Dental Asia January/February 2023

CLINICAL FEATURE
Pre-operative radiographs
Post-operative radiographs
Post-operative intraoral photos
The CMA creates a mesial out rotation
around the palatal roots of the first molars
and enhance the mandible to a forward
position as the molars were de-rotating. Also,
the lower teeth were extruded due to upward
vector pull from the elastics. Therefore, it
reduces overbite and promotes changes on
the occlusal plane. Stage I corrects sagittal,
and stage II corrects dental discrepancies.
Rodriguez in 2019 reported the long-term
sagittal stability of the treatment was good 9 .
Popowich in 2005 reported that for nonextraction
Class II patients, the average time
Class II elastic wear was about 10 months
and 25.7 months for fixed appliance. In the
CMA sample, the first phase averaged 5.1
months (±2.8 months), and the second phase
with fixed appliance was about 13.0 months
(±4.2 months). The total treatment duration
was 18.2 months (±4.8 months). Therefore,
the advantages of CMA treatment were the
reduced duration of elastic wear and overall
treatment time 8 .
McNamara et al. in 2012 traced 32 patients
with serial of cephalograms at three-time
intervals: T1 (initial), T2 (removal of CMA),
and T3 (post-treatment). The results were
digitised, and superimpositions were
constructed to compare the linear and
angular variables with untreated subjects
who were presented with normal facial
profile and occlusions. Variable of ≥2.0mm
or ≥2.0° was used as an indication of clinical
significance. They found the nature of
treatment effects of CMA are dento-alveloar
with only little skeletal changes 4 .
These findings were also investigated by
O’Brien and coworkers. They measured
skeletal and dentoalveolar changes and
used P value of