[Assessment of facial skeletal growth and response to implanted functional appliance therapy with three-dimensional images].
OBJECTIVE
To evaluate the facial skeletal growth and response to implanted functional appliance therapy with three-dimensional images.


METHODS
Eleven male Beagle dogs (7 months old and in late mixed dentition) were randomly divided into four groups: implanted functional appliance group, semi-implanted functional appliance group, modified Forsus(TM) group and the control group. After the appliances were inserted in the experimental groups for 4, 8, 12 weeks and 4 weeks after the appliances were removed, the facial skeleton and teeth of the Beagle dogs digital information was obtained by using spiral computed tomography, then Mimics 8.1 software and a kind of retro-engineering software called qualify V8.0 were used to establish three-dimensional facial skeletal and dental images of the Beagle dogs. Three-dimensional structure changes of the facial skeleton and teeth in each group at different stages were assessed by the Bjork method, i.e. the superimposition technique based on the "best fit" of anterior cranial base structure and mandible metallic implants.


RESULTS
Mandibles in the groups with implanted functional appliance, semi-implanted functional appliance, and modified ForsusTM were obviously displaced forward, while the growth of the maxilla was inhibited in some degree. The displacement of upper teeth in the group with implanted functional appliance was not obvious, while the distal movement of upper teeth in the group with semi-implanted functional appliance and modified ForsusTM was significant compared with that in the control group.


CONCLUSIONS
The implanted functional appliance can significantly stimulate the growth of the mandible and avoid the unwanted movement of teeth which is frequently found in other functional appliances. Supported by Wenzhou International Cooperative Research Project (Grant No. B00260027).
Lin
Xin-Ping
XP
Department of Orthodontics, School & Hospital of Stomatology, Zhejiang University, Hangzhou 310006, Zhejiang Province, China.
Lin
Jiu-Xiang
JX
Wang
Jian-Feng
JF
Cao
Ya-Bo
YB
Sun
Xu-Rong
XR
Chen
Wei-Ting
WT
Xu
Ting
T
D000818:Animals; D002508:Cephalometry; D004285:Dogs; D021621:Imaging, Three-Dimensional; D008297:Male; D008334:Mandible / Q000254:growth & development*; D008437:Maxilla / Q000254:growth & development*