Influence of Protrusive Functions on Electromyographic Activity of Elevator Muscles

Several authors have studied the influence of varied centric and eccentric occlusal relationships on neuromusculature. However, the authors know of no research comparing the effects on mandibular muscle activity of different occlusal functions in protrusive guidance.

This study used an orthopedic splint to compare the influence exerted by different protrusive occlusal functions on elevator muscle activity. The paper also explains the neuromusculature involved and quantifies the activity in comparison with registration in the mandibular centric position.     

Longitudinal evaluation of the impact of dental caries treatment on oral health‐related quality of life among schoolchildren

This study aimed to evaluate the impact of dental caries treatment on oral health‐related quality of life (OHRQoL) among schoolchildren and the responsiveness of the Child Perceptions Questionnaire (CPQ_8‐10) instrument. Brazilian schoolchildren, 8–10 yr of age, were randomly selected and assigned to two groups – dental caries treatment (DCT) and caries‐free (CF) – according to their caries experience [decayed, missing, or filled primary teeth (dmft) and decayed, missing or filled secondary teeth (DMFT) values of ≥0]. The CPQ_8‐10 instrument was administered at baseline and at 4 wk of follow‐up (i.e. 4 wk after completion of dental treatment). In the DCT group, increases in CPQ_8‐10 scores were observed between the baseline and follow‐up results. However, longitudinal evaluation of the CF group demonstrated no statistically significant difference in CPQ_8‐10 scores. Responsiveness of the CPQ_8‐10 instrument (magnitude of change in CPQ_8‐10 scores) in the DCT group was greater (effect size >0.7) than in the CF group. The findings of this study show that dental caries treatment has an important impact on OHRQoL of children. The CPQ_8‐10 was considered an acceptable instrument for longitudinal measurement of changes in OHRQoL.     

Chronic sleep loss disrupts blood–testis and blood–epididymis barriers,and reduces male fertility

Sleep loss increases blood–brain barrier permeability. As the blood–brain barrier and the blood–tissue barriers in the reproductive tract (blood–testis and blood–epididymis barriers) share common characteristics, we hypothesized that sleep restriction may also modify their barrier function. Previous reports showed that sleep loss decreased sperm viability and progressive fast mobility, which may be a consequence of altered blood–testis and blood–epididymis barrier. Therefore, we quantified changes in blood–testis and blood–epididymis barrier after sleep loss and related them to male fertility. Adult male Wistar rats were sleep restricted using the multiple‐platform technique in a protocol of 20 hr daily sleep deprivation plus 4 hr of sleep recovery in the home‐cage. At the 10th day, barrier permeability assays were performed with Na‐fluorescein, 10 kDa Cascade blue‐dextrans and Evans blue, and the expression of tight junction proteins, actin and androgen receptor was quantified. At the 10th day of sleep restriction and after sleep recovery days 1–7, males were placed with sexually receptive females, sexual behaviour was tested, and the percentage of pregnancies was calculated. Sleep restriction increased the barrier permeability to low‐ and high‐molecular‐weight tracers, and decreased the expression of tight junction proteins, actin and androgen receptor. Concomitantly, sleep restriction reduced the percentage of ejaculating males and the number of pregnancies. Sleep recovery for 2–3 days progressively re‐established fertility, as indicated by a higher percentage of ejaculating males and impregnated females. In conclusion, chronic sleep loss alters fertility concomitantly with the disruption of the blood–tissue barriers at the reproductive tract, the mechanism involves androgen signalling.