Comparison of the outcomes of the lower incisor extraction, premolar extraction and non-extraction treatments
ABSTRACT The aim of this retrospective study was to evaluate the treatment outcome of lower incisor extraction and to compare it with premolar extraction and non-extraction treatment. The sample consisted of 60 subjects with Class I malocclusion and moderate crowding. The sample was separated into three groups: extraction of a lower incisor group, extraction of a four first premolar group and a non-extraction group. All groups involved 13 girls and 7 boys with a total of 20 patients. The Peer assessment rating (PAR) index was applied to a patient's pre-treatment (T1) and post-treatment (T2) dental casts. T1 dental casts were also used for determining Bolton discrepancy. One-way analysis of variance and post hoc Tukey HSD tests were used for statistical analysis. For the mean percentage PAR score reduction for each group, there was one significant difference seen between the lower incisor extraction group and the non-extraction group (P = 0.047). For the mean anterior ratios, there were significant differences among premolar extraction group versus non-extraction group (P = 0.042) and non-extraction group versus lower incisor extraction group (P = 0.000). For the mean overall ratios, there were significant differences among the premolar extraction group versus lower incisor extraction group (P = 0.048) and the non-extraction group versus lower incisor extraction group (P = 0.001). Orthodontic treatment without extraction has a better treatment outcome than the four-first premolar extraction and single lower incisor extraction protocols in Class I cases with moderate to severe mandibular anterior crowding.
- SourceAvailable from: Giordani Santos Silveira[Show abstract] [Hide abstract]
ABSTRACT: To determine by means of a systematic review the best treatment, whether interproximal wear or incisor extraction, to correct anterior lower crowding in Class I patients in permanent dentition. A literature review was conducted using MEDLINE, Scopus and Web of Science to retrieve studies published between January 1950 and October 2013. In selecting the sample, the following inclusion criteria were applied: studies involving interproximal wear and/or extraction of mandibular incisors, as well as Class I cases with anterior lower crowding in permanent dentition. Out of a total of 943 articles found after excluding duplicates, 925 were excluded after abstract analysis. After full articles were read, 13 were excluded by the eligibility criteria and one due to methodological quality; therefore, only fours articles remained: two retrospective and two randomized prospective studies. Data were collected, analyzed and organized in tables. Both interproximal wear and mandibular incisor extraction are effective in treating Class I malocclusion in permanent dentition with moderate anterior lower crowding and pleasant facial profile. There is scant evidence to determine the best treatment option for each case. Clinical decision should be made on an individual basis by taking into account dental characteristics, crowding, dental and oral health, patient's expectations and the use of set-up models.01/2015; 20(1):66-73. DOI:10.1590/2176-9451.20.1.066-073.oar
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ABSTRACT: Mandibular incisor extraction in carefully selected cases as an alternative option to four bicuspid extraction or non extraction treatment has been advocated. The purpose of this study was to determine the degree of improvement in occlusion in patients with Bolton discrepancy treated by one lower incisor extraction using Peer Assessment Rating Index (PAR indexes). Pre and post treatment dental casts of 14 patients treated with one lower incisor extraction were included in the study. Pre and post treatment dental casts were scored with PAR index. 70% reduction in PAR index was considered as high standard improvement. To test the hypothesis that the mean improvement in dental occlusion after one mandibular incisor extraction is at least 70%, one-tail one-sample student t-test was used. The mean improvement in dental occlusion in this group of patients was 78%. Fifty percent of the cases finished with a post treatment PAR score of 2. Spearman correlation coefficient was 0.763 (p<0.01), showing that more severe cases had greater post treatment PAR scores. Mandibular incisor extraction treatment may provide a high standard treatment outcome.03/2012; 9(1):27-34.
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ABSTRACT: The purpose of the present study was to examine the efficiency of correcting a Class II, Division 2 malocclusion using a completely customized lingual appliance. In 18 consecutively completed, Class II, Division 2 malocclusion patients, the correction of the upper incisor inclination, deep and distal bite were assessed by means of plaster casts, digital lateral cephalograms, and intraoral photographs taken at the time of debond. Furthermore, two independent calibrated examiners determined the weighted Peer Assessment Rating index (PAR Index) of the initial and end models. All Class II, Division 2 patients were treated successfully: upper incisor inclination using the palatal plane as a reference improved on average from 95.4° to 111.2°. The deep bite was reduced on average from 3.6 mm to 1.7 mm. Neutral occlusion was achieved in all patients who had undergone correction of an initially pronounced distal occlusion (4.5 mm on average). An 86.2% marked improvement was observed in the weighted PAR index score from an average of 24.7 at the beginning of treatment to 2.9 at the end of treatment, with no patient classified as "worse or no different." Class II, Division 2 malocclusions can be efficiently and reliably treated by a combination of a completely customized lingual appliance and the Herbst device.Fortschritte der Kieferorthopädie 05/2012; 73(3):225-35. DOI:10.1007/s00056-012-0077-0 · 0.82 Impact Factor