Pre-Adolescent Diet Normalization Restores Cognitive Function in Young Mice.

Mastication is a fundamental function critical for human health. Controlled by the central nervous system (CNS), it influences CNS development and function. A poor masticatory performance causes cognitive dysfunction in both older adults and children. Improving mastication may prevent cognitive decline. However, no study has determined the period of masticatory dysfunction that impairs children's later acquisition of cognitive function. Herein, we developed an animal model wherein a soft diet was switched to a normal diet at early and late time points in young mice. We aimed to investigate the impact of restored mastication on learning and memory function. Behavioral studies were conducted to evaluate learning and memory. Micro-CT was used to evaluate orofacial structural differences, while histological and biochemical approaches were employed to assess differences in the hippocampal morphology and function. Correction to a hard-textured diet before adolescence restored mastication and cognitive function through the stimulation of neurogenesis, extracellular signal-regulated kinases, the cyclic adenosine monophosphate-response element-binding protein pathway, and the brain-derived neurotrophic factor, tyrosine receptor B. In contrast, post-adolescent diet normalization failed to rescue full mastication and led to impaired cognitive function, neuronal loss, and decreased hippocampal neurogenesis. These findings revealed a functional linkage between the masticatory and cognitive function in mice during the juvenile to adolescent period, highlighting the need for adequate food texture and early intervention for mastication-related cognitive impairment in children.

The impact of rotating work schedules, chronotype, and restless legs syndrome/Willis-Ekbom disease on sleep quality among female hospital nurses and midwives: A cross-sectional survey.

BACKGROUND: Decreases in subjective sleep quality are prevalent among nurses and midwives engaged in rotating shift work. OBJECTIVES: The present study aimed to examine the relationship between differences in work schedules and subjective sleep quality among female nursing staff. DESIGN: A cross-sectional survey design was used for descriptive and logistic regression analyses. Data collection was conducted from December 2016 to September 2017. SETTINGS: Participants were recruited from five regional core hospitals in Japan. PARTICIPANTS: A total of 1253 nurses and midwives were included in the final analysis. METHODS: Subjective sleep quality was assessed using the Japanese version of the Pittsburgh Sleep Quality Index. Chronotype and social jet lag were calculated for both work day and work-free day. Symptoms related to restless legs syndrome/Willis-Ekbom disease were assessed using the Japanese version of the Cambridge-Hopkins questionnaire short form 13. Participants with the urge to move their legs, though not fulfilling the restless legs syndrome/Willis-Ekbom disease criteria, were classified as having leg motor restlessness. Logistic regression analyses for poor sleep were adjusted for age, body mass index, smoking, drinking, menstruation status, the presence of premenstrual syndrome, and the presence of a spouse. RESULTS: Rates of poor sleep (Pittsburgh Sleep Quality Index score ≥6) among those working, day shifts, rotating 12.5 hour night shifts, rotating 16 hour night shifts, and three-shift rotations were 41.2%, 51.1%, 44.5%, and 60.4%, respectively. Approximately 40% of three-shift rotation workers experienced difficulty initiating sleep. Shift workers tended to exhibit evening chronotype, delayed sleep phase, and high social jet lag. The prevalence of restless legs syndrome/Willis-Ekbom disease was 2.5%. Leg motor restlessness was observed in. 15.5% of participants. The adjusted odds ratios (95% confidence interval) of three-shift work (vs. day shift), evening chronotype (vs. morning chronotype), and the presence of leg motor restlessness (vs. no leg motor restlessness) for those with poor sleep were 2.20 (1.47-3.30), 1.95 (1.29-2.94), and 1.66 (1.15-2.39), respectively. CONCLUSIONS: Regardless of the working schedules, rates of poor sleep were high among female hospital nurses and midwives. Our findings suggest that poor sleep quality is influenced by three-shift rotation, the evening chronotype, and leg motor restlessness.

Anterior open bite due to temporomandibular joint osteoarthrosis with muscle dysfunction treated with temporary anchorage devices.

Skeletal Class II high-angle open bite is often accompanied by osteoarthrosis of the temporomandibular joint (TMJ-OA). This type of malocclusion is challenging to correct, and it has been reported that patients with TMJ-OA treated with orthognathic surgery often experience skeletal relapse and a poor prognosis. This case report describes the treatment of a 25-year-old woman with retrognathia and TMJ-OA, whose masseter and temporal muscle activities were weak. Temporary anchorage devices were placed in the maxilla and the mandible, and the first molars were intruded. We used improved superelastic nickel-titanium alloy wires with tip-back bends for both arches, and intermaxillary elastics were used to upright the molars. After treatment, intrusion of the maxillary and mandibular first molars, counterclockwise rotation of the mandible, and improvement of occlusion and profile had been achieved. The patient's condyles were repositioned into ideal positions, and masticatory muscle activity was augmented and balanced. After 2 years of retention, the mandibular and condylar positions were stable, and acceptable occlusion was maintained without recurrence of TMJ symptoms; harmonious activity of the masticatory muscles was retained. The findings of this case report suggest that molar intrusion using temporary anchorage devices for a patient with severe anterior open bite and TMJ-OA may be useful for improving stomatognathic function, occlusion, and facial esthetics.