Toshiko Ikeda

Sex differences in the zygomatic angle in Japanese patients analyzed by MRI with reference to moiré fringe patterns

To quantitate the degree of zygomatic protrusion, a new item, “zygomatic angle,” was measured on MRI cross sections in the orbitomeatal plane. The sex differences in the zygomatic angle were highly significant on both sides, being larger in males than in females. The shape of the zygomatic protrusion was classified into angulate, intermediate, and massive types according to the value of the zygomatic angle. The incidence of the angulated type was significantly more frequent in females, and that of the massive type was significantly more frequent in males. Another analysis was made of horizontal cross sections in the orbitomeatal plane in moiré photographs. In these cross sections, it was possible to judge the abovementioned three types of protrusions. The number of moiré fringes in the infraorbital region was measured in relation to the amount of zygomatic protrusion. The results on moiré photographs coincided with those obtained by MRI analysis.

Side-to-side earlobe variations with respect to surface area and shape: A quantitative study

Side-to-side earlobe variations, based on the size of the earlobe surface area and a classification into earlobe types, were quantitatively analyzed in 58 female students, ranging from 20 to 22 years old. Using a new earlobe measurement technique, a closed-circuit outline of each ear was directly traced onto a clear polyethylene sheet, after which the surface area of the earlobe portion of each ear was identified, measured by a digital planimeter, and analyzed. Results revealed that side-to-side differences in the size of the earlobe surface area existed in all subjects. In contrast, based on classifying the earlobe shape into three types (i.e., tapering, square, or pendulous), differences in the mean earlobe surface area value among the three types were not significant. However, when the classification of the earlobe shape was reduced to only two types (pendulous or nonpendulous), the mean earlobe surface area value between the two types was highly significant. These results thus suggest that for a quantitative analysis of earlobe variations, classification of the earlobe shape into two types rather than into three types is the better method. This method makes it easy to distinguish earlobe differences. Further, if the earlobe differences are noted before ear piercing, a balanced ear piercing effect can be achieved.

Fibulo-Tibial Weight Index – A New Criterion for Sex Identification Based on the Lower Leg Bones

This study was designed in an attempt to determine whether the fibula can provide reliable information for sexing human bones, if measurements include tibial indices. Our results allow us to introduce a new criterion for sexing long bones: the fibulo-tibial weight index. Bone weight was determined, together with conventional measurements, such as maximum bone length and mid-shaft circumference. The materials consisted of dried tibiae and fibulae of 71 recently decreased Japanese males and 31 females. The mean value of the fibulo-tibial weight index was very significantly greater in females than in males. In discriminant analysis, the rate of correct sex discrimination was improved by the inclusion of the fibulo-tibial weight index.

Photogrammetric Application Of Moire Fringes Produced With A Parallel Beam Of Light

The use of moire interference fringes in biostereometrical applications has the advantage that contour fringes on the surface of an object are visible to the unaided eye and that these fringes may be recorded photographically. The movement of such fringes as would accompany the motion of the human body can be recorded by movie or video camera when the fringes are used to study human subjects. One of the limitations of this moire method using noncollimated light is that the value of the contour interval increases with the increase of the order number of the fringes as counted from the grating. To overcome this limitation, a new moire technique using parallel light has been developed. An optical system, which includes a field lens, provides the parallel light which makes it possible to obtain equal valued contour intervals, independent of fringe order. Any desired contour interval is obtained by choosing a grating with suitable pitch and/or an appropriate angle of incidence for the parallel light at the grating. Analogue data from the moire pattern is automatically fed into the central processing unit of a computer by means of a TV camera and an A/D converter. Examples of the line printer output of this conversion system are given.