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A geometric morphometric evaluation of hard and soft tissue profile changes in borderline extraction versus non-extraction patients.
- Source :
-
European journal of orthodontics [Eur J Orthod] 2019 May 24; Vol. 41 (3), pp. 264-272. - Publication Year :
- 2019
-
Abstract
- Objectives: To evaluate the hard tissue and facial profile changes in matched extraction and non-extraction Class I patients by the use of geometric morphometrics.<br />Subjects and Methods: From a parent sample of 542 Class I patients, previously subjected to discriminant analysis, a subsample of 68 borderline cases was obtained, 34 treated with extraction and 34 without extraction of 4 first premolars. Geometric morphometric methods (Procrustes superimposition and Principal Component Analysis) were applied on cephalometric tracings to assess the validity of the discriminant analysis in successfully identifying a morphologically homogeneous group and to evaluate inter- and intra-group skeletal and facial profile shape changes.<br />Results: No significant pre-treatment shape difference between the two groups was found, thus validating the discriminant analysis. The non-extraction group showed increase in hard tissue facial height (P < 0.001), with slight lower lip retrusion and upper lip protrusion (P = 0.027). The extraction group showed retraction of the hard tissue and facial profile outline (P < 0.001). Permutation tests for post-treatment inter-group differences resulted in P = 0.054 for the soft tissue outline and P = 0.078 for the hard tissue skeletal component.<br />Conclusions: The evidence indicates that borderline cases treated with four premolar extractions will exhibit lip retrusion compared to non-extraction treatment.<br /> (© The Author(s) 2018. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Subjects :
- Bicuspid
Humans
Cephalometry
Face anatomy & histology
Lip
Tooth Extraction
Subjects
Details
- Language :
- English
- ISSN :
- 1460-2210
- Volume :
- 41
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- European journal of orthodontics
- Publication Type :
- Academic Journal
- Accession number :
- 30212892
- Full Text :
- https://doi.org/10.1093/ejo/cjy056