title: Differences in biomechanical properties and thickness among frontal and parietal bones in a Japanese sample.
abstract: The aim of this study was to assess the mechanical properties and thickness of adult frontal and parietal bones. The heads of 114 Japanese cadavers (78 male cadavers and 36 female cadavers) of known age and sex were used. A total of 912 cranial samples, 8 from each skull, were collected. Samples were imaged using multidetector computed tomography to measure sample thickness. The fracture load of each sample was measured using a bending test with calculation of flexural strength. Statistical analyses demonstrated no significant bilateral difference in either the mechanical properties or thickness of frontal or parietal bones. The mechanical properties and thicknesses of frontal bones were significantly greater than those of parietal bones regardless of sex. Therefore, the skull may have a great ability to resist frontal impacts compared with parietal impacts. In female samples, parietal bones were found to have a more uniform structure when compared with male samples. Male parietal bones were found to be thicker at medial sites than at lateral sites. This study also revealed parietal bones at lateral sites in female samples were thicker than in male samples. No strong association was observed between age and flexural strength of frontal or parietal bones. However, the fracture load was negatively correlated with age most likely due to the reduction of thickness.
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: number60188@chiba-u.jp.
authors.forename: Suguru
authors.initials: S
authors.lastname: Torimitsu
authors.affiliation: Designing Everyday Life Function and Social System Team, Digital Human Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 2-3-26 Aomi, Koto-ku, Tokyo 135-0064, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Nishida
authors.affiliation: Designing Everyday Life Function and Social System Team, Digital Human Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 2-3-26 Aomi, Koto-ku, Tokyo 135-0064, Japan.
authors.forename: Tachio
authors.initials: T
authors.lastname: Takano
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yajima
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Inokuchi
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan; Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yohsuke
authors.initials: Y
authors.lastname: Makino
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Motomura
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan; Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Chiba
authors.affiliation: Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Rutsuko
authors.initials: R
authors.lastname: Yamaguchi
authors.affiliation: Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Hashimoto
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Hoshioka
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan; Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Hirotaro
authors.initials: H
authors.lastname: Iwase
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D001696:Biomechanical Phenomena / Q000502:physiology*; D005260:Female; D018732:Forensic Anthropology; D005624:Frontal Bone / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D010294:Parietal Bone / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D012727:Sex Characteristics; D012887:Skull Fractures / Q000503:physiopathology
keywords: Adult skull; Flexural strength; Forensic Anthropology Population Data; Fracture load; Japanese; Thickness