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Finite Element Analysis Model for Assessing Expansion Patterns from Surgically Assisted Rapid Palatal Expansion
Published on: October 20, 2023
[Effect of repetitive rapid palatal expansions and constrictions by double hinged expander in maxillary protraction
1Department of Orthodontics, Peking University School, Beijing, China.
Objective:
To investigate the benefits of repetitive rapid palatal expansions/constrictions therapy using double hinged expander over rapid palatal expansion alone with Hyrax expander in maxillary protractions cases and to discuss the indications of the combination therapy.
Methods:
Thirty four children with retrognathic maxilla were selected and randomly divided into two treatment groups. Eighteen children were in group A and received maxillary protraction with Hyrax expander rapid palatal expansion alone. Sixteen children were in group B and received maxillary protraction with double hinged expander repetitive rapid palatal expansions/constrictions combin therapy. Cephalometric analysis was done to compare the pre and post-treatment lateral cephalograms.
Results:
Significant difference in forward movement of maxilla (P<0.05)were observed between group B [A-Np increased 2.53 mm, A-vertical line (A-VRL) increased 2.78 mm] and group A (relatively 1.86 mm and 2.01 mm). Significant difference in soft tissue backward movement of mandible (P<0.05)were also observed between group A (LLC-VRL decreased 2.82 mm) and group B (relatively 1.63 mm).
Conclusion:
Repetitive rapid palatal expansions/constrictions using double hinged expander resulted in more maxilla forward movement compared with Hyrax rapid palatal expansion alone in maxillary protraction cases.
