LITHUANIAN UNIVERSITY OF HEALTH SCIENCES LUHS LIBRARY REPOSITORY

The effect of early headgear treatment on the dental arches

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dc.contributor.author Krušinskienė, Viktorija
dc.date.accessioned 2017-08-21T08:09:00Z
dc.date.available 2017-08-21T08:09:00Z
dc.date.issued 2010
dc.identifier.uri http://repository.lsmuni.lt/handle/1/60159
dc.description.abstract The aim of this longitudinal randomized-controlled study was to assess the long-term effects of early expanding HG treatment on dental arches and craniofacial morphology, when treatment started during the early mixed dentition and to compare it with the randomized control group. The objectives were: to evaluate the dental arch and skeletal changes; to measure occlusal stability and lower incisor irregularity; to assess the dental aesthetic outcome and to analyze the influence of permanent teeth extractions on dental arch changes and occlusal and lower incisor stability. The project was carried out at the University of Oulu, Finland in 1992–2005. Two hundred and forty 7-year-old children were screened for the investigation. Children in need of orthodontic treatment due to moderate crowding and Class II tendency were selected for comprehensive ortho¬don¬tic examination. The crowding was diagnosed as moderate, based on the degree of space deficiency in the anterior regions of dental arches du¬ring clinical examination. The selection intention was to treat the patients with non-extraction approach. The class II tendency was categorized as full cusp or cusp-to-cusp molar relationship on either side. The study de¬sign was randomized controlled trial of early HG treatment. The total stu¬dy group comprised 68 children of both sexes (40 males and 28 females) aged 7.6 years (SD 0.3). The children were randomly divided into two groups of equal size. In the first group, HG treatment was initiated im¬me¬diately. The maxillary first molars were banded and cervical HG was used, but no other appliances were applied. The long outer bows of the HG were bent 10 degrees upwards in relation to the inner bow and a force of 700–1000 g was applied. The inner bow of the HG was expanded and was constantly held 10 mm wider than the dental arch. The patients were instruc¬ted to wear the HG during sleep, for 8–10 hours. In the control group only minor interceptive procedures were performed during the follow-up period. Between T1 and T2 there was no difference between the groups in the treatment protocol. Orthodontic treatment, if needed, during this phase comp¬rised the fixed appliance treatment, including extractions of per¬manent premolars due to crowding. Fifty four patients (83% of total study group) who continued to the phase II of treatment completed the follow-up at T2 and full records were available. Thirty four subjects (53% of total study group) attended a recall appointment at T3 at the mean age of 20.6 years. The records included to present study were taken before (T0) and after follow-up periods of 2 (T1) years or completing the phase I – early cervi¬cal HG treatment, 8 (T2) years, or completing the phase II fixed appliance treatment including extractions of permanent teeth and 13 (T3) years, or five years post fixed appliance treatment. The comprehensive investiga¬tions included a clinical examination, impressions for dental casts and a ra¬dio¬graphic examination (dental orthopantomogram and a lateral cephalo¬gram). Considering ethical issues, lateral cephalograms were not taken at the last follow-up (T3). The dental arch, occlusal and skeletal changes also the aesthetic outco¬me of treatment were evaluated by using linear measurements on dental casts, cephalometric analysis, PAR-index, Little’s Irregularity Index (LII) and Aesthetic Component of IOTN (AC/IOTN). The most evident effect of early treatment was the longer and wider dental arches in HG group found at the long-term follow-up. Cephalo¬met¬ric values show that early HG treatment effect was more dental than skeletal. There was a reduction in the PAR-index after the second phase of the treatment and a worsening after 13-year follow-up both in the HG and the control groups. No differences were found between the HG and the control groups neither in the PAR, nor in the LII at any observation periods. The patients with extractions had larger increase and a higher level of PAR scores but smaller LII when compared to patients without extractions. Greater LII at the start of trial was characteristic for the patients who had teeth extractions in the second phase of the treatment. No significant differences were found in the dental aesthetics between the HG and the control group. When aesthetics was evaluated by dental specialists, occlusion and the upper anterior segment alignment was found to be more important than the lower incisor alignment. It seems that treatment timing has no influence on stability but if the need for fewer extractions and wider dental arch are considered benefits then early treatment should be justified.
dc.description.abstract Darbo tikslas: Šio atsitiktinių imčių klinikinio kontrolinio tyrimo tikslas – įvertinti gydymo ankstyvuoju mišriojo sąkandžio laikotarpiu, taikant išorinį kakli-nio tempimo aparatą su išplėstu vidiniu lanku, ilgalaikius rezultatus ir gydymo įtaką dantų lankų bei veido skeleto pokyčiams. Darbo uždaviniai: 1. Įvertinti dantų lankų pokyčius, matuojant gipsinius dantų modelius; 2. Išanalizuoti veido skeleto pakitimus, atliekant cefalometrinę anali¬zę; 3. Įvertinti okliuzijos stabilumą, taikant PAR indeksą; 4. Įvertinti apatinių kandžių taisyklingą padėtį, taikant Little Irre¬gu¬la-rity indeksą; 5. Įvertinti galutinę estetinę dantų lankų išvaizdą, taikant estetinį IOTN indekso komponentą (AC/IOTN); 6. Išsiaiškinti nuolatinių dantų pašalinimo įtaką dantų lankams bei ok-liu¬zijos ir apatinių kandžių padėties stabilumui.
dc.language.iso eng
dc.subject Early orthodontic treatment
dc.subject Cervical headgear
dc.subject RCT
dc.subject Ankstyvas ortodontinis gydymas
dc.subject Išorinis kaklinio tempimo aparatas
dc.subject Atsitiktinių imčių klinikinis tyrimas
dc.title The effect of early headgear treatment on the dental arches
dc.title.alternative Ankstyvojo gydymo išoriniu tempimo aparatu poveikis dantų lankams
dc.type Daktaro disertacija


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