The role of non-contact digitizer in geometrical evaluation of mandibular prostheses effect on facial asymmetry of mandibulectomy patients

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

Your Contribution is A Further Step Closer to the Development of Our Field!

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

Healthcare (Basel)

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

Use of Digital Technologies in Maxillofacial Prosthetics in Japan

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

Three-dimensional Printed Immediate Surgical Obturator Before Maxillectomy: A Pilot Study

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

Effect of triangular mesh resolution on the geometrical trueness of segmented CBCT maxillofacial data into STL format.

OBJECTIVES To determine the optimal level of mesh reduction that would maintain acceptable levels of geometrical trueness while also minimizing the impact on other parameters such as file size and processing time. METHODS AND METHODS Intraoral and extraoral maxillofacial defects were created on 8 cadaver heads and scanned by using a CBCT scanner (NewTom 3D Imaging, Verona). DICOM data were segmented to produce head (n=8) and skull models (n=8) saved as standard tessellation language (STL) files. A further processing of head models was preformed to produce face (n=8) and ear models (n=8). A mesh reduction process was performed for each STL model (reference, R0) by generating 50% (R1), 75% (R2), and 90% (R3) reductions. The 3 datasets were compared to the R0 file using 3D evaluation software (GOM Inspect) using a global best-fit algorithm, to calculate the root mean square (RMS) deviations. Statistical analyses were performed at a level of significance of α=0.05. RESULTS There was no 3D deviation after the 50% triangular mesh reduction in the 4 datasets. Minor 3D deviations were observed after 75% reduction, in all groups. After 90% reduction, higher 3D deviations were observed, and especially in head and skull. Statistically significant increase in 3D deviations was observed with higher degrees of mesh reduction (p < 0.001). CONCLUSION The resolution of CBCT-based maxillofacial defect models can be reduced up to 50%, with neglectable concern to inaccuracy. CLINICAL SIGNIFICANCE Accurate maxillofacial models can be obtained from CBCT DICOM files after segmentation and export as STL files, even when the mesh resolution is reduced up to 50%. This information can be valuable for practitioners and researchers working with 3D models of maxillofacial defects

A Nonconventional Approach to Prevent Mouth Dryness in A Patient with A Complex Maxillofacial Defect

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