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Introduction: How does the behavior of putting things away ( putting them in ) in a container and using them again ( taking them out ) develop in young children? Though object interaction is one of the most examined topics in child development, research on organized behavior with various objects and containers at home is lacking. Rather than conducting experiments on young children's interactions with objects, this study focused on natural child-object interaction in the home., Methods: We conducted a case study on a young child's natural interaction with objects at home, focusing on when the child puts them in or takes them out of a container (the shelf, the cabinet, or the box). The study took place over 2½ years., Results: The behaviors of putting many objects in a container and taking them out appeared at 9 months old. After acquiring the skill of walking, the child carried the objects using bags. Putting objects in and taking them out was embedded in the locomotion, and the child prepared the containers of toys before play. Pulling as many objects out as possible became rare after 19 months of age. Taking objects out became more appropriate in that context. The child brought out the container before the activity and put things away afterward., Discussion: Based on these findings, the development of organized object interaction as well as the anticipation and significance of the naturalistic longitudinal observations are discussed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Nishio, Nozawa, Yamazaki and Kudo.)

Introduction: Vitamin D (VitD) maintains bone health and may influence orthodontic tooth movement (OTM). The objective was to evaluate the VitD effect on bone morphometry and the rate and stability of OTM., Methods: Thirty-two male Sprague Dawley rats were assigned into 2 experimental groups, treated with VitD by gavage (systemic) or injection (local), and 2 respective control groups treated with phosphate-buffered saline for 47 days. OTM was performed for 7 days with a nickel-titanium coil bonded between the maxillary first molar and incisors. Microcomputed tomography scanning was performed at 5 time points: before administration of VitD, the start of OTM, the end of OTM, 7 days post-OTM, and 30 days post-OTM. The rate and stability of OTM were assessed. Bone morphometry was analyzed by bone mineral density, bone volume/total volume, total porosity, trabecular pattern factor, structure model index, and connectivity density., Results: The systemic VitD group showed a lower OTM rate and a lower relapse than the control (P <0.05). It also demonstrated increased bone mineral density, bone volume/total volume, and a decrease in total porosity (P <0.05). The bone structure appeared more fragmented and presented a lower connectivity density than the control (P <0.05). No statistical difference was found between VitD local administration and the other groups for the rate and stability of OTM or bone morphometry., Conclusions: The systemic administration of VitD caused a decrease in the OTM rate by generating more bone resistance but also contributed to a lower relapse with a higher bone mineral density., (Copyright © 2022 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)