In recent years, oral functional decline in older adults has been shown to be closely associated with nutritional status, with masticatory difficulties and dysphagia contributing to malnutrition and the progression of frailty. The palatal augmentation prosthesis (PAP) is considered effective in improving eating and swallowing function; however, studies examining its impact on nutritional outcomes remain limited. Although there are reports of functional improvement through multidisciplinary collaboration, as well as improvements in tongue pressure and swallowing-related parameters, nutritional evaluations—such as body weight, dietary intake, and biochemical markers—are still insufficient. In older populations, multiple factors influence nutritional status, making it difficult to establish direct causal relationships. Future prospective studies incorporating nutritional indicators and clarifying target patient populations are therefore needed. This project brings together experts in prosthodontics, nutrition, and dysphagia rehabilitation to share current knowledge and discuss the potential of oral function support as an integrated intervention.

Dysphagia, aspiration pneumonia, and malnutrition are interrelated conditions that pose major health challenges among older adults in super-aging society. The prevalence of dysphagia is high in this population, and its progression is associated with an increased risk of aspiration pneumonia. Malnutrition further exacerbates this condition by impairing immune function and reducing muscle mass and strength, thereby accelerating sarcopenia and worsening swallowing function. In addition, impaired masticatory function contributes to insufficient protein intake and reduced dietary diversity, leading to further deterioration of nutritional status.

Therefore, dental professionals should not focus solely on occlusal rehabilitation but also evaluate the ability to consume adequate amounts of food. Early detection of decreased oral function and malnutrition is essential. Practical approaches include monitoring dietary intake and body weight, providing appropriate guidance for denture use, and collaborating with medical and nutritional professionals.

Such comprehensive and multidisciplinary interventions are expected to break the vicious cycle of dysphagia and malnutrition, improve quality of life, and support older adults in maintaining oral intake until the end of life.

This paper outlines the correlation between dysphagia and malnutrition in older adults and proposes strategic countermeasures. Nutritional status is a critical determinant of prognosis in this population. Notably, more than half of individuals with dysphagia are malnourished, a condition frequently underdiagnosed through visual assessment alone. The Mini Nutritional Assessment Short-Form^Ⓡ (MNA-SF^Ⓡ) serves as a simple, highly sensitive, and essential tool for early screening. To prevent energy deficits that exacerbate malnutrition, maintaining oral intake is paramount, and fasting should be avoided whenever possible. Given that muscle protein synthesis capacity declines with age, a protein intake of approximately 20 g per meal is recommended, with particular emphasis on breakfast. For effective weight management, caloric fortification using medium-chain triglyceride (MCT) oil is highly beneficial. Furthermore, as dysphagia-modified diets often suffer from reduced nutrient density, the strategic integration of oral nutritional supplements is a practical necessity. Ultimately, preserving tongue pressure and overall physical function is vital for the maintenance of a regular diet, and a multifaceted intervention strategy is indispensable for the prevention of malnutrition in older adults.

Oral hypofunction can be identified through subtle changes observed in routine dental practice, including medical interviews, patient conversations, and oral examinations. Patient complaints such as “difficulty eating hard foods” and “prolonged mealtime,” as well as abnormalities during swallowing, poor oral hygiene, and changes in articulation or voice quality, serve as important indicators. Based on these findings, it is essential to conduct masticatory function assessments and evaluate swallowing function as needed to facilitate early detection.

In terms of management, prosthodontic treatment aimed at restoring both morphology and function forms the foundation, while device design and support for use should be tailored to the patient’s systemic condition and living environment. Furthermore, collaboration with multidisciplinary teams is crucial to maintain and improve the ability to eat orally, which represents a key role of prosthodontists in a super-aging society.

The palatal augmentation prosthesis (PAP) utilizes the thickness of the palatal surface to facilitate tongue movement. It improves bolus transport to the pharynx, shortens mealtime duration, increases tongue pressure, and reduces pharyngeal residue. PAP is indicated for impaired tongue movement caused by conditions such as postoperative tongue cancer, cerebrovascular disorders, neuromuscular diseases, and sarcopenia. In some cases, modifications—such as weight reduction of the prosthesis or combination with other devices—are required. A combined prosthesis integrating a palatal lift prosthesis (PLP) and a PAP has been developed to simultaneously improve velopharyngeal insufficiency and dysphagia. In addition, intraoral appliances are available to support the IOE method, a nutritional approach involving intermittent oral insertion of a feeding tube. Various intraoral prostheses, including dentures, can contribute to dysphagia rehabilitation. These devices not only compensate for missing teeth and impaired mastication but also assist in the appropriate intraoral transport of the bolus. This is a field in which the expertise of prosthodontists should be fully utilized. Since feeding and swallowing rehabilitation is often performed in hospital settings, the need for prosthodontic intervention in hospitals is substantial. This need is particularly high during the convalescent phase, and a multi-institutional study has shown a high frequency of removable prosthodontic treatment and involvement in swallowing rehabilitation. Within multidisciplinary collaboration, prosthodontics play an important role in improving swallowing function.

The concept of occlusal discomfort syndrome (ODS) was proposed by the Japan Prosthodontic Society in 2013. In October 2025, after searching and scrutinizing past key papers and thorough discussion among experts in the related fields, the “Clinical Guidelines for Diagnosis and Treatment of Occlusal Discomfort Syndrome (ODS): 2025” were published. In further clinical practices, it is desirable that clinicians refer to these clinical guidelines to perform appropriate examinations and diagnoses, and select reasonable treatment methods that do not induce iatrogenic conditions.

This paper presents the classification and modifying factors of ODS, and methods for treating patients based on the treatment flow chart, and outlines the key points of how dental clinicians had better utilize the guidelines when they encounter patients complaining of occlusal discomfort.

ISO standards constitute one of the major international standards responsible for industrial and service sectors other than electrical/electronic and communication/network technologies, and currently comprise more than 300 technical committees (TCs). Among them, ISO/TC 106 serves as the technical committee for dentistry, with a scope of standardization in oral health care that includes (i) terms and definitions, (ii) requirements and safety of dental products, and (iii) laboratory testing methods. Medical devices conforming to ISO standards, including dental materials, provide dental professionals and patients with reliable, safe and high-quality care. The proper use of these products is essential to ensure their intended performance. Furthermore, for Japanese products to expand into global markets, it is important that Japan actively contributes to international standardization activities, for example, by obtaining conveners of working groups (WGs), thereby enabling Japanese perspectives, such as those reflected in the JIS, to be incorporated into international standards.

In this report, the indications for rigid support in removable partial denture design were examined through clinical cases. In particular, cases classified as Area 4 of the occlusal triangle demonstrated a tendency for rigid support to be highly effective, as the number of abutment teeth and occlusal supports was limited, while a larger denture base area could be secured, resulting in a favorable balance between loading and supporting elements. In contrast, in cases with cross occlusion or strong occlusal forces, complications such as detachment of abutment components and loss of retention were more likely to occur, requiring symptomatic management. Furthermore, even among cases in Area 2 with similar patterns of tooth loss, differences in prognosis were observed depending on the direction of occlusal forces and the arrangement of abutment teeth. These findings suggest that, when determining the indications for rigid support, it is essential to control occlusal forces along the long axis of the abutment teeth, and that denture design should consider not only occlusal support but also the direction of force.

Successful prosthodontic treatment requires recovering both function and esthetics, and appropriate material selection is important for achieving these outcomes. From a functional perspective, dental materials must possess sufficient mechanical strength to withstand occlusal force. From an esthetic standpoint, harmony with adjacent teeth and surrounding soft tissues is important. Materials used in dentistry can be classified into polymers, ceramics, metals, and composite materials. Dentists must thoroughly understand the characteristics of each material and select the most appropriate option according to the clinical situation.

The aim of this article is to revisit the fundamental principles of dental materials and to provide a basis for considering material selection in future clinical practice.

Occlusal veneers have recently attracted attention as a new design of posterior restoration. This prosthetic approach is designed to restore and maintain long-term tooth substance loss and occlusal relationships by adhesively bonding a high-strength restorative material to an abutment tooth in which the occlusal surface has been minimally reduced. Occlusal veneers are indicated for cases with substantial occlusal tooth structure loss, teeth damaged by tooth wear, and cases requiring improvement of the occlusal relationship, and favorable clinical outcomes have been reported. The clinical requirements for this type of posterior veneer restoration include factors related to the restoration, adhesion, and abutment tooth preparation. In addition, the intraoral process of exploring and determining the final morphology of the restoration, in relation to these factors, is also considered important. This article discusses the clinical requirements and key considerations that are considered important when applying occlusal veneers in clinical practice.

While implants are an effective treatment for patients who have lost teeth, autologous bone grafting, which is considered the gold standard for bone regeneration in patients with insufficient bone volume, is highly invasive. In this context, jawbone regeneration therapy using a combination of cells and bone grafting materials is expected to become a next-generation bone regeneration therapy. Among various studies on bone regeneration that have used cells harvested from different tissues, we aim to develop jawbone regeneration therapy using autologous transplantation of mesenchymal stromal cells derived from jaw marrow. This article presents the results of research conducted with a comprehensive view of the entire treatment process, from cell collection to the production of the graft (bone regeneration agent), and aims to deepen understanding of the current state of bone regeneration medicine in the dental field.

In December 2025, three-dimensionally printed removable dentures were included in the Japanese national health insurance system, and CAD/CAM technology has been increasingly adopted in the field of removable prosthodontics. In addition, it has become possible to fabricate all components of removable partial dentures using CAD/CAM technology. However, the clinical application of intraoral scanners in partially edentulous cases remains limited because functional impressions of the residual ridge mucosa are required.

This article reviews the research and clinical efforts conducted in our department on removable partial dentures fabricated using CAD/CAM technology and discusses the current status and future challenges in applying digital dentistry to removable partial dentures.

To review dental sleep medicine, focuses on sleep physiology, common sleep disorders, and obstructive sleep apnea (OSA), in older adults and their management based on the literature. Sleep disturbances occurring more frequently in older adults. The prevalence of insomnia increases in older adults due to age-related changes in sleep physiology. OSA is more prevalent in older adults, and its effects on them are considered more substantial than those on younger adults. As older adults have comorbidities that affect sleep quality, dentists should consider the effects of sleep physiology and sleep disorders in these patients. OSA may decrease the quality of life and increase the risk of developing other diseases. The risks and benefits should be informed to the older adult patient when mandibular advancement device is indicated for OSA.

Purpose: To examine the association between the number of functional teeth and the dietary inflammatory index (DII) in middle-aged and older Japanese adults.

Methods: We analyzed data from 2,407 non-institutionalized Japanese individuals aged ≥45 years using the 2016 National Health and Nutrition Survey and Survey of Dental Diseases. Multiple linear regression analyses were performed to assess the association between functional teeth and DII scores, stratified by age group.

Results: In participants aged ≥75 years, the number of functional teeth was significantly inversely associated with the DII score (coefficient per one-tooth increase = −0.048; 95% confidence interval = −0.087 to −0.009). No significant association was observed in the 45–64 and 65–74 age groups.

Conclusions: A greater number of functional teeth was associated with a lower DII (indicating a more anti-inflammatory diet) in Japanese adults aged ≥75 years.

Purpose: Marginal bone loss (MBL) occurs in the periapical cervical bone after dental implant placement and abutment connection. MBL may not result in peri-implantitis; however, it is always accompanied by MBL. Recent studies have demonstrated that early MBL is a predictor of peri-implantitis. In this narrative review, we aimed to provide an evidence base for recommended treatment strategies for clinicians to prevent MBL.

Study Selection: We reviewed the recent literature and performed a narrative synthesis of the evidence, focusing on available systematic reviews and meta-analyses of implant marginal bone resorption.

Results: The available evidence indicates that certain biological, material, and technical factors can influence MBL and consequently dictate the risk of developing peri-implant disease in later years. The order of the impact of the strength of each factor is unknown. Current recommendations to prevent MBL include controlling patients’ smoking and hemoglobin A1c levels to sufficiently low levels before surgery and throughout their lifetime. Regarding the material, a platform-switching, conical-connecting implant system, and an abutment with a height of at least 2 mm should be selected. Placement should be performed using techniques that ensure sufficient soft tissue (keratinized gingival width > 2 mm, supracrestal tissue height > 3 mm), and non-undersized preparations in the cortical bone should be made with connected concave abutments during primary or secondary surgery. Patients should receive supportive peri-implant therapy during maintenance.

Conclusion: MBL development is multifactorial and can be reduced by considering the biological, material, and technical factors.

Purpose: This study aimed to identify factors influencing the survival and success rates of indirectly fabricated fiber post-based resin cores (FC) and metal cores (MC).

Methods: A prospective cohort study was conducted on patients at Hokkaido University Hospital, comparing the FC and MC groups. Kaplan–Meier analysis and the log-rank test were used for survival time analysis. Information on multiple factors, including remaining tooth structure height and final prosthetic material, was collected and analyzed using the Cox proportional hazards model. The cutoff values for remaining tooth structure height were determined by ROC curve analysis.

Results: A total of 233 teeth, comprising FC (199 teeth) and MC (34 teeth), were included. No significant difference was found between the two groups in survival and success rates five years after core placement. Maximum height of remaining tooth structure (MaxH) and the elastic modulus of the final prosthetic material were independently identified as significant prognostic factors for survival and success rates. Specifically, the prognosis worsened in cases where MaxH was 2.0 mm or less for survival rate and 2.5 mm or less for success rate, and where crowns made of materials with a low elastic modulus were used.

Discussion: Securing a MaxH above a certain threshold may have mitigated stress concentration on the core, thereby reducing the risk of decementation, fracture, and other complications. Furthermore, crowns made of materials with a high elastic modulus, such as metal or zirconia, suppressed excessive stress transmission to the root under occlusal force compared to those made of materials with a low elastic modulus, such as resin.

Conclusion: The study suggests there may be no difference in the five-year prognosis between FC and MC. The findings suggest that MaxH greater than 2.5 mm and the use of a dental crown with a high elastic modulus may be associated with a better prognosis of the core build-up.

Patient: A 58 year-old male patient presented with occlusal discomfort and pain along the lingual margin that appeared during the replacement of a crown following root canal treatment of his lower left second molar. Based on the medical interview, examination, and tests, he was diagnosed with type III occlusal discomfort syndrome (ODS). A case formulation (CF) was performed and functional analysis conducted. After two months of managing his symptoms, a trusting relationship was established between the patient and the dentists (or the healthcare providers). Subsequently, patient satisfaction was achieved, and subjective symptoms improved significantly. In this study, we created a simplified CF questionnaire by drawing up a list of questions designed for natural dialogue and short-term application, organized based on the patient’s own responses. This questionnaire was designed as a step to easily gather information on the three key CF factors: ① antecedent stimulus, ② response, and ③ outcome. It is structured to enable functional analysis (maintenance factors) to be derived from these elements. Finally, based on this patient’s CF, a simplified CF form was used to simulate this patient, evaluating its practicality and effectiveness in clinical settings.

Discussion: This simplified CF questionnaire clarifies the patient’s interpretive model, assists psychological assessment, and suggests the potential for functional analysis of contributing dental factors and influencing factors. Furthermore, use of the questionnaire is expected not only to enable more detailed psychological assessments of patients but also to contribute to building relationships with patients through communication with practitioners during interviews.

Conclusion: The CF creation method using a simplified CF questionnaire suggests that for general practitioners with limited time and skills, the questionnaire can clarify the psychological problems of ODS patients and may be useful for treatment and management.

Patient: A 72-year-old woman presented with the complaint of esthetic and masticatory dysfunction. The diagnosis was determined to be esthetic dissatisfaction and masticatory disorder due to reduction of occlusal vertical dimension and posterior tooth loss. Prosthodontic treatment involving increasing the occlusal vertical dimension was performed using fixed restorations and removable partial dentures.

Discussion: The final prosthesis was designed based on diagnostic waxing, and the intermaxillary relationship was explored using provisional restorations. After confirming satisfactory occlusion or esthetics, the morphology of the provisional restorations was transferred to the definitive prosthesis. As a result, high patient satisfaction was achieved in both masticatory function and esthetics.

Conclusion: Occlusal reconstruction by increasing the occlusal vertical dimension was performed in this case of esthetic and masticatory impairment due to decreased occlusal vertical dimension and posterior tooth loss, resulting in favorable outcomes for the chief complaints of esthetics and mastication.

Patient: A 64-year-old female first visited the Department of Crown and Bridge Prosthodontics with the chief complaint of difficulty eating due to mobility of a maxillary fixed partial denture. Partial retention loss of the retainer, secondary caries and mobility of the abutment teeth were observed. The patient was diagnosed with masticatory dysfunction caused by failure of the maxillary fixed partial denture associated with secondary caries, abutment tooth mobility, and retention loss of the retainer. Dental implant treatment was performed following the fabrication of a removable partial denture after extraction of hopeless teeth to achieve early functional recovery in unilateral distal-extension edentulism.

Discussion: Improvement in discomfort following dental implant treatment may contribute to an enhanced quality of eating, as demonstrated by quantitative evaluation of masticatory function.

Conclusion: Dental implant treatment in unilateral distal-extension edentulism improved masticatory function and oral health-related QOL.

Patient: The patient was a 73-year-old woman with the chief complaint of difficulty in mastication. Open bite associated with osteoarthritis of the temporomandibular joint (TMJ) and an unstable mandibular position were observed. To achieve uniform occlusal contacts and stabilization of the mandibular position, an oral appliance (OA) was applied. Functional recovery was achieved by using a definitive OA incorporating metal occlusal surfaces.

Discussion: In this case, functional recovery and long-term occlusal stabilization were achieved by using an OA to establish an appropriate mandibular position and incorporating metal occlusal surfaces with enhanced durability.

Conclusion: In this case of open bite associated with deformation of the TMJ, a definitive oral appliance with metal occlusal surfaces was applied. This treatment resulted in alleviation of symptoms and improvement in patient satisfaction.