All ETDs from UAB

Advisory Committee Chair

Chung How Kau

Advisory Committee Members

Kyounga Cecilia Cheon

Amjad Javed

Christos Vlachos

Document Type


Date of Award


Degree Name by School

Master of Dentistry (MDent) School of Dentistry


Objective: The purpose of this study was to evaluate the maxillary central incisor position changes after orthodontic treatment in Class I, II and III malocclusions. Material and Methods: This retrospective cohort study evaluated nighty non extraction orthodontic Class I, II and III cases which were collected randomly from the Orthodontic clinic at the University of Alabama at Birmingham and the Institutional Review Board of the University of Alabama at Birmingham approved the study. All the chosen cases were treated with fixed appliances and according to the standards of American Board of Orthodontics. All the lateral cephalo-metric radiographs were taken using the Orthopantomograph OP100, Instrumentarium Corp.Imaging Division machine(Finland) and traced digitally using the Dolphin Management and Imaging Software, Version05.05.5070.221436(US &Canada). In order to evaluate the maxillary incisor position changes ,the U1-PP(°), U1-SNº, U1-NAº, U1-NA(mm), U1 perpendicular to FH mm(U1-FH) and U1-Oc° cephalometric measurements were carried out based on the post-treatment lateral cephalometric measurements. In order to determine if there is a statistically significant difference in Maxillary central incisor positions among class I, II and III malocclusions , equivalence tests for post-treatment cephalometric measurements were performed using a range of ± 2 either degrees or millimeters Results: The maxillary incisors position does show a significant difference from the normal value among the Class I, II and III. Class III malocclusion presented a greater proclination of maxillary incisor teeth compared to Class I and Class II malocclusions. Class I has a tendency to be more positive of the normal and Class II to be more negative than the normal. The maxillary incisors changes, seem to not fall within the range of ±2 mm according with the equivalent tests for post-treatment cephalometric measurements compared to the respective normal value. The final position of the maxillary incisors after orthodontic treatment depends mainly on the initial position of these teeth and the discrepancy of jaws. Conclusion: There is a significant difference in the positioning of the maxillary incisors among the class I, II and III malocclusions. The post-treatment measurements such as U1-FHmm, U1-NA mm and U1-SN° and U1-NA° present a significance difference among Class I, II and III malocclusions. In In the class II, the maxillary teeth showed to be more upright than Class I and III malocclusions after orthodontic treatment. The U1-PP° showed no significant difference among the malocclusions. In this study, the U1-PP° was the same for r the Class I and III.

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