Kyung Lhi Kang

Purpose This comprehensive systematic review examined the relationship between oral health and function and the incidence of physical disability and mortality. Methods Ovid-MEDLINE, Ovid-EMBASE, and the Cochrane Library were systematically searched, updated February 24th, 2025. Eligible studies included community-dwelling adults aged 50 years or older who underwent oral health-related assessments or interventions and reported outcomes related to physical disability or mortality. Random-effects meta-analysis was used to pool estimates, and subgroup analyses were performed by follow-up duration, study design, and participant age. Risk of bias was assessed using the Risk of Bias for Assessment tool for Nonrandomized Studies version 2.0. tool. Results Of the 32 articles included, 7 explored the association between oral health or function-related factors and physical disability, 22 investigated mortality outcomes, and 3 examined both outcomes. In total, 441,508 participants were included. Edentulism (OR, 1.73, 95% CI [1.48–2.01], I² = 0%) was significantly associated with physical disability. Regarding mortality, significant risk factors included reduced swallowing function (OR, 2.11, 95% CI [1.88–2.37], I² = 0%), oral frailty (OR, 2.06, 95% CI [1.87–2.27], I² = 0%), fewer than 20 teeth (OR, 2.04, 95% CI [1.67–2.49], I² = 89.7%), edentulism (OR, 1.87, 95% CI [1.35–2.59], I² = 97.0%), and chewing difficulty (OR, 1.77, 95% CI [1.08–2.91], I² = 95.9%). Conclusions This systematic review revealed that oral health and function, particularly, masticatory ability and the number of teeth, significantly contributed to physical disability and mortality in older adults.

Background: Oral health is closely linked to overall health conditions, particularly in older adults. Objectives: To explore the longitudinal effects of the number of remaining natural teeth on the incidence of falls and fractures among Korean community‐dwelling adults utilising the data from the Korean Frailty and Aging Cohort Study. Methods: Participants were categorised into five categories based on their number of teeth: 0–4, 5–10, 11–20, 21–25 and more than 25. The number of remaining natural teeth was recorded using dental panoramic radiographs. Diagnostic criteria proposed by the Asian Working Group on Sarcopenia were adopted to diagnose sarcopenia. The Activities‐Specific Balance Confidence (ABC) was utilised to evaluate balance confidence. Incidences of falls and fractures were assessed at the baseline, 2‐year and 4‐year follow‐ups. Results: Among the 1404 participants initially enrolled, 1275 remained at the 2‐year follow‐up and 1030 continued through the 4‐year follow‐up. Participants with fewer teeth at baseline had significantly higher rates of falls in the preceding year. Significant differences were observed in handgrip strength, walking speed, the 5‐time chair stand test, Short Physical Performance Battery score, appendicular skeletal muscle mass index and ABC scales. In the Cox regression model, fewer than five teeth were significantly associated with increased risk of falls (HR, 1.606; 95% CI, 1.008–2.557; p = 0.046) and fractures (HR, 4.322; 95% CI, 1.037–18.015; p = 0.044) within the 4‐year follow‐up, after adjustments for potential confounders. Conclusions: Having fewer than five dentitions in older adults is a significant predictor of falls and fall‐related fractures over 4 years.

Objectives: This study evaluated the impact of masticatory difficulty on the development and progression of malnutrition, frailty, sarcopenia, and disability in community‐dwelling adults, using data from the Korean Frailty and Aging Cohort Study.Methods: Participants were categorised by presence of masticatory difficulty. The Fried frailty phenotype, mini‐nutritional assessments, and diagnostic criteria proposed by Asian Working Group on Sarcopenia were adopted to diagnose frailty, malnutrition, and sarcopenia respectively. Physical disabilities were measured using the Korean activities of daily living (ADL) and Korean instrumental activities of daily living (IADL) scales.Results: A total of, 3010 participants were initially enrolled, 2864 participants remained in the study after 2 years, reflecting a 95.1% retention compliance. At baseline, the prevalence of frailty (28.0% vs. 18.1%), malnutrition (1.5% vs. 0.8%), IADL disability (10.1% vs. 7.7%), and ADL disability (10.8% vs. 8.0%) was higher among those experiencing masticatory difficulty than in those without. After 2 years, baseline masticatory difficulty was associated with the incidence of malnutrition (OR, 2.62; 95% CI, 0.99–6.90; p = 0.042) after full adjustment for confounders. However, no associations were found between baseline masticatory difficulty and the incidence of frailty, sarcopenia or physical disability over 2 years after adjustment. Additionally, masticatory difficulty did not affect the persistence or remission of malnutrition, frailty, sarcopenia, IADL disability, and ADL disability in individuals who already had these conditions at baseline.Conclusion: Restoring chewing function and masticatory satisfaction improves not only oral health but also contributes to overall health and promotes healthy aging in older individuals.

Htay PE, et al. J Adv Prosthodont. 2023 Oct;15(5):259-270. https://doi.org/10.4047/jap.2023.15.5.259

Objective: The purpose of this study was to investigate the curriculum of geriatric dentistry for undergraduates in Korean dental schools.Background: For development purposes, it was necessary to compare geriatric dentistry education programmes in South Korea to programmes in the United States and Europe.Methods: The most recent curriculum and related information on geriatric dentistry at the undergraduate level in all 11 dental schools in South Korea were collected by both official letter and e‐mail. A symposium for gathering expert opinions to improve geriatric dentistry education in South Korea was also held. The collected data were analysed, and the expert opinions at the symposium were summarised.Results: Six of 11 schools had a didactic course as compulsory and three schools as elective. The course was usually conducted as a form of integrated lectures, and the level of standardisation of lecture content was very low. There were no topics for older people who cannot access dental clinics due to functional frailty or disability. No dental school‐affiliated hospitals had an independent department for geriatric dentistry. No schools provided clinical teaching for geriatric dentistry. There were no outreach programmes for geriatric dentistry.Conclusions: The educational curriculum for geriatric dentistry in South Korea was insufficient to cope with social and demographic changes. Curriculum content should include clinical practice education and needs to be focused on frail and dependent older adult patients. An essential educational curriculum and core competency for geriatric dentistry should be prepared.

Maxillary sinus floor augmentation (MSFA) is widely used and considered a predictable procedure for implant placement. However, the influence of MSFA on implant survival and marginal bone loss (MBL) is still inconclusive. The purpose of this retrospective observational study is to evaluate the long-term genuine influence of MSFA on the survival and MBL of implants by comparing those with and without MSFA only in maxillary molars within the same patients. Thirty-eight patients (28 male and 10 female), with a total of 119 implants, received implants with and without MSFA, and were followed up for 5.8 to 22 years. Patient- and implant-related factors were assessed with a frailty model for implant survival and with generalized estimation equations (GEE) for MBL around the implant. No variables showed a statistical significance for implant failure in the frailty model. In GEE analysis for MBL, MSFA did not show any statistical significance. In conclusion, MSFA demonstrated no significant influence on implant failure and MBL in posterior maxilla in this study.

Objectives: To evaluate the long‐term influence of residual bone height (RBH), sinus membrane perforation and the presence of voids on the survival of implants placed simultaneously with lateral maxillary sinus floor augmentation (MSFA).Materials and Methods: A total of 207 patients (613 implants) who underwent MSFA from 1999 to 2003 and followed up until 2018 were included in this study. RBH and marginal bone loss were assessed using a series of panoramic and periapical radiographs. Cumulative survival rates (CSR) with log‐rank tests and hazard ratios of implant failure according to RBH, membrane perforation, and the presence of voids were assessed.Results: The overall 10‐year and 20‐year CSRs were 95% (95% CI: 84.95%–85.05%) and 85% (95% CI: 84.95%–85.05%), respectively. CSR was significantly higher for implants with ≥3 mm RBH (n = 260, 92.4%) than those with n = 353, 78.8%) (p = .002). CSR of non‐smoking group (n = 312, 90.0%) was higher than that of smoking group (n = 301, 77.1%) (p = .009). There was no significant difference in the hazard ratio of implant failure between the perforated membrane group (n = 245) and the non‐perforated group (n = 368). In two out of 11 patients with voids, the inflammation of peri‐implantitis progressed into voids, resulting in severe bone resorption.Conclusions: The survival of implants placed in <3 mm of RBH, even though it showed a lower CSR, could be considered acceptable. Neither sinus membrane perforation nor the presence of voids appeared to affect implant survival as long as supportive maintenance therapy with proper oral hygiene was provided.

According to the burst of aged people, researchers have focused on aging-related diseases. Cognitive impairment including Alzheimer's disease (AD), one of the representative diseases related to aging, has no treatment option until now. Recently, it has been revealed that systemic inflammation plays a fundamental role in the pathogenesis of AD. Previous studies have suggested the association between poor oral health and cognitive impairment. Poor oral health can cause dental caries, chronic periodontitis, multiple tooth loss, and poor chewing ability, etc. Especially, periodontitis is a well-known chronic inflammatory disease and affects cognitive impairment directly and indirectly by inflammatory products mediators. Therefore, reduction of pathogenic microbial burden and inflammatory products by treating periodontitis can be a therapeutic modality to prevent cognitive impairment or to slow down the progression of it. Future studies are necessary to elucidate the causal relations and plausible mechanisms between poor oral health and cognitive impairment.

Oxysterols, oxygenated by-products of cholesterol biosynthesis, play roles in various physiological and pathological systems. However, the effects of oxysterols on periodontal regeneration are unknown. This study investigated the effects of the specific oxysterol combination of 22(S)-hydroxycholesterol and 20(S)-hydroxycholesterol (SS) on the regeneration of periodontal tissues using in-vitro periodontal ligament stem cells (PDLSCs) and in-vivo models of alveolar bone defect. To evaluate the effects of the combined oxysterols on PDLSC biology, we studied the SS-induced osteogenic differentiation of PDLSCs by assessing alkaline phosphatase activity, intracellular calcium levels [Ca2+]i, matrix mineralization, and osteogenic marker mRNA expression and protein levels. To verify the effect of oxysterols on alveolar bone regeneration, we employed tooth extraction bone defect models. Oxysterols increased the osteogenic activity of PDLSCs compared with the control group. The expression of liver X receptor (LXR) α and β, the nuclear receptors for oxysterols, and their target gene, ATP-binding cassette transporter A1 (ABCA1), increased significantly during osteogenesis. Oxysterols also increased protein levels of the hedgehog (Hh) receptor Smo and the transcription factor Gli1. We further confirmed the reciprocal reaction between the LXRs and Hh signaling. Transfection of both LXRα and LXRβ siRNAs decreased Smo and Gli1 protein levels. In contrast, the inhibition of Hh signaling attenuated the LXRα and LXRβ protein levels. Subsequently, SS-induced osteogenic activity of PDLSCs was suppressed by the inhibition of LXRs or Hh signaling. The application of SS also enhanced bone formation in the defect sites of in-vivo models, showing equivalent efficacy to recombinant human bone morphogenetic protein-2. These findings suggest that a specific combination of oxysterols promoted periodontal regeneration by regulating PDLSC activity and alveolar bone regeneration.