Changes in glenoid fossa of adult female patients with Class II division 1 malocclusion during premolar extraction treatment and mini-implant anchorage: a cone-beam computed tomography study.

Abstract

Objectives: To evaluate changes in glenoid fossa morphology before, during, and after orthodontic treatment with extractions.

Materials and methods: Eighty-four cone-beam computed tomograms from 28 adult female patients with Angle Class II, division 1 malocclusion, who underwent orthodontic treatment involving premolar extraction and mini-implant insertion, were collected at three time points: before treatment (T0), during treatment (just before extraction space closure, T1), and after treatment (T2). Changes in the morphology of the glenoid fossa and the relationship of the anterior teeth among T0, T1, and T2 were recorded.

Results: Inclination of the articular eminence (AEI-BFL and AEI-TRL) increased from T1 to T2 and from T0 to T2, whereas the width of the glenoid fossa (GFW) decreased from T1 to T2 and from T0 to T2. Changes in depth of the glenoid fossa (GFD) and the ratio of GFW to GFD were observed only in T0-T2. The height of the articular eminence (AEH) showed no significant differences among the three time points. Except for incisor overbite, which decreased from T0 to T1 and then to T2, all other dental parameters showed differences only in T1-T2 and T0-T2.

Conclusions: Orthodontic treatment with extractions can induce adaptive morphological changes in the glenoid fossa, primarily during the stage of extraction space closure. These changes are mainly characterized by a steeper AEI and a reduction in GFW.