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Premolar Extractions (premolar + extraction)
Selected AbstractsPalatally displaced upper lateral incisors: relapse after orthodontic treatment and its correlation with dentoskeletal morphologyORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 4 2000M. Okamoto The purpose of the present study was to determine whether the relapse tendency of the palatally positioned upper lateral incisor differs in patients treated with or without premolar extraction, and if there is any correlation between the amount of upper lateral incisor relapse and pretreatment dentoskeletal morphology or post-treatment changes. Forty-six patients with bilateral palatally displaced upper laterals who also exhibit maxillary dental constriction were separated into two groups: a premolar extraction (30 cases) group and a non-extraction (16 cases) group. All subjects had undergone orthodontic treatment with quad helix and edgewise appliances, followed by a 2-year retention period. Differences in the amount of the upper lateral incisor relapse and their correlations with the dentoskeletal morphology before and after treatment were determined on the lateral and postero-anterior cephalograms and dental casts. Results revealed that the upper lateral incisor relapse in the extraction group was significantly greater (p=0.0002) than the relapse in the non-extraction group. There was a positive correlation between incisor relapse and the distance of lateral incisor movement in both groups (r=0.539; p=0.030). Relapse in the non-extraction group was correlated with the widths of the upper dental arch (r,,0.507, p,0.044), with the naso-maxillary variables before treatment (r=,0.514, p=0.041), and also with changes in the upper inter-premolar and inter-molar widths during retention (r=0.514, p=0.040). [source] Changes in occlusal force and occlusal contact area after active orthodontic treatment: a pilot study using pressure-sensitive sheetsJOURNAL OF ORAL REHABILITATION, Issue 5 2002M. H. Sultana The aim of this study was to investigate functional changes in occlusion during retention. Data on occlusal force (OcFr) and occlusal contact area (OcAr) was obtained using the pressure-sensitive sheet, from a treated group (20 female patients) who had had four premolar extractions and treatment with standard edgewise appliances, and a control sample who matched the treated group of retainer for sex, age and Angle classification at 1 year after removal. A repeated measures analysis of variance showed that the mean values of total OcFr and OcAr in the treatment group gradually increased during retention and were 669·3 N and 15·1 mm2, respectively, at 1 year after removal of retainer. The increases of OcFr and OcAr were larger in the molar region, especially at the second molar. At 1 year after removal of retainer, OcFr and OcAr in the second molar were significantly larger in the treatment group than in the control sample, and a similar distribution pattern of OcFr and OcAr to those in normal occlusion was seen. These results suggested that balanced OcFr and OcAr might be obtained during and after retention, due to the settling of molars that had been discluded by active orthodontic treatment. [source] Is orthodontic treatment without premolar extractions always non-extraction treatment?AUSTRALIAN DENTAL JOURNAL, Issue 3 2005S. Kandasamy Abstract While it is common in contemporary orthodontic and orthopaedic treatment to commence treatment for many growing patients during the mixed-dentition, the creation of anterior space, often involving the attempted distalization or holding-back of the upper and lower permanent molar teeth has been shown to commonly result in posterior space deficiencies. Although the extractions of permanent premolar teeth may have been avoided, the developing second and third permanent molars are often affected, so that third molar impaction results in many cases. This is not to say that orthodontic treatment carried-out without premolar extractions is not ideal in many cases, but on the available evidence, so-called absolute ,non-extraction' protocols should be questioned, so that both the dental profession and the public at large are not misled. [source] | ||||||||||