[Changes of cranio-facial hard tissue after orthodontic treatment in bimaxillary protrusive patients].
OBJECTIVE
The aim of this study is to investigate the changes of hard tissue profile in anterior-posterior and vertical direction in bimaxillary protrusion patients after orthodontic treatment.


METHODS
A total of 24 bimaxillary protrusion patients (male 8, female 16), aged from 11.2 to 29.0 (average 16.9 years old), were selected to be treated with standard edgewise technique consisted of 4 first premolars extraction. Cephalometrics were taken before and after treatment. The changes of hard tissue profile were studied using the computer-aid X-ray cephalometric analysis.


RESULTS
1. The length of the maxillary and the mandible increased significantly, but the anterior-posterior relationship of the maxillary and the mandible did not change significantly. 2. The anterior and posterior facial height increased significantly, but the ratio of anterior and posterior facial height and the angle of MP-FH which reflected the inclination of the mandible plane did not change significantly. 3. The height of the upper and lower first molar increased significantly along with the increase of the anterior and posterior facial height. 4. The height of the upper incisors increased significantly, but the height of the lower incisors decreased significantly.


CONCLUSIONS
The anchorage in anterior-posterior and vertical direction were controlled preferably, the patients did not manifest disadvantageous vertical growth trend.
Xie
Yong-jian
YJ
Dept. of Orthodontics, Guanghua College of Stomatology, Sun Yat-Sen University, Guangzhou 510055, China.
Wang
Da-wei
DW
Lin
Jie-wei
JW
Lu
Xin-hua
XH
He
Xu-shun
XS
D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D002648:Child; D005147:Facial Bones / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D009969:Orthodontic Wires; D009971:Orthodontics, Corrective; D011378:Prognathism / Q000628:therapy*; D012886:Skull / Q000473:pathology*