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Third Molar Position and Angulation In Orthodontically Treated Patients With Class II Malocclusion

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posted on 27.10.2017, 00:00 by Rory A Chong
Purpose: To determine whether Class II correction with non-extraction appliance therapy with mandibular advancement results in favorable rotational and positional changes in the mandibular third molar. Objective: To evaluate in 3D the treatment effects on the mandibular third molar angulation and position of Class II Division 1 patients pre-treatment to post-treatment with non-extraction orthodontic therapy with mandibular advancement. Methods: The sample will consist of CBCT images, pre-treatment and post-treatment, of an experimental group of 34 subjects with Class II Division 1 malocclusion treated orthodontically into Class I with non-extraction appliance therapy. Pre-treatment and post-treatment changes in position and angulation will be compared for left and right mandibular third molars. Additionally, pre-treatment and post-treatment changes in a group of 35 subjects with Class I malocclusion treated orthodontically with non-extraction appliance therapy will be used as a control group to compare changes resulting from treatment. Invivo5 Dental Version 5.4(Anatomage, San Jose, CA) software will be used to measure the changes in position and angulation in 3-D from the pre-treatment and post-treatment CBCT images. An analysis will be conducted to determine the changes of third molar angulation and position resulting from growth and treatment. Results: Mesial angulation and buccal uprighting improved for the Class II group. Change in anterior displacement evident in both groups, but a greater change anteriorly noted for the Class II group. Change in transverse position medially for both groups as a result of treatment. Positional changes for total distance and transverse displacement within subjects of Class I subjects between left and right third molars evident due to treatment. Conclusions: Class II correction mandibular advancement appliance therapy results in favorable rotational and positional changes in mandibular third molars.



Evans, Carla


Evans, Carla


Oral Sciences

Degree Grantor

University of Illinois at Chicago

Degree Level


Committee Member

Li, Haitao da Fonseca, Marcio Viana, Grace

Submitted date

May 2017

Issue date


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