Changes Following the Treatment of Lower Jaw Protrusion Using Two Appliances
Condition: Class III Malocclusion in Growing Patients
MeSH terms: Prognathism; Malocclusion; Malocclusion, Angle Class III
Study type: Interventional

Summary: 
      An in vivo study evaluating the efficacy of the Tandem appliance in the treatment of
      maxillary deficiency in growing patients compared to the conventional facemask appliance
      treatment. Pre-treatment and post-treatment lateral cephalograms will be taken. Dentofacial,
      sagittal and vertical skeletal measurements will be taken at three assessment times. Changes
      within each group will be assessed. In addition, the changes between the two groups will be
      compared.
    

Detailed description: 
      Maxillary deficiency or retrusion is generally accepted as one of the most difficult and
      complex orthodontic anomalies to diagnose and treat. Facemask therapy is usually preferred
      for the treatment of subjects with skeletal and dental Class III malocclusions with a
      retruded maxilla, and it is known that if the patient is sufficiently motivated to wear a
      facemask, this type of therapy is quite successful. patient compliance required during
      facemask therapy due to its poor aesthetics and intraoral appliances for Class III
      malocclusion treatment such as the Fränkel III , bionator III don't give treatment goals
      .Hybrid appliance tandem traction bow appliance (TTBA)is introduced by Chun et al. 1999 , as
      a more aesthetic, effective and comfortable device. Klempner, 2003 modified tandem appliance
      and published two case reports suggested that TTBA and modified applications have a similar
      treatment effect to that of an expander-facemask combination(2). A review of the literature
      showed that there were no statistical studies documenting the effects of modified tandem
      appliance comparing to traditional expander-facemask therapy and these are the investigators
      study purposes.

      Study design: patients aged between 8-10 with anterior cross bite will be selected from
      orthodontic department in faculty of dentistry in Damascus university. Pretreatment
      cephalometric radiography will be taken. Subjects follow inclusion criteria (Skeletal Class
      III (ANB < 0 degree), due to maxillary retrusion, or a combination of maxillary retrusion and
      mandibular protrusion, Angle Class III malocclusion with an anterior crossbite., an optimum
      SN/GoGn angle between 26 and 38 degrees ,fully erupted maxillary incisors,,no congenitally
      missing teeth or congenital syndromes such as a cleft lip/palate will be . Patient will
      divided to two group tandem group and face mask group depended on growth pattern. Where from
      patients in face mask group have normal or horizontal growth pattern,tandem group have
      vertical one.

      Appliance Design The Tandem Appliance comprises three separate components,two fixed and one
      removable. The upper section is a fixed McNamara expander with buccal arms soldered for
      attachment of protraction elastics. The lower section is consist of two bands with buccal
      headgear tubes and buccolingual welded arch for support . Third one is head-gear facebow
      inserted into the lower tubes and the outer bows bent out for elastics attachment. At the
      beginning of treatment, patients or Panther are instructed to wear the appliance with light,
      8oz /14-16/ hours a day training elastics from the outer face-bow to the buccal arms of the
      upper expander. Subsequently, heavy orthopedic traction with 14oz /14-16/ hours a
      day,elastics effectively delivers the protraction force to the maxilla. Lateral cephalometric
      radiographs without the expander will be taken after a Class I molar relationship and a
      minimum overjet of 2 mm is obtained. Pre-treatment and post-treatment lateral cephalmetric
      dentofacial , sagittal and vertical skeletal parameters will be retraced by the author .
      Statistical analysis will be undertaken using the Statistical Package for Social Sciences,
      Windows version 19.0 (SPSS Inc., Chicago, Illinois, USA) Paired t-test will be used to
      evaluate the treatment effects and changes in same group. In depended t-test will be used to
      evaluate the treatment effects I between groups. confidence level 95% (P< 0.05).
    

Intervention name(s): Tandem Appliance
Intervention type(s): Device
Intervention description(s): We are going to use a modified version of the Tandem Appliance
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Maxillary protraction; Modified Tandem Appliance; Face mask therapy; Class III malocclusion; Maxillary deficiency