Malocclusion of Molar Teeth Is Associated with Activities of Daily Living Loss and Delirium in Elderly Critically Ill Older Patients

Malocclusion Worsens Survival Following Sepsis Due to the Disruption of Innate and Acquired Immunity

Sepsis is a severe condition with high mortality, in which immune dysfunction plays a critical role. Poor oral health has been linked to frailty, but its impact on sepsis outcomes remains unclear. Therefore, we used a mouse model of malocclusion and sepsis to investigate how tooth loss affects immune responses during sepsis. Adult male C57BL/6 mice were divided into four groups: Control, Malocclusion (Mal), Sepsis (CS), and Malocclusion with Sepsis (Mal + CS). Malocclusion was induced by tooth extraction, and sepsis was induced using cecal slurry injection. We assessed survival rates, immune cell counts, and biochemical markers. The Mal + CS group exhibited significantly lower survival rates and greater weight loss compared to the CS group. The flow cytometry showed reduced neutrophils, monocytes, and T cells in the Mal + CS group. Elevated ALT and AST levels indicated liver damage. No significant differences in bacterial loads were observed, but immune suppression was exacerbated in the Mal + CS group. Malocclusion worsens sepsis outcomes by impairing both innate and adaptive immune responses. These findings emphasize the importance of oral health in improving sepsis prognosis and immune function during critical illnesses.

Relationship between the number of remaining teeth and postoperative delirium in patients after gastrointestinal surgery

AIM

Malnutrition is reportedly associated with the development of delirium. As dental health is essential for nutritional intake, tooth loss may be a risk factor for the development of delirium. This study aimed to investigate the relationship between postoperative delirium and the number of remaining teeth in patients undergoing gastrointestinal surgery.

METHODS

This retrospective study included 453 consecutive patients aged ≥65 years who underwent programmed gastrointestinal cancer surgery under general anesthesia at the Department of Surgery, Fujita Health University Hospital, between January 2022 and December 2022. Background factors were prepared between the participants with and without dental intervention. In the dental intervention group, associations between background and surgical factors and the presence of postoperative delirium were explored. Factors with significant associations with postoperative delirium in the univariate analysis were subjected to logistic regression analysis to determine their association with the number of remaining teeth.

RESULTS

Overall, 189 participants underwent postoperative management. They had a significantly lower Prognostic Nutritional Index and higher cognitive decline than the 264 patients who underwent no dental intervention during this period. However, no significant difference was observed in the incidence of postoperative delirium between the two groups. In the dental intervention group, logistic regression analyses revealed that postoperative complications and the number of remaining teeth were significantly associated with postoperative delirium development.

CONCLUSION

The results revealed that a decrease in the number of remaining teeth is associated with postoperative delirium. The cause of this is not clear, but it is thought to be related to brain fragility. Geriatr Gerontol Int 2025; 25: 90-95.

Decrease in Tongue Pressure in Frail Patients in the Sitting Position and Its Alleviation by Plantar Grounding

PURPOSE

The deterioration of oral function has received much attention, also being referred to as "Oral frailty". This study evaluated the change in tongue pressure, one of the objective items of oral frailty, to examine the relationship between body position and tongue pressure.

METHODS

This study was a prospective, observational study conducted in a single center. The participants were categorized by their Clinical Frailty Scale (CFS) scores. Tongue pressure was measured in the following positions: dorsal, sitting, and sitting with plantar grounding. Differences in tongue pressure between CFS and between body positions were statistically analyzed.

RESULTS

A significant decrease in tongue pressure was demonstrated in CFS4 compared to CFS3. Furthermore, in CFS5 and CFS6, tongue pressure decreased in the sitting position compared to that in the dorsal position, and tongue pressure recovered to the dorsal level with plantar grounding.

CONCLUSIONS

Tongue pressure decreased with the progression of frailty. It was decreased by sitting, and this decrease was alleviated by plantar grounding.

Association of the Number of Teeth With Physical Function and Length of Hospital Stay After Hip Fracture Surgery: A Prospective Observational Study at a Tertiary Hospital in Japan

OBJECTIVES

Although lower-extremity muscle strength is associated with physical function, there are challenges in assessing the muscle strength of patients after hip surgery due to pain or limited cognitive function. The number of teeth is a characteristic that can be easily examined. Although the relationship between the number of teeth and physical function has been reported in recent years, there are no reports examining the relationship with prognosis in patients with hip fractures. Therefore, this study aimed to investigate the relationship between the number of teeth and physical function and length of hospital stay after hip fracture surgery and to evaluate the predictive efficacy of the number of teeth on postoperative prognosis.

METHODS

This prospective cohort study was conducted in a tertiary clinical care facility. Patients aged ≥65 years who underwent hip surgery were included. A total of 101 patients (mean age: 85.1±8.0 years) were included. The factor analyzed was the number of teeth at admission. Patients were divided into two groups according to the number of teeth: those with ≥20 and those with ≤19 teeth. The outcomes were knee extension muscle strength-to-weight ratio at two weeks postoperatively and the length of hospital stay. A multiple regression analysis was performed to determine the association between the two groups.

RESULTS

Of 101 patients, 79 (78.2%) had ≤19 teeth, whereas 22 (21.8%) had ≥20 teeth. The mean muscle strength-to-weight ratio and length of hospital stay were 0.26±0.11 kgf/kg and 57.5±31.4 days, respectively. Multiple regression analysis revealed that the number of teeth was significantly associated with the muscle strength-to-weight ratio (β=-0.26, p=0.04) but not with the duration of hospitalization (β=0.17, p=0.09).

CONCLUSIONS

We suggest that assessment of the number of teeth at admission may be a useful predictor of patient physical function.

Sepsis causes neutrophil infiltration in muscle leading to muscle atrophy and weakness in mice

BACKGROUND

Sepsis-induced muscle atrophy leads to prolonged physical dysfunction. Although the interaction of muscle atrophy and macrophage has been reported in sepsis, the role of neutrophils in muscle atrophy has not been thoroughly investigated. This study sought to investigate the long-term changes in muscle-localized neutrophils after sepsis induction and their possible role in sepsis.

METHODS

Sepsis was induced in seven-week-old male C57BL/6J mice 8-12 (cecal slurry [CS] model) via intraperitoneal injection of 1 mg/g cecal slurry. The percentage change in body weight and grip strength was evaluated. The tibialis anterior muscles were dissected for microscopic examination of the cross-sectional area of myofibers or Fluorescence-activated cell sorting (FACS) analysis of immune cells. These changes were evaluated in the following conditions: (1) Longitudinal change until day 61, (2) CS concentration-dependent change on day 14 at the low (0.3 mg/g), middle (1.0 mg/g), and high (2.0 mg/g) concentrations, and (3) CS mice on day 14 treated with an anti-Ly6G antibody that depletes neutrophils.

RESULTS

Body weight and grip strength were significantly lower in the CS model until day 61 (body weight: 123.1% ± 1.8% vs. 130.3% ± 2.5%, p = 0.04; grip strength: 104.5% ± 3.8% vs. 119.3% ± 5.3%, p = 0.04). Likewise, cross-sectional muscle area gradually decreased until day 61 from the CS induction (895.6 [606.0-1304.9] μm2 vs. 718.8 [536.2-937.0] μm2, p < 0.01). The number of muscle-localized neutrophils increased from 2.3 ± 0.6 cell/mg on day 0 to 22.2 ± 13.0 cell/mg on day 14, and decreased thereafter. In terms of CS concentration-dependent change, cross-sectional area was smaller (484.4 ± 221.2 vs. 825.8 ± 436.2 μm2 [p < 0.001]) and grip strength was lower (71.4% ± 12.8% vs. 116.3% ± 7.4%, p = 0.01) in the CS High group compared with the control, with increased neutrophils (p = 0.03). Ly6G-depleted mice demonstrated significant increase of muscle cross-sectional area and grip strength compared with control mice (p < 0.01).

CONCLUSIONS

Sepsis causes infiltration of neutrophils in muscles, leading to muscle atrophy and weakness. Depletion of neutrophils in muscle reverses sepsis-induced muscle atrophy and weakness. These results suggest that neutrophils may play a critical role in sepsis-induced muscle atrophy and weakness.