Treatment results with the Begg technique

Cephalometric comparison of vertical changes between Begg and preadjusted edgewise appliances

The purpose of this retrospective study was to quantify and compare the vertical dimensional changes in bialveolar dental protrusion patients undergoing extraction of all four first premolars between the preadjusted edgewise appliance (PEA) and the Begg appliance. The cephalometric records of 55 patients (14 males and 41 females) with Class I bimaxillary protrusion were selected and divided into two groups based on the appliance used, i.e Begg or PEA mechanotherapy. To minimize the effects of growth, the subjects were at least in stage VI of skeletal maturation. The mean age was 18.25 ± 3.2 years for the Begg group and 18.03 ± 3.5 years for the PEA group. Skeletal and dental changes were analysed in both groups on lateral cephalograms taken pre- (T1) and post- (T2) treatment. A Student's t-test was used to analyse the treatment changes. Within group results showed a significant increase in face height and extrusion and mesial movement of the upper and lower molars for both groups. However, no significant differences were observed when the groups were compared. A significant correlation was found between the change in lower molar to mandibular plane angle and lower anterior face height for both groups. No significant difference was found when the Begg mechanotherapy was compared to the PEA technique on vertical dimensional changes. It can be speculated that mesial movement of the molars tended to keep pace with their extrusion and negated any bite opening effect with both mechanotherapies.

Treatment stability with the eruption guidance appliance

INTRODUCTION

Although the eruption guidance appliance has been used to correct Class II malocclusions for many years and its effects have been demonstrated, there is no study on the stability of the changes it produces. Therefore, the objective of this study was to investigate the long-term stability of cephalometric dentoskeletal and occlusal changes after eruption guidance appliance therapy.

METHODS

Thirty-nine patients were evaluated. Occlusal evaluations were made with the peer asseessment rating index, and anterior tooth irregularity was evaluated with the Little irregularity index. Cephalometric and occlusal data were obtained at pretreatment, posttreatment, and postretention. The data were analyzed by dependent 1-way analysis of variance (ANOVA) for comparison between the 3 stages of the experimental group, with the Newman-Keuls test as a second step. To compare the cephalometric experimental group changes with mean population changes, the t test was used.

RESULTS

Cephalometrically, in the postretention stage, overjet remained stable, overbite showed significant relapse, and molar relationship improved toward a Class I relationship. The peer asseessment rating index showed stability of the occlusion. The Little irregularity index demonstrated a statistically significant relapse of crowding in the postretention stage.

CONCLUSIONS

Cephalometrically, overjet and molar relationship were stable in the long term after treatment with the eruption guidance appliance; however, there was relapse of the overbite. Occlusally, correction of the malocclusion elevated by the peer assessment rating was stable. There was relapse of the anterior teeth crowding.

Stability of the lower labial segment following orthodontic treatment--a comparison of treatment with Andresen and Begg appliances

This retrospective cephalometric study of Class II division 1 malocclusions investigates the effects on the lower labial segment of two forms of orthodontic treatment. Non-extraction Andresen myofunctional therapy and first premolar extraction Begg treatment are compared to the lower incisor changes found in appropriate non-extraction and first premolar extraction control groups, which also presented with Class II division 1 malocclusions. Using four angular and two linear measurements, the lower labial segment was found to procline during Andresen therapy (1-2 degrees, 1-2 mm), and on withdrawal of the appliance it retroclined by about one-half of the in-treatment proclination (0.4-0.8 degrees, 0.1-0.5 mm). During extraction Begg mechanics, the lower incisors were found to retrocline (1.3-1.5 degrees, 0.4-0.9 mm), and they continued to retrocline following removal of the appliance (0.2-3.0 degrees, 0.8-1.1 mm). In general, the variables used to measure lower incisor position demonstrated only very small changes, and were near method error. The reliability of these changes are discussed. It is considered that the axial inclination of the lower incisor in relation to the mandibular plane is the most consistent and therefore still the most useful clinical measurement of lower incisor change available from cephalometric radiographs.

A cephalometric investigation of overjet changes in fifty severe Class II division I malocclusions

A retrospective cephalometric study of 50 consecutively completed Class II Division I malocclusion cases was carried out in order to analyse the resultant data for craniofacial features which might act as predictors for successful overjet reduction. All the patients had clinically measured overjets of between 10 mm and 15 mm at the start of treatment. The sample was subsequently divided into two groups depending on whether or not the overjet had been reduced to 4 mm or less at the end of treatment. No firm predictors were found, but the most favourable results were achieved with the Begg appliance.

First premolar extractions and fixed appliances in the Class II division 1 malocclusion

This cephalometric study investigates the changes in the facial skeleton and dento-alveolar structures which occur during orthodontic treatment of the Class II Division 1 malocclusion by extraction of four first premolars followed by fixed appliances. The Begg and edgewise appliances are compared, and both are contrasted with a group of untreated Class II Division 1 subjects. The main effects of treatment were in the dento-alveolar structures, the changes in the overall facial pattern being small and largely due to extrusion of the molars during overbite reduction. Molar extrusion tended to interrupt forward growth rotation of the mandible, temporarily making it more backwards in direction, and increasing the lower anterior face height. An increase in the posterior lower face height was also noted in the edgewise group. Whilst SN A, and therefore AN B, reduced significantly during treatment, this was probably the result of palatal root torque to the upper incisors. The Begg appliance was more successful than edgewise in this respect.

A cephalometric appraisal of nonextraction Begg treatment of Class II malocclusions

Initial and final cephalometric evaluations are compared in a sample of 42 patients with Class II malocclusions treated in a nonextraction manner with the Begg appliance. The sample was analyzed as a group. Subgroups of patients with Division 1 and Division 2 characteristics were analyzed separately. To depict skeletal and dental changes, measurements were made using the sella nasion, palatal, and mandibular planes as reference planes. The findings show that on the average: The upper first molar maintained its anteroposterior position at the same time that SNA was reduced. This suggests a restriction of anterior maxillary growth. The mandibular first molar moved forward by 1.2 mm. Part of this change was attributed to anchorage consumption. Vertical changes in both the maxilla and the mandible were found to be within the normal range. No significant change in occlusal or mandibular plane angles was observed except for the Division 1 subgroup in whom a mild increase in the mandibular plane angle was observed.