Influence of cephalometric characteristics on the occlusal success rate of Class II malocclusions treated with 2-and 4-premolar extraction protocols

Introduction: The objectives of this investigation were to compare the initial cephalometric characteristics of complete Class II Division 1 malocclusions treated with 2 or 4 premolar extractions and to verify their influence on the occlusal success rate of these treatment protocols. Methods: A sample of 98 records from patients with complete Class II Division 1 malocclusion was divided into 2 groups with the following characteristics: group 1 consisted of 55 patients treated with 2 maxillary first premolar extractions at an initial mean age of 13.07 years; group 2 included 43 patients treated with 4 premolar extractions, with an initial mean age of 12.92 years. Initial and final occlusal statuses were evaluated on dental casts with Grainger`s treatment priority index (TPI), and the initial cephalometric characteristics were obtained from the pretreatment cephalograms. The initial cephalometric characteristics and the initial and final occlusal statuses of the groups were compared with the t test. A multiple regression analysis was used to evaluate the influence of all variables in the final TPI. Results: The 2-premolar extraction protocol provided a statistically smaller TPI and consequently a better occlusal success rate than the 4-premolar extraction protocol. The 4-premolar extraction group had statistically smaller apical base lengths, more vertical facial growth patterns, and greater hard- and soft-tissue convexities at pretreatment than the 2-premolar extraction group. However, the multiple regression analysis showed that only the extraction protocol was significantly associated with the final occlusal status. Conclusions: The initial cephalometric characteristics of the groups did not influence the occlusal success rate of these 2 treatment protocols.

Six-year evaluation of the atraumatic restorative treatment approach in permanent-tooth Class III restorations

Purpose: The aim of this study was to assess the 6-year performance of the ART (atraumatic restorative treatment) approach in Class III restorations in permanent teeth. Materials and Methods: A total of 127 ART Class III restorations, using Ketac-Molar (3M ESPE) ionomer cement, was performed in 58 adult patients by one experienced operator in 1998. After a 6 years, 34 patients and 65 restorations were evaluated according to ART criteria. Two calibrated examiners carried out the evaluation. Data were analyzed by exact 95% Confidence Interval and Survival Analysis using the Jackknife method for standard error determination. Results: Among assessed restorations, 73.8% (95% CI = 61.5% to 86.2%) were in good condition and classified as successful, with a 67.6% (95% CI = 54.4% to 80.7%) cumulative survival rate. Failed restorations included 13.9% completely or partially missing restorations, 9.2% restorations that had been replaced by other treatment, 1.5% restorations with a large defect at the margin, and 1.5% restorations that presented high wear on the surface. No caries was observed even in those teeth in which restorations were absent. Conclusion: The 6-year success rate of the ART approach in anterior permanent teeth (Class III) was considered high.

Occlusal outcomes and efficiency of 1-and 2-phase protocols in the treatment of Class II Division 1 malocclusion

Introduction: The purpose of this study was to compare the occlusal outcomes and the efficiency of 1-phase and 2-phase treatment protocols in Class II Division 1 malocclusions. Treatment efficiency was defined as a change in the occlusal characteristics in a shorter treatment time. Methods: Class II Division 1 subjects ( n = 139) were divided into 2 groups according to the treatment protocol for Class II correction. Group 1 comprised 78 patients treated with a 1-phase treatment protocol at initial and final mean ages of 12.51 and 14.68 years. Group 2 comprised 61 patients treated with a 2-phase treatment protocol at initial and final mean ages of 11.21 and 14.70 years. Lateral cephalometric radiographs were taken at the pretreatment stage to evaluate morphological differences in the groups. The initial and final study models of the patients were evaluated by using the peer assessment rating index. Chi-square tests were used to test for differences between the 2 groups for categorical variables. Variables regarding occlusal results were compared by using independent t tests. A linear regression analysis was completed, with total treatment time as the dependent variable, to identify clinical factors that predict treatment length for patients with Class II malocclusions. Results: Similar occlusal outcomes were obtained between the 1-phase and the 2-phase treatment protocols, but the duration of treatment was significantly shorter in the 1-phase treatment protocol group. Conclusions: Treatment of Class II Division 1 malocclusions is more efficient with the 1-phase than the 2-phase treatment protocol.

A 24-month randomized clinical trial of a two- and three-step etch-and-rinse technique

Purpose This 24-month randomized paired tooth clinical study evaluated the performance of All Bond 3 used in the simplified (2-step) and full (3-step) versions Methods 33 patients, with at least two similar sized non-carious cervical lesions participated in this study A total of 66 restorations were placed, half using the 2-step All Bond 3 (AB3-2) and the other half using 3-step All Bond 3 (AB3-3) The restorations were placed incrementally using the composite resin Aelite The restorations were evaluated at baseline and after 6, 12 and 24 months following the modified USPHS criteria Statistical differences between the adhesive were tested using with McNemar`s test and clinical performance over time for each material with the Fisher`s exact test (alpha= 0 05) Results After 24 months, six AB3-2 and four AB3-3 were rated as bravo for marginal discoloration but did not differ from each other significantly (P> 0 05) The retention rates at 24 months of AB3-2 and AB3-3 were 90 9% and 97 0%, respectively (P> 0 05) (Am J Dent 2010,23 231-236)

Class III subdivision malocclusion corrected with asymmetric intermaxillary elastics

Correcting a Class III subdivision malocclusion is usually a challenge for an orthodontist, especially if the patient`s profile does not allow for any extractions. One treatment option is to use asymmetric intermaxillary elastics to correct the unilateral anteroposterior discrepancy. However, the success of this method depends on the individual response of each patient and his or her compliance in using the elastics. The objectives of this article were to present a successful treatment of a Class III subdivision patient with this approach and to illustrate and discuss the dentoskeletal changes that contributed to the correction. (Am J Orthod Dentofacial Orthop 2010;138:221-30)

A modified orthodontic protocol for advanced periodontal disease in Class II division 1 malocclusion

An interdisciplinary approach is often the best option for achieving a predictable outcome for an adult patient with complex clinical problems. This case report demonstrates the combined periodontal/orthodontic treatment for a 49-year-old woman presenting with a Class II Division 1 malocclusion with moderate maxillary anterior crowding, a 9-mm overjet, and moderate to severe bone loss as the main characteristics of the periodontal disease. The orthodontic treatment included 2 maxillary first premolar extractions through forced extrusion. Active orthodontic treatment was completed in 30 months. The treatment outcomes, including the periodontal condition, were stable 17 months after active orthodontic treatment. The advantages of this interdisciplinary approach are discussed. Periodontally compromised orthodontic patients can be satisfactorily treated, achieving most of the conventional orthodontic goals, if a combined orthodontic/periodontic approach is used. (Am J Orthod Dentofacial Orthop 2011; 139:S133-44)

Vitamin D receptor haplotypes affect lead levels during pregnancy

Pregnant women are particularly susceptible to toxic effects associated with lead (Pb) exposure. Pb accumulates in bone tissue and is rapidly mobilized from bones during pregnancy, thus resulting in fetal contamination. While vitamin D receptor (VDR) polymorphisms modify bone mineralization and affect Pb biomarkers including blood (Pb-B) and serum (Pb-S) Pb concentrations, and %Pb-S/Pb-B ratio, the effects of these polymorphisms on Pb levels in pregnant women are unknown. This study aimed at examining the effects of three (Fokl, Bsml and Apal) VDR polymorphisms (and VDR haplotypes) on Pb levels in pregnant women. Pb-B and Pb-S were determined by inductively coupled plasma mass spectrometry in samples from 256 healthy pregnant women and their respective umbilical cords. Genotypes for the VDR polymorphisms were determined by PCR and restriction fragment length digestion. While the three VDR polymorphisms had no significant effects on Pb-B, Pb-S or %Pb-S/Pb-B ratio, the haplotype combining the f, a, and b alleles for the Fokl, Apal and Bsml polymorphisms, respectively, was associated with significantly lower Pb-S and %Pb-S/Pb-B (P<0.05). However, maternal VDR haplotypes had no effects on Pb levels in the umbilical cords. To our knowledge, this is the first study showing that a combination of genetic polymorphisms (haplotype) commonly found in the VDR gene affects Pb-S and %Pb-S/Pb-B ratios in pregnant women. These findings may have major implications for Pb toxicity because they may help to predict the existence of a group of subjects that is genetically less prone to Pb toxicity during pregnancy. (C) 2010 Elsevier B.V. All rights reserved.