Premium
Mandibular kinematic changes after unilateral cross‐bite with lateral shift correction
Author(s) -
Venancio F.,
Alarcon J. A.,
Lenguas L.,
Kassem M.,
Martin C.
Publication year - 2014
Publication title -
journal of oral rehabilitation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 93
eISSN - 1365-2842
pISSN - 0305-182X
DOI - 10.1111/joor.12199
Subject(s) - occlusion , medicine , excursion , mandible (arthropod mouthpart) , orthodontics , surgery , botany , political science , law , biology , genus
Summary The aim of this randomised prospective study was to evaluate the effects of slow maxillary expansion with expansion plates and H yrax expanders on the kinematics of the mandible after cross‐bite correction. Thirty children (15 boys and 15 girls), aged 7·1–11·8, with unilateral cross‐bite and functional shift were divided into two groups: expansion plate ( n = 15) and H yrax expander ( n = 15). Thirty children with normal occlusion (14 boys and 16 girls, aged 7·3–11·6) served as control group. The maximum vertical opening, lateral mandibular shift (from maximum vertical opening to maximum intercuspation, from rest position to maximum intercuspation and from maximum vertical opening to rest position) and lateral excursions were recorded before and 4 months after treatment. After treatment, the expansion plate group showed a greater lateral shift from rest position to maximum intercuspation than did the control group. The expansion plate patients also presented greater left/contralateral excursion than did the control group. Comparisons of changes after treatment in the cross‐bite groups showed significant decreases in the lateral shift from the maximum vertical opening to maximum intercuspation and from the maximum vertical opening to rest position, a significant increase in the homolateral excursion and a significant decrease in the contralateral excursion in the Hyrax expander group, whereas no significant differences were found in the expansion plate group. In conclusion, the H yrax expander showed better results than did the expansion plate. The H yrax expander with acrylic occlusal covering significantly improved the mandibular lateral shift and normalised the range of lateral excursion.