Tooth-Borne Versus Tooth-Bone-Borne Rapid Maxillary Expanders: A Stereophotogrammetric Evaluation of Soft Tissues
Condition: Posterior Crossbite
MeSH terms: Malocclusion
Study type: Interventional

Summary: 
      The force exerted by the rapid maxillary expansion (RME) appliances provides expansion of the
      transverse dimension by splitting of the midpalatal suture. This expansion results in
      three-dimensional (3D) changes in maxillary position which also effects circummaxillary
      surrounding structures. The aim of this randomized clinical trial (RCT) was to evaluate the
      effects of tooth-borne and tooth-bone-borne rapid maxillary expansion (RME) on soft tissue
      with stereophotogrammetry.
    

Detailed description: 
      Introduction: To evaluate the effects of tooth-borne and tooth-bone-borne rapid maxillary
      expansion (RME) on soft tissue with stereophotogrammetry. Methods: 32 patients (15 males, 17
      females) who met inclusion criteria were divided into two groups. In the first group,
      tooth-borne RME appliance (Hyrax) was applied to 16 patients (9 males, 7 females mean age
      13.4 ± 1.3 years) and in the second group, tooth-bone-borne RME appliance (Hybrid Hyrax) was
      applied to 16 patients (6 males, 10 females mean age 13.05 ±1.24 years). A simple
      electronically generated randomization was performed before trial commencement using the
      Random Allocation Software program. Allocation concealment involved numbered, sealed, and
      opaque envelopes prepared before trial commencement. One envelope was sequentially opened for
      each participant during recruitment. Each envelope contained a card with the name of 1
      expander. The initials of the name of the participant, the type of expander, and the date of
      allocation were identified in the external surface of the envelope. One operator was
      responsible for the randomization process, allocation concealment, and implementation. The
      primary outcomes of this study was assessment of changes in soft tissues before RME (T0) and
      post-retention (T1) period by stereophotogrammetry. Independent and dependent sample t tests
      were used to compare intra- and inter-group differences at P<0.05 significance level.
    

Intervention name(s): Rapid Maxillary Expansion Treatment with Tooth-borne RME appliance (Hyrax); Rapid Maxillary Expansion Treatment with Hybrid hyrax RME appliance
Intervention type(s): Device; Device
Intervention description(s): The patients were treated with a expansion appliance containing a Hyrax expansion screw positioned parallel to the second premolars and were used to correct the posterior crossbite. RME activation was performed twice a day for the first week and then once per day. When it was decided that the expansion was sufficient (until the palatal tubercles of the upper molars came into contact with the buccal tubercles of the lower molars), the screw was fixed with the 0.012-inch ligature wire (American Orthodontics) and the appliance was kept in the mouth without being activated for 3 months.; The patients were treated with a Hybrid hyrax RME appliance containing a Hyrax expansion screw positioned parallel to the second premolars and mini-screws. RME activation was performed twice a day for the first week and then once per day. When it was decided that the expansion was sufficient (until the palatal tubercles of the upper molars came into contact with the buccal tubercles of the lower molars), the screw was fixed with the 0.012-inch ligature wire (American Orthodontics) and the appliance was kept in the mouth without being activated for 3 months.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: 2-arm parallel trial
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: stereophotogrammetry; Tooth-bone-borne rapid maxillary expansion; skeletal anchorage; mini-screws