Second premolar agenesis is associated with mandibular form: a geometric morphometric analysis of mandibular cross-sections
Autor: | Manuel Wagner, Andreas Stavropoulos, Kristina Bertl, Christian Ulm, Michael H. Bertl, André Gahleitner, Philipp Mitteroecker |
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Jazyk: | angličtina |
Rok vydání: | 2016 |
Předmět: |
0106 biological sciences
Molar Tooth eruption Submandibular fossa Mandible Odontologi agenesis 010603 evolutionary biology 01 natural sciences Mandibular first molar mandibular form Tooth Eruption Mandibular second molar 03 medical and health sciences 0302 clinical medicine stomatognathic system Premolar Medicine Humans Bicuspid Tooth Deciduous cross-sections geometric morphometrics General Dentistry Anodontia Orthodontics business.industry 030206 dentistry medicine.disease stomatognathic diseases medicine.anatomical_structure Cross-Sectional Studies Dentistry Agenesis Original Article business |
Zdroj: | International Journal of Oral Science |
ISSN: | 2049-3169 1674-2818 |
Popis: | The aim of this study was to compare mandibular form (i.e., size and shape) between patients with agenesis of the lower second premolar (P2) and a control group with no agenesis. Three hypotheses were tested: (H1) agenesis causes a change in mandibular morphology because of inadequate alveolar ridge development in the area of the missing tooth (mandibular plasticity); (H2) agenesis is caused by spatial limitations within the mandible (dental plasticity); and (H3) common genetic/ epigenetic factors cause agenesis and affect mandibular form (pleiotropy). A geometric morphometric analysis was applied to cross-sectional images of computed tomography (CT) scans of three matched groups (n = 50 each): (1) regularly erupted P2; (2) agenesis of P2 and the primary second molar in situ; and (3) agenesis of P2 and the primary second molar missing for 43 months. Cross-sections of the three areas of interest (first premolar, P2, first molar) were digitized with 23 landmarks and superimposed by a generalized Procrustes analysis. On average, the mandibular cross-sections were narrower and shorter in patients with P2 agenesis compared with that in the control group. Both agenesis groups featured a pronounced submandibular fossa. These differences extended at least one tooth beyond the agenesis-affected region. Taken together with the large interindividual variation that resulted in massively overlapping group distributions, these findings support genetic and/or epigenetic pleiotropy (H3) as the most likely origin of the observed covariation between mandibular form and odontogenesis. Clinically, reduced dimensions and greater variability of mandibular form, as well as a pronounced submandibular fossa, should be expected during the treatment planning of patients with P2 agenesis. |
Databáze: | OpenAIRE |
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