Stability of first and second premolars extraction space closure.

Introduction: Premolars are the teeth most often extracted to provide space to correct crowding, excessive dental and/or labial protrusion, and to compensate for the sagittal discrepancy. After treatment, the extraction spaces have to remain closed. Nevertheless, several studies have shown a tendency for some relapse even in patients finished with an adequate occlusion.

Prevalence of extraction space reopening in different orthodontic treatment protocols.

Introduction: In this study, we aimed to compare the amount and frequency of extraction space reopening after 2- and 4-premolar extraction treatments in Class II and 4-premolar extractions in Class I malocclusion patients.

Methods: The sample comprised 105 subjects with full-cusp Class II and Class I malocclusions, divided into 3 groups. Group 1 consisted of 33 full-cusp Class II malocclusion patients treated with a 2-premolar extraction protocol.

Posterior teeth angulation in non-extraction and extraction treatment of anterior open-bite patients.

Backgound: This study cephalometrically evaluated the posterior teeth angulation changes of anterior open-bite non-extraction and extraction treatment in the permanent dentition, with anterior vertical elastics.

Methods: The sample consisted of initial and final lateral headfilms of 60 patients divided into 2 groups: Group 1 consisted of 30 patients treated with non-extraction with an initial mean age of 15.26 years and treated with fixed appliances for a mean period of 2.

Posterior tooth angulations in patients with anterior open bite and normal occlusion.

Introduction: The aim of this study was to compare the posterior tooth angulations in patients with open-bite malocclusion and normal occlusion.

Methods: Lateral cephalometric headfilms of 45 untreated open-bite subjects were compared with the lateral headfilms of 45 subjects with normal occlusion in the permanent dentition. The groups were matched for age and sex distribution and compared with t tests.