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We present the requirements, design, and evaluation of the cryogenic continuously rotating half-wave plate (CHWP) for the Simons Observatory (SO). SO is a cosmic microwave background polarization experiment at Parque Astronómico de Atacama in northern Chile that covers a wide range of angular scales using both small (⌀0.42 m) and large (⌀6 m) aperture telescopes. In particular, the small aperture telescopes (SATs) focus on large angular scales for primordial B-mode polarization. To this end, the SATs employ a CHWP to modulate the polarization of the incident light at 8 Hz, suppressing atmospheric 1/f noise and mitigating systematic uncertainties that would otherwise arise due to the differential response of detectors sensitive to orthogonal polarizations. The CHWP consists of a 505 mm diameter achromatic sapphire HWP and a cryogenic rotation mechanism, both of which are cooled down to ∼50 K to reduce detector thermal loading. Under normal operation, the HWP is suspended by a superconducting magnetic bearing and rotates with a constant 2 Hz frequency, controlled by an electromagnetic synchronous motor. We find that the number of superconductors and the number of magnets that make up the superconducting magnetic bearing are important design parameters, especially for the rotation mechanism's vibration performance. The rotation angle is detected through an angular encoder with a noise level of 0.07 μrad s. During a cooldown process, the rotor is held in place by a grip-and-release mechanism that serves as both an alignment device and a thermal path. In this paper, we provide an overview of the SO SAT CHWP: its requirements, hardware design, and laboratory performance.

Background: Children's pain in dentistry has undesirable short- and long-term consequences; therefore, less invasive treatments merit consideration., Aim: To investigate procedural pain scores for two treatments for carious primary molars in New Zealand primary care., Design: This study was a split-mouth randomised control trial, with secondary outcome analysis. Children (4-8 years) with proximal carious lesions on matched primary molars had one tooth treated with the Hall technique (HT) and one treated with a conventional stainless steel crown (CT); treatment type and order of treatment were randomly allocated (allocation concealment). The Wong-Baker self-report pain scale measured pretreatment dental pain, procedural pain at each treatment and post-operative pain., Results: Data were analysed for 103 children: 49 children had the HT first and 54 children had the CT first. Procedural pain scores did not differ by treatment type, with 71.8% and 76.7% of children reporting low pain for the HT and the CT, respectively. Fewer children reported low procedural pain for the second treatment than the first (p = .047). Most children reported low procedural pain for both treatments (58.3%), although 41.7% experienced moderate-high procedural pain with at least one treatment., Conclusions: The HT caused pain for as many children as the CT. There is an opportunity for better dental pain management in this setting., (© 2023 The Authors. International Journal of Paediatric Dentistry published by BSPD, IAPD and John Wiley & Sons Ltd.)

Introduction: The demands of operational deployment mean that defense force personnel must be dentally fit. Although medical evacuation for dental causes should be avoided, dental emergencies are a major non-combat-related contributor to withdrawal from deployment. Information on the oral health status of recruits and officer cadets entering the New Zealand Defence Force (NZDF) is scarce, yet it is useful for service and workforce planning. We investigated oral health status and its associations in new recruits and officer cadets entering the NZDF over a 13-month period., Materials and Methods: This study used data from recruits' initial dental examination (including baseline forensic charting), posterior bitewing radiographs, orthopantomograph radiograph, and a socio-dental questionnaire. The impaction status of third molar teeth was evaluated. Ethical approval was obtained from the University of Otago Ethics Committee (reference number D18/200) and the NZDF Organisational Research Committee., Results: Of the 874 (83%) of the 1,053 recruits (age range 17-59 years) who participated, one in five were Māori. Nearly two-thirds were Army recruits. Caries prevalence was almost 70%. Mean Decayed, Missing, and Filled Teeth (DMFT) (3.0 overall) was higher among females and Māori. Few teeth were missing due to caries. Third molars were common, seen in 745 (88.3%). One in four maxillary third molars (but only one in six mandibular ones) had fully erupted. The most common type of impaction among mandibular third molars was the mesioangular type, followed by vertical, horizontal, and distoangular. Almost 60% of recruits had one or more potentially problematic third molars. The prevalence was highest in the youngest age groups, those of medium or low socioeconomic status and in Army or Navy recruits., Conclusions: Recruits' oral health was acceptable, but potentially problematic third molars were common, indicating a need for careful assessment (and their possible removal) before operational deployment., (© The Association of Military Surgeons of the United States 2021. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: US data on the validity and reliability of the short-form Family Impact Scale (FIS-8; a scale for measuring the impact of a child's oral condition on his/her family) are lacking., Methods: Cross-sectional analysis of data on four-year-old US children taking part in a multi-center cohort study. For child-caregiver dyads recruited at child age 12 months, the impact of the child's oral condition on the family was assessed at age 48 months using the FIS-8, with a subsample of 422 caregivers (from 686 who were approached). Internal consistency reliability was assessed using Cronbach's α, with concurrent validity assessed against a global family impact item ("How much are your family's daily lives affected by your child's teeth, lips, jaws or mouth?") and a global oral health item ("How would you describe the health of your child's teeth and mouth?")., Results: Cronbach's alpha was 0.83. Although gradients in mean scores across ordinal response categories of the global family impact item were inconsistent, there were marked, consistent gradients across the ordinal categories of the global item on the child's oral health, with scores highest for those rating their child's oral health as 'Poor'., Conclusions: While the findings provide some evidence for the utility of the FIS in a US child sample, the study's replication in samples of preschoolers with greater disease experience would be useful., (© 2022. The Author(s).)

Aotearoa New Zealand (NZ) has a long tradition of providing publicly funded oral health care for children and young people; however, substantial inequities in child oral health remain. Dental caries is the most prevalent non-communicable childhood disease in NZ, with Māori and Pasifika, those from low socio-economic backgrounds, and those without access to community water fluoridation most affected. Children and whānau with dental caries suffer consequences that seriously affect their day-to-day lives; it is critical not to underestimate the disease or fail to include it when considering children's overall health. Dental caries is a complex disease, as is its prevention. This is particularly so in the current social context of child poverty, our food environment, the exploitation of children in advertising of non-healthy foods and drinks, and the immense challenges of meeting demand for oral health care in primary, secondary and tertiary care within current constraints. We review children's oral health in NZ and make recommendations for change among oral health professionals, all health professionals, health services and society. Further research in oral health services will be an essential part of improving oral health, recognising that there is an urgent need for a shift towards much greater prevention of caries. Glossary of Māori terms: Aotearoa: New Zealand; He Korowai Oranga: New Zealand Māori Health Strategy; Hui: meeting; Manaakitanga: hospitality, kindness, generosity and support; Mana Motuhake: self-determination; Māori: the indigenous people of Aotearoa New Zealand; Mātauranga Māori: Māori knowledge; Rangatahi: adolescents; Tamariki: children; Te Ao Māori: the Māori worldview; Te Kauae Parāoa: Division of Health Sciences Policy on Admissions; Te reo Māori: the indigenous Māori language; Te Tiriti o Waitangi: Māori language version of the Treaty of Waitangi; Tikanga: customs; Whānau: family; Whakamaua: Māori Health Action Plan 2020-2025; Whakawhanaungatanga: the process of establishing relationships and relating well to others., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2022 The Royal Society of New Zealand.)