Time-study research on maxillofacial prosthetic treatment

Unreasonable medical fees can cause problems such as increased medical costs, greater medical disparities, decreased medical standards, and physician shortages. To prevent such problems, it is important to set appropriate medical fees, ensure their proper use, and improve the efficiency of medical care. The treatment of patients with maxillofacial defects is generally more expensive compared with general prosthodontic treatment because it involves more materials and requires more frequently follow-ups for longer period. However, the actual time required for maxillofacial prosthetic treatment is unclear. Therefore, in this study, we aimed to clarify the amount of time spent treating maxillofacial prosthetic patients. We analyzed clinical data from patients undergoing routine maxillofacial prosthetic treatment, irrespective of difficulty level, at 8 university hospitals and 2 dental clinics. We also collected data from maxillofacial prosthodontists on the treatment time required for various Japanese health insurance items, including the fabrication of maxillofacial prostheses. The results revealed that some aspects of maxillofacial prosthetic treatment may take longer to perform and are more costly to perform than previously thought, suggesting the need for some adjustments to the health insurance reimbursement system. Maintaining an appropriate balance between expenditures and fees will greatly benefit patients and physicians, ensuring positive health outcomes and a healthy society.

Advancing maxillofacial prosthodontics by using pre-trained convolutional neural networks: Image-based classification of the maxilla

PURPOSE

The study aimed to compare the performance of four pre-trained convolutional neural networks in recognizing seven distinct prosthodontic scenarios involving the maxilla, as a preliminary step in developing an artificial intelligence (AI)-powered prosthesis design system.

MATERIALS AND METHODS

Seven distinct classes, including cleft palate, dentulous maxillectomy, edentulous maxillectomy, reconstructed maxillectomy, completely dentulous, partially edentulous, and completely edentulous, were considered for recognition. Utilizing transfer learning and fine-tuned hyperparameters, four AI models (VGG16, Inception-ResNet-V2, DenseNet-201, and Xception) were employed. The dataset, consisting of 3541 preprocessed intraoral occlusal images, was divided into training, validation, and test sets. Model performance metrics encompassed accuracy, precision, recall, F1 score, area under the receiver operating characteristic curve (AUC), and confusion matrix.

RESULTS

VGG16, Inception-ResNet-V2, DenseNet-201, and Xception demonstrated comparable performance, with maximum test accuracies of 0.92, 0.90, 0.94, and 0.95, respectively. Xception and DenseNet-201 slightly outperformed the other models, particularly compared with InceptionResNet-V2. Precision, recall, and F1 scores exceeded 90% for most classes in Xception and DenseNet-201 and the average AUC values for all models ranged between 0.98 and 1.00.

CONCLUSIONS

While DenseNet-201 and Xception demonstrated superior performance, all models consistently achieved diagnostic accuracy exceeding 90%, highlighting their potential in dental image analysis. This AI application could help work assignments based on difficulty levels and enable the development of an automated diagnosis system at patient admission. It also facilitates prosthesis designing by integrating necessary prosthesis morphology, oral function, and treatment difficulty. Furthermore, it tackles dataset size challenges in model optimization, providing valuable insights for future research.

An integration protocol for aligning intraoral scans to facial scans using the nasal geometry reference in a fully dentate patient

Advanced digital technologies have rapidly been integrated into prosthodontics to improve the digital workflow for prosthetic rehabilitation. The integration of 3D datasets acquired from various imaging sources such as intraoral scanners and facial optical scanners allows the creation of virtual patients to perform presurgical simulation and prosthetic rehabilitation. The presented technique introduced a straightforward protocol for aligning intraoral scans (Trios 4, 3Shape) to optical face scans (Face Hunter, Zirkonzahn) using a global best-fit algorithm of 3D evaluation software (GOM Inspect). Nasal geometry data were used as the matching reference to produce virtual dental patients. This integration protocol ensured that the intraoral scanner (Trios 4, 3Shape) was used not only to scan dental arches but also used effectively to scan the nose. These scans along with professional facial scans can be successfully aligned to produce virtual dental patients. As only a single fully dentate patient case with an alignment deviation of 243.6 µm was used, further research to evaluate the accuracy of this protocol is needed.

Applications and performance of artificial intelligence models in removable prosthodontics: A literature review

PURPOSE

In this narrative review, we present the current applications and performances of artificial intelligence (AI) models in different phases of the removable prosthodontic workflow and related research topics.

STUDY SELECTION

A literature search was conducted using PubMed, Scopus, Web of Science, and Google Scholar databases between January 2010 and January 2023. Search terms related to AI were combined with terms related to removable prosthodontics. Articles reporting the structure and performance of the developed AI model were selected for this literature review.

RESULTS

A total of 15 articles were relevant to the application of AI in removable prosthodontics, including maxillofacial prosthetics. These applications included the design of removable partial dentures, classification of partially edentulous arches, functional evaluation and outcome prediction in complete denture treatment, early prosthetic management of patients with cleft lip and palate, coloration of maxillofacial prostheses, and prediction of the material properties of denture teeth. Various AI models with reliable prediction accuracy have been developed using supervised learning.

CONCLUSIONS

The current applications of AI in removable prosthodontics exhibit significant potential for improving the prosthodontic workflow, with high accuracy levels reported in most of the reviewed studies. However, the focus has been predominantly on the diagnostic phase, with few studies addressing treatment planning and implementation. Because the number of AI-related studies in removable prosthodontics is limited, more models targeting different prosthodontic disciplines are required.

Combined digital-conventional workflow to fabricate a definitive obturator from an interim obturator for a patient with an anterior maxillectomy defect

An existing interim obturator can be reproduced as the definitive one using digital technology, with benefits for a patient with a maxillectomy. By digitally scanning the oral condition and the existing interim obturator, a definitive obturator, including a computer-aided designed and computer-aided manufactured metal framework, was fabricated and delivered to a patient with an anterior maxillectomy defect by following a combined digital and conventional workflow. This technique can hasten the adaptation of the patient to the new obturator and ensure a more comfortable and safer clinical procedure.

Comparison of Praat and Computerized Speech Lab for formant analysis of five Japanese vowels in maxillectomy patients

Introduction

Speech impairment is a common complication after surgical resection of maxillary tumors. Maxillofacial prosthodontists play a critical role in restoring this function so that affected patients can enjoy better lives. For that purpose, several acoustic software packages have been used for speech evaluation, among which Computerized Speech Lab (CSL) and Praat are widely used in clinical and research contexts. Although CSL is a commercial product, Praat is freely available on the internet and can be used by patients and clinicians to practice several therapy goals. Therefore, this study aimed to determine if both software produced comparable results for the first two formant frequencies (F1 and F2) and their respective formant ranges obtained from the same voice samples from Japanese participants with maxillectomy defects.

Methods

CSL was used as a reference to evaluate the accuracy of Praat with both the default and newly proposed adjusted settings. Thirty-seven participants were enrolled in this study for formant analysis of the five Japanese vowels (a/i/u/e/o) using CSL and Praat. Spearman's rank correlation coefficient was used to judge the correlation between the analysis results of both programs regarding F1 and F2 and their respective formant ranges.

Results

As the findings pointed out, highly positive correlations between both software were found for all acoustic features and all Praat settings.

Discussion

The strong correlations between the results of both CSL and Praat suggest that both programs may have similar decision strategies for atypical speech and for both sexes. This study highlights that the default settings in Praat can be used for formant analysis in maxillectomy patients with predictable accuracy. The proposed adjusted settings in Praat can yield more accurate results for formant analysis of atypical speech in maxillectomy cases when the examiner cannot precisely locate the formant frequencies using the default settings or confirm analysis results obtained using CSL.

Refabrication of an implant-retained obturator using the denture duplication technique in a bilateral maxillectomy patient with a free fibula osteocutaneous flap

PURPOSE

We aimed to introduce a simple method for refabrication of an implant-retained obturator using the denture duplication technique while retaining the custom abutments for a patient who underwent bilateral maxillectomy and reconstruction with a free fibula osteocutaneous flap. We have proposed this technique to facilitate the impression-making procedure for this extensive maxillary defect and to avoid lengthy and complicated laboratory procedures.

METHODS

A custom tray was developed by duplicating the fitting surface of an old obturator using silicone putty. The tray was used for a bite-pressure impression wherein both definitive impression and jaw relation were obtained simultaneously, reducing the time required for the placement of a new obturator.

CONCLUSIONS

We used the denture duplication technique to refabricate an implant-retained obturator while retaining the custom abutments. Decreased chairside time, fewer visits, the use of easily available materials, and uncomplicated laboratory procedures make this technique more economical and acceptable for patients. Using this approach, the patient was able to use the old prosthesis until the delivery of the new prosthesis. The replacement obturator that was developed using this method maintained an acceptable level of oral function.

Medication-related osteonecrosis of the jaw: Prosthodontic considerations

Medication-related osteonecrosis of the jaw (MRONJ) can be triggered by several antiresorptive and antiangiogenic medications, including bisphosphonates (BRONJ), denosumab (DRONJ), and other agents used to treat osteoporosis and metastatic bone cancer. Prosthodontists and surgeons continue to face new challenges because of this condition. Despite the current evidence showing that extensive surgical intervention and laser surgery have the highest healing rates, surgical reconstruction is not always possible for large jaw defects requiring prosthetic reconstruction. Moreover, surgical treatment may not be an option in some patients because of other medical conditions. In these patients, MRONJ may develop into a chronic disease with limited resolution and they may seek prosthetic rehabilitation for aesthetic and functional reasons. Therefore, prosthetic intervention may be necessary for some patients with MRONJ even in the absence of a surgical defect. Denture trauma has been reported to be a risk factor for MRONJ, and few reports have discussed the prosthodontic considerations needed for patients with this condition. The aim of this review is to highlight the prosthodontic considerations that would decrease the risk of triggering MRONJ in susceptible patients.

The nationwide registry of hospitalized heart failure patients in Japan: Japanese Registry Of Acute Decompensated Heart Failure (JROADHF)

Background and aim

Heart failure (HF) is a growing healthcare problem worldwide. This study aimed to describe clinical characteristics and long-term outcomes of HF patients in Japan.

Methods and results

JROADHF (the Japanese Registry Of Acute Decompensated Heart Failure) is a retrospective, multicentre, nationwide observational database of 13,238 patients hospitalized due to HF in 128 hospitals randomly selected from Japanese Circulation Society (JCS)-certified teaching hospitals during 2013. At inclusion, demographic and clinical data were collected from medical records with linkage to a nationwide claim-based database, the Japanese Diagnosis Procedure Combination (DPC). Patients were followed up to 5 years after discharge at each participating site. Patients were old as the median age of 81 years and women were older (74.8±12.8 vs 81.6±11.1 y.o). Mean left ventricular ejection fraction (LVEF) was 47%, and 45% were HF with preserved ejection fraction of >50% (HFpEF). Causes of HF included ischemic in 27%, valvular in 19%, arrhythmia in 17%, and hypertensive in 16%. Median length of hospital stay was 18 days and in-hospital mortality was 7.7%. All-cause mortality during 1 and 4 years were 22.3% and 48.4%, respectively. Hospitalization rates due to HF within 1 and 4 years were as high as 30.5 and 48.4%, respectively.

Conclusions

Contemporary nationwide registry revealed that hospitalized HF patients were elder and had more HFpEF, and their prognosis was still poor compared to the data shown in prior registries.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development (AMED) Practical Research Project for Life-Style related Diseases including Cardiovascular Diseases and Diabetes Mellitus

Impact of endovascular repair on the outcomes of octogenarians with ruptured abdominal aortic aneurysms: a nationwide Japanese study

Objective

This study aimed to clarify the impact of endovascular aneurysm repair (EVAR) on clinical outcomes in Japanese patients of advanced age with ruptured abdominal aortic aneurysm (rAAA).

Methods

This was a national registry based retrospective comparative study, using data from the Japanese Registry Of All cardiac and vascular Diseases-Diagnostic Procedure Combination (JROAD-DPC), a nationwide claim based database from more than 600 hospitals. Patients admitted with rAAA between April 1, 2012, and March 31, 2015 were included in the study. Patient characteristics, management, and outcomes were compared between the elderly (aged ≥80 y) and the less old. The primary endpoint was in hospital mortality; the secondary endpoint was the functional status at discharge.

Results

Of 3 969 eligible patients, 49.9% were categorised as elderly. Elderly patients had a higher prevalence of female gender (41.8% vs. 17.0%, p<0.001) and disturbance of consciousness on admission (28.6% vs. 20.7%, p<0.001). They were less likely to undergo open surgical repair (31.6% vs. 56.7%, p<0.001), although EVAR was performed similarly in both groups (13.7% vs. 14.8%, p<0.33). The unadjusted mortality rate (61.8% vs. 37.6%, p<0.001) and mean Barthel index at discharge (73.0 vs. 91.8, p<0.001) were statistically significantly worse in the elderly. Multilevel mixed effect logistic regression analyses showed that old age was detected as an independent predictor of in hospital death (odds ratio 2.75; 95% confidence interval, 2.39–3.17; p<0.001). However, for patients who received EVAR, old age was not statistically significant (odds ratio 1.13; 95% confidence interval, 0.77–1.66; p<0.53).

Conclusion

Elderly patients with rAAA were less likely to be offered open surgical repair, and the mortality among those who received surgery was high. However, for the small subgroup of elderly patients currently selected for EVAR there was a favourable outcome. The further implementation of EVAR for rAAA in Japan, especially for elderly patients with suitable anatomy, may be justified.

Funding Acknowledgement

Type of funding source: None

The safety of catheter ablation of atrial fibrillation in elderly patients -analysis of the nationwide database in Japan, JROAD-DPC-

Background

“Age” is one of the major concerns and determinants of the indications for catheter ablation (CA) of atrial fibrillation (AF). There are little safety data on CA of AF according to the age. This study aimed to assess the safety of CA in elderly patients undergoing CA of AF.

Methods and results

We investigated the complication rate of CA of AF for the different age groups (<60 years, 60–65, 65–70, 70–75, 75–80, 80–85, and ≥85) by a nationwide database (Japanese Registry Of All cardiac and vascular Diseases [JROAD]-DPC). The JROAD-DPC included 73,296 patients (65±11 years, 52,883 men) who underwent CA of AF from 516 hospitals in Japan. Aged patients had more comorbidities and a significantly increased CHADS2 score and higher rate of female according to a higher age. The overall complication rate was 2.6% and in-hospital mortality was 0.05%. By comparing each age group, complications occurred more frequently in higher aged groups. A multivariate adjusted hazard ratio revealed an increased age was independently and significantly associated with the overall complications (odds ratio was 1.25, 1.35, 1.72, 1.86, 2.76 and 3.13 respectively; reference <60 years).

Conclusions

The frequency of complications was significantly higher according to a higher age. We should take note of the indications and procedure for CA of AF in aged patients.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Intramural Research Fund 17 (Kusano) for Cardiovascular Diseases of the National Cerebral and Cardiovascular Center

Fabrication technique of obturator-type sports mouthguard for a patient who had undergone maxillectomy and its speech intelligibility assessment:A case report

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.

P5599Prognostic impact of quality indicators on outcomes of acute aortic dissection in Japan

Background

Despite recent advances in diagnosis and management, the mortality of acute aortic dissection (AAD) remains high.

Purpose

This study aims to develop quality indicators (QIs) for the management of AAD, and to evaluate the associations between QIs and outcomes of AAD in a Japanese nationwide administrative database.

Methods

A total of 18,348 patients suffered from AAD (Type A: 10,131, Type B: 8,217) in the Japanese Registry of All Cardiac and Vascular Diseases database between 2012 and 2015 were studied. A systematic review was performed to establish initial index items for QIs. Evaluation was performed through the expert consensus meeting using a Delphi method. Associations between developed QIs and the mortality were determined by multivariate mixed logistic regression analyses.

Results

A total of nine QIs (five structural and four processatic) were developed. Achievements of developed QIs (High: 7–9, Middle: 4–6, Low: 0–3) were significantly associated with lower in-hospital mortality even after adjustment for covariates in both type A (Middle: odds ratio [OR], 0.257; 95% confidence interval [CI], 0.211–0.312; P<0.001; High: OR, 0.064; 95% CI, 0.047–0.086; P<0.001 vs. Low) and type B (Middle: OR, 0.447; 95% CI, 0.338–0.590; P<0.001; High: OR, 0.128; 95% CI, 0.077–0.215; P<0.001 vs. Low). Additionally, achievements of structural and processatic QIs were consistently associated with reduced in-hospital mortality.

QIs and in-hospital mortality

Conclusions

Developed QIs for AAD management were significantly associated with lower in-hospital mortality. Evaluation of each hospital's management with QIs could be helpful to equalize quality of treatment and to fill the evidence-to-practice gaps in the real-world treatment.

6131Association between hospital care quality and readmission among Japanese patients with heart failure. From JROAD-DPC study

Background

Measuring the process of care has become a widely used practice to improve a quality of care. Recently, some studies have demonstrated poor to no correlation between 30-day readmission rates and quality of care for heart failure (HF) among hospitalized HF patients. However the investigation about relationships of care quality for HF and 1 year outcome is limited.

Purpose

To investigate the relationship between quality of care in each hospitals and readmission among HF patients in Japan.

Methods

From Japanese Registry of All cardiac and vascular diseases (JROAD-DPC) database in 2014, 84,325 HF patients hospitalized to 741 certificated hospitals by Japanese Circulation Society were analyzed. A primary endpoint was readmission for HF in one year. Five performance measures were defined as prescription rate of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB), prescription rate of beta blocker and prescription rate of spironolactone, measurement rate of echocardiography and measurement rate of B-type natriuretic peptide (BNP) during hospitalization. For each of the five measures, a composite score was created by giving points ranging from 1 to 4 from the lower quartile of rates, with the score ranging from 5 to 20 points. Hazard ratios (HR) indicating the effects of the performance measures were estimated using Cox proportional hazard models. Covariates included age, gender, Charson score, and NYHA class.

Results

In Japanese HF patients (age; 78.1 years old, man 52%), the HF readmission rate in one year was 14,520 (17.2%). The readmission rate decreased with higher quartiles of prescription rate in each medications and performance rates. The highest quartile of each measurements was significantly lower risk for readmission compared to the lowest quartile (ACE/ARB, adjusted HR 0.87 [95% CI, 0.83–0.91], p<0.001; beta-blocker, 0.83 [0.79–0.88], p<0.001; spironolactone, 0.88 [0.83–0.92], p<0.001; echocardiography, 0.90 [0.86–0.94], p<0.001; BNP, 0.92 [0.87–0.96], p<0.001). Kaplan-Meier curves showed that readmission rates were better among higher composite score, compared to lower composite score (Log-rank test=p<0.001). (Figure) Higher composite scores were associated with statistically significant risk reduction of 23% for HF readmission (HR 0.77, 95% CI [0.73–0.81], p<0.001).

Figure 1

Conclusion

The hospital performance measures were associated with a significant risk reduction of readmission in Japanese patients with HF.

P5605The impact of institutional case volume on the Ppognosis of ruptured aortic aneurysms: a Japanese nationwide study

Background

To improve outcome for ruptured aortic aneurysms (rAA), centralization of treatment is potentially effective. However, there is no nationwide survey for the current managements and outcomes of rAA in Japan.

Purpose

The aim of this study was to assess the volume-outcome relationship for rAA treatment using the nationwide claim-based database.

Methods

Using the Japanese Registry Of All cardiac and vascular Diseases- Diagnostic Procedure Combination database, we identified patients admitted to 564 certified teaching-hospitals with rAA between April 1, 2012 and March 31, 2015. Institutional case volume (cardiovascular surgeries per year) was categorized into quartiles (Lowest, Low, High, and Highest) and the odds ratios (ORs) for in-hospital mortality and neurological status at discharge were analyzed for each quartile.

Results

Of 7086 eligible patients, 3925 (55.4%) died in hospital. Mortality rates decreased from 69.4% in the lowest-volume to 43.8% in the highest-volume category (P<0.001). The favourable impact of institutional case volume was sustained even after adjustment for covariates (Low-volume: OR, 0.83; 95% confidence interval [CI], 0.65–1.07; P=0.147; High-volume: OR, 0.69; 95% CI, 0.54–0.89; P=0.005; and Highest-volume: OR, 0.55; 95% CI, 0.42–0.72; P<0.001 vs. Lowest-volume). Additionally, other three institutional parameters (increased aortic surgery volume, cardiovascular surgeons' volume, and certified cardiologists' volume) were consistently associated with reduced in-hospital mortality. The rate of coma at discharge was the lowest in the Highest-volume group (P<0.001).

Institutional volume and mortality

Conclusions

Increased institutional volume was associated with lower in-hospital mortality. Establishing regionally tailored systems to transfer patients to high-volume centers is needed to improve outcomes.

P884Short-term exposure to asian dust is associated with myocardial infarction with nonobstructive coronary arteries

Background

Asian dust (AD) is considered as one of air pollution that increases risk of acute myocardial infarction (AMI). However, it has not been elucidated whether AD might increase the risk of myocardial infarction with nonobstructive coronary arteries (MINOCA).

Methods

A time-stratified case-crossover design and conditional logistic regression models was used to investigate the association between short-term exposure to AD and admission of AMI during the spring months in a nationwide administrative Diagnostic Procedure Combination (DPC) database, the Japanese Of All cardiac and vascular Diseases (JROAD)-DPC, between April 2012 through March 2016. MINOCA was defined as AMI having angiography without revascularization and coronary atherosclerosis, whereas myocardial infarction with obstructive coronary artery disease (MI-CAD) was AMI with revascularization and/or coronary atherosclerosis. Data for AD events, air pollutants (PM2.5, Ox, NO2, SO2), and meteorological variables were obtained from the nearest monitoring station of the hospital.

Results

During the study period, 3,233 MINOCA and 27,202 MI-CAD patients were identified from 30,435 AMI patients. Although the occurrence of AD events 2 days before the admission was not associated with the admission of AMI and MI-CAD, the AD events was significantly associated with the admission of MINOCA with adjustment for meteorological variables and each air pollutant. In subgroup analysis of MINOCA, patients without low ADL was associated with higher risk of the admission due to AD exposure than those with low ADL, with significant interaction.

Conclusions

AD events might be more likely to trigger onset of MINOCA than MI-CAD.

Acknowledgement/Funding

None

Clinical survey over the past 35 years at the clinic for maxillofacial prosthetics Tokyo Medical and Dental University

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.

Evaluation of swallowing ability using swallowing sounds in maxillectomy patients

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.

Evaluation of Swallowing Sound Using a Throat Microphone with an AE Sensor in Patients Wearing Palatal Augmentation Prosthesis

An increase in the population of dysphagia patients due to an aging population has led to increased attention on examination methods based on swallowing sound as simple methods of screening aspiration. However, an issue with the conventional method of cervical auscultation is that its accuracy varies based on the examiner. Previous studies examined the use of throat microphones and acceleration sensors to examine the acoustic characteristics of swallowing sound. Nevertheless, extant studies to date did not reach a level of clinical application. This study focused on using a throat microphone that is conventionally used to measure swallowing sound and an AE sensor to measurement a high-frequency range equal to and exceeding 20 kHz (upper limit 2 MHz). The study involved measuring the sounds of swallowing water of healthy subjects and patients wearing palatal augmentation prosthesis who had done surgical operation to treat head and neck cancer with the objective of using swallowing sound for screening aspiration. Acoustic characteristics of measured swallowing sound were analyzed using probability distributions using Quantile-Quantile (Q-Q) plots and spectral analysis based on wavelet transform. The findings indicated that with respect to patients with PAP, the duration time of the swallowing sound and the Q-Q plot departure rate were both significantly higher when compared with those in healthy subjects. The analysis based on wavelet transform indicated that the AE sensor allowed measurements of waveforms at a higher frequency range when compared to those in the case of the throat microphone. Additionally, an increased frequency of higher-frequency signals was associated with patients with PAP when compared to healthy subjects. The results revealed that it is possible to measure waveforms in the high-frequency range by using the AE sensor. The findings suggested the validity of analysis of the swallowing sound based on probability distributions using the Q-Q plot to evaluate the swallowing sound.

Pilot Study on an Acoustic Measurements System of the Swallowing Function Using an Acoustic-Emissions Microphone

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.

Creating a digitized database of maxillofacial prostheses (obturators): A pilot study

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.

Bone Marrow-derived Cell Therapy for Oral Mucosal Repair after Irradiation

Oral mucositis (ulcer) is a serious and painful side effect for patients with head and neck cancer following radiation therapy. However, current clinical strategies cannot efficiently prevent the occurrence of oral mucositis. In this study, we investigated whether bone marrow-derived cells (BMDCs) prevented the occurrence and/or decreased the severity of radiation-induced oral mucositis. Fresh concentrated BMDCs from male C3H mice were transplanted intravenously into female mice after tongue irradiation. For 14 days postirradiation, the changes of body weight and the time courses of ulceration were observed. Until the ulcer reached maximum size (7 days postirradiation), macroscopic and histologic analyses of harvested tongues were performed to detect the behavior of donor BMDCs. Between 2 and 5 days postirradiation, BMDCs-transplanted mice showed more expression of stem cell markers (c-Kit, Sca-1) and EGFR and fewer apoptotic cells when compared with nontransplanted control mice (irradiation group). On day 7, there were fewer and smaller ulcers observed in the BMDCs-transplanted group. Tongues of these mice had preserved their epithelial thickness, and regenerative activities (blood vessels formation, cell proliferation) were higher than they were in the irradiation group. Fluorescently labeled BMDCs were not detected in tongue epithelium but rather in connective tissue (dermis) just below the basal cell layer. These findings suggest that exogenous BMDCs behave to reduce radiogenic oral mucositis in a paracrine manner.

[Three kinds of speech evaluation in maxillectomy patients during the fabrication process of a hollow-type obturator]

Speech evaluation is essential to the rehabilitation of maxillectomy patients. A speech intelligibility test has been frequently used for the evaluation because of its simplicity. However, the test needs human listeners and this has been a shortcoming of the test. Thus, objective evaluation methods have been discussed. One of them is formant analysis for vowel evaluation and another is psychoacoustic analysis for consonants. In this research, to evaluate the speech in five maxillectomy patients, the F2-range was examined as formant analysis and the sharpness of /sa/ was examined as psychoacoustic analysis, in addition to the speech intelligibility test, during the fabrication process of a hollow-type obturator. The objective evaluation of patients' speech was effectively performed using those three methods. The F2-range was larger, the sharpness of /sa/ was higher and the speech intelligibility was higher when patients wore an obturator compared to when patients did not wear an obturator. The difference in speech when changing the types of obturator was not clear. The method and the findings are important for future research in this field, since speech is one of the important factors in maxillofacial rehabilitation.

Elevated BAFF levels in the cerebrospinal fluid of patients with neuro-Behçet's disease: BAFF is correlated with progressive dementia and psychosis

Neuro-Behçet's disease (NBD) is a serious complication of Behçet's disease. Generally, NBD patients with a chronic course are refractory to immunosuppressive treatment, resulting in the deterioration of personality. In this study, levels of B cell-activating factor belonging to the TNF family (BAFF) were measured in the cerebrospinal fluid (CSF) from 18 patients with NBD, 27 patients with epidemic aseptic meningitis (AM), 24 patients with multiple sclerosis (MS) and 34 healthy controls. BAFF levels in patients with NBD were significantly elevated compared with healthy controls, but showed no statistically significant elevation compared with either of the disease controls. In contrast, CSF IL-6 levels were slightly elevated in patients with NBD and significantly elevated in patients with AM and MS compared with healthy controls. Patients with NBD were subdivided into two groups according to their clinical course (eight patients with a slowly progressive course presenting with psychosis and dementia and 10 patients with an acute course including aseptic meningitis, brainstem involvement and myelopathy). BAFF levels were significantly increased in those with a slowly progressive course compared with those with an acute course. CSF BAFF levels did not correlate with serum BAFF levels, CSF cell counts or CSF IL-6 levels in patients with NBD. These data suggested that BAFF was produced within the central nervous system and may be associated with the development of NBD, particularly with a progressive course.

Formation of Engineered Bone with Adipose Stromal Cells from Buccal Fat Pad

A robust method for inducing bone formation from adipose-derived stromal cells (ADSCs) has not been established. Moreover, the efficacy of strong osteogenic inducers including BMP-2 for ADSC-mediated bone engineering remains controversial. Meanwhile, the buccal fat pad (BFP), which is found in the oral cavity as an adipose-encapsulated mass, has been shown to have potential as a new accessible source of ADSCs for oral surgeons. However, to date, there have been no reports that define the practical usefulness of ADSCs from BFP (B-ADSCs) for bone engineering. Here, we report an efficient method of generating bone from B-ADSCs using rhBMP-2. The analyses show that B-ADSCs can differentiate in vitro toward the osteoblastic lineage by the addition of rhBMP-2 to culture medium, regardless of the presence of osteoinductive reagents (OSR), as demonstrated by measurements of ALP activity, in vitro calcification, and osteogenic gene expression. Interestingly, adipogenic genes were clearly detectable only in cultures with rhBMP-2 and OSR. However, in vivo bone formation was most substantial when B-ADSCs cultured in this condition were transplanted. Thus, B-ADSCs reliably formed engineered bone when pre-treated with rhBMP-2 for inducing mature osteoblastic differentiation. This study supports the potential translation for B-ADSC use in the clinical treatment of bone defects.

Effect of GDF-5 and BMP-2 on the expression of tendo/ligamentogenesis-related markers in human PDL-derived cells

OBJECTIVES

The effect of growth differentiation factor 5 and bone morphogenetic protein 2 on human periodontal ligament-derived cells was investigated with special reference to tendo/ligamentogenesis-related markers.

MATERIALS AND METHODS

Effects of each factor were analyzed by quantitative PCR for scleraxis and tenomodulin and by western blotting for scleraxis. After exposure to those factors, STRO-1-positive and STRO-1-negative fractions of human periodontal ligament tissues were isolated with an immunomagnetic cell sorting system, and the expression of scleraxis in each fraction was analyzed by western blotting. Non-separated crude cells were used as a control.

RESULTS

Growth differentiation factor 5 and bone morphogenetic protein 2 did not increase alkaline phosphatase activity in crude periodontal ligament-derived cells. Growth differentiation factor 5, but not bone morphogenetic protein 2, increased the expression of scleraxis in crude, STRO-1-positive and STRO-1-negative periodontal ligament-derived cells. The expression of scleraxis in STRO-1-positive periodontal ligament-derived cells was significantly less compared to that in crude P2 and STRO-1-negative periodontal ligament-derived cells.

CONCLUSION

Growth differentiation factor 5 induced the expression of scleraxis and may enhance tendo/ligamentogenesis in human periodontal ligament-derived cells. The expression of scleraxis was higher in STRO-1-negative fraction, suggesting more differentiated state of the cells.

Genetic polymorphisms in the surfactant proteins in systemic sclerosis in Japanese: T/T genotype at 1580 C/T (Thr131Ile) in the SP-B gene reduces the risk of interstitial lung disease

OBJECTIVES

To investigate the association between single-nucleotide polymorphisms (SNPs) in the pulmonary surfactant protein (SP) genes and the presence or absence of interstitial lung disease (ILD) in SSc patients.

METHODS

We studied 127 Japanese patients with SSc and 206 normal subjects. Investigated SNPs were C/T within amino acid (aa) 219, Arg219Trp in the SP-A1 gene (rs4253527), C/T within aa 131 (at nucleotide 1580) and Thr131Ile of the SP-B gene (rs1130866). Genotypes were determined by the TaqMan method.

RESULTS

Genotype frequencies were not different between the SSc patients and normal controls for both loci. The patients were subsequently divided into two groups based on presence or absence of ILD. In the SNP in the SP-B gene, the frequency of the T/T genotype was significantly lower in the patients with ILD than in those without ILD. Limited in the patients who were positive for anti-Scl-70 antibody, the difference in the frequency of the T/T genotype between the ILD-positive and ILD-negative groups became more apparent. On the other hand, in the SNP in the SP-A1 gene, there was no significant skewing for a certain genotype.

CONCLUSION

In SSc, where massive fibrosis occurs, possession of the T/T genotype in the SP-B gene would reduce the risk of ILD in Japanese.

Odontoblast marker gene expression is enhanced by a CC-chemokine family protein MIP-3alpha in human mesenchymal stem cells

OBJECTIVE

Macrophage inflammatory protein-3 alpha (MIP-3alpha) is a major CC-chemokine family protein, which serves as a differentiation factor for mesenchymal cells, including osteoblasts and dental pulp cells. The purpose of this study was to investigate the influence of MIP-3alpha on human mesenchymal stem cell differentiation in vitro.

DESIGN

Human mesenchymal stem cells were maintained in Dulbecco's modified Eagle's medium in the presence or absence of MIP-3alpha and the presence or absence of osteogenic factors (dexamethasone, beta-glycerophoshate and ascorbic acid). Alkaline phosphatase (ALP) activity was measured, and expression of odontoblast and osteoblast markers were examined by RT-PCR and Western blotting.

RESULTS

MIP-3alpha alone did not increase ALP activity, as compared to controls. The combination of MIP-3alpha and osteogenic factors increased ALP activity beyond increases observed with osteogenic factors alone. mRNA expression of the odontoblast marker dspp was only detectable when MIP-3alpha was added together with osteogenic factors at day 7 in three out of four samples. DSP protein level was increased only in the samples treated with both MIP-3alpha and osteogenic factors until day 5. In contrast, MIP-3alpha did not influence levels of the osteoblast markers CBFA1 or BSP.

CONCLUSIONS

The present study demonstrated that MIP-3alpha enhanced gene expression and protein levels of odontoblast-related genes, without affecting levels of the osteogenic proteins CBFA1 or BSP.

Shear stress facilitates tissue-engineered odontogenesis

Numerous studies have demonstrated the effect of shear stress on osteoblasts, but its effect on odontogenic cells has never been reported. In this study, we focused on the effect of shear stress on facilitating tissue-engineered odontogenesis by dissociated single cells. Cells were harvested from the porcine third molar tooth at the early stage of crown formation, and the isolated heterogeneous cells were seeded on a biodegradable polyglycolic acid fiber mesh. Then, cell-polymer constructs with and without exposure to shear stress were evaluated by in vitro and in vivo studies. In in vitro studies, the expression of both epithelial and mesenchymal odontogenic-related mRNAs was significantly enhanced by shear stress for 2 h. At 12 h after exposure to shear stress, the expression of amelogenin, bone sialoprotein and vimentin protein was significantly enhanced compared with that of control. Moreover, after 7 days, alkaline phosphatase activity exhibited a significant increase without any significant effect on cell proliferation in vitro. In vivo, enamel and dentin tissues formed after 15 weeks of in vivo implantation in constructs exposure to in vitro shear stress for 12 h. Such was not the case in controls. We concluded that shear stress facilitates odontogenic cell differentiation in vitro as well as the process of tooth tissue engineering in vivo.

Validity and reproducibility of echocardiographic measurement of left ventricular ejection fraction by acoustic quantification with tissue harmonic imaging technique

The tissue harmonic imaging technique can enhance detection of the cardiac endocardial border. When combined with an acoustic quantification (AQ) method, an improvement of accuracy and reproducibility of real-time measurement of left ventricular (LV) function might be expected. However, few data exist regarding the measurement of LV function by AQ with the harmonic imaging technique. Therefore, we evaluated the validity and reproducibility of AQ measurement of LV ejection fraction with or without harmonic imaging technique. A total of 50 patients (mean age 58 +/- 10 years) who underwent left ventriculography were included in our study. The LV end-diastolic and end-systolic volumes by ventriculography were 131 +/- 52 mL and 72 +/- 43 mL, respectively, and were underestimated by both conventional (70 +/- 32 mL and 36 +/- 25 mL) and harmonic (67 +/- 30 mL and 34 +/- 22 mL) AQ obtained in the apical 4-chamber view. The calculated ejection fraction by ventriculography was 0.49 +/- 0. 11 and correlated with that by conventional AQ (0.51 +/- 0.11; y = 0. 72x + 0.152; r = 0.73). This was a marked improvement when compared with the ejection fraction by harmonic AQ (0.50 +/- 0.11; y = 0.89x + 0.065; r = 0.91). Interestingly, interobserver and intraobserver variabilities of conventional AQ, which were 15.6% and 8.6%, respectively, were much improved by harmonic AQ (8.9% and 4.5%, respectively). These results indicate the feasibility of real-time measurement of LV ejection fraction by harmonic imaging, although absolute LV volume can be underestimated even by this technique.

Nucleosides and nucleotides. 192. Toward the total synthesis of cyclic ADP-carbocyclic-ribose. Formation of the intramolecular pyrophosphate linkage by a conformation-restriction strategy in a syn-form using a halogen substitution at the 8-position of the adenine ring

The synthesis of cyclic ADP-carbocyclic-ribose (2), as a stable mimic for cyclic ADP-ribose, was investigated. Construction of the 18-membered backbone structure was successfully achieved by condensation of the two phosphate groups of 19, possibly due to restriction of the conformation of the substrate in a syn-form using an 8-chloro substituent at the adenine moiety. SN2 reactions between an optically active carbocyclic unit 8, which was constructed by a previously developed method, and 8-bromo-N6-trichloroacetyl-2',3'-O-isopropylideneadenosine 9c gave N-1-carbocyclic derivative, which was deprotected to give 5'-5"-diol derivatives 18. When 18 was treated with POCl3 in PO(OEt)3, the bromo group at the 8-position was replaced to give N-1-carbocyclic-8-chloroadenosine 5',5"-diphosphate derivative 19 in 43% yield. Treatment of 19 with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride gave the desired intramolecular condensation product 20 in 10% yield. This is the first chemical construction of the 18-membered backbone structure containing an intramolecular pyrophosphate linkage of a cADPR-related compound with an adenine base.