L. Eslamian ,
Volume 15, Issue 1 (3-2002)
Abstract
Various comparative studies have been conducted to investigate the effect of functional and fixed appliances in treatment of class II skeletal disorders. The aim of this study was to compare Bionator and Edgewise appliances associated with class II elastics in the treatment of class II skeletal patients, without extraction. Lateral cephalograms of 30 patients (16 girls, 14 boys), 10-13 years old, with class II div I maolocclusion, treated with Bionater and Edgewise appliances were investigated before and after treatment. SNA, SNB, ANB, " to SN, IMP A, mandibular and maxillary lengths, upper anterior facial height to lower anterior facial height, overjet and overbite were measured in each group before and after treatment. The results were analyzed by paired t- test. The magnification of linear measurements were calculated. The differences between variables in 2 groups were compared by t-test. There was no significant difference, regarding age and sex. In both groups, increase in SNB, mandibular length, and IMPA and decrease in " to SN, overjet and overbite and upper anterior face height to lower anterior face height after treatment were statistically significant. Comparing 2 groups before and after treatment showed that increase in SNB and decrease of ANB, overjet and overbite were more in Bionator group than fixed group, which were significant. Decrease in upper anterior face height to lower anterior face height, and increase in IMPA and mandibular length were more in Bionater group but the differences were not statistically significant.
F. Heravi , Sh. Sahafian ,
Volume 17, Issue 3 (8-2004)
Abstract
Statement of Problem: Tooth extraction is a common technique in orthodontics and most of the specialists believe that this technique is able to change the facial appearance.
Purpose: The aim of this study was to investigate facial vertical changes in orthodontic patients following tooth extraction.
Materials and Methods: Thirty patients, after their growth spurt, with CLI malocclusion all treated by a specific orthodontist through Edgewise technique along with the extraction of four first premolars were chosen. Lateral cephalograms of patients, before and after treatment were compared and facial vertical changes and teeth were studied.
Results: Anterior and posterior facial heights were increased during treatment. Despite the limited use of intermaxillary elastics, teeth were extruded. The most increase in facial heights was observed in the lower third of face. Patients with longer faces before treatment showed more extrusion of mandibular molars as well as more increase of mandibular slope.
Conclusion: Tooth extraction in orthodontic treatments can not guarantee the decrease or even non-increase of facial height. Among patients with long faces, it is particularly suggested to refrain from the application of extrusive orthodontic forces.
