Cm. Mills et Kj. Mcculloch, TREATMENT EFFECTS OF THE TWIN BLOCK APPLIANCE - A CEPHALOMETRIC STUDY, American journal of orthodontics and dentofacial orthopedics, 114(1), 1998, pp. 15-24
A clinical study was undertaken to investigate the treatment effects o
f a modified Twin Block appliance. Pretreatment and posttreatment ceph
alometric records of 28 consecutively treated patients with Class II m
alocclusions were evaluated and compared with an age- and sex-matched
sample of untreated Class II control subjects, The treatment group was
considered to have severe skeletal Class II malocclusions and was tre
ated using only the Twin Block appliance. Results indicated that mandi
bular growth in the treatment group was on average 4.2 mm greater than
in the control group over the 14-month treatment period. In addition,
some dentoalveolar effects in both arches contributed to the overjet
correction. No statistically significant increase in the SN-mandibular
plane angle occurred during treatment and, in;general, the magnitude
and direction of the skeletal changes were found to be quite favorable
.