[Comparison of hard tissue changes by treatment of angle class II malocclusion with Kloehn's extraoral arch in periods of transitional dentition and permanent tooth].
OBJECTIVE
The optimal treatment period by use of extraoral arch was understood by comparison of the changes of facial hard tissue in treatment of Angle II malocclusion with Kloehn's extraoral arch and Edgwise appliance.


METHODS
A group of 7-8 year old children and a group of 10-11 year-old children were selected, including 16 Angle II malocclusion cases in each group, respectively. Data of cephalograms and model analysis were compared between pretreatment and posttreatment.


RESULTS
The more distance of maxillary molar and more obvious inhibition of maxilla bone growth forward in group of 7-8 year-old children (group of transitional dentition) were detected than that in group of 10-11 year-old children(group of permanent tooth).


CONCLUSIONS
More effective treatment by use of extraoral arch was detected in the period of transitional dentition than that in permanent tooth.
Li
S H
SH
Department of Stomatology, University Hospital, Ocean University of Qingdao, Qingdao 266003, Shandong province, China.
Qin
Y L
YL
Zhao
J
J