Out of the loupe: The prevalence of coaxial misalignment of surgical loupes among dental professionals.

BACKGROUND: Surgical loupes have been increasingly popular among dental professionals for their visual and postural benefits. However, dental professionals will receive the full benefit of surgical loupes only if the loupes are adjusted fully to fit the individual needs of each clinician. In this study, the authors examine coaxial alignment of surgical loupes, a critical criterion for the proper adjustment of these optical systems. METHODS: The authors conducted an in-person survey by using a simple, quantitative visual tool to assess the coaxial alignment of surgical loupes among 97 dental professionals in British Columbia, Canada. RESULTS: Findings indicated that 82% of dental professionals surveyed experienced coaxial misalignment with their surgical loupes. Dental professionals wearing front-lens-mounted (flip-up) surgical loupes with full vertical adjustability, front-lens-mounted surgical loupes with limited vertical adjustability, and through-the-lens surgical loupes were equally likely to be practicing with coaxial misalignment of their surgical loupes. Front-lens-mounted surgical loupes with full vertical adjustability were the only type of surgical loupe that can be adjusted to achieve full coaxial alignment reliably (P < .05). CONCLUSIONS: There was a high prevalence of coaxial misalignment among dental professionals in this cohort. Not all surgical loupes on the market satisfy the criteria for optimal postural and visual support of clinicians. PRACTICAL IMPLICATIONS: The visual tool developed in this study enabled dental professionals to identify coaxial misalignment effectively and efficiently. Findings from this study will assist dental professionals in making informed decisions when choosing their magnification equipment and prompt surgical loupe manufacturers to develop more evidence-based products.

Aldehyde dehydrogenases are regulators of hematopoietic stem cell numbers and B-cell development.

High levels of the aldehyde dehydrogenase isoform ALDH1A1 are expressed in hematopoietic stem cells (HSCs); however, its importance in these cells remains unclear. Consistent with an earlier report, we find that loss of ALDH1A1 does not affect HSCs. Intriguingly, however, we find that ALDH1A1 deficiency is associated with increased expression of the ALDH3A1 isoform, suggesting its potential to compensate for ALDH1A1. Mice deficient in ALDH3A1 have a block in B-cell development as well as abnormalities in cell cycling, intracellular signaling, and gene expression. Early B cells from these mice exhibit excess reactive oxygen species and reduced metabolism of reactive aldehydes. Mice deficient in both ALDH3A1 and ALDH1A1 have reduced numbers of HSCs as well as aberrant cell cycle distribution, increased reactive oxygen species levels, p38 mitogen-activated protein kinase activity and sensitivity to DNA damage. These findings demonstrate that ALDH3A1 can compensate for ALDH1A1 in bone marrow and is important in B-cell development, both ALDH1A1 and 3A1 are important in HSC biology; and these effects may be due, in part, to changes in metabolism of reactive oxygen species and reactive aldehydes.