The skeletal anchorage system (SAS) consists of titanium anchor
plates and monocortical screws that are temporarily implanted in either
the maxilla or the mandible as absolute orthodontic anchorage.
With SAS, anterior open bite can be improved by the counterclockwise
rotation of the mandible, accompanied by the intrusion of molars. The
present study was designed to evaluate treatment and posttreatment
dentoalveolar changes following the intrusion of mandibular molars.
Nine adult open bite patients (7 women and 2 men) successfully
treated with SAS were included in the following study. The amount of
intrusion, relapse, and dentoalveolar changes were measured on
cephalometric radiographs, panoramic radiographs, and dental casts.
The results of this study were as follows: (1) the average amount of intrusion
of the mandibular first and second molars was 1.7 mm and 2.8
mm, respectively; (2) the average relapse rates were 27.2% at the first
molars and 30.3% at the second molars; (3) there were no significant
changes in crestal bone heights, clinical crown length, or root length;
and (4) counterclockwise rotation of the mandible and decrease of anterior
facial height were observed during treatment. Thus, it was concluded
that SAS would be a valid modality to intrude mandibular molars
for correction of open bite.