Mandibular kinematic changes after unilateral cross‐bite with lateral shift correction

Abstract

The aim of this randomised prospective study was to evaluate the effects of slow maxillary expansion with expansion plates and Hyrax 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 Hyrax 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 Hyrax expander showed better results than did the expansion plate. The Hyrax expander with acrylic occlusal covering significantly improved the mandibular lateral shift and normalised the range of lateral excursion.

Improvement of masticatory kinematic parameters after correction of unilateral posterior crossbite: Reasons for functional retention

“…These results are in agreement with the literature. [3][4][5][6]10,[13][14][15] There are no other reports in the literature demonstrating a significant decrease of reverse-sequencing chewing patterns after crossbite correction with other devices. In this study, the FGB appliance successfully corrected the malocclusion and recovered masticatory function symmetry.…”

A New Approach to Diagnosis to Posterior Cross Bite: Intraoral Photography and Wala Ridge

“…About the treatment of the posterior crossbite several authors have suggested that early treatment of posterior crossbite is necessary to avoid long-term effects on the normal growth of the jaws and teeth [ 14 , 15 ]. The treatment of the posterior crossbite produced favorable changes in the position of the mandible and prevented functional alterations [ 32 ]. Otherwise, the lack of treatment can cause alterations in the activity of some muscles of mastication (i.e., the masseter and temporalis muscles) in children and promote craniomandibular disorders in adolescents [ 9 , 10 ].…”

Positional and dimensional temporomandibular joint changes after correction of posterior crossbite in growing patients:A systematic review

“…Subsequently, the remaining 15 studies were read in full text for eligibility assessment according to the inclusion criteria. The excluded studies 7,10,[22][23][24][25][26][27][28][29][30][31][32] and reasons for their exclusion are summarized in Table 1. Finally, two studies were included in this review: Lippold et al (2008) 11 and McLeod et al (2016).…”

“…This review included two RCTs. According to the Cochrane Risk of Bias Tool, both studies were judged as having low RoB for random-sequence generation 7 No control group Kecik et al 10 No untreated control group Hesse et al 22 No control group de Boer and Steenks 23 No joint measurements Martin et al 24 No joint measurements Arat et al 25 No control group Costa et al 26 No control group Matta et al 27 No control group Masi et al 28 No control group Lagravere et al 29 No joint measurements Leonardi et al 30 No untreated control group Venancio et al 31 No joint measurements Melgaco et al 32 No crossbite in the treatment group Figure 2 and Appendix 2.…”