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Statement of problem Patients with a mandibular defect can develop mandibular deviation, resulting in a loss of or reduction in occlusal contact and ultimately loss of function. The occlusal ramp is a prosthesis used to help restore the masticatory function of such patients and is used particularly in the maxillofacial rehabilitation of patients with masticatory dysfunction resulting from mandibular deviation. The occlusal ramp is usually attached to a mandibular denture or worn as an independent device placed on the palate corresponding to the mandible that produces the offset. However, evidence of the effects of its use is sparse. Purpose The purpose of this clinical study was to investigate the effects of occlusal ramp use in functional rehabilitation. Materials and methods This study included 10 patients who had received mandibulectomies (5 men and 5 women; mean age 76.7 years, range 67 to 90 years) with deviation of the mandible. An occlusal ramp was fabricated for each participant as part of their maxillofacial prosthetic treatment. Masticatory performance was evaluated before and after the treatment by measuring glucose extraction while masticating a piece of gummy jelly. The Wilcoxon signed-rank test was used for statistical analysis (α=.05). Results The median masticatory performance score, represented as glucose concentration (mg/dL), was 82.45 before treatment and 115.45 after treatment, with an overall improvement of 33.00. Scores differed significantly before and after treatment (P=.005). Masticatory performance for each participant improved in the range of 17.7 to 103.3, highlighting the role that the occlusal ramp played in mastication, although with differing effects in each participant. Conclusions Masticatory performance in participants with mandibular deviation after a mandibulectomy was significantly improved with an occlusal ramp. This suggests the effectiveness of using occlusal ramps in maxillofacial prosthetic treatment for the recovery of masticatory function in patients with mandibular deviation.

Definitive radiotherapy is an effective treatment for early-stage lip cancer. The goal of radiotherapy is to irradiate the cancer site effectively while protecting healthy surrounding tissue from the adverse effects of radiation. To this end, radiotherapy prostheses have been widely and effectively used. A maxillofacial prosthodontist working in collaboration with a radiation oncologist can create a custom-made radiotherapy prosthesis that minimizes adverse effects. This report demonstrates the successful use of spacers in external beam radiotherapy and brachytherapy in consideration of the patient's radiation therapy treatment plan and wearing conditions, ensuring adequate availability and preventing radiation-related complications.

Prosthetic rehabilitation with an obturator can help to restore or improve the intelligibility of speech in patients after maxillectomy. The frequency of formants 1 and 2 as well as their ranges were initially reported in patients with maxillary defects in 2002, and the evaluation method that was used is now applied in clinical evaluation. However, the details of formant 3 are not known and warrant investigation because, according to speech science, formant 3 is related to the pharyngeal volume. Clarifying the formant frequency values of formant 3 in patients after maxillectomy would enable prosthodontists to refer to these data when planning treatment and when assessing the outcome of an obturator.The purpose of this clinical study was to determine the acoustic characteristics of formant 3, together with those of formants 1 and 2, by using a digital acoustic analysis during maxillofacial prosthetic treatment. The utility of determining formant 3 in the evaluation of speech in patients after maxillectomy was also evaluated.Twenty-six male participants after a maxillectomy (mean age, 63 years; range, 20 to 93 years) were included, and the 5 Japanese vowels /a/, /e/, /i/, /o/, and /u/ produced with and without a definitive obturator prosthesis were recorded. The frequencies of the 3 formants were determined, and their ranges were calculated by using a speech analysis system (Computerized Speech Lab CSL 4400). The Wilcoxon signed rank test was used to compare the formants between the 2 use conditions (α=0.05).Significant differences were found in the frequencies and ranges of all 3 formants between the use conditions. The ranges of all 3 formants produced with the prosthesis were significantly greater than those produced without it.Based on the findings, both the first 2 formants and the third formant were changed by wearing an obturator prosthesis. Because formant 3 is related to the volume of the pharynx, evaluation of this formant and its range can reflect the effectiveness of the prosthesis to seal the oronasal communication and help reduce hypernasality, suggesting the utility of formant 3 analysis in prosthodontic rehabilitation.

Fracture or carious lesions in an abutment tooth may require the fabrication of a crown under an existing removable partial denture. Typically, once the crown has been fabricated, the prosthesis will need to be modified or refabricated. However, if the partial denture is in good clinical condition, special techniques may be applied to make the new crown fit the existing prosthesis. This article describes a straightforward indirect-direct technique for fabricating a cast metal crown under an existing removable partial denture with hot water. The technique does not require expertise or any special device and can be performed chairside by general dentists.

To provide a mandibular complete denture for a patient with a partial glossectomy and partial mandibulectomy, the denture space was captured using a piezography technique involving silicone impression materials with two different viscosities. Artificial teeth were arranged within the obtained piezographic index, and the denture was processed in the conventional manner. Using the piezography technique described enables physiologically appropriate complete dentures to be fabricated based on the neutral zone concept. (Int J Maxillofac Prosthetics 2021;4:37-42)

Purpose: Xerostomia is a symptom of reduced oral functioning and can cause dysphagia and worsen dental disease. This study sought to investigate the actual status of xerostomia in head and neck tumor patients and the beneficial effects of maxillofacial prosthesis use on xerostomia. Materials and Methods: We conducted a questionnaire survey on xerostomia and measured resting salivary flow rate and oral mucosa moisture levels in 26 patients who had been treated for head and neck tumor. Results: After treatment, 16 of the 26 patients (62%) reported experiencing dry mouth. Moreover, 12 patients (46%) reported a tendency for dry mouth compared with before tumor treatment, indicating they perceived worsening of xerostomia after treatment. Mean resting salivary flow rate measured by the cotton roll method was 0.183 ± 0.178 g over 30 seconds. Resting salivary flow rate was significantly lower in patients who reported always having dry mouth than in those who did not report experiencing dry mouth. Patients who had been treated for mandibular/lingual tumors had a significantly lower resting salivary flow rate than those who had been treated for maxillary tumors. Mean moisture content in the oral mucosa measured with an oral moisture checker was 27.6 ± 1.6. Those who reported always having dry mouth had significantly lower oral mucosa moisture content than those who reported having dry mouth sometimes/a little. Five patients reported that wearing a maxillofacial prosthesis alleviated dry mouth. Conclusion: This study demonstrated that the maxillofacial prosthesis use can improve xerostomia after head and neck tumor treatment. (Int J Maxillofac Prosthetics 2021;4:9-17)

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)

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.

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.

This report describes the prosthetic rehabilitation of a patient with a large maxillary defect. It is often risky and difficult to take an impression of a large defect in a single-step procedure. In this study, we present a clinical technique where the maxillary obturator prosthesis was fabricated by combining two methods: conventional processing using an impression followed by relining of the obturator part to improve retention and support of the prosthesis. This report also describes how digital speech analysis using formants of five vowels can be utilized during the relining and adjustment step, resulting in improved patient satisfaction and comfort. (Int J Maxillofac Prosthetics 2020;3:32-36)

Evaluation of speech function is essential to maxillofacial prosthetic treatment. Measurement of nasalance with a nasometer is practical and typically done to detect hypernasality in maxillofacial defect patients. This case report describes a nasalance test used in the evaluation and rehabilitation of a patient who needed a speech aid. A 70-year-old man sought help at our clinic because his old speech aid had broken. Although a new speech aid was fabricated, he continued to have difficulty speaking and breathing. A nasalance test using nasal and non-nasal test words revealed hyponasality. The patient was satisfied with the speech aid after its adjustment in accordance with the nasalance test results. Nasalance testing that considers not only hypernasality but hyponasality helped the maxillofacial prosthodontist in the successful rehabilitation of this maxillofacial defect patient. (Int J Maxillofac Prosthetics 2020;3:23-27)

Maxillectomy patients require a maxillofacial prosthesis for improving quality of life from the preoperative period to the stage of palliative care. This case report describes maxillofacial prosthetic treatment from the aspect of nutrition by following the condition of a 69-year-old woman who received surgery for a right-side carcinoma of the maxilla. After the initial treatment, metastatic disease was found, and her nutritional status worsened steadily. Although the prognosis may be poor, maxillofacial prosthodontic treatment should be given in order to maintain nutritional status and quality of life and to achieve optimal function for the patient as palliative care. (Int J Maxillofac Prosthetics 2020;3:28-31)

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)

This study evaluated the risk of oral injury in Kendo. We hypothesized that Kendo players in Japan may experience oral injury due to the use of face protector for kendo (men) with inaccurate measurements or wearing it incorrectly. The survey included 400 kendo players (male, 276; female, 174) and covered four areas: the relationship between the characteristics, percentage of oral injury, temporomandibular disorder (TMD), and use of men. Based on the who experience of oral injury, participants were classified into ‘trauma’ and ‘non-trauma’ groups. Those who suffered oral injury were 179 (44.8 %; males, n=118; females, n=61). In the past month, 32 (8.2%) Kendo players reported that their matches/training were affected by dental/oral problems. For TMD, 50 participants had a total score >8.5 from four screening questions. For 289 (72.3%) participants, the men they are currently wearing fit well. Of those that reported that their men do not fit properly, 48 (12.0%) felt that their men were too large, and 14 (3.5%) felt that their men were too small. Years of experience and clenching of one’s jaws during an offensive Kendo movement significantly contributed to oral injury. Clenching one’s jaws during a defensive Kendo move, current men fit, sleep bruxism, and morning symptoms from sleep bruxism significantly contributed to TMD. Men with an accurate sizing allows proper field of vision, eliminating head shifting inside men during strikes and movements. This suggests that vision can be secured by adjusting the ties on men, chin movement, and the way one looks through the men. Since Kendo equipment is originally a Japanese craft, it has high artistry. Thus, properly worn Kendo equipment brings higher functionality and esthetic appeal.

This review examines the importance of prosthetic rehabilitation after surgical treatment of mucormycosis in the context of expected increases in cases during the current COVID-19 pandemic.Google Scholar, Web of Science, Scopus, and PubMed databases were searched for relevant articles published between 2010 and 2021. Articles that provided a full description of prosthetic treatment after surgical treatment of mucormycosis were included in the review.Out of 30 articles describing orofacial prosthetic rehabilitation after surgical treatment of mucormycosis published during the 12-year target period, 19 reported patients with diabetes, two described mucormycosis as a post-COVID-19 complication, and 25 were reports from India. Most of the prosthetic treatments used a definitive obturator (63.3%) either alone or in combination with other forms of prosthetic rehabilitation. Other prosthetic strategies included an orbital prosthesis (26.6%), a facial prosthesis with or without a nasal replacement (16.6%), a surgical or interim obturator, a conventional complete denture, and a cast partial denture. Six articles (20%) mentioned the use of combined prosthetic rehabilitation involving multiple regions of the face and oral cavity.Prosthetic rehabilitation after surgical treatment of mucormycosis is essential for the early restoration of oral function and facial esthetics. Given the aggressive nature of mucormycosis and the increasing number of cases reported during the COVID-19 pandemic, prosthodontists need to share their experiences with prosthetic rehabilitation of the defects that result from this disease to improve patients' quality of life.

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.

Brachytherapy is a type of radiotherapy used to eradicate malignancies in the head-and-neck region. Early-stage mucosal carcinomas, such as carcinomas of the hard palate and gingival mucosa, can be treated with low-dose-rate brachytherapy by using a radiotherapy prosthesis called a mold. Prosthodontists play a significant role in the design and fabrication of these molds, which deliver therapeutic doses to the primary lesion and protect adjacent tissues from radiation exposure. However, planning and observing ongoing treatment is difficult for radiation oncologists because the shield part cannot be removed from the carrier part or requires an attachment to do so. This article describes a technique for fabricating a 2-piece detachable interlocking mold without any special attachment for low-dose-rate brachytherapy.

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

Patient A 69-year-old Japanese male with squamous cell carcinoma of the right maxilla (T4M0N0) was referred to our department for a preoperative examination. An immediate surgical obturator was fabricated before surgery. He underwent surgical treatment, which included right subtotal maxillectomy and reconstruction with a split skin graft. One week postoperatively, the immediate surgical obturator was modified to expand the nasal cavity for obturator prosthesis. Oral intake was started 12 days postoperatively with an immediate surgical obturator in situ. The definitive obturator was fabricated after the wound surface had healed 8 months postoperatively. Assessment of the nutritional status included body mass index, serum albumin level, resting energy expenditure (REE) measured using indirect calorimetry, and predicted REE using the Harris-Benedict equation. These assessments were performed several times, from the time of admission until the definitive obturator was applied. Discussion Malnutrition occurs frequently in patients with head and neck cancer because this region is vital for swallowing and mastication. Maxillectomy patients require a maxillofacial prosthesis to improve their nutritional status from the preoperative period to recovery. This case report describes maxillofacial prosthetic treatment from the perspective of nutrition. The patient wore the immediate surgical obturator postoperatively, which was followed by marked weight loss after restoration, and then weight gain returned to the normal range when wearing the definitive obturator. Conclusion Maxillofacial prosthetic treatments should make efforts to maintain nutritional status and achieve optimal function and quality of life in patients with head and neck cancers.

Background: The aim of this clinical study was to reveal the relationship between body dehydration and oral mucosa moisture measured by the use of a capacitance sensor for oral epithelial moisture. Methods: The following clinical parameters were recorded from each one of 19 athletes in a one-week period of high-intensity exercise at the U-23 Triathlon Training Camp in summer and winter; body weight, urine specific gravity, oral mucosa moisture, subjective oral thirst, and subjective throat thirst (within 30 min after waking and before breakfast at 7:00 a.m. on Day2 and Day6). Results: There were no significant differences in the mean values of body weight, urine specific gravity, oral mucosa moisture, oral thirst, and throat thirst between Day2 and Day6 in both measurements in summer and winter. The oral mucosa moisture had a moderate negative correlation with urine specific gravity (p < 0.05, r = −0.45). Conclusions: This study suggests that oral mucosal moisture determined using an oral moisture-checking device could be a potential index for assessing dehydration during sports activities.

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.

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 Wearing a sports mouthguard is not only recommended in collision sports, such as American football, boxing, and rugby football, but also in low-contact sports, such as basketball, handball, and soccer. It is recommended to remove oral prosthetic devices while playing sports to avoid the risk of fracturing the device. However, players with maxillectomy must wear obturator-type prosthetic devices for speech, breathing, and deglutition even while playing sports. Therefore, there is a need for an oral appliance to prevent dental injury while playing sports without the risk of fracturing the device for players who have undergone maxillectomy.In this case, we fabricated and proposed overlay-type and obturator-type customized sports mouthguards for a patient who had undergone maxillectomy and assessments of satisfaction, speech intelligibility, nasopharyngeal closure function, and swallowing function while playing soccer. Results The patient was only satisfied with the obturator-type mouthguard, and the results of the speech intelligibility, nasopharyngeal closure function, and swallowing tests using the obturator-type mouthguard showed no differences compared to those associated with the previously used prosthetic device. Conclusions This case may help highlight the importance of providing obturator-type mouthguards for players who have undergone maxillectomy to prevent dental injury and physical and mental discomfort.

The role of the prosthodontist in radiation therapy includes fabrication of radiation therapy prosthetic applicators. Brachytherapy is a form of cancer treatment that involves direct insertion of radioactive implants into the tissue. In the case of vaginal cancer, brachytherapy requires the radiation oncologist to use a device called an applicator. Conventional applicators have limitations in terms of the number of radiation tubes that can be inserted, positioning of the tubes, applicator misfit, and pain when inserted. A well-fitted applicator is needed to improve the orientation of the radiation source toward the target area and to reduce the amount of scatter radiation and tissue irritation. Using an appropriate dental material to make an impression can serve to achieve these aims. This article describes a technique for fabricating an acrylic resin custom-made applicator by using techniques used in dentistry.

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 The purpose of this survey was to examine the overview of maxillofacial prosthetic treatment at our department, in order to ascertain the actual status of patients and discuss future needs. Methods Subjects were all patients who visited Clinic for Maxillofacial Prosthetics, Dental Hospital, Tokyo Medical and Dental University (TMDU) in the period from January 1, 1980 to December 31, 2014. Using medical records of the Clinic for Maxillofacial Prosthetics, Dental Hospital, TMDU, patients' data including sex, address, referring institution, and primary condition were analyzed throughout the period. Results The number of patients over 35 years was 6219, with a man-to-woman ratio of 6:4. The number of patients in their 60s, 70s, and 80s showed an increasing trend. Patients with tumors accounted for about 50 % of cases in 1980–1984 and increased to 80 % in 2010–2014. Conclusions The survey showed an increasing number of elderly patients and patients with tumors. This suggests that more awareness and education about maxillofacial prosthetics are needed.

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.

The purpose of dental treatments normally includes the recovery from the functional impairments and aesthetic problems. This case report describes the rehabilitation of a maxillectomy patient with dementia and cerebral infarction, using obturators made of different materials to facilitate speech and swallowing. The patient had difficulty inserting the original prosthesis by himself and would sometimes bite down on the obturator to position it in his mouth instead of using his hands. As a result, the obturator caused irritation and bleeding, especially in the sensitive maxillectomy area. Ultimately, a new obturator with a base made of heat-cured acrylic resin and a bulb made of silicone was delivered. In this article, we describe the case and discuss the use of the obturator to recover swallowing and speech function in this patient. (Int J Maxillofac Prosthetics 2019;1:33-35)

Maxillectomy for oral tumours often results in debilitating oral hypofunction, which markedly decreases quality of life. Dysphagia, in particular, is one of the most serious problems following maxillectomy. This study used swallowing sounds as a simple evaluation method to evaluate swallowing ability in maxillectomy patients with and without their obturator prosthesis placed. Twenty-seven maxillectomy patients (15 men, 12 women; mean age 66.0 ± 12.1 years) and 30 healthy controls (14 men, 16 women; mean age 44.9 ± 21.3 years) were recruited for this study. Participants were asked to swallow 4 mL of water, and swallowing sounds were recorded using a throat microphone. Duration of the acoustic signal and duration of peak intensity (DPI) were measured. Duration of peak intensity was significantly longer in maxillectomy patients without their obturator than with it (P < .05) and was significantly longer in maxillectomy patients without their obturator than in healthy controls (P < .025 after Bonferroni correction). With the obturator placed, DPI was significantly longer in maxillectomy patients who had undergone soft palate resection than in those who had not (P < .05). These results suggest swallowing ability in maxillectomy patients could be improved by wearing an obturator prosthesis, particularly during the oral stage. However, it is difficult to improve the oral stage of swallowing in patients who have undergone soft palate resection even with obturator placement.

The goal of this study is to evaluate the swallowing functions of people with dysphagia using an acoustic microphone sensor. As a basic investigation towards this end, we measured the swallowing sounds using an acoustic emissions microphone sensor (AE sensor), then analyzed the frequency range of the measured signals, and we examined the method for obtaining the necessary information to evaluate the swallowing functions. For the measurement, two types of sensors, i.e., a condenser throat microphone and an AE sensor, were employed to measure the swallowing sounds. The acoustic signals obtained were subjected to spectral analysis using the wavelet transformation, and a comparison was performed between the measurable ranges of the acoustic signals obtained by the AE and the acoustic sensors. The results from the wavelet transformation of the acoustic signals obtained by the AE sensor indicated that acoustic signals generated during swallowing contained frequency information of 3 kHz and higher, which were not measurable with the acoustic sensor used in the experiment. In addition, we proposed a method of evaluating swallowing sounds using a novel approach based on the probability distribution. From the analysis results, it was found that the distance between the theoretical values and the measured values has a high correlation with the sample viscosity. Furthermore, it was found that the data measured with the AE sensor more sensitively reflected the difference in the sample viscosity. We were thus able to demonstrate the possibility of evaluating the swallowing function via the proposed method.

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.

Objective The aims of this study were to reveal the nutritional status of patients after head and neck tumour treatment by using the Mini Nutritional Assessment-Short Form (MNA-SF) and to analyse the factors affecting nutritional status in patients with head and neck tumour. Background Elderly patients with loss of teeth and maxillary/mandibular bone due to head and neck tumour treatment could be at high risk of malnutrition. However, there are few reports on the nutritional status of these patients. Materials and methods Forty-six participants (average age 74.7 years) were selected from patients who visited the maxillofacial prosthetics clinic of Tokyo Medical and Dental University Hospital Faculty of Dentistry in Japan. Nutritional status was evaluated using the MNA-SF. Multiple regression analysis was used to identify predictors affecting MNA-SF score. The candidate explanatory variables were age, sex, maxillofacial prosthesis use, number of residual teeth, resection side, neck dissection and treatment option. Results The results showed that approximately half of the patients were at risk of malnutrition, and a regression equation for MNA-SF score was developed using two predictors: maxillofacial prosthesis use and neck dissection. Conclusion Use of a maxillofacial prosthesis can improve nutritional status. On the other hand, a medical history of neck dissection can decrease nutritional status.