吉田 光由

BACKGROUND: Measurement of bite force is important for understanding oral function. OBJECTIVES: We aimed to clarify the relationship between the values of a newly developed one-sided measurement-type bite force meter (OBM-01 Prototype, JMS, Hiroshima) and those of a full-dentition bite force meter (Dental Prescale II, GC, Tokyo). Furthermore, we examined the intra- and inter-rater reliability (intraclass correlation coefficients; ICCs) using the OBM-01 Prototype. METHODS: Three studies were conducted. The first examined the ICC of the OBM-01 Prototype in 22 healthy adults; the second evaluated the relationship between the habitual chewing side bite force measured by the OBM-01 Prototype in 343 older adults, with or without dentures; and the third assessed the relationship between measurements obtained from the OBM-01 Prototype and Dental Prescale II in 201 older adults. RESULTS: The ICCs showed good reliability. A moderate correlation was observed between the OBM-01 Prototype and Dental Prescale II, regardless of sex or denture presence on the habitual chewing side (Spearman's Rho; men 0.65, women 0.51 in non-denture group, men 0.51, women 0.55 in denture group). In both men and women, compared with the non-habitual chewing side, the habitual chewing side had significantly greater bite force. Additionally, the bite forces on the habitual and non-habitual chewing sides were strongly and positively correlated with the total bite force measured using the Dental Prescale II (Spearman's Rho; men: habitual 0.676, non-habitual 0.746, women: habitual 0.705, non-habitual 0.640). CONCLUSIONS: A correlation was observed between the measurements obtained from the OBM-01 Prototype and Dental Prescale II.

Background/Objectives: Providing an appropriate diet to older adults with dysphagia can prevent aspiration, choking, and nutritional deficiencies and help preserve their quality of life. Therefore, assessments for determining the appropriateness of food types are required. This multicenter study aimed to determine the reliability and validity of the Meal Rounds Observation Form (MROF), which was developed to identify food forms that can be safely consumed by older adults with dysphagia. Methods: We analyzed 532 food-texture observations obtained from 155 participants (114 men and 41 women). The reliability and validity of the MROF were compared with those of videofluoroscopic (VF) or videoendoscopic (VE) examinations of swallowing. Results: The food-form categories were water (108 pairs), 0j (54 pairs), 0t (118 pairs), 1j (20 pairs), 2-1 (28 pairs), 2-2 (37 pairs), 3 (68 pairs), 4 (67 pairs), and normal food (32 pairs) based on JDD 2021 codes. The AUC was lowest for the water (0.568) category and highest for food forms requiring chewing, such as those of the 4 and normal food (0.678) categories. The sensitivity and specificity of the Gugging Swallowing Screen were 60.1% and 69.1%, respectively (p < 0.001). The agreement between the Gugging Swallowing Screen and the MROF evaluation for food types requiring mastication was 73.2%. Logistic regression analysis revealed asymmetric movement of the corners of the mouth and coughing as important indicators when evaluating food types requiring mastication. Conclusions: The MROF is useful for determining food intake safety when VF or VE tests cannot be performed in medical and nursing care settings and can guide clinical decision-making. However, caution is required in applying it clinically because of its relatively low specificity.

Objectives: Malnutrition can influence perioperative complications and long-term survival in patients with gastrointestinal (GI) cancers. Oral functional decline is associated with decreased food intake, and a reduced number of remaining teeth contributes to malnutrition. However, the impact of preoperative oral conditions on perioperative nutritional status remains unclear. This study investigated the relationship between the number of remaining teeth and the prognostic nutritional index (PNI) in patients undergoing surgery for gastrointestinal malignancies. Methods: In total, 178 patients who underwent gastrointestinal surgery with perioperative oral management at our hospital between January and December 2022 were retrospectively analyzed. Data, including age, sex, tumor site, number of remaining teeth, blood test results, skeletal muscle index, and body mass index (BMI), were extracted from electronic medical records. The PNI and CRP-albumin ratio (CAR) were calculated. Correlations between the number of remaining teeth and nutritional indicators were examined. Results: The number of remaining teeth showed a significant correlation with the PNI in the upper gastrointestinal group (r = 0.336, p = 0.015) and with BMI in the hepatobiliary-pancreatic group (r = -0.519, p = 0.001), after adjusting for age using partial correlation analysis. No significant correlations were observed in the lower GI group. Conclusions: Among patients with upper GI cancer, a lower number of remaining teeth was associated with a lower PNI, influencing postoperative outcomes. Impaired oral function may affect the prognosis of patients with upper GI tumors, emphasizing the need for careful, comprehensive nutritional and oral management as part of perioperative support.

BACKGROUND: Muscle quality, along with muscle mass, deteriorates with disuse, ageing and various disorders, underscoring the need to evaluate the internal characteristics of swallowing-related muscles. Previous studies have reported an association between oral function and echo intensity (EI), but the association between oral function and the stiffness of swallowing-related muscles, as well as the degree of this association, remains insufficiently understood. OBJECTIVE: To examine the association between oral function and the intramuscular characteristics of swallowing-related muscles, focusing on muscle stiffness. MATERIALS AND METHODS: A total of 196 older women (78.1 ± 5.2 years) participated in a physical fitness measurement session in this cross-sectional study. The stiffness and EI of the geniohyoid muscle (GHM) were measured, and oral function was evaluated using oral diadochokinesis (ODK; /pa/, /ta/, /ka/) and tongue pressure. Multiple regression analysis was used to investigate the association between oral function, stiffness and EI. By standardising the variables, we evaluated these associations independently of the units. RESULTS: ODK, /pa/ (β = -0.144, p = 0.002), /ta/ (β = -0.134, p = 0.011) and /ka/ (β = -0.093, p = 0.043) showed a negative association with GHM stiffness. After standardisation, the association between ODK (/pa/, /ta/, /ka/) and GHM stiffness (β: -0.144, -0.134, -0.093) was comparable to that between ODK and EI (β: -0.008, -0.148, -0.075). CONCLUSION: GHM stiffness was associated with oral motor function in older women living in the community. Assessing the stiffness of swallowing-related muscles could be important for evaluating oral function to a degree comparable to EI.