Cephalometric evaluation of hyoid bone position and pharyngeal spaces following treatment with Twin block appliance.

J Orthod Sci

Faculty of Dental Sciences, CSMMU (Upgraded KGMC), Lucknow, Uttar Pradesh, India.

Published: July 2012

Objective: To evaluate the position of hyoid bone in the subjects treated with Twin block appliance.

Materials And Methods: The sample consisted of 40 Angle's Class II division 1 subjects treated with Twin block appliance. Lateral radiographs were taken before and after treatment. According to Schudy's facial divergence angle (SN-MP), the subjects were classified in to three groups: group I (hypodivergent, SN-MP: <31° (27°-30°), n=15), group II (normodivergent, SN-MP: 31°-34°, n=15), and group III (hyperdivergent, SN-MP: >34° (35°-38°), n=10). Lateral cephalograms were traced and analyzed manually. After measurements of variables, Student's t-test and one-way analysis of variance (ANOVA) were performed.

Results: Post treatment with Twin block therapy, hyoid bone shifted significantly (P<0.01) forward in horizontal dimension in all three groups, although it was highest in group III. However, there was no significant difference amongst the groups. In vertical dimension, hyoid bone shifted in upward direction in all three groups; however, the shift was significant (P<0.01) only in group I and there was a significant difference between group I and rest of the two groups. Width of upper airway significantly (P<0.01) increased and ANB angle significantly (P<0.001) decreased in all three groups with forward movement of mandible.

Conclusions: After treatment with Twin block appliance, significant changes occurred in horizontal dimension (anterior displacement), which resulted in significant increase in width of upper pharynx in all three groups.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4072360PMC
http://dx.doi.org/10.4103/2278-0203.103863DOI Listing

Publication Analysis

Top Keywords

twin block
16
hyoid bone
12
treatment twin
8
block appliance
8
subjects treated
8
treated twin
8
cephalometric evaluation
4
evaluation hyoid
4
bone position
4
position pharyngeal
4

Similar Publications

Due to the spread of SARS-CoV-2 virus infectious disease (COVID-19), blood donation events had to be cancelled, and there were concerns about a decrease in the number of blood donors from late February 2020 in Japan. The purpose of this study is to investigate the numbers of whole blood donation, manufacture and inventory adjustment of red blood cell (RBC) products at the Japanese Red Cross Society (JRCS), and to evaluate the effects of COVID-19 on the donation of blood and the supply of RBC products to medical institutions for transfusion medicine in Japan. We focused on RBC products, which are the most frequently used blood products and are easily reflected under the spread of COVID-19.

View Article and Find Full Text PDF

While polyethylene terephthalate glycol (PETG) is widely used in orthodontic appliances such as clear aligners and retainers, there is limited experimental data assessing its performance under functional stresses, such as those encountered during dental movements and palatal expansion. This study aims to evaluate the ability of PETG thermoplastic material to withstand deformation under functional and expansion forces, specifically within the context of orthodontic applications. To estimate the firmness of the screw within the appliance, a universal Instron testing machine was used to record the forces released by each activation of the expander within the upper part of 10 clear modified twin blocks (MTBs) made from PETG and compare it with that released by 10 conventional twin blocks (CTBs).

View Article and Find Full Text PDF

Although China's low-permeability and tight oil reservoir utilization and newly proven reserves are growing annually, the overall recovery of such reservoirs is generally low. One of the main factors influencing the low recovery is the effect of intricate dynamic fracture propagations on the remaining oil distribution. Constrained by the evolution of an in situ stress field and the accumulation of fluid injection volumes, the growth of dynamic fractures allows a production profile of water breakthrough.

View Article and Find Full Text PDF

Some one-dimensional (1D) crystals containing a screw dislocation along their longer axis exhibit a helical twist due to lattice strain. These chiral structures have been thoroughly investigated by using transmission electron microscopy. However, whether two-dimensional (2D) crystals with a spiral surface pattern, presumably containing a screw dislocation, are structurally chiral remains unclear because their internal structures are not visible.

View Article and Find Full Text PDF

Quantification of heavy metal exposure in a British population cohort links total mercury levels in plasma with skin tissue-specific changes in mitochondrial-related gene expression.

Sci Total Environ

January 2025

Department of Twin Research and Genetic Epidemiology, King's College London, 3-4th Floor South Wing Block D, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK. Electronic address:

Heavy metals in our direct environment have profound effects on human health and while some are essential for life, others can be toxic. In vivo studies often focus on clinical features caused by overexposure to, or by deprivation of a heavy metal. However, to understand the cellular impact of heavy metals on health, studies in healthy volunteers before symptom onset are needed.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!