Abstract:
AIMS:The aim of this work was to investigate the effects of commonly used orthodontic appliances on the magnetic resonance (MR) image quality of the craniofacial region, with special interest in the soft palate and velopharyngeal wall using real-time speech imaging sequences and anatomical imaging of the temporomandibular joints (TMJ) and pituitaries. METHODS:Common orthodontic appliances were studied on 1.5 T scanner using standard spin and gradient echo sequences (based on the American Society for Testing and Materials standard test method) and sequences previously applied for high-resolution anatomical and dynamic real-time imaging during speech. Images were evaluated for the presence and size of artefacts. RESULTS:Metallic orthodontic appliances had different effects on image quality. The most extensive individual effects were associated with the presence of stainless steel archwire, particularly if combined with stainless steel brackets and stainless steel molar bands. With those appliances, diagnostic quality of magnetic resonance imaging speech and palate images will be most likely severely degraded, or speech imaging and imaging of pituitaries and TMJ will be not possible. All non-metallic, non-metallic with Ni/Cr reinforcement or Ni/Ti alloys appliances were of little concern. LIMITATIONS:The results in the study are only valid at 1.5 T and for the sequences and devices used and cannot necessarily be extrapolated to all sequences and devices. Furthermore, both geometry and size of some appliances are subject dependent, and consequently, the effects on the image quality can vary between subjects. Therefore, the results presented in this article should be treated as a guide when assessing the risks of image quality degradation rather than an absolute evaluation of possible artefacts. CONCLUSIONS:Appliances manufactured from stainless steel cause extensive artefacts, which may render image non-diagnostic. The presence and type of orthodontic appliances should be always included in the patient's screening, so the risks of artefacts can be assessed prior to imaging. Although the risks to patients with fixed orthodontic appliances at 1.5 T MR scanners are low, their secure attachment should be confirmed prior to the examination.
journal_name
Eur J Orthodjournal_title
European journal of orthodonticsauthors
Wylezinska M,Pinkstone M,Hay N,Scott AD,Birch MJ,Miquel MEdoi
10.1093/ejo/cju103subject
Has Abstractpub_date
2015-12-01 00:00:00pages
610-7issue
6eissn
0141-5387issn
1460-2210pii
cju103journal_volume
37pub_type
杂志文章abstract::Many animal experiments dealing with function-form interaction and mandibular condylar growth have utilized hyperpropulsion of the animal's mandible. Numerous hyperpropulsive appliances have been described in the literature. However, there are significant discrepancies between reported results which are most likely du...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/19.1.1
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abstract::Katz's quantitative modification of Angle's occlusion classification has been found to have a high intra- and inter-examiner agreement among orthodontists. In the present study an attempt was made to introduce a 'combined' system comprising Katz's modification and overjet/overbite millimetric measurements in order to ...
journal_title:European journal of orthodontics
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abstract:OBJECTIVE:This study investigated the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) in the compression area during orthodontic relapse in rat molars. MATERIALS AND METHODS:Thirty Wistar rats (6 weeks old) underwent orthodontic tooth movement (OTM) of the left first maxillary molar for 21 days,...
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abstract::The aim of this retrospective study was to examine the dental changes which occurred during buccal segment retraction in 39 subjects considered suitable for treatment with headgear to the maxillary dentition. Initially, a removable en masse appliance was fitted to distalize the buccal segments. Once the molar relation...
journal_title:European journal of orthodontics
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journal_title:European journal of orthodontics
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journal_title:European journal of orthodontics
pub_type: 杂志文章,随机对照试验
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更新日期:2019-11-15 00:00:00
abstract:AIM:Compare surface roughness of 'aesthetic' nickel-titanium (NiTi) archwires with their dynamic frictional properties. METHODS:Archwires investigated were: four fully coated tooth coloured [Forestadent: Biocosmetic (FB) and Titanol Cosmetic (FT); TOC Tooth Tone (TT); and Hawley Russell Coated Superelastic NiTi (HRC)]...
journal_title:European journal of orthodontics
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abstract::The aim of the present study was to examine dentoalveolar development in subjects with an 'ideal' (normal) occlusion. The material comprised 436 study casts of 189 male and 247 female subjects of Swedish origin between the ages of 5 and 31 years with no history of orthodontic treatment. Tooth width, and arch length, w...
journal_title:European journal of orthodontics
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journal_title:European journal of orthodontics
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doi:10.1093/ejo/21.4.377
更新日期:1999-08-01 00:00:00
abstract::This study, performed using a specially designed apparatus that included 10 aligned brackets, evaluated the frictional resistance generated by conventional stainless steel (SS) brackets (Victory Series), self-ligating Damon SL II brackets, Time Plus brackets, and low-friction ligatures (Slide) coupled with various SS,...
journal_title:European journal of orthodontics
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更新日期:2007-08-01 00:00:00
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更新日期:2011-08-01 00:00:00
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journal_title:European journal of orthodontics
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更新日期:2011-08-01 00:00:00
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更新日期:2009-02-01 00:00:00
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更新日期:1993-10-01 00:00:00
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abstract:Background/objectives:Functional appliances are commonly used to correct Class II malocclusion. This study aimed to compare the facial soft tissue changes in Caucasians between pre-treatment and with the construction bite versus pre-treatment and completion of treatment with a modified Twin-block appliance (MTBA). Mat...
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abstract::It has been suggested that subjects with increased vertical craniofacial dimensions have relatively oblique orientated jaw muscles with a reduced possibility to restrain the vertical component of craniofacial growth. To test this hypothesis, relationships were investigated between the spatial orientation of the jaw mu...
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journal_title:European journal of orthodontics
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abstract::Clinical outcomes in children born with a cleft lip and palate (CLP) have been an area of interest for orthodontists for a number of years. Whilst tools for measurement of these outcomes are available, there is no widely accepted measure of initial cleft severity and no known quantitative indices. Therefore, the poten...
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