facial defects. (Int J Maxillofac Prosthetics 2020;3:7-11)

Making conventional facial impressions can be uncomfortable for the patient and complicated for the prosthodontist. Using facial scanners to digitize faces is an alternative approach. However, the initial costs of the equipment have prevented their widespread use in dental practice, and the accuracy of ear scanning is unclear.The purpose of this in vitro study was to investigate the accuracy of a widely used intraoral scanner for digitizing an ear model.For reference, a silicone model of an ear was scanned with an industrial scanner. Then, the model was scanned 5 times with an intraoral scanner. Five conventional impressions of the model were made with a hydrocolloid impression material and poured with dental stone. The stone casts were then digitized with a desktop scanner. The data sets acquired with the 3 approaches were analyzed by using a 3-dimensional (3D) evaluation software program. Trueness and precision values were calculated for each approach. Linear mixed models with random intercepts were fitted to each sample to evaluate the effects of the impression method on mean deviations (α=.05).Mean ±standard deviation trueness and precision values were 0.097 ±0.012 mm and 0.033 ±0.015 mm, respectively, for the digital scan, and 0.092 ±0.022 mm and 0.081 ±0.024 mm for the conventional impression, showing a significantly lower deviation in precision for the digital approach (P.001).The feasibility of digitizing an ear efficiently by using the investigated intraoral scanner was demonstrated, and similar trueness and significantly better precision values were achieved than when using conventional impressions. These promising results suggest the need for clinical investigations.

OBJECTIVES To evaluate the effect of different amounts of triangular mesh reduction on the trueness of digitized complete-arch dentate and edentulous maxillectomy defects models. MATERIAL AND METHODS Twenty gypsum maxillectomy defect models (dentate and edentate group: n=10) were digitized using the Trios 3 intraoral scanner, scanning the teeth, mucosa and maxillectomy defect. These datasets (reference, R0) were saved as standard tessellation language (STL) files, and triangular mesh reduction was performed using Meshmixer's reduction tool. Digital test-datasets with file sizes reduced by 50%(R1), 75%(R2), and 90%(R3) were generated (each: n=20). Each test-dataset was compared to the R0 file using 3D evaluation software (GOM Inspect), applying automated pre-alignment followed by a global best-fit alignment, and root mean square (RMS) 3-dimensional (3D) deviations were calculated. Statistical analyses were performed, at a level of significance of ��=0.05. RESULTS The number of triangles, and STL file size were synchronized with each other and inversely proportional to the amount of mesh reduction. The resulting mean percentages of the STL file sizes were 50.00% for R1, 24.93% for R2, and 10.00% for R3. There were no 3D deviations at 50% triangular mesh reduction. The 3D deviations increased with the amount of mesh reduction: at 75% reduction the median deviations were lower (dentate:0.0016mm, IQR:0.0015-0.0018; edentate:0.0016mm, IQR:0.0015-0.0016), than at 90% (dentate:0.004mm, IQR:0.0038-0.0041; edentate:0.003mm, IQR:0.0036-0.0039). A statistically significant increase in 3D deviations was observed with higher degrees of mesh reduction (p

Purpose To geometrically evaluate facial asymmetry in patients with mandibulectomy defects with and without their mandibular prostheses in place and to compare the results to a nonpatient group. Materials and methods Facial data from a convenience sample of 16 patients with mandibulectomy defects and a control group of 16 nonpatients were acquired using a noncontact 3D digitizer. Facial asymmetry was evaluated by superimposing a facial scan onto its mirror scan for each patient's 3D dataset using 3D evaluation software. Results Facial asymmetry was significantly different between mandibulectomy patients and control participants. As expected, asymmetry was significantly different in mandibulectomy patients with and without their prostheses. Conclusion Wearing a mandibular prosthesis notably improved facial asymmetry.

Rendering three-dimensional (3D) structures of maxillofacial prosthetics within a single two-dimensional (2D) document offers great opportunities for the readers of scientific publications to interactively visualize these structures with in-depth 3D perception. The capabilities of Portable document format (PDF) have not yet been fully utilized in maxillofacial prosthetics publications especially when considering that PDF is the most common file format for publishing articles. This article briefly reviews the application of PDF in the visualization of 3D data within scientific publications. It also introduces an effective interactive visualization approach by embedding 3D data into PDF file for journal publications and discuss its impact on maxillofacial prosthetic publications. It emphasizes on the usage of this electronic document, when used to its full potential, could be used to illustrate embedded 3D interactive maxillofacial prosthetic data, which can be viewed and manipulated by the reader without the need for specific 3D viewing softwares. Thus, this article compiles the capabilities of PDF which is beyond just an electronic documentation exchange and viewing static 2D structures in scientific publications. (Int J Maxillofac Prosthetics 2019;1:2-8)

Three-dimensional files featuring patients’ geometry can be obtained through common tools in dental practice, such as an intraoral scanner (IOS) or Cone Beam Computed Tomography (CBCT). The use of 3D files in medical education is promoted, but only few methodologies were reported due to the lack of ease to use and accessible protocols for educators. The aim of this work was to present innovative and accessible methodologies to create 3D files in dental education. The first step requires the definition of the educational outcomes and the situations of interest. The second step relies on the use of IOS and CBCT to digitize the content. The last “post-treatment” steps involve free software for analysis of quality, re-meshing and simplifying the file in accordance with the desired educational activity. Several examples of educational activities using 3D files are illustrated in dental education and discussed. Three-dimensional files open up many accessible applications for a dental educator, but further investigations are required to develop collaborative tools and prevent educational inequalities between establishments.

Purpose This study sought to geometrically evaluate the effect of a mandibular prosthesis on facial asymmetry in patients with one of two different types of mandibulectomy defect. Methods Facial data from 20 participants (9 men and 11 women; mean age 68 years) with either a reconstructed segmental defect (segmental group,n = 10) or a marginal mandibulectomy defect (marginal group, n =10) were acquired with a non-contact three-dimensional (3D) digitizer. Facial asymmetry was evaluated by superimposing a facial scan onto its mirror scan using 3D evaluation software. Facial scans with and without the mandibular prosthesis in place were also superimposed to evaluate the effect of the mandibular prosthesis. Results Facial asymmetry differed significantly between subjects with and without the prosthesis in the segmental group (P = 0.005) but not in the marginal group (P = 0.16). There was no significant difference in the effect of the prosthesis on facial appearance between the two groups (P = 0.052). The ratio of 3D deviation of facial asymmetry without the prosthesis and in the mirror scan with the prosthesis differed significantly between the two groups (P = 0.01). Conclusions Placement of a mandibular prosthesis has a notable effect on facial asymmetry in patients with segmental mandibulectomy defects.

PURPOSE To evaluate the feasibility and accuracy of noncontact three-dimensional (3D) digitization systems for capturing facial defects. MATERIALS AND METHODS A stone model of a facial defect was digitized using high-accuracy industrial computed tomography as a reference scan. The model was also scanned using four different types of noncontact 3D digitizers: a laser beam light-sectioning technology with camera system and three different stereophotogrammetry systems. All 3D images were reconstructed with corresponding software and saved as standard triangulated language (STL) files. The 3D datasets were geometrically evaluated and compared to the reference data using 3D evaluation software. Kruskal-Wallis H tests were performed to assess differences in absolute 3D deviations between scans, with statistical significance defined as P < .05. RESULTS The four noncontact 3D digitization systems were feasible for digitizing the facial defect model, although the median 3D deviation of the four digitizers varied. There was a significant difference in accuracy among the digitizers (P < .001). CONCLUSION Digitization of facial defect models using various noncontact 3D digitizers appears to be feasible and is most accurate with laser beam light-sectioning technology. Further investigations assessing digitization of facial defects among patients are required to clinically verify the results of this study.

PURPOSE This study aimed (1) to geometrically evaluate areas of facial asymmetry in patients with two different types of maxillectomy defect compared to a control group, (2) to geometrically evaluate the effect of an obturator prosthesis on facial asymmetry, and (3) to investigate the correlation between three-dimensional (3D) deviation values and number of missing teeth. MATERIALS AND METHODS Facial data from 13 normal control participants and 26 participants with two types of maxillectomy defect (groups 1 and 2) were acquired with a noncontact 3D digitizer. Facial asymmetry was evaluated by superimposing a facial scan onto its mirror scan using 3D evaluation software. Facial scans with and without obturator prostheses were also superimposed to evaluate the obturator effect. The correlation between 3D deviation values and number of missing teeth was also evaluated. Statistical analyses were performed. RESULTS Facial asymmetry was significantly different between the control group and each maxillectomy defect group (group 1: P < .0001 and P = .020 without and with obturator, respectively; group 2: P < .0001 for both conditions). There were no significant differences in asymmetry between groups 1 and 2 either without or with obturator (P = .457 and P = .980, respectively). There was a significant difference in the obturator effect between groups 1 and 2 (P = .038). 3D deviation values were positively correlated with number of missing teeth in group 1 (r = 0.594, P = .032), but not in group 2. CONCLUSION A noncontact 3D digitizer and 3D deviation assessment were effective for analyzing facial data of maxillectomy patients. Obturators were effective for improving facial deformities in these patients.

Purpose To identify trends in the application of various types of digital technologies in maxillofacial prosthetics by identifying these digital technologies and their characteristics and reviewing the prevalence of applied digital technologies and their recent trends in the maxillofacial prosthetics literature. Materials and methods Five leading peer-reviewed prosthodontics journals were manually searched for maxillofacial prosthetics articles on the use of digital technologies published from January 2008 to December 2017. Descriptive statistics were used to analyze data collected on productivity, type of digital technology used, type of article, type of defect, number of authors, and geographic distribution. Results Of the 336 maxillofacial prosthetics articles screened, 87 (26%) were selected for analysis. A remarkable increase was found in article productivity in the last 5 years (63%) compared to the first 5 years (37%). There was also a notable increase over the last 10 years in all digital technologies used except for evaluation technologies, which remained almost constant. Case reports most frequently mentioned use of digitization technologies (61%), design technologies (66%), and rapid prototyping technologies (66%). Original research articles most frequently mentioned use of evaluation technologies (89%); 39% of these technologies were used for intraoral defects and 27% for extraoral defects. Most often, articles had four to five authors (54%). Most published articles were from the Asia-Pacific region (44%), followed by North America (22%) and Europe (20%). Conclusion Although the application of digital technologies reported in the maxillofacial prosthetics literature has increased notably in leading prosthodontics journals over the last 10 years, total article productivity has remained relatively small.

Purpose To evaluate the accuracy of a smartphone application as a low-cost approach for digitizing a facial defect for 3D modeling. Materials and methods A stone model of a facial defect was scanned using industrial computed tomography (reference scan) and was also scanned five times using a commercial laser scanner. A series of 24 sequenced digital photographs was taken five times by smartphone at two elevations. These images were uploaded and processed by a cloud-based server to create virtual 3D models. The 3D datasets were geometrically evaluated and compared to the reference data using 3D evaluation software. Mann-Whitney U test was used for statistical analysis, and the significance was set at P Results The overall mean 3D deviation ± standard deviation for the smartphone dataset was 604.9 ± 123.5 μm compared to 67.5 ± 0.49 μm for the laser scanner. There was a significant difference in the accuracy between the commercial laser scanner and the smartphone application (P = .009). Conclusion The results showed that within the limits of this study and in reference to standard computed tomography imaging, data acquisition with a smartphone for 3D modeling is not as accurate as commercially available laser scanning.

PURPOSE To evaluate the precision and trueness of computerized optical impressions of maxillectomy defects. MATERIALS AND METHODS Three different maxillectomy defect models based on the Aramany classification system were used. Reference digitization of the models was performed with an industrial computerized tomography scanner. Each model was scanned five times using an intraoral scanner (True Definition). With the use of 3D evaluation software, the 3D datasets were geometrically superimposed using a best-fit algorithm to evaluate precision and trueness. Statistical analysis was performed to determine differences between the scans. RESULTS There was a statistically significant difference in both precision and trueness between Aramany classes (P < .001). CONCLUSION Digitizing maxillectomy defect models with an intraoral scanner appears to be accurate and reliable.

This report describes the postmaxillectomy prosthetic rehabilitation of a child with maxillary chondrosarcoma over an 8-year period. Specifically, it (1) describes the planning and rehabilitation procedures carried out during the period from before the operation to the time when the patient started elementary school and (2) reports the results of evaluations of the patient's oral and psychosocial function conducted during the school phase. The prosthetic treatment plan was separated into two phases (the preschool and school phases) and was started prior to surgery, when an immediate surgical obturator was designed by the surgeons. After the operation, it was considered important to provide the patient and her mother with training regarding how the defect should be cleaned, trismus prevention, and how the prosthesis should be fitted. In addition, esthetic improvements and the ability to speak clearly were also targeted during treatment planning. After surgery, obturators were fabricated in a conventional manner and fitted at the ages of 2, 4, 6, 8, and 10 years. The patient's oral function during the use of the obturators was evaluated objectively. Marked improvements in oral function were seen during both treatment phases. The patient's ability to perform psychosocial functions at school also improved during the use of the obturators.

PURPOSE Objective evaluation of a patient's speech is needed in prosthetic dentistry because the prostheses can affect the intelligibility of speech. Measurement of voice onset time is one evaluation method of consonant production used in phonetic science. The purpose of this study was to confirm the influence of a palatal prosthesis on consonant production by measuring voice onset time. MATERIALS AND METHODS In this study, voice onset time was measured in 10 healthy women (mean age 26.5 years) under two conditions: with and without an experimental palatal prosthesis. In this study, voice onset time of /ta/ and /ka/ were used to determine the effect of wearing a palatal prosthesis; /pa/ was tested as a control, with the null hypothesis that voice onset time of /ta/ and /ka/ would not change when wearing a palatal prosthesis. RESULTS Medial voice onset time of /pa/, /ta/, and /ka/ syllables without the palatal prosthesis was 22.5 ms, 19.5 ms, and 42.5 ms, whereas that with the palatal prosthesis was 22.5 ms, 23.5 ms, and 55.0 ms. Voice onset times for /ta/ and /ka/ were prolonged when wearing the experimental palatal prosthesis, whereas /pa/ showed no significant difference. CONCLUSION Consonant production was affected by wearing a palatal prosthesis, and this change in sound was detected by measuring voice onset time.

Purpose: The purpose of this study was to geometrically evaluate the effect of prosthetic rehabilitation on the facial appearance of mandibulectomy patients. Materials and Methods: Facial scans (with and without prostheses) were performed for 16 mandibulectomy patients using a noncontact three-dimensional (3D) digitizer, and 3D images were reconstructed with the corresponding software. The 3D datasets were geometrically evaluated and compared using 3D evaluation software. Results: The mean difference in absolute 3D deviations for full face scans was 382.2 μm. Conclusion: This method may be useful in evaluating the effect of conventional prostheses on the facial appearance of individuals with mandibulectomy defects.

This clinical technique provides a key procedure for successful prosthetic treatment in patients with an anatomical compromise after a maxillectomy. When making a preliminary impression, the clinician must keep the handle of the stock tray parallel to the patient's interpupillary line extraorally to maintain the correct position of the tray and to make a record of the inclination of the occlusal plane. This simple consideration during this first step of making a preliminary impression can be an important guide for both dentists and dental technicians. Information about the correct positioning of the tray and the inclination of the occlusal plane obtained by using a stock tray handle will greatly reduce the stress experienced by dentists, dental technicians, and patients during the fabrication of the prosthesis and will ultimately lead to successful prosthetic treatment in patients with anatomic compromise resulting from a maxillectomy.

Advances in treatment planning have changed patients’ expectations of the functional and aesthetic outcomes of maxillofacial prosthetic treatments. This case report describes and discusses the role of digital technology in the treatment planning of a facial prosthesis for a patient with complex maxillofacial prosthetic needs. A 75-year-old man was diagnosed with squamous cell carcinoma of the left maxillary sinus. The tumor was surgically resected and resulted in extensive tissue loss. The four key elements of visualization, design, manufacture, and evaluation were considered in digital treatment planning of the facial prosthesis; the first two are discussed in this report. The defect areas were three-dimensionally digitized using computed tomography and stereophotogrammetry. The scanned data were saved as a standard tessellation language file. From these data, virtual three-dimensional models were created for treatment planning options. With the aid of computer-aided design software, two types of facial prostheses were designed: an open-eyeprosthesis and a closed-eye prosthesis. These designs were discussed with the patient to determine the one most suitable to meet his aesthetic expectations. Patients’ expectations of treatment options can be improved through the virtual visualization and design offered by digital treatment planning. This case report confirms the applicability of digital treatment planning in managing patients with complex maxillofacial prosthetic needs.

Digital technologies have a great role in revolutionized prosthodontics in general, and more specifically in maxillofacial prosthetics. Digitized prosthetic rehabilitation modalities are becoming an essential approach for the maxillofacial prosthetic field. This article reviews the role of digital technology in overseas maxillofacial prosthetic collaboration and introduces a model of prospective collaboration in the field of maxillofacial prosthetics using digital technology. Various intraoral and extraoral maxillofacial prostheses were briefly reviewed. Numerous digital technologies in prosthetics were also concisely reviewed in perspective of digitization and visualization, modeling and designing, and fabrication. Internet-based audiovisual synchronous and asynchronous technologies were also reviewed. In addition, a model of future collaboration in the field of maxillofacial prosthetics using digital technology was introduced.

Statement of problem A palatogram aids prosthodontists and speech pathologists in evaluating the precise prosthetic treatment needed and the effectiveness of such treatment to improve speech intelligibility. Powder is commonly used to visualize tongue-palate contact, where wetted areas of powder in the oral cavity reveal such contact during palatography. However, discomfort and the risk of aspiration are among the shortcomings of this method, and an improved method is needed. Purpose The purpose of this in vitro study was to examine the feasibility of a new method of palatography that uses airborne-particle–abraded acrylic resin so that wet areas can be easily distinguished from dry areas. Material and methods Seventy-two specimens of heat-polymerized acrylic resin were prepared in 6 different resin colors. After the specimens had been airborne-particle abraded, CIELab color values for each specimen were measured using a colorimeter under dry and wet conditions and recorded. Color difference (ΔE) was then computed, and a paired Student t test, 1-way analysis of variance, and multiple comparison using the Tukey post hoc analysis were applied (α=.05). Results A significant color difference was found between the 2 conditions in all acrylic resin specimens examined. Mean ΔE ranged from 5.58 to 6.76. Conclusions The results indicated that an airborne-particle–abraded acrylic resin surface can show color differences made by wetting on palatograms.

Among the functional disabilities that patients face following maxillectomy, speech impairment is a major factor influencing quality of life. Proper rehabilitation of speech, which may include prosthodontic and surgical treatments and speech therapy, requires accurate evaluation of speech intelligibility (SI). A simple, less time-consuming yet accurate evaluation is desirable both for maxillectomy patients and the various clinicians providing maxillofacial treatment. This study sought to determine the utility of digital acoustic analysis of vowels for the prediction of SI in maxillectomy patients, based on a comprehensive understanding of speech production in the vocal tract of maxillectomy patients and its perception. Speech samples were collected from 33 male maxillectomy patients (mean age 57.4 years) in two conditions, without and with a maxillofacial prosthesis, and formant data for the vowels /a/,/e/,/i/,/o/, and /u/ were calculated based on linear predictive coding. The frequency range of formant 2 (F2) was determined by differences between the minimum and maximum frequency. An SI test was also conducted to reveal the relationship between SI score and F2 range. Statistical analyses were applied. F2 range and SI score were significantly different between the two conditions without and with a prosthesis (both P < .0001). F2 range was significantly correlated with SI score in both the conditions (Spearman's r = .843, P < .0001; r = .832, P < .0001, respectively). These findings indicate that calculating the F2 range from 5 vowels has clinical utility for the prediction of SI after maxillectomy.

Maxillofacial prosthetics is a subspecialty of prosthodontics with a relatively wide scope in that it provides prosthetic rehabilitation and therapeutic appliances for numerous disorders, injuries, and defects of the head and neck region. This subspecialty is widely recognized in developed countries, but less so in many developing countries. This special article is an initial effort to review the current status of maxillofacial prosthetics in Libya’s health and higher education sectors and its future establishment. In addition, we outline the steps needed to move beyond the current status quo in Libya. Based on a review of internationally recognized maxillofacial prosthetic programs based in North America, Europe, Japan, and South Africa, two plans for establishment are recommended for this purpose: an urgent short-term plan and an institutional long-term plan. Applying both plans would initially support maxillofacial prosthetic providers in managing patients with maxillofacial defects and developing contingency plans for follow-up and maintenance.

Purpose Accurate evaluation of speech characteristics through formant frequency measurement is important for proper speech rehabilitation in patients after maxillectomy. This study aimed to evaluate the utility of digital acoustic analysis and vowel pentagon space for the prediction of speech ability after maxillectomy, by comparing the acoustic characteristics of vowel articulation in three classes of maxillectomy defects. Materials and methods Aramany's classifications I, II, and IV were used to group 27 male patients after maxillectomy. Digital acoustic analysis of five Japanese vowels-/a/, /e/, /i/, /o/, and /u/-was performed using a speech analysis system. First formant (F1) and second formant (F2) frequencies were calculated using an autocorrelation method. Data were plotted on an F1-F2 plane for each patient, and the F1 and F2 ranges were calculated. The vowel pentagon spaces were also determined. One-way ANOVA was applied to compare all results between the three groups. Results Class II maxillectomy patients had a significantly higher F2 range than did Class I and Class IV patients (p = 0.002). In contrast, there was no significant difference in the F1 range between the three classes. The vowel pentagon spaces were significantly larger in class II maxillectomy patients than in Class I and Class IV patients (p = 0.014). Conclusion The results of this study indicate that the acoustic characteristics of maxillectomy patients are affected by the defect area. This finding may provide information for obturator design based on vowel articulation and defect class.

Purpose: The aim of this study was to evaluate the feasibility and accuracy of using an intraoral scanner to digitize edentulous maxillectomy defects. Materials and Methods: A total of 20 maxillectomy models with two defect types were digitized using cone beam computed tomography. Conventional and digital impressions were made using silicone impression material and a laboratory optical scanner as well as a chairside intraoral scanner. The 3D datasets were analyzed using 3D evaluation software. Results: Two-way analysis of variance revealed no interaction between defect types and impression methods, and the accuracy of the impression methods was significantly different (P = .0374). Conclusion: Digitizing edentulous maxillectomy defect models using a chairside intraoral scanner appears to be feasible and accurate.

Although digital technology has advanced the visualization of treatment planning and rehabilitation in prosthodontics, the field of maxillofacial prosthetics is in vital need of an accessible document for exchange of interactive three-dimensional (3D) model visualization without requiring installation of any additional software. This article introduces a 3D data documentation method for effective interactive digital visualization in maxillofacial prosthetics using a portable documentation format (PDF).

It has been more than a year since the first issue of the International Journal of Maxillofacial Prosthetics (iJMP) was published. During this period, the editorial board has been working hard towards the aim of bridging the gap in various aspects of maxillofacial prosthetics and its related fields by provides a unique platform for all maxillofacial prosthetic publications. Although the number of articles in maxillofacial prosthetics has rapidly increased in the last ten years in various prosthodontic journals, many researchers are still not aware that there is a new journal dedicated to our field. To counter this issue, iJMP has worked from the beginning to have international renowned experts in various specialities of maxillofacial prosthetic rehabilitation to serve on its advisory board. The editorial board also includes many young maxillofacial prosthetic professionals and researchers who are enthusiastic to bring the journal up to the highest standards of scholarly publishing.

This case report describes the reproduction of the current obturator of a frail elderly patient using the digitization concept. A computed tomography scanner was used to scan the obturator. The virtual model was created using three-dimensional modeling software. The model was printed using a plastic with a low melting point with a fused deposition modeling technique in a three-dimensional printer and then conventionally processed. The definitive obturator was inserted and evaluated for fit, function, and esthetics and was successfully delivered at the second visit. The patient was satisfied with the oral function and esthetics of the reproduced obturator. This case report confirms the effectiveness of digitization in the reproduction of an obturator that enabled satisfactory oral function and esthetics.

This report describes the postmaxillectomy prosthetic rehabilitation of a child with maxillary chondrosarcoma over an 8-year period. Specifically, it (1) describes the planning and rehabilitation procedures carried out during the period from before the operation to the time when the patient started elementary school and (2) reports the results of evaluations of the patient's oral and psychosocial function conducted during the school phase. The prosthetic treatment plan was separated into two phases (the preschool and school phases) and was started prior to surgery, when an immediate surgical obturator was designed by the surgeons. After the operation, it was considered important to provide the patient and her mother with training regarding how the defect should be cleaned, trismus prevention, and how the prosthesis should be fitted. In addition, esthetic improvements and the ability to speak clearly were also targeted during treatment planning. After surgery, obturators were fabricated in a conventional manner and fitted at the ages of 2, 4, 6, 8, and 10 years. The patient's oral function during the use of the obturators was evaluated objectively. Marked improvements in oral function were seen during both treatment phases. The patient's ability to perform psychosocial functions at school also improved during the use of the obturators.

Objective evaluation of a patient's speech is needed in prosthetic dentistry because the prostheses can affect the intelligibility of speech. Measurement of voice onset time is one evaluation method of consonant production used in phonetic science. The purpose of this study was to confirm the influence of a palatal prosthesis on consonant production by measuring voice onset time.In this study, voice onset time was measured in 10 healthy women (mean age 26.5 years) under two conditions: with and without an experimental palatal prosthesis. In this study, voice onset time of /ta/ and /ka/ were used to determine the effect of wearing a palatal prosthesis; /pa/ was tested as a control, with the null hypothesis that voice onset time of /ta/ and /ka/ would not change when wearing a palatal prosthesis.Medial voice onset time of /pa/, /ta/, and /ka/ syllables without the palatal prosthesis was 22.5 ms, 19.5 ms, and 42.5 ms, whereas that with the palatal prosthesis was 22.5 ms, 23.5 ms, and 55.0 ms. Voice onset times for /ta/ and /ka/ were prolonged when wearing the experimental palatal prosthesis, whereas /pa/ showed no significant difference.Consonant production was affected by wearing a palatal prosthesis, and this change in sound was detected by measuring voice onset time.

PURPOSE. This study aimed to create a digitized database of fabricated obturators to be kept for patients’ potential emergency needs. MATERIALS AND METHODS. A chairside intraoral scanner was used to scan the surfaces of an acrylic resin obturator. The scanned data was recorded and saved as a single standard tessellation language file using a three-dimensional modeling software. A simulated obturator model was manufactured using fused deposition modeling technique in a three-dimensional printer. RESULTS. The entire obturator was successfully scanned regardless of its structural complexity, modeled as three-dimensional data, and stored in the digital system of our clinic at a relatively small size (19.6 MB). A simulated obturator model was then accurately manufactured from these data. CONCLUSION. This study provides a proof-of-concept for the use of digital technology to create a digitized database of obturators for edentulous maxillectomy patients. [J Adv Prosthodont 2016;8:219-23]

Acoustic evaluation is valuable for guiding the treatment of maxillofacial defects and determining the effectiveness of rehabilitation with an obturator prosthesis. Model simulations are important in terms of pre-surgical planning and pre- and post-operative speech function. This study aimed to evaluate the acoustic characteristics of voice generated by an articulation simulation system using a vocal tract model with or without artificial maxillectomy defects. More specifically, we aimed to establish a speech simulation system for maxillectomy defect models that both surgeons and maxillofacial prosthodontists can use in guiding treatment planning. Artificially simulated maxillectomy defects were prepared according to Aramany's classification (Classes I-VI) in a three-dimensional vocal tract plaster model of a subject uttering the vowel /a/. Formant and nasalance acoustic data were analysed using Computerized Speech Lab and the Nasometer, respectively. Formants and nasalance of simulated /a/ sounds were successfully detected and analysed. Values of Formants 1 and 2 for the non-defect model were 675.43 and 976.64 Hz, respectively. Median values of Formants 1 and 2 for the defect models were 634.36 and 1026.84 Hz, respectively. Nasalance was 11% in the non-defect model, whereas median nasalance was 28% in the defect models. The results suggest that an articulation simulation system can be used to help surgeons and maxillofacial prosthodontists to plan post-surgical defects that will be facilitate maxillofacial rehabilitation.