Mental health impacts of climate change and extreme weather events on mothers

Background: The perinatal period is a time of increased vulnerability for perinatal mood and anxiety disorders (PMADs). Emotional trauma is a risk factor for PMAD development and is common among survivors of extreme weather events (EWEs), which are becoming more frequent and intense as the climate crisis progresses. EWE-related stress and anxiety have not been extensively studied in the perinatal population. However, the limited available data suggest a negative impact of EWE exposure on perinatal mental health, warranting further investigation and investment.Objective: To address this knowledge gap, we interviewed new Australian mothers to understand how EWEs affect the mental health of the perinatal population.Method: Australian mothers (18 years of age or older) with a baby under 12 months of age were recruited to participate in a single virtual focus group session (seven group sessions were run in total) and complete an anonymous survey. Participants were asked questions regarding their concerns about extreme weather and its impact, as well as their general maternal functioning. Maternal functioning, depression, and climate distress were measured via the survey.Results: The study sample comprised 31 Australian mothers (Mage = 31.74, SD = 4.86), predominantly located in Queensland. Findings from the focus groups suggested six key themes; however, of focus to this study are three themes related to maternal mental health: health and well-being, helplessness and avoidant coping, and resilience and adaptation. Predominant subthemes focused on trauma resulting from EWE exposure, economic and heat concerns, social isolation, hopelessness about the future, and feelings of resilience.Conclusions: The evidence linking adverse perinatal mental health outcomes with climate change and EWEs highlights the urgent need for interventions in this context to protect perinatal mental health and well-being. By acknowledging the traumatic impact of these experiences on mothers, this study supports advocacy for policies that specifically address this issue.

Biomechanics of sacropelvic fixation: a comprehensive finite element comparison of three techniques

PURPOSE

Sacropelvic fixation is frequently used in combination with thoracolumbar instrumentation for complex deformity correction and is commonly associated with pseudoarthrosis, implant failure and loosening. This study compared pedicle screw fixation (PED) with three different sacropelvic fixation techniques, namely iliac screws (IL), S2 alar-iliac screws (S2AI) and laterally placed triangular titanium implants (SI), all in combination with lumbosacral instrumentation, accounting for implant micromotion.

METHODS

Existing finite element models of pelvis-L5 of three patients including lumbopelvic instrumentation were utilized. Moments of 7.5 Nm in the three directions combined with a 500 N compressive load were simulated. Measured metrics included flexibility, instrumentation stresses and bone-implant interface loads.

RESULTS

Fixation effectively reduced the sacroiliac flexibility. Compared to PED, IL and S2AI induced a reduction in peak stresses in the S1 pedicle screws. Rod stresses were mostly unaffected by S2AI and SI, but IL demonstrated a stress increase. In comparison with a previous work depicting full osteointegration, SI was found to have similar instrumentation stresses as those due to PED.

CONCLUSIONS

Fixation with triangular implants did not result in stress increase on the lumbosacral instrumentation, likely due to the lack of connection with the posterior rods. IL and S2AI had a mild protective effect on S1 pedicle screws in terms of stresses and bone-implant loads. IL resulted in an increase in the rod stresses. A comparison between this study and previous work incorporating full osteointegration demonstrates how these results may be applied clinically to better understand the effects of different treatments on patient outcomes. These slides can be retrieved under Electronic Supplementary Material.

Effect of restoration volume on stresses in a mandibular molar: a finite element study

STATEMENT OF PROBLEM

There can be significant disagreement among dentists when planning treatment for a tooth with a failing medium-to-large--sized restoration. The clinician must determine whether the restoration should be replaced or treated with a crown, which covers and protects the remaining weakened tooth structure during function.

PURPOSE

The purpose of this study was to evaluate the stresses generated in different sized amalgam restorations via a computational modeling approach and reveal whether a predictable pattern emerges.

MATERIAL AND METHODS

A computer tomography scan was performed of an extracted mandibular first molar, and the resulting images were imported into a medical imaging software package for tissue segmentation. The software was used to separate the enamel, dentin, and pulp cavity through density thresholding and surface rendering. These tissue structures then were imported into 3-dimensional computer-aided design software in which material properties appropriate to the tissues in the model were assigned. A static finite element analysis was conducted to investigate the stresses that result from normal occlusal forces. Five models were analyzed, 1 with no restoration and 4 with increasingly larger restoration volume proportions: a normal-sized tooth, a small-sized restoration, 2 medium-sized restorations, and 1 large restoration as determined from bitewing radiographs and occlusal surface digital photographs.

RESULTS

The resulting von Mises stresses for dentin-enamel of the loaded portion of the tooth grew progressively greater as the size of the restoration increased. The average stress in the normal, unrestored tooth was 4.13 MPa, whereas the smallest restoration size increased this stress to 5.52 MPa. The largest restoration had a dentin-enamel stress of 6.47 MPa. A linear correlation existed between restoration size and dentin-enamel stress, with an R(2) of 0.97.

CONCLUSIONS

A larger restoration volume proportion resulted in higher dentin-enamel stresses under static loading. A comparison of the von Mises stresses to the yield strengths of the materials revealed a relationship between a tooth's restoration volume proportion and the potential for failure, although factors other than restoration volume proportion may also impact the stresses generated in moderate-sized restorations.