Comparison of Two Miniscrew Anchored Maxillary Protraction Protocols
Condition: Malocclusion, Angle Class III; Crossbite (Anterior) (Posterior)
MeSH terms: Prognathism; Malocclusion; Malocclusion, Angle Class III
Study type: Interventional

Summary: 
      This study evaluates the dentoskeletal effects produced by two maxillary protraction
      protocols in adolescent patients. Half of participants will be treated with a tooth-borne and
      tooth-bone-borne expanders as anchorage in the maxillary arch. Miniscrews will be used as
      anchorage in the mandibular arch for both groups.
    

Detailed description: 
      Class III malocclusion treatment in growing patients is challenging. A new treatment for
      maxillary protraction using skeletal anchorage reported an efficient maxillary protraction in
      the late mixed dentition an early permanent dentition. Therefore, the aim of this study is to
      compare the dentoskeletal effects produced by two maxillary protraction protocols anchored on
      miniscrews.

      The sample will be recruited at the Orthodontic Clinic of Bauru Dental School, University of
      São Paulo, Brazil. A sample of thirty-five patients, between 9 and 13 years old will be
      selected. The inclusion criteria are: Class III malocclusion associated with anterior
      crossbite. The participants will be allocated into 2 groups. Group 1 will comprise 20
      individuals treated with a tooth-bone-borne expander and 2 miniscrews in the mandible Group 2
      will comprise 15 individuals treated with a tooth-borne expander and 2 miniscrews in the
      mandible. Digital models and cone-beam computed tomography (CBCT) will be obtained before
      (T1) and 12 months after treatment (T2). Occlusal radiographs and partial (canine to canine)
      models will be obtained before and immediately after expansion. Two-dimensional cephalometric
      evaluations will be performed in the Dolphin® software. The arch width, arch perimeter and
      arch length will be analyzed with the Orthoanalyzer® software. Three-dimensional
      superimposition at the cranial base of T1 and T2 CBCT images will be performed. The inter
      incisor diastema will be evaluated by occlusal radiographs and dental models. Discomfort,
      pain and quality of life will evaluated by questionnaires. After verifying the normal
      distribution, the intragroup comparison will be performed with paired t test and intergroup
      comparison will be performed with t test. In the case of lost to follow-up patients,
      intention to treat analysis will be used. A significance level of 5% will be regarded for all
      tests.

      Temporary pain and discomfort are possible after the installation of the miniscrews. Patients
      and legal guardians will be informed. After the consent, the treatment can be stoped at any
      time.
    

Intervention name(s): MAMP therapy with MARPE expander; MAMP therapy with Hyrax expander
Intervention type(s): Device; Device
Intervention description(s): Twenty patients will be submitted to MAMP therapy with MARPE expander as anchorage in the maxillary arch. The appliance anchorage will be provided by bands adapted on the maxillary first permanent molars and circumferential clamps in the maxillary canines or premolars. The maxillary and mandibular miniscrews will be placed in the same section. After a 24-hour period, parents will be oriented to activate the expander screw. Patients will be instructed to wear intermaxillary elastics connecting the maxillary first molar hooks to the mandibular mini-implants.; Fifteen patients will be submitted to MAMP therapy with Hyrax expander as anchorage in the maxillary arch. The appliance anchorage will be provided by bands adapted on the maxillary first permanent molars and circumferential clamps in the maxillary canines or premolars. The mandibular miniscrews will be placed and after a 24-hour period, parents will be oriented to activate the expander screw. Patients will be instructed to wear intermaxillary elastics connecting the maxillary first molar hooks and the mandibular mini-implants.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Orthodontic Anchorage Procedures; Malocclusion, Angle Class III; Palatal Expansion Technique.; Cone-Beam Computed Tomography; Dental Models