Purpose: This study was aimed to clarify the characteristic clinical findings of sleep bruxism by comparing various accumulated clinical findings of patients with sleep bruxism (SB) with those of temporomandibular disorders (TMD) patients and those of obstructive sleep apnea syndrome (OSAS) patients.
Method: Findings of investigated items, i.e., report of SB by someone other than patients, awareness of teeth grinding sound, awareness of clenching, jaw dullness/pain, tooth pain, headache, sleepiness, feeling of deep sleep, awareness of mental stress, changes in living environment, tooth wear, tenderness and tooth impression on mucosa, were compared among SB, TMD and OSAS groups. Furthermore, binomial logistic regression analysis was performed by using presence of diagnosis of SB, presence of bruxism pointed out by a dentist, presence of TMD diagnosis and presence of OSAS diagnosis as objective variables.
Result: Pointing out by family, awareness of bruxism sound, jaw dullness when waking up, tooth wear and gender (female) showed a positive relation with SB diagnosis significantly. Items used in the clinical diagnostic criteria for SB didn’t show a significant relationship with the presence of pointing out of SB by dentists. Temporomandibular joint and masticatory muscle tenderness and gender (female) showed a positive relation with TMD diagnosis significantly. Daytime drowsiness, age and gender (male) showed a positive relation with OSAS diagnosis significantly. Among the finding items, gender (female) was the only item that showed an association with both SB and TMD. However, the rate of gender was significantly different between SB and TMD. Conclusion: In the present study, there was no clinical finding characteristic of SB which was highly common among SB, TMD and OSAS. It was suggested that diagnosis of SB based on clinical findings should be performed independently from TMD and OSAS.

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Nutritional intake is a crucial determinant of health and well-being in older adults. Undernutrition is linked to an increased risk of frailty and sarcopenia, both of which are associated with higher mortality risk. When considering nutrition, the concept of “comprehensive eating ability” has gained attention, encompassing not only chewing capability but also a broader range of factors, such as food selection, satisfaction with the dining experience, and meal enjoyment. This study examined the relationship between “comprehensive eating ability” and factors like occlusion and swallowing function in older adults, using data from a cohort study conducted in a mountainous region of Japan. Occlusal force, occlusal contact area, anterior-posterior and horizontal occlusal balance, a repeated salivary swallow test (RSST), and a 10-item questionnaire to assess “comprehensive eating ability” were measured in a total of 63 older participants from the Mima-SONGS study. Results showed that specific masticatory behaviors, such as “chewing slowly” and “eating with fewer foods”, received relatively low ratings. In contrast, general eating behaviors, like “eating with fluids” and “familiarity with a variety of foods, ” were rated more positively. The findings suggest that older adults with lower bite strength are more inclined to prepare food in simpler forms and chew more slowly. Additionally, participants with more anterior occlusal balance perceived it as “easier to eat and cook. ” As a conclusion, the older adults adjust their eating behavior according to their own oral functional status.

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A 72-year-old woman visited our hospital complaining of pain when chewing. She had been wearing upper and lower complete dentures 3 months before, but she had difficulty chewing from the beginning, and repeated adjustments did not improve her condition. The upper and lower dentures were fitted to the respective alveolar ridges, but redness was observed in the mucosa beneath the mandibular molars and pain was caused during chewing. Because of a suspicion of incorrect mandibular position, the patient was asked to quietly close the mouth while wearing dentures, which led to the mandible being guided backwards. Therefore, it was thought that the cause was a misalignment of the mandible due to the forward displacement of the mandible during the bite registration. A bite registration was taken with the patient's mouth quietly closed using the existing dentures, and the upper and lower dentures were removed as a unit. The upper and lower dentures were scanned using a lab scanner, the lower denture was created using a 3D printer, and a new denture was produced to correct the misalignment of the mandibular position. After fitting a new denture that corrected the mandibular position and adjusting the fit of the inner surface of the denture and the occlusion, the redness and pain in the mucosa disappeared and the masticatory performance test score improved. The application of digital technology has made it possible to fabricate a new denture only with bite taking, which is thought to have contributed to reducing the psychological and physical burden on the patient.

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