label: url

en: 徳島大学病院歯科放射線科における過去10年間のX線撮影件数・内容の分析

ja: 徳島大学病院歯科放射線科における過去10年間のX線撮影件数・内容の分析

en: Dental Radiology

ja: 歯科放射線


en: Effective use of an extraoral vacuum in preventing the dispersal of particulate matter from metal dental materials.

en: When dentists adjust prostheses at the dental chairside, particulate matter (PM) from the dental material is dispersed. Little is known about the effective use of an extraoral vacuum (EOV) in preventing PM dispersal. This study aimed to evaluate the effective use of an EOV in preventing the dispersal of metal PM in dental offices. The following experimental conditions were planned: the distance from the EOV to the metallic materials (50, 100, 150, and 200 mm), the horizontal angle between the long axis of the micromotor handpiece and EOV (0°, 45°, and 90°), and the operating time of the EOV (during grinding, during grinding and 1 min thereafter, during grinding and the preceding 1 min, 1 min before and after grinding, and during grinding). Carborundum and silicone points were used for grinding and PM dispersal. Diameters (0.3, 0.5, 1.0, and 3.0 μm) were measured using a laser particle counter. Depending on the instrument used to grind, there were undetectable PMs of different diameters (Carborundum point: 0.3 and 0.5 μm, Silicone point: 0.3 μm). PMNs were reduced as the distance from the EOV to metal materials decreased. Operating the EOV before grinding along the long axis of the micromotor handpiece was effective in reducing the PMNs. PMNs dispersed when grinding metals were effectively reduced by positioning the EOV closer to the grinding surface (within 150 mm) along the long axis of the micromotor handpiece and operating the EOV before grinding.

en: Journal of Occupational Health

ja: Journal of Occupational Health


en: Development of a Low Radioactivity Detection System Using a Digital Intraoral Radiography Detector (Imaging Plate)

ja: デジタル口内法X線撮影検出器(イメージングプレート)を応用した低放射能検出システムの開発


en: Effect of Palatal Augmentation Prosthesis on Speech and Swallowing in Tongue Dysfunction:A Literature Review

en: Purpose: Palatal augmentation prosthesis (PAP) is used on patients with dysphagia and dysarthria. While several studies have evaluated the effects of PAP, evidence regarding the adaptation criteria, effects, and limitations of PAP are not well organized. This review aims to summarize its functions, limitations, and applications. Procedure: To investigate the adaptation criteria, effects, and limitations of PAP, we searched the English language literature published in PubMed from its inception through April 20, 2022. The leading search terms included ``palatal augmentation prosthesis.'' Main findings: The primary search used keywords that reflected 31 studies. Finally, nine cross-sectional studies and nine case reports were selected for full-text assessment after applying the inclusion criteria. Eleven studies described the efficacy of speech function: two for motility factors and nine for organic factors (with overlap). Thirteen studies described the effectiveness of swallowing function, four related to motility factors, and ten for organic factors (with overlap). Several studies have demonstrated that PAP effectively restores articulation and swallowing in patients with impaired tongue function after glossectomy for oropharyngeal cancer, sequelae of cranial nerve disease, or neuromuscular disease. However, few papers describe the scope of glossectomy and tongue movement restrictions, so it is impossible to describe the adaptation criteria, effects, and limitations. In this review, most case reports and cross-sectional studies did not provide information on the fabrication methods of PAP or the dentistsʼ experience. Thus, the effect of bias on palatal morphology in PAP patients remains unclear. Conclusions: The number of patients with dysarthria and dysphagia is increasing worldwide, similar to what is already occurring in Japan. Therefore, additional high-quality studies on the effects of PAP are required.

en: Journal of Oral Health and Biosciences

ja: Journal of Oral Health and Biosciences


en: Can Measurement of Ultrasonic Echo Intensity Predict Physical Frailty in Older Adults?

en: Echo intensity (EI) of the tongue in ultrasonography is an easy and quantitative assessment of tongue function. Elucidating the relationship between EI and frailty, is expected to aid in the early detection of frailty and oral hypofunction in older adults. We assessed tongue function and frailty in older outpatients visiting a hospital. The subjects were 101 individuals aged 65 or older (35 men and 66 women, mean age 76.4 ± 7.0 years). Tongue pressure and EI were measured as assessments of tongue function and grip strength, and Kihon Checklist (KCL) scores were measured as assessments of frailty. In women, a significant correlation was not found between the mean EI and grip strength, whereas a significant correlation was noted between each score of the KCL and the mean EI; the scores increased as the mean EI increased. A significant positive correlation was found between tongue pressure and grip strength, but no significant correlation was observed between tongue pressure and the KCL scores. In men, no significant correlation was found between tongue assessments and frailty, except for a significant positive correlation between tongue pressure and grip strength. The results of this study suggest that EI of the tongue is positively associated with physical frailty in women and may be useful for early detection of physical frailty status.

en: Diagnostics

ja: Diagnostics


en: Measurement of ultrasonic echo intensity predicts the mass and strength of the tongue muscles in the elderly

en: Journal of Oral Science

ja: Journal of Oral Science


en: Does Masticatory Ability Contribute to Nutritional Status in Older Individuals?

en: Mastication plays a primary role in the process of eating. Hence, compromised masticatory ability may affect the nutrition and quality of life, which are particularly important concerns among older individuals. It remains unclear how is the masticatory ability assessed regarding the nutritional status. We examined the effect of various oral factors on three masticatory ability tests conducted among older individuals. A total of 100 older individuals were enrolled in this study. Body mass index (BMI) as an indicator of nutritional status; and age, sex, and the number of occlusal and molar occlusal supports as clinical attributes were recorded. Three masticatory ability tests (masticatory efficiency, masticatory score, and satisfaction with mastication) were conducted, and tongue pressure, cheek pressure, and occlusal force were assessed as oral functions. A significant but weak correlation was found between masticatory efficiency and the masticatory score, but not between masticatory efficiency and satisfaction score. Objective masticatory efficiency was strongly associated with objective oral factors, whereas subjective assessments of masticatory ability (masticatory score and satisfaction score) were not. Furthermore, BMI was significantly associated with subjective assessments of masticatory ability but not with objective masticatory efficiency. Both subjective and objective assessments of masticatory ability, along with considerations of nutritional formulations, are required for the maintenance and improvement of nutritional status in older individuals.

en: International Journal of Environmental Research and Public Health


en: Changes in Image Examinations at the Department of Oral Radiology -The Number of Intraoral and Panoramic Radiographs-

ja: 歯科放射線科の撮影件数の推移 -口内法枚数と口外法件数-

en:
After the computed radiography (CR) system was developed in 1986, it became possible to acquire, view and save digital images for medical diagnosis. Around that time, panoramic radiography was digitized by the CR system, but it was limited to large hospitals. From 1994, it has been digitized at large hospitals and dental clinics. We examined the changes in the number of intraoral and panoramic radiographs in dentistry, and based on the relationships among the numbers of radiographs, patients and dental operations, we discussed the clinical significance of digitization.
We extracted intraoral and panoramic radiography data, the number of dental operations and the number of patients from the database of Tokushima University Hospital from 2002 to 2017. Then, we extracted nationwide data from Statistics of Medical Care Activities in Public Health by the Ministry of Health, Labour and Welfare from 2002 to 2017.
As a result, although the numbers of patients and dental operations at Tokushima UniversityHospital have remained constant, the number of intraoral radiographs has decreased (72%), whereas the number of panoramic radiographs has increased annually since 2011 (131%). In addition, although the number of patients and nationwide insurance points increased in a different manner than that at Tokushima University Hospital, a decrease in the number of intraoral radiographs and an increase in the number of panoramic radiographs were noted across Japan. As panoramic imaging has been improved and adapted to different settings, panoramic radiography has been used instead of intraoral radiography, and it has been widely used in screening applications such as for perioperative patients. Although digitization is progressing, the analog images are still used (intraoral radiography analog rate, 29.7%, panoramic radiography analog rate, 12.4% in 2017).


en: Geniohyoid muscle affects directly masticatory function: Evaluation using a decision tree analysis

en: To clarify the effect of geniohyoid (GH) muscle morphology and related function on masticatory ability using a decision-tree analysis. A total of 103 participants were enrolled. A cross-sectional area (CSA) of the GH muscle, neck circumference, body mass index, tongue pressure, jaw opening strength, and masticatory ability score were measured. The CSA of the GH muscle was selected as an independent variable for the first layer of the decision tree, with masticatory score as the dependent variable. These data suggest that the CSA of the GH muscle may have a large impact on the masticatory ability score when evaluating masticatory ability.

en: The International Journal of Prosthodontics


en: Dental students' levels of understanding normal panoramic anatomy

en: In dentistry, panoramic radiography is an important examination technique. The Faculty of Dentistry at Tokushima University educates students about panoramic radiographic anatomical landmarks. The purpose of this study was to investigate differences in the understanding of each panoramic anatomical landmark among students. This study analyzed the results of 40 fifth- and 79 sixth-year faculty students who had taken a written examination to clarify their knowledge of anatomical landmarks in 28 panoramic radiographic regions. Anatomical landmarks were classified into 3 categories: <bone structure>, <soft tissue/air layer>, and <ghost images > to compare correct answer rates. The mean overall correct answer rate by the 119 students for the 28 regions was 53%. The rate did not vary between the 2 academic years. On comparison of the 3 categories, significant differences were only observed between <bone structure> and <soft tissue/air layer>, as the values for the latter were lower. Among the anatomical landmarks, the rates for the condylar head, hyoid bone, panoramic innominate line, styloid process, and nasopalatine line were higher, and those for ghost images of the contralateral nasopalatine line, the cervical vertebrae, mandibular foramen, mastoid air cell, and posterior pharyngeal wall were lower. The values for <soft tissue/air layer>, such as the dorsum of tongue, middle and inferior nasal conche, and middle and inferior nasal meatuses, were also lower. These results indicate the necessity of improving educational approaches for regions with lower rates of correct answers.

en: Journal of Dental Sciences

ja: Journal of Dental Sciences


en: Tongue thickness and its clinical significance

en: Journal of Oral Health and Biosciences


en: Time-course observation of patients with arthrosis of the temporomandibular joint on MRI

en:
Patients with arthrosis of the temporomandibular joint are examined by MRI, but fewer cases are followed over time by performing MRI several times. The objective of this study was to investigate the presence or absence and types of changes in the structure of the mandibular condyle and articular disc on MR images over time in patients examined by MRI for the diagnosis of arthritis of the temporomandibular joint in order to clarify the usefulness of performing MRI several times.
 MR images for patients who underwent MRI several times based on the clinical diagnosis of arthrosis of the temporomandibular joint were analyzed.
 Twenty-three patients were examined by MRI twice or more. The shortest and longest intervals between the first and final examinations were 75 and 2,588 days, respectively, and the mean was 735 days. Changes in the bone structure of the mandibular condyle were noted on the first MRI in approximately 63 % and new changes were noted on the final examination in approximately 24 %. In addition, the articular disc position in the closed or open mouth had changed on the later examinationin approximately 15 %.
 Performing MRI several times along the clinical course was found to be useful to diagnose the disease stage, judge the treatment effects, and help predict the outcome in patients with arthrosis of the temporomandibular joint.


en: 磁性材料のミニインプラントオーバーデンチャーへの応用に関する研究

ja: 磁性材料のミニインプラントオーバーデンチャーへの応用に関する研究

en: Shikoku Dental Research

ja: 四国歯学会雑誌


en: Oral factors affecting titanium elution and corrosion: an in vitro study using simulated body fluid.

en: Ti, which is biocompatible and resistant to corrosion, is widely used for dental implants, particularly in patients allergic to other materials. However, numerous studies have reported on Ti allergy and the in vitro corrosion of Ti. This study investigated the conditions that promote the elution of Ti ions from Ti implants. Specimens of commercially pure Ti, pure nickel, a magnetic alloy, and a gold alloy were tested. Each specimen was immersed in a simulated body fluid (SBF) whose pH value was controlled (2.0, 3.0, 5.0, 7.4, and 9.0) using either hydrochloric or lactic acid. The parameters investigated were the following: duration of immersion, pH of the SBF, contact with a dissimilar metal, and mechanical stimulus. The amounts of Ti ions eluted were measured using a polarized Zeeman atomic absorption spectrophotometer. Eluted Ti ions were detected after 24 h (pH of 2.0 and 3.0) and after 48 h (pH of 9.0). However, even after 4 weeks, eluted Ti ions were not detected in SBF solutions with pH values of 5.0 and 7.4. Ti elution was affected by immersion time, pH, acid type, mechanical stimulus, and contact with a dissimilar metal. Elution of Ti ions in a Candida albicans culture medium was observed after 72 h. Elution of Ti ions in the SBF was influenced by its pH and by crevice corrosion. The results of this study elucidate the conditions that lead to the elution of Ti ions in humans, which results in implant corrosion and Ti allergy.

en: PLoS ONE

ja: PLoS ONE


en: 磁性アッタチメントを用いたミニインプラントオーバーデンチャーの力学的解析

ja: 磁性アッタチメントを用いたミニインプラントオーバーデンチャーの力学的解析

en: Journal of Japanese Society of Oral Implantology

ja: 日本口腔インプラント学会誌


en: 固定方法からみたインプラント上部構造の臨床的・文献的考察

ja: 固定方法からみたインプラント上部構造の臨床的・文献的考察

en: As the connection mechanism between the superstructure and implant, the cement-retained type and screw-retained type are mainly used. The choice of a screw-retained versus a cement-retained superstructure is a complex and comprehensive decision involving many points of consideration. On the other hand, various retained methods that is complementary with each retained type have been proposed. In this article, various retained types which have been reported in the literatures and developed by us, were systematically assorted from the standpoints of retreivability, and the advantages were pointed out showing case photographs. This systematical information would help the selection of retained type of the superstructure.


en: Survival of immediate implant restoration: A retrospective study through 9-year-observation

en: The purpose of this retrospective study was to assess the implant survival rate and the risk factors associated with implant failure in patients who had undergone immediate implant restoration. We performed a retrospective review and an outcome assessment of all patients who received immediate implant restoration between 2000 and 2010 in our department at Tokushima University Hospital. The patients were divided into groups on the basis of the predictor variables: age, gender, implant location, and number of implants per jaw. The cumulative implant survival rate in the paired groups was determined by using Kaplan-Meier analysis and the log-rank test. Cox proportional hazards model was subsequently used to identify exposures associated with implant failure. Using the Kaplan-Meier method, the survival rates at 1, 3, and 9 years were calculated to be 98.8%, 98.0%, and 94.7%, respectively. No statistically significant association was observed between the implant survival rates and the predictor variables: gender, age, location, and number of implants. Immediate implant restoration is a reliable prosthetic procedure with an acceptable survival rate compared to the conventional implant procedure.

en: Journal of Prosthodontic Research

ja: Journal of Prosthodontic Research