Objective: To test the questions "Does cervical headgear treatment necessarily lead to a reduction of overbite?" and "Are there differences in treatment results due to different growth patterns or the initial overbite?"
Materials And Methods: Initial and intermediary casts of 247 patients who had been treated exclusively with headgear were analyzed for changes in the occlusal relationship of the first molars and overbite. Orthodontic treatment consisted of the application of cervical headgear with nonangulated external arms applied at a force of 3.5-4.0 N. Only patients showing dental changes of occlusal relationship > or = 4 mm during at least a 6-month treatment duration were selected. Growth patterns were identified by the y-axis values measured on lateral cephalograms obtained at study entry. Six groups were formed on the basis of these growth patterns.
Results: Headgear treatment induced bite deepening in patients with vertical growth patterns and bite opening in patients with horizontal growth patterns. Further subdivision based on initial overbite revealed bite deepening in patients with small initial overbite and bite opening in patients with large initial overbite. These differences were statistically significant (P < .05). Only minor changes were observed in patients with an initial overbite of 3-4 mm.
Conclusions: Overbite reductions were not dependent on the growth pattern. Orthodontists should expect bite opening in deep-bite situations and bite deepening in open-bite situations. However, initial overbite situations of 3-4 mm should not be expected to change in a significant way.
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http://dx.doi.org/10.2319/121305-436R.1 | DOI Listing |
J Neurosurg
January 2025
1Department of Bioengineering, George Mason University, Fairfax, Virginia.
Objective: The complex mix of factors, including hemodynamic forces and wall remodeling mechanisms, that drive intracranial aneurysm growth is unclear. This study focuses on the specific regions within aneurysm walls where growth occurs and their relationship to the prevalent hemodynamic conditions to reveal critical mechanisms leading to enlargement.
Methods: The authors examined hemodynamic models of 67 longitudinally followed aneurysms, identifying 88 growth regions.
PLoS One
January 2025
Joint Global Change Research Institute, Pacific Northwest National Laboratory, Richland, WA, United States of America.
Evolving environmental conditions due to climate change have brought about changes in agriculture, which is required for human life as both a source of food and income. International trade can act as a buffer against potential negative impacts of climate change on crop yields, but recent years have seen breakdowns in global trade, including export bans to improve domestic food security. For countries that rely heavily on imported food, governments may institute policies to protect their agricultural industry from changes in climate-induced crop yield changes and other countries' potential trade restrictions.
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January 2025
School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR.
To investigate the pattern and threshold of physiological growth, defining as axial length (AL) elongation that results in little refraction progression, among Chinese children and teenagers, a total of 916 children aged between 7 and 18 years from a 6-year longitudinal cohort study were included for analysis. Ocular biometry, cycloplegic refraction and demographic data were obtained annually. Physiological growth was calculated based on myopic progression and Gullstrand eye model, respectively.
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January 2025
College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, China.
Influenced by urban expansion, population growth, and various socio-economic activities, land use in the Yangtze River Delta (YRD) area has undergone prominent changes. Modifications in land use have resulted in adjustments to ecological structures, leading to subsequent fluctuations in carbon storage. This study focuses on YRD region and analyzes the characteristics of land use changes in the area using land use data from 2000 to 2020, with a 10-year interval.
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January 2025
School of Mathematics and Statistics, College of Science, Rochester Institute of Technology, Rochester, New York, United States of America.
This study presents a novel non-autonomous mathematical model to explore the intricate relationship between temperature and desert locust population dynamics, considering the influence of both solitarious and gregarious phases across all life stages. The model incorporates temperature-dependent parameters for key biological processes, including egg development, hopper growth, adult maturation, and reproduction. Theoretical analysis reveals the model's capacity for complex dynamical behaviors, such as multiple stable states and backward bifurcations, suggesting the potential for sudden and unpredictable population shifts.
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