Class III Malocclusion in Growing Patients Clinical Trial
Official title:
A Comparison of the Skeletal and Dento-alveolar Changes After Treatment of Class III Malocclusion With a Modified Tandem Appliance Versus the Face Mask
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.
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).
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Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment