Thesis
Maxillary central incisor crown-root relationships in Class I normal occlusions and Class II division 2 malocclusions
University of Iowa
Master of Science (MS), University of Iowa
Spring 2014
DOI: 10.17077/etd.woaa47kp
Abstract
<p><strong>Introduction:</strong> The purposes of this study were several. The first was to establish a mean value for the crown-to-root angle, or collum angle (CA), for maxillary central incisors in Class I normal occlusions. The second was to create a new crown-to-root angle based on anatomic points, the labial crown-root angle (LCRA), and correlate it with the CA for Class I normal occlusions and Class II division 2 malocclusions. Third, torque values were measured for maxillary central incisors using these anatomic points, and mean values were calculated for Class I normal occlusions and Class II division 2 malocclusions. Finally, mean values for CA and LCRA were analyzed for Class I normal occlusions and Class II division 2 malocclusions to detect differences between the two groups. <strong> Methods:</strong> 51 Class I normal samples and 42 Class II division 2 samples who met the inclusion criteria were studied cephalometrically. Relevant landmarks were placed, analyzed for reliability, and recorded for the measurements of interest. <strong> Results:</strong> The mean CA for Class I normal occlusions was not statistically different from zero (p= .0657). A strong increasing correlation between CA and LCRA was found for all samples (Pearson's correlation coefficient = 0.88, p < .0001). Mean torque values for Class I normal occlusions and Class II division 2 malocclusions were statistically different (3.95±10.85 degrees vs. 12.54±5.82 degrees, p < .0001). The mean CA for Class I normal occlusions and Class II division 2 malocclusions were statistically different (4.29±5.77 degrees vs. 1.78±3.94 degrees, p = .0178). The mean LCRA for Class I normal occlusions and Class II division 2 malocclusions were statistically different (31.60±4.24 degrees vs. 34.84±5.95 degrees, p = .00037). <strong> Conclusions:</strong> The mean CA in Class I normal occlusions is not statistically different from zero degrees. The LCRA is strongly correlated with the CA in both Class I normal occlusions and Class II division 2 malocclusions. The mean maxillary central incisor torque values for Class I normal occlusions is similar to that found in bracket prescriptions currently offered. Patients with Class II division 2 malocclusion exhibit statistically higher mean CA and LCRA values than patients with Class I ideal occlusion.</p>
Details
- Title: Subtitle
- Maxillary central incisor crown-root relationships in Class I normal occlusions and Class II division 2 malocclusions
- Creators
- Thomas J. Bauer - University of Iowa
- Contributors
- Robert N. Staley (Advisor)David A. Jones (Committee Member)Fang Qian (Committee Member)Lina M. Moreno Uribe (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Orthodontics
- Date degree season
- Spring 2014
- DOI
- 10.17077/etd.woaa47kp
- Publisher
- University of Iowa
- Number of pages
- v, 50 pages
- Copyright
- Copyright 2014 Thomas John Bauer
- Language
- English
- Description illustrations
- color illustrations
- Description bibliographic
- Includes bibliographical references (pages 49-50).
- Academic Unit
- Orthodontics; Craniofacial Anomalies Research Center
- Record Identifier
- 9983777499802771
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