Yoshifumi Toyoshita

Effect of Mastication on Functional Recoveries after Permanent Middle Cerebral Artery Occlusion in Rats

OBJECTIVESnWe evaluated whether solid feed is more effective for functional recoveries than liquid feed in rats with ischemic brain injury after permanent middle cerebral artery occlusion (MCAO).nnnMETHODSnA total of 36 male Wistar/ST rats were subjected to MCAO or sham surgery. After MCAO or sham surgery, all rats were provided liquid feed for 14 days. Then, all rats were divided into 3 groups: the solid feeding group, the liquid feeding group, and the solid feeding group of sham. Effect of mastication on functional recoveries after permanent MCAO in rats was evaluated by the limb placement test and Morris water maze (MWM) task.nnnRESULTSnAfter surgery, limb placement test scores were equal in both MCAO groups. In the acquisition trials of MWM task, statistically significant differences in escape latency were observed between the liquid feeding group and sham groups at all days, and between the solid feeding group and sham groups at days 3 and 4 of the trials. In the probe trial, statistically significant differences in time spent were observed between the liquid feeding group and sham group. On day 5 of acquisition trials, the time spent in the periphery of the pool in MWM task was significantly different among the 3 groups.nnnCONCLUSIONnThis study suggested that solid diet mastication could be effective for the rehabilitation of sensorimotor and learning/memory dysfunction induced by cerebral infarction.

Effect of wearing a palatal plate on swallowing function

PURPOSEnThe purpose of this study was to determine the effect of wearing a palatal plate on swallowing function.nnnMETHODSnThe subject group consisted of 10 healthy, fully dentate males. Two experimental palatal plates (EPP) were used in this study: one was 1.4mm thick (EPP1), and the other was 2.8mm thick (EPP2). Tongue movements and swallowing sounds were simultaneously recorded. The position of the surface of the tongue was recorded by using ultrasound diagnostic equipment in the sagittal plane. Swallowing tests were performed under three conditions: without EPP (WOE), with EPP1 (WP1), and with EPP2 (WP2). Swallowing index (SI) and tongue contact time (TCT) was calculated.nnnRESULTSnThe value of SI was lowest under WOE, and highest under WP2, with a statistically significant difference. There was no statistical significance, however, between SI under WOE and that under WP1. The value of TCT was longest under WOE, and shortest under WP2, with a statistically significant difference.nnnCONCLUSIONSnThis investigation suggests that the thickness of a palatal plate influences SI and TCT, which correlate with swallowing function.

Relationship between periodontal status and intellectual function among community-dwelling elderly persons.

OBJECTIVEnThe aim of this study was to indicate the relationship between periodontal status and intellectual function in the elderly.nnnBACKGROUNDnPeriodontal status has been shown to be related to demographic, socioeconomic, and psychological status. Intellectual function is a significant indicator of health status. Nevertheless, the relationship between periodontal status and intellectual function has not been elucidated in detail among the elderly.nnnMATERIALS AND METHODSnA total of 152 community-dwelling elderly persons, aged 70-74 years, were enrolled in the study. Periodontal status was evaluated using the WHO Community Periodontal Index of Treatment Needs (CPITN). Intellectual function was assessed by four neuropsychological tests: Ravens Coloured Progressive Matrices (RCPM) test, the Verbal Paired Associates 1 (VerPA) task and the Visual Paired Associates 1 (VirPA) task, extracted from the Wechsler Memory Scale Revised Edition, and the Block Design subtest, extracted from the Wechsler Adult Intelligence Scales, Third Edition. Correlations between CPITN and each test were examined using Spearman rank correlation coefficients. The ordinal regression model was constructed with CPITN as the dependent variable and neuropsychological test as the principal independent variable to adjust for demographic factors, general health, lifestyle and oral health behaviour.nnnRESULTSnSignificant correlations were found between the RCPM test, the VerPA task, the Visual Paired Associates 1 and CPITN. In the ordinal regression model, CPITN was significantly related to measures of RCPM after adjusting for demographic factors, general health status, lifestyle and oral health behaviour.nnnCONCLUSIONnIntellectual function is considered a significant indicator of periodontal status among community-dwelling elderly persons.