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Non‐circular geometry and radiogrammetry of the second metacarpal
Author(s) -
Lazenby Richard
Publication year - 1995
Publication title -
american journal of physical anthropology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.146
H-Index - 119
eISSN - 1096-8644
pISSN - 0002-9483
DOI - 10.1002/ajpa.1330970306
Subject(s) - medullary cavity , medicine , radiography , orthodontics , geometry , mathematics , anatomy , nuclear medicine , surgery
Traditional radiogrammetry of the second metacarpal mid‐shaft reconstructs cortical cross‐sectional geometry from mediolateral (ML) linear dimensions based on a circular model. However, comparison of antero‐posterior (AP) versus mediolateral radiographic dimensions in a sample of paired metacarpals shows that AP total and medullary widths typically exceed ML widths by 5% to 10%. As well, in 13% of males and 25% of females, the two metacarpals are dissimilarly shaped, i.e., the AP/ML ratio is >1.0 for one side and <1.0 for the other. This situation exaggerates the differences in geometric properties between sides and constitutes a potentially significant source of bias for analyses of bilateral asymmetry. These results suggest that the circular model is inappropriate for estimation of cross‐sectional geometry at this anatomical location. © 1995 Wiley‐Liss, Inc.