The load-displacement characteristics of neonatal rat cranial sutures.

OBJECTIVE Recently several centers have attempted to distract the craniofacial skeleton in infants with craniosynostosis. To effectively achieve this goal, we must first understand the normal sutural response to tensile forces. The objective of this study was to determine the load-displacement characteristics of neonatal rat sutures. METHODS Thirty cranial sutures were harvested from 1-week-old Wistar rats (10 each coronal, posterior frontal, and sagittal). The width of the harvested bone-suture-bone construct was standardized to 4 mm. The specimens, kept moist, were mounted fresh and distracted at 10 microm/sec until rupture using a Vitrodyne V1000 universal tester. Standard load-displacement curves were constructed. The stiffness, defined as tensile force/change in suture length, and the ultimate stress, defined as tensile force at suture rupture/cross sectional area, were calculated. RESULTS These sutures demonstrated classical viscoelastic behavior. During the elastic phase, they elongated approximately 1 microm for every 1 g of force (10(4) N/m). The ultimate tensile stress was approximately 4 MN/m2. The estimated mean elastic modulus was 10 megapascals. The posterior frontal sutures were significantly less stiff than the other two sutures (Kruskal-Wallis nonparametric analysis of variance, p = .0023). The difference in the ultimate stress was also significant (p = .0201). CONCLUSIONS This study provides data regarding the basic mechanical behavior of neonatal cranial sutures in a mammalian system.

[1]  H. Slavkin.  Recombinant DNA Technology and Oral Medicine , 1995, Annals of the New York Academy of Sciences.

[2]  N. Sasaki,et al.  Stress-strain curve and Young's modulus of a collagen molecule as determined by the X-ray diffraction technique. , 1996, Journal of biomechanics.

[3]  C. V. Vander Kolk,et al.  Etiopathogenesis of craniofacial anomalies. , 1994, Clinics in plastic surgery.

[4]  J. McCarthy,et al.  Studies in Cranial Suture Biology: Part I. Increased Immunoreactivity for TGF‐β Isoforms (β1, β2, and β3) During Rat Cranial Suture Fusion , 1997 .

[5]  P. Mcneil,et al.  Mini-review Loss, Restoration, and Maintenance of Plasma Membrane Integrity Occurrence of Mechanically Initiated Plasma Membrane Disruptions Surviving/resealing Plasma Membrane Disruptions , 2022 .

[6]  R Vanderby,et al.  A structurally based stress-stretch relationship for tendon and ligament. , 1997, Journal of biomechanical engineering.

[7]  T. Littlefield,et al.  Treatment of Craniofacial Asymmetry With Dynamic Orthotic Cranioplasty , 1998, The Journal of craniofacial surgery.

[8]  D. Rénier,et al.  Intracranial pressure and intracranial volume in children with craniosynostosis. , 1992, Plastic and reconstructive surgery.

[9]  J. Richtsmeier,et al.  Perspectives on craniofacial growth. , 1994, Clinics in plastic surgery.

[10]  D. Rice,et al.  FGF-, BMP- and Shh-mediated signalling pathways in the regulation of cranial suture morphogenesis and calvarial bone development. , 1998, Development.

[11]  L. Opperman,et al.  TGF‐β1, TGF‐β2, and TGF‐β3 Exhibit Distinct Patterns of Expression During Cranial Suture Formation and Obliteration In Vivo and In Vitro , 1997 .

[12]  F. Girgis,et al.  The structure and development of cranial and facial sutures. , 1956, Journal of anatomy.

[13]  M. Moss,et al.  Growth of the calvaria in the rat; the determination of osseous morphology. , 1954, The American journal of anatomy.

[14]  E. Haan,et al.  Mutation detection in FGFR2 craniosynostosis syndromes , 1997, Human Genetics.

[15]  J. McCarthy,et al.  The role of distraction osteogenesis in the reconstruction of the mandible in unilateral craniofacial microsomia. , 1994, Clinics in plastic surgery.

[16]  C. Dolce,et al.  Immediate early-gene induction in rat osteoblastic cells after mechanical deformation. , 1996, Archives of oral biology.

[17]  P. Alberch,et al.  Strategies of head development: workshop report. , 1988, Development.

[18]  M. Moss,et al.  The pathogenesis of premature cranial synostosis in man. , 1959, Acta anatomica.

[19]  A. Barakat,et al.  Spatial relationships in early signaling events of flow-mediated endothelial mechanotransduction. , 1997, Annual review of physiology.

[20]  S. Malcolm,et al.  Fibroblast Growth Factor Receptor‐2 Mutations in Craniosynostosis a , 1996, Annals of the New York Academy of Sciences.

[21]  P. Libby,et al.  Mechanical strain tightly controls fibroblast growth factor-2 release from cultured human vascular smooth muscle cells. , 1997, Circulation research.

[22]  Y. Fung,et al.  Biomechanics: Mechanical Properties of Living Tissues , 1981 .

[23]  Henry Eyring,et al.  The Mechanical Properties of Rat Tail Tendon , 1959, The Journal of general physiology.

[24]  S. Beals,et al.  Treatment of positional plagiocephaly with dynamic orthotic cranioplasty. , 1994 .

[25]  E. Zackai,et al.  Identical mutations in three different fibroblast growth factor receptor genes in autosomal dominant craniosynostosis syndromes , 1996, Nature Genetics.

[26]  V. Johansen,et al.  Morphogenesis of the mouse coronal suture. , 1982, Acta anatomica.