A posteroanterior cephalometric radiographic study was performed on the right- and left-handed men and women with normal occlusion. A posteroanterior cephalometric radiography was conducted in these subjects. Method of triangulation was used to measure various face areas. The surface areas of these triangles were compared with their equivalents on the contralateral side. Sex and its interactions with handedness and side were significant factors influencing facial areas. Areas on the left were found to be significantly larger than those on the right in right-handers. Left-handers were inconsistent in facial asymmetry, but they tended to have larger facial areas on the right than the left. Sex was especially significant for left-handers. It was suggested that an asymmetric development in some brain regions may be responsible for the development of asymmetric facial regions.

The present study investigated the changes in the heights and anteroposterior diameters of human intervertebral discs by means of measurements from radiographs, to determine age changes of lumbar intervertebral discs in Turkish people. Measurements of anterior and posterior disc heights and disc depths were made for 200 clinic subjects of different age groups from lateral radiographs. The height of the intervertebral disc increases with aging only in males and the disc depth in both sexes. Our findings generally corroborate previous studies. It is suggested that the different findings from the present study might be peculiar to the society.

Sex and handedness differences in the volumes of cerebral ventricles were studied in 20 right- and 21 left-handed subjects. To assess the volumes of cerebral ventricles, Cavalieri's method was used using MRI. In right-handers, the volume of the lateral ventricle was higher in the right side than in the left side, but, in left-handers, it was higher in the left side than in the right side. The volumes of right-lateral and third ventricles were larger in right-handers than in left -handers. There were no sex related differences in terms of the volumes of right- and left -lateral, third, and fourth ventricles. These results suggest that left-handedness is an important factor reducing the sizes of all the brain ventricles.

During an investigation performed on cadaver forearms in the anatomy department, an unusual insertion of the abductor pollicis longus (APL) muscle together with the extensor pollicis brevis (EPB) muscle was encountered unilaterally in a 40-year-old male cadaver forearm. APL originated from the posterior ulnar surface distal to the anconeus, the adjoining interosseous membrane and middle third of the posterior radial surface. It lay distal to the supinator muscle and close to the EPB, while the EPB arose from the posterior radial surface and from the adjacent interosseous membrane. These muscles were inserted to the palmar side of the base of the first metacarpal bone together. To our knowledge, this variation has not been cited in recent medical literature.

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