The Journal
However , in the study of Kravit et al . 2009 , while comparing the predicted treatment outcomes in ClinCheck with the achieved outcomes , the average accuracy of labial expansion of the maxillary central incisors was 48.5 %, the maxillary lateral incisors was 49 %, the maxillary canines was 36 %, the lower incisor was 27.4 %, the mandibular incisors was 50.8 %, and the mandibular canines was 29.9 %. The average accuracy of anterior labial expansion was
9
40.5 %.
B . Constriction Constriction is used to reduce the alveolar arch length , so it can reduce the discrepancy dentoalveolar . There was one study on the accuracy of constriction so far . The invisalign move teeth
Maintaining torque control in the process of intrusion is very important , because if the root apex contacts with the labial or lingual cortical bone , a root resorption can be produced . The mandibular central incisors had the highest accuracy ( 46.6 %) and the maxillary lateral incisors had the lowest ( 32.5 %) accuracy for intrusion9 . Nguyen and Cheng however , reported that incisor intrusion showed high achievement of 85 %. Canine intrusion was
5 above the average achievement ( 64 %) .
Krieger et al . 2011 reported that the mean difference in the treatment of overbites between the post treatment cast and the final position in the Clin Check was 0.9 mm ( from 1mm to 3mm )
AUTHOR
INTRUSION
Nguyen and Cheng [ 5 ] Incisor 85 % Anterior 79 %
Kravitz et al . [ 9 ] Anterior 41.3 %
with the most accuracy with the lingual constriction ( 47.1 %). The highest accuracy was the lingual constriction of the mandibular canines ( 59.3 %) and the lowest accuracy was the lingual constriction of the maxillary canines ( 34.7 %). This suggests that Invisalign can be successfully treated with the highest accuracy
9 in anterior spacing cases .
C . Intrusion To intrude the teeth , a labio-lingual inclination ( torque ) should be corrected , then the intrusion can be done in the spongy bone .
AUTHOR and that “ the amount of concordance between predicted and actual treatment results was
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14.3 %” .
D . Due to lack of retention for extrusion , it is difficult to extrude the teeth by Clear Aligner . Extrusion is unpredictable by Invisalign , but
1
using attachments can overcome this difficulty . The mean accuracy of anterior extrusion is similar in the study of Kravitz ( 29.6 %) and of
9 , 5
Nguyen and Cheng ( 29 %) .
INTRUSION
Nguyen and Cheng Incisor 26 % Anterior 29 % Posterior 52 %
Kravitz et al . 2009 Anterior 41.3 %
5 Vol . 14 No . 1 Jan-Apr 2018