The superior beneficial effects of exercise training versus hormone replacement therapy on skeletal muscle of ovariectomized rats

Previous studies have highlighted the positive effects of Estradiol (E2) replacement therapy and physical exercise on skeletal muscle during menopause. However, the comparison effects of exercise training (ET) and estradiol replacement therapy during menopause on skeletal muscle have not been investigated to date. This study aimed to compare the effects of endurance exercise training versus E2 replacement therapy on mitochondrial density, redox status, and inflammatory biomarkers in the skeletal muscle of ovariectomized rats. Thirty female Wistar rats (12-week-old) were randomly assigned into three groups: Untrained ovariectomized rats (UN-OVX, n = 10); untrained ovariectomized rats treated with estradiol replacement therapy (E2-OVX); and, trained ovariectomized rats (TR-OVX). After ovariectomy, the E2-OVX rats were treated subcutaneously with E2 (implanted Silastic® capsule containing 360 μg of 17β-estradiol/mL) while the TR-OVX group performed an exercise training protocol (50–70% of maximal running speed on a treadmill, 60 min/day, 5 days/week for 8 weeks). After euthanasia, the soleus muscle was processed for histological and biochemical evaluations. Only exercise prevented the reduction of maximal oxygen consumption and increased mechanical efficiency (ME). While mitochondrial muscle density, total antioxidant capacity (FRAP), catalase (CAT) activity, and interleukin 10 levels were higher in TR-OVX, only OVX-E2 presented higher CAT activity and lower interleukin 6 levels. Endurance exercise training compared with E2 replacement therapy maintains the aerobic capacity improving the ME of OVX rats. In addition, only endurance exercise training raises the skeletal muscle mitochondrial content and tends to balance the redox and inflammatory status in the skeletal muscle of OVX rats.

Association between mandibular third molar position and the occurrence of pericoronitis: A systematic review and meta-analysis

OBJECTIVE

The aim of this study was to investigate the association between mandibular third molar position and occurrence of pericoronitis.

DESIGN

The systematic review was performed based on PRISMA criteria (Prospero: CRD42018102835). The electronic search was performed in Medline, Virtual Health Library and Web of Science (until August 2018), without language restriction. Two researchers independently selected studies, extracted data, and assessed methodologic quality. Twenty-one articles were included in the review, comprising 6895 patients, with 1913 third mandibular molars being affected by pericoronitis. Ten studies were incuded in meta-analysis.

RESULTS

The third molar in vertical position of Winter is the one with the greatest chance of presenting pericoronitis, compared to the other positions, while the horizontal position decreases this chance. There was no significant difference in the chance of pericoronitis between positions I and II of Pell & Gregory (OR: 0.29; IC: 0.07-1.23, I² = 88%). Third molars classified in position A had greater chance of pericoronitis when compared to those in position B (OR: 7.13; IC: 1.31-38.74, I² = 93%). The vertical position of the lower third molar is more associated with the occurrence of pericoronitis when compared to the other positions.

CONCLUSIONS

Vertical position of the lower third molar is more associated with the occurrence of pericoronitis when compared to the other Winter' positions. Considering Pell and Gregory positions, position A had a greater chance of pericoronitis compared to position B. The prophylactic removal of lower third semi-erupted vertical molar or in position A is indicated to prevent pericoronitis.