Abstract:
:The analysis of the non-linear and time-dependent viscoelasticity of the periodontal ligament (PDL) enables a better understanding of the biomechanical features of the key regulator tissue for tooth movement. This is of great significance in the field of orthodontics as targeted tooth movement remains still one of the main goals to accomplish. The investigation of biomechanical aspects of the PDL function, a difficult area of research, helps towards this direction. After analysing the time-dependent biomechanical properties of pig PDL specimens in an in vitro experimental study, it was possible to confirm that PDL has a viscoelastic anisotropic behaviour. Three-dimensional finite element models of mini-pig mandibular premolars with surrounding tissues were developed, based on micro-computed tomography (μCT) data of the experimental specimens. Tooth mobility was numerically analysed under the same force systems as used in the experiment. A bilinear material parameter set was assumed to simulate tooth displacements. The numerical force/displacement curves were fitted to the experimental curves by repeatedly calculating tooth displacements of 0.2mm varying the loading velocities and the parameters, which describe the nonlinearity. The experimental results showed a good agreement with the numerical calculations. Mean values of Young's moduli E1, E2 and ultimate strain ε12 were derived for the elastic behaviour of the PDL for all loading velocities. E1 and E2 values increased with increasing the velocity, while ε12 remained relatively stable. A bilinear approximation of material properties of the PDL is a suitable description of measured force/displacement diagrams. The numerical results can be used to describe mechanical processes, especially stress-strain distributions in the PDL, accurately. Further development of suitable modelling assumptions for the response of PDL under load would be instrumental to orthodontists and engineers for designing more predictable orthodontic force systems and appliances.
journal_name
Eur J Orthodjournal_title
European journal of orthodonticsauthors
Papadopoulou K,Hasan I,Keilig L,Reimann S,Eliades T,Jäger A,Deschner J,Bourauel Cdoi
10.1093/ejo/cjs103subject
Has Abstractpub_date
2013-12-01 00:00:00pages
811-8issue
6eissn
0141-5387issn
1460-2210pii
cjs103journal_volume
35pub_type
杂志文章abstract::This study was undertaken to assess the factors affecting self-perception and the demand for orthodontic treatment among north Jordanian school children. In total, 1404 students randomly selected to represent five geographical areas of northern Jordan were examined. The students were further subgrouped according to ge...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjh094
更新日期:2005-06-01 00:00:00
abstract:Aim:To assess the association between tooth wear (TW) and gingival recession (GR). Materials and Methods:Two hundred and ten orthodontically treated participants (100 males) were evaluated. GR and TW were rated independently by four raters on plaster models at four time points: before treatment (T1), mean age 13.8 yea...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjx083
更新日期:2018-07-27 00:00:00
abstract:SUMMARY:The aim of this study was to evaluate the effects of orthodontic treatment on systemic levels of the inflammatory markers, C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6). The study group comprised 11 girls and 6 boys (mean age 13.1 years) treated with fixed applianc...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjp108
更新日期:2010-08-01 00:00:00
abstract::The surface topography of 100 clinically used archwires of stainless steel, beta-, or nickel-titanium were investigated that had contacted either ceramic or stainless steel brackets. One group consisted of two sets: 60 wires with no treatment records accessed to bias analyses, and 40 wires for which extensive clinical...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/22.4.409
更新日期:2000-08-01 00:00:00
abstract::This study investigated whether there were differences between the debond stress and adhesive remnant index (ARI) of an adhesive cured with three different orthodontic light sources. Sixty sound premolar teeth were divided into three groups of 20. A standard pre-adjusted edgewise premolar bracket (Victory Series) was ...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cji076
更新日期:2006-02-01 00:00:00
abstract:OBJECTIVES:During orthodontic arch expansion, the teeth are displaced against the perioral soft tissues. This can affect the equilibrium of forces that are thought to act on teeth, with consequent implications for long-term stability. The aim of this study was to investigate the effect of incremental lower lip advancem...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjt094
更新日期:2014-12-01 00:00:00
abstract::The purpose of this study was to clarify the contributing factors and their influences on temporomandibular joint internal derangement (TMJ ID) symptoms in subjects with mandibular asymmetry. Postero-anterior (PA) cephalograms of 187 pre-orthodontic treatment subjects (aged 18-45 years, mean 23.9 years) were used to i...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cji073
更新日期:2006-02-01 00:00:00
abstract::The purpose of this study was to evaluate the Denture Frame Analysis. This adjunctive cephalometric analysis of the lateral headfilm was introduced in Japan, but no data exist for the Caucasian population at present. One-hundred-and-six Caucasians were randomly selected and assigned to one of four groups, according to...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/20.5.579
更新日期:1998-10-01 00:00:00
abstract:OBJECTIVE:To investigate the factors associated with the change in alveolar bone level of mandibular second and third molars after second molar protraction into the space of the missing first molar (L6) or second premolar (LE). METHODS:Fifty-one patients in whom space of the missing L6 or LE was treated with second mo...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjz001
更新日期:2019-09-21 00:00:00
abstract::The aim of this study was to compare the effects of the Gjessing (PG) retraction spring used with and without the zygoma anchorage system (ZAS) on canine retraction. Thirty patients, with an Angle Class I or Class II malocclusion, whose upper first premolars were scheduled for extraction, were divided into two equal g...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjp167
更新日期:2010-10-01 00:00:00
abstract::The aim of this study was to investigate if debonding microspheres (DM) could enhance electrothermal orthodontic debonding, and specifically to evaluate if the addition of DM, in varying concentrations to the orthodontic adhesive process, will affect bond strength. Bovine teeth (n=8) were mounted in acrylic using a si...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjq091
更新日期:2011-08-01 00:00:00
abstract::The aim of this study was to evaluate the effects of the headgear activator (HGA) and Herbst appliance during active treatment and retention and at follow-up in children with a skeletal Class II malocclusion. The two groups comprised 16 consecutive male patients (mean age 11.6 +/- 1.42 years) treated with a HGA and 16...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjl052
更新日期:2006-12-01 00:00:00
abstract::The aim of this study was to investigate the in vivo bonding of orthodontic brackets using two resin-modified glass poly(alkenoate) cements and to compare them with a conventional light-cured diacrylate bonding agent. Twenty consecutive patients attending for bond up appointments took part in this randomized cross-mou...
journal_title:European journal of orthodontics
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1093/ejo/23.4.403
更新日期:2001-08-01 00:00:00
abstract::Fifty-two patients with malocclusions underwent orthodontic treatment in combination with orthognathic surgery involving a Le Fort I and/or sagittal split osteotomy. Approximately 5 years after surgery, the patients were examined for signs and symptoms of temporomandibular disorders (TMD). The frequencies were found t...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/22.5.537
更新日期:2000-10-01 00:00:00
abstract:AIM:To assess the risk of bias (RoB) in a subset of randomized controlled trials (RCTs) published in orthodontic journals using the Cochrane RoB tool and to identify associations between domain RoB assessment and treatment effect estimates. MATERIALS AND METHODS:Fifty consecutive issues of four major orthodontic journ...
journal_title:European journal of orthodontics
pub_type: 杂志文章,评审
doi:10.1093/ejo/cjv049
更新日期:2016-06-01 00:00:00
abstract::Occlusal traits and craniofacial morphology were studied in growing patients with Duchenne muscular dystrophy (DMD). Sixteen patients from 6 to 20 years of age were examined and compared with 16 healthy male individuals matched according to age. The dental arches and occlusal traits of both groups were analysed on den...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjm045
更新日期:2007-10-01 00:00:00
abstract::The purpose of the present study was to evaluate the accuracy and reliability of airway volume digital measurements of cone-beam computed tomography (CBCT) compared with the manual measurements of an airway model. An acrylic airway model was constructed and attached to a human dry skull in the natural position of the ...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjr099
更新日期:2013-04-01 00:00:00
abstract::Mechanical stress induces human periodontal ligament (PDL) cells to express an osteoblastic phenotype in vitro. Core binding factor a1 (CBFA1) is a key regulator of osteoblast differentiation. This study was designed to investigate the role of CBFA1 in alveolar bone remodelling, specifically the expression of CBFA1 me...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjq010
更新日期:2010-12-01 00:00:00
abstract::This study was designed to explore a new method for the assessment of dental crowding from study models, which would be both valid and reproducible. This was then tested against two previously reported strategies. A single examiner compared the following methods: visual examination, brass wire/callipers, and a reflex ...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/19.5.543
更新日期:1997-10-01 00:00:00
abstract:SUMMARY:The purpose of this study was to assess the short-term psychosocial impact of dental aesthetic improvement in adult subjects. Sixty-nine adult patients (61 females and 8 males, aged 21-59 years) requesting aesthetic dental improvement were prospectively and randomly recruited for the study in a private orthodon...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjp144
更新日期:2010-08-01 00:00:00
abstract::A logical basis for the sequence of wires chosen during orthodontic treatment with fixed appliances is presented. This utilizes a new more realistic model for the radial deflection of a segment of the archwire in which the wire is restrained by the ligatures on the misaligned tooth, contacts the inner edges of the bra...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/14.3.240
更新日期:1992-06-01 00:00:00
abstract::The long-term goal of this research is to define the dimensions of nasal airway adequacy in children. Nasal airway size and variables associated with growth were assessed in 138 healthy children aged 7-15 years. The pressure-flow technique (Warren, 1984) was used to calculate the smallest cross-sectional area of the n...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/13.4.311
更新日期:1991-08-01 00:00:00
abstract:Objective:To assess the dental, skeletal, and profile changes after functional appliances and subsequent fixed appliances treatment in order to quantify their effect and evaluate the influence of initial incisal inclination and growth pattern. Materials and methods:A retrospective cephalometric analysis was performed ...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjw064
更新日期:2017-06-01 00:00:00
abstract::P561T heterozygous missense mutation in the growth hormone receptor (GHR) is a candidate genetic polymorphism (single-nucleotide polymorphism) for human mandibular growth. The purpose of this study was to assess whether this mutation affects mandibular growth during early childhood. The difference in mandibular growth...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjp017
更新日期:2009-10-01 00:00:00
abstract:OBJECTIVE:The aim of this trial was to test whether the use of a smartphone application (app) connected to a toothbrush improves the oral hygiene compliance of adolescent orthodontic patients. DESIGN:The study was designed as a multicentre, randomized, controlled clinical trial. SETTING:Two academic hospitals. ETHIC...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjz105
更新日期:2020-02-01 00:00:00
abstract::Many more adults are undergoing orthodontic therapy than in the past. Since adult dentitions often exhibit diminished alveolar support, it is important to recognize the related apical migration of the dental centre of resistance when applying force systems to the teeth. The force system compensations necessary to prod...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/15.1.73
更新日期:1993-02-01 00:00:00
abstract::This investigation was designed to repeat classic studies into the associations between head posture and growth as a single unified study using up-dated methods for gathering and analysing the data. The material comprised the cephalometric radiographs of 59 children (34 males and 25 females) recorded in natural head p...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjq131
更新日期:2012-08-01 00:00:00
abstract:OBJECTIVE:To compare treatment duration between 0.018-inch and 0.022-inch slot systems and determine factors influencing treatment duration. SUBJECTS AND METHODS:Eligible participants aged 12 years or over were allocated to the 0.018-inch or 0.022-inch slot MBT appliance (3M-Unitek, Monrovia, California, USA) using bl...
journal_title:European journal of orthodontics
pub_type: 杂志文章,随机对照试验
doi:10.1093/ejo/cjy037
更新日期:2019-03-29 00:00:00
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...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/19.3.313
更新日期:1997-06-01 00:00:00
abstract::This prospective study investigated the skeletal, dental, and soft-tissue effects of a mini maxillary protractor appliance in class III subjects with maxillary retrusion and mandibular protrusion and compared these changes with those of untreated, well matched control sample with normal occlusions. Twenty patients wit...
journal_title:European journal of orthodontics
pub_type: 杂志文章
doi:10.1093/ejo/cjt006
更新日期:2014-02-01 00:00:00