title: Statistical analysis of biomechanical properties of the adult sagittal suture using a bending method in a Japanese forensic sample.
abstract: This study examined the mechanical properties of the adult sagittal suture compared with surrounding parietal bones using bending tests and investigated the association between the mechanical properties of the suture and age. We used the heads of 116 Japanese cadavers (76 male cadavers and 40 female cadavers) of known age and sex. A total of 1160 cranial samples, 10 from each skull, were collected. The samples were imaged using multidetector computed tomography, and the sample thickness at the center of each sample (ST) was measured. The failure stress of each sample (FS) was measured by a bending test, and the ratio of failure stress to the square of sample thickness (FS/ST(2)) was calculated. Statistical analyses revealed that the FS and FS/ST(2) values were significantly lower at all suture sites than at all bone sites regardless of sex. There were not significant but slight positive correlations between age and FS and FS/ST(2) values at any suture site in male samples. In female samples, age had significant positive correlations with FS and FS/ST(2) values at the middle suture sites, whereas there were not significant but slight positive correlations between age and FS and FS/ST(2) values at the edges of the suture. Statistical analyses also demonstrated that FS and FS/ST(2) values were significantly greater in male samples than in female samples at the middle suture sites. These findings suggest that the bending strength of the adult sagittal suture is significantly lower than that of surrounding parietal bones. Therefore, avoiding direct impact on cranial sutures may be important for preventing skull fractures and severe complications that can cause death. The results of this study also revealed that the bending strength of the middle sagittal suture significantly increases with age in only female samples, whereas the bending strength is significantly higher in male samples than in female samples at the middle suture sites, indicating the possibility of sex difference in the bony interdigitation of the sutures during childhood.
authors: 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: Suguru
authors: S
authors: Torimitsu
authors: 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. Electronic address: y.nishida@aist.go.jp.
authors: Yoshifumi
authors: Y
authors: Nishida
authors: 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. Electronic address: t.takano@amail.plala.or.jp.
authors: Tachio
authors: T
authors: Takano
authors: 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. Electronic address: y.koizumi@aist.go.jp.
authors: Yoshinori
authors: Y
authors: Koizumi
authors: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: moo600@faculty.chiba-u.jp.
authors: Mutsumi
authors: M
authors: Hayakawa
authors: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: yajima.d@faculty.chiba-u.jp.
authors: Daisuke
authors: D
authors: Yajima
authors: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: goinokuchi@chiba-u.jp.
authors: Go
authors: G
authors: Inokuchi
authors: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: ymakino-tky@umin.ac.jp.
authors: Yohsuke
authors: Y
authors: Makino
authors: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: tsunetoa@graduate.chiba-u.jp.
authors: Ayumi
authors: A
authors: Motomura
authors: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: chibafumico@chiba-u.jp.
authors: Fumiko
authors: F
authors: Chiba
authors: Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: iwase@faculty.chiba-u.jp.
authors: Hirotaro
authors: H
authors: Iwase
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002102:Cadaver; D003393:Cranial Sutures / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D049429:Forensic Pathology / Q000379:methods*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D010294:Parietal Bone / Q000000981:diagnostic imaging / Q000503:physiopathology; D012727:Sex Characteristics; D055815:Young Adult
keywords: Adult; Bending strength; Cranial bone; Fracture; Mechanical properties; Suture