Tooth crown mesiodistal measurements for the determination of sexual dimorphism across a range of populations: A systematic review and meta-analysis

OBJECTIVE

The aim of this study was to determine whether the tooth crown sexual dimorphism pattern reported in previous small studies can be generalized for a broader range of populations.

LITERATURE REVIEW

A systematic literature review was performed by two independent examiners. The following databases were searched from October 2015 to July 2016: PubMed, Scopus, Lilacs, ScienceDirect, Medline, and Cochrane Reviews. No language restrictions were applied to the search.

SELECTION CRITERIA

The inclusion criteria comprised original studies investigating mesiodistal permanent teeth that reported the sample population and standard deviation. All right-sided teeth, except the third molars, were measured and separated by sex in the included studies. Thirty-one studies were included in the quantitative data synthesis and meta-analysis. Studies of non-human teeth, skeletal remains, or an overly specific study population were excluded.

MAIN RESULTS

Thirty-one trials, involving 6481 participants, provided data for the meta-analysis of teeth. Sexual dimorphism in mesiodistal crowns was found in all teeth across a range of populations, principally in lower canines (5.73%) and maxillary canines (4.72%), followed by the lower second molars (3.54%) and upper second molars(3.20%), and finally in the lower first molars(3.14%) and upper first molars(2.64%).

CONCLUSIONS

A small degree of sexual dimorphism exists in all human teeth. Second molars and canines show the greatest sexual dimorphism. Additionally, smaller racial differences are present in mesiodistal crowns among groups living in different geographic areas; however, it is not possible to establish a single value applicable for all populations.

Effect of forest fragmentation on microsporogenesis and pollen viability in Eugenia uniflora, a tree native to the Atlantic Forest

Habitat fragmentation, caused by the expansion of agriculture in natural areas, may be one of the strongest impacts humans have on the ecosystem. These changes can decrease the number of individuals in a population, leading to endogamy. In allogamous species, endogamy can have a negative effect on reproductive capacity. In this study, we analyzed the effects of forest fragmentation on microsporogenesis and pollen viability in Eugenia uniflora L., a tree species native to the Atlantic Forest. We analyzed 4 populations, 3 of which were connected by forest corridors and 1 of which was isolated by agricultural fields on all sides. For microsporogenesis analysis, 9000 meiocytes representing all stages of meiosis were evaluated. To perform the pollen viability test, we evaluated 152,000 pollen grains. Microsporogenesis was stable in plants from populations that were connected by forest corridors (abnormalities, less than 6%), while microsporogenesis in plants from the isolated population showed a higher level of abnormalities (13-29%). Average pollen viability was found to be more than 93% in the non-isolated populations and 82.62% in the isolated population. The χ(2) test showed that, in the isolated population, the meiotic index was significantly lower than that in the non-isolated populations (P = 0.03). The analysis of variance for the percentage of viable pollen grains confirmed the significant difference between the isolated and non-isolated populations. Our data show that forest fragmentation has a direct effect on microsporogenesis and pollen viability in E. uniflora and can directly influence the reproductive capacity of isolated populations of this species.

Aortic stenosis. Gender influence on left ventricular geometry and function in patients under 70 years of age

OBJECTIVE

To verify if adaptive left ventricle (LV) characteristics are also present in individuals under 70 years of age with severe aortic stenosis (AS).

METHODS

The study comprised 40 consecutive patients under 70 years of age with AS and no associated coronary artery disease, referred for valve surgery. Out of the 40 patients, 22 were men and 18 women, and the mean age was 49.8 +/- 14.3 years. Cardiac symptoms, presence of systemic hypertension (SH), functional class according to the New York Heart Association (NYHA), and valve lesion etiology were considered. LV cavity dimensions, ejection fraction (EF), fractional shortening (FS), mass (MS), and relative diastolic thickness (RDT) were examined by Doppler echocardiography.

RESULTS

Fourteen (63.6%) men and 11 (61.6%) women were classified as NYHA class III/IV (p = 0.70). There was no difference in the frequency of angina, syncope or dyspnea between genders. The incidence of SH was greater in women than in men (10 versus 2, p = 0.0044). Women had a smaller LV end-diastolic diameter index (32.1 +/- 6.5 x 36.5 +/- 5.3 mm/m2, p = 0.027), LV end-systolic diameter index (19.9 +/- 5.9 x 26.5 +/- 6.4 mm/m2, p = 0.0022) and LV mass index (MS) (211.4 +/- 71.1 x 270.9 +/- 74.9 g/m2, p = 0.017) when compared with men. EF (66.2 +/- 13.4 x 52.0 +/- 14.6%, p = 0.0032), FS (37.6 +/- 10.7 x 27.9 +/- 9.6%, p = 0.0046) and RDT (0.58 +/- 0.22 x 0.44 +/- 0.09, p = 0.0095) were significantly greater in women than in men.

CONCLUSION

It is the patient gender rather than age that influences left ventricular adaptive response to AS.

[Silent myocardial ischemia. Experience with ambulatory electrocardiographic monitoring]

A 24-hour recording of ambulatory EKG (Holter) was obtained in 159 patients with coronary disease: previous myocardial infarction (n = 76), myocardial revascularization (n = 66), severe obstruction during cine-coronarography (n = 13) or during coronary angioplasty (n = 4). Prophylactic anti-anginal drugs were maintained during the Holter and, despite the medication, transitory episodes of myocardial ischemia (MI) were recorded in 51 patients (32%), either with angina (AMI) or silent (SMI), isolated SMI was recorded in 44 patients (86%), 6 subjects had both SMI (16 episodes) and AMI (12 episodes) and one patient had only one episode of AMI. There was a total of 119 episodes of MI, 106 of SMI (89.1%) and 13 AMI (10.9%). The total duration of the episodes of SMI per patient varied from 1 min to 235 min and the IMS maximal duration was 221 min. In the six cases with both SMI and AMI, the total duration of SMI was 461 min and AMI was 306 min. The circadian distribution of the episodes of SMI was: from 12:00 to 18:00-31.4%, 18:00 to 24:00-27.6%, 0:00 to 6:00-7.7% and 6:00 to 12:00-33.3%. The SMI activity was recorded in 89 episodes-23.6% during sleep, 22.4% at rest, 46% during physical activity and 8% during other activities. The mean ST segment depression during SMI (n = 106) was of -2.25 mm and during AMI (n = 13) was of -3.25 mm.(ABSTRACT TRUNCATED AT 250 WORDS)