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Remesz R, Khurelbaatar T, Rabey KN, Doschak MR, Romanyk DL. Three-dimensional morphometric analysis of cranial sutures - A novel approach to quantitative analysis. Bone Rep 2023; 19:101714. [PMID: 37767331 PMCID: PMC10520544 DOI: 10.1016/j.bonr.2023.101714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/16/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023] Open
Abstract
Objective Differences in complexity of cranial suture forms on the endocranial (i.e., deep) and ectocranial (i.e., superficial) skull surfaces have been noted in the literature, indicating through thickness three-dimensional (3D) suture variability depending on the chosen section and necessity for considering the complete 3D structure in many cases. This study aims to evaluate the variability of suture morphology through the skull thickness using a rat model, and to provide more robust metrics and methodologies to analyze suture morphology. Design X-ray micro-computed tomographic (μCT) imaging methods were utilized in order to provide internal structure information. Methods were developed to isolate and analyze sutures widths and linear interdigitation index (LII) values on each adjacent offset transverse plane of the μCT datasets. LII was defined as the curved path length of the suture divided by the linear length between the ends of the region of interest. Scans were obtained on 15 female rats at ages of 16, 20, and 24 weeks (n = 5/age). Samples were imaged at 18 μm resolutions with 90 kV source voltage, 278 μA source amperage, and 0.7° increments. Suture widths and LII values were compared using a Kruskal-Wallis test. Results 3D variability in local suture widths within individuals, as well as through thickness variabilities in planar widths and LII was observed. Kruskal-Wallis tests for bulk through thickness averaged suture widths and LII were found to be statistically insignificant, despite clear geometric differences through suture thicknesses. Conclusion Although the bulk morphometric variability between age groups was found to be statistically insignificant, the 3D variability within individuals point to the importance of analyzing suture form using 3D metrics when studying suture development, response to functional activity, or morphometry in general.
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Affiliation(s)
- Ross Remesz
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
| | | | - Karyne N. Rabey
- Division of Anatomy, Department of Surgery, University of Alberta, Edmonton, AB, Canada
- Department of Anthropology, University of Alberta, Edmonton, AB, Canada
| | - Michael R. Doschak
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Dan L. Romanyk
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada
- School of Dentistry, University of Alberta, Edmonton, AB, Canada
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Byron C, Reed D, Iriarte-Diaz J, Wang Q, Strait D, Laird MF, Ross CF. Sagittal suture strain in capuchin monkeys (Sapajus and Cebus) during feeding. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2023; 180:633-654. [PMID: 36790169 DOI: 10.1002/ajpa.24701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 12/13/2022] [Accepted: 01/16/2023] [Indexed: 05/26/2023]
Abstract
OBJECTIVES Morphological variation in cranial sutures is used to infer aspects of primate feeding behavior, including diet, but strain regimes across sutures are not well documented. Our aim is to test hypotheses about sagittal suture morphology, strain regime, feeding behavior, and muscle activity relationships in robust Sapajus and gracile Cebus capuchin primates. MATERIALS AND METHODS Morphometrics of sinuosity in three regions of the sagittal suture were compared among museum specimens of Sapajus and Cebus, as well as in robust and gracile lab specimens. In vivo strains and bilateral electromyographic (EMG) activity were recorded from these regions in the temporalis muscles of capuchin primates while they fed on mechanically-varying foods. RESULTS Sapajus and the anterior suture region exhibited greater sinuosity than Cebus and posterior regions. In vivo data reveal minor differences in strain regime between robust and gracile phenotypes but show higher strain magnitudes in the middle suture region and higher tensile strains anteriorly. After gage location, feeding behavior has the most consistent and strongest impact on strain regime in the sagittal suture. Strain in the anterior suture has a high tension to compression ratio compared to the posterior region, especially during forceful biting in the robust Sapajus-like individual. DISCUSSION Sagittal suture complexity in robust capuchins likely reflects feeding behaviors associated with mechanically challenging foods. Sutural strain regimes in other anthropoid primates may also be affected by activity in feeding muscles.
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Affiliation(s)
- Craig Byron
- Department of Biology, Mercer University, Macon, Georgia, USA
| | - David Reed
- Department of Oral Biology, University of Illinois, Chicago, Illinois, USA
| | - Jose Iriarte-Diaz
- Department of Biology, University of the South, Sewanee, Tennessee, USA
| | - Qian Wang
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas, USA
| | - David Strait
- Department of Anthropology, Washington University in St. Louis, St. Louis, Missouri, USA
- Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa
| | - Myra F Laird
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Callum F Ross
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois, USA
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Sharp AC, Dutel H, Watson PJ, Gröning F, Crumpton N, Fagan MJ, Evans SE. Assessment of the mechanical role of cranial sutures in the mammalian skull: Computational biomechanical modelling of the rat skull. J Morphol 2023; 284:e21555. [PMID: 36630615 PMCID: PMC10107956 DOI: 10.1002/jmor.21555] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 01/13/2023]
Abstract
Cranial sutures are fibrocellular joints between the skull bones that are progressively replaced with bone throughout ontogeny, facilitating growth and cranial shape change. This transition from soft tissue to bone is reflected in the biomechanical properties of the craniofacial complex. However, the mechanical significance of cranial sutures has only been explored at a few localised areas within the mammalian skull, and as such our understanding of suture function in overall skull biomechanics is still limited. Here, we sought to determine how the overall strain environment is affected by the complex network of cranial sutures in the mammal skull. We combined two computational biomechanical methods, multibody dynamics analysis and finite element analysis, to simulate biting in a rat skull and compared models with and without cranial sutures. Our results show that including complex sutures in the rat model does not substantially change overall strain gradients across the cranium, particularly strain magnitudes in the bones overlying the brain. However, local variations in strain magnitudes and patterns can be observed in areas close to the sutures. These results show that, during feeding, sutures may be more important in some regions than others. Sutures should therefore be included in models that require accurate local strain magnitudes and patterns of cranial strain, particularly if models are developed for analysis of specific regions, such as the temporomandibular joint or zygomatic arch. Our results suggest that, for mammalian skulls, cranial sutures might be more important for allowing brain expansion during growth than redistributing biting loads across the cranium in adults.
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Affiliation(s)
- Alana C Sharp
- Department of Musculoskeletal and Ageing Sciences, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK.,Department of Cell and Developmental Biology, University College London, London, UK
| | - Hugo Dutel
- Department of Engineering, University of Hull, Hull, UK.,Faculty of Science, School of Earth Sciences, University of Bristol, Bristol, UK
| | | | - Flora Gröning
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK
| | - Nick Crumpton
- Department of Cell and Developmental Biology, University College London, London, UK
| | | | - Susan E Evans
- Department of Cell and Developmental Biology, University College London, London, UK
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Abel P, Pommery Y, Ford DP, Koyabu D, Werneburg I. Skull Sutures and Cranial Mechanics in the Permian Reptile Captorhinus aguti and the Evolution of the Temporal Region in Early Amniotes. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.841784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
While most early limbed vertebrates possessed a fully-roofed dermatocranium in their temporal skull region, temporal fenestrae and excavations evolved independently at least twice in the earliest amniotes, with several different variations in shape and position of the openings. Yet, the specific drivers behind this evolution have been only barely understood. It has been mostly explained by adaptations of the feeding apparatus as a response to new functional demands in the terrestrial realm, including a rearrangement of the jaw musculature as well as changes in strain distribution. Temporal fenestrae have been retained in most extant amniotes but have also been lost again, notably in turtles. However, even turtles do not represent an optimal analog for the condition in the ancestral amniote, highlighting the necessity to examine Paleozoic fossil material. Here, we describe in detail the sutures in the dermatocranium of the Permian reptile Captorhinus aguti (Amniota, Captorhinidae) to illustrate bone integrity in an early non-fenestrated amniote skull. We reconstruct the jaw adductor musculature and discuss its relation to intracranial articulations and bone flexibility within the temporal region. Lastly, we examine whether the reconstructed cranial mechanics in C. aguti could be treated as a model for the ancestor of fenestrated amniotes. We show that C. aguti likely exhibited a reduced loading in the areas at the intersection of jugal, squamosal, and postorbital, as well as at the contact between parietal and postorbital. We argue that these “weak” areas are prone for the development of temporal openings and may be treated as the possible precursors for infratemporal and supratemporal fenestrae in early amniotes. These findings provide a good basis for future studies on other non-fenestrated taxa close to the amniote base, for example diadectomorphs or other non-diapsid reptiles.
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Arnaout B, MacKenzie EM, Lantigua KE, Brzezinski K, McKinnell IW, Maddin HC. The histology of sutures in chicken skulls: Types, conservation, and ontogeny. J Anat 2022; 240:503-515. [PMID: 34668205 PMCID: PMC8819051 DOI: 10.1111/joa.13574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 09/28/2021] [Accepted: 10/07/2021] [Indexed: 10/20/2022] Open
Abstract
Sutures are fibrous joints that occur between bone elements in vertebrate skulls, where they play a variety of roles including facilitating skull growth and function. In addition, a variety of studies examining sutures from diverse perspectives in many taxa have enabled the determination of anatomical homologs. Surprisingly, one important aspect of sutures-histology-remains unknown in the key model organism of the chicken. To fill this gap in our knowledge, we generated histological sections of six different cranial sutures across a range of developmental stages in embryonic chicken. Despite having a skull that is largely co-ossified or fused as an adult, we found that the types, components, and ontogeny of sutures in chicken skulls are very similar to sutures in other vertebrates. We did, however, find a new transient stage in the ontogeny of sutures between endochondral bone elements, in which one element has ossified and one was still cartilaginous. Moreover, to better understand the morphogenetic events at the onset of suture formation, we compared the developmental histology of six sutures with that of the space between the two ossification centers of the frontal-a location expected to be void of suture structures. We found that the mesenchymal cells in sutures condense and form a middle vascular layer. This was not found to be the case in the space between the two ossifications of the frontal, where instead only osteoid occurs.
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Affiliation(s)
- Bassel Arnaout
- Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada
| | - Erin M MacKenzie
- Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada
| | - Kayla E Lantigua
- Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada
| | | | - Iain W McKinnell
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Hillary C Maddin
- Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada
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Closure times of neurocranial sutures and synchondroses in Persian compared to Domestic Shorthair cats. Sci Rep 2022; 12:573. [PMID: 35022503 PMCID: PMC8755779 DOI: 10.1038/s41598-022-04783-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 12/16/2021] [Indexed: 11/26/2022] Open
Abstract
Human-directed selective breeding has modified the phenotype of the modern Persian cat towards an extreme brachycephalic phenotype (‘peke-face’ Persian), which originates from a spontaneous mutation that first appeared in the 1950s in traditional Persian types. It was suggested that the peke-face phenotype results from pathologic skull development and might represent a craniosynostosis of the coronal sutures. We followed this hypothesis and investigated the time dependent status of the neurocranial sutures and synchondroses in an ontogenetic series of doll-faced and peke-faced Persian cats compared to Domestic Shorthair cats (DSHs). Cranial suture closure was assessed by examining an ontogenetic series of formalin-fixed head specimens (n = 55) and dry skulls (n = 32) using micro-computed tomography. Sagittal, metopic, coronal and lambdoid sutures as well as intersphenoidal, spheno-occipital and spheno-ethmoid synchondroses were examined. Logistic regression analysis was performed to test the global effect of age on suture closure within a group of peke-face Persians, doll-face Persians and DSHs and the 50% probability of having a closed suture was calculated and compared between groups. Age was a perfect predictor for the condition of the coronal sutures in peke-face Persians. Coronal sutures were found to be closed at 0–0.3 months. In doll-face and DSHs, coronal sutures were open throughout the lifetime with the exception of a few very old cats. Results of this study confirmed a coronal craniosynostosis that likely causes the extreme brachycephalic skull morphology in the peke-face Persian.
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Abstract
Relationships between the complexity of the cranial sutures and the inferred ecology of dicynodont synapsids are explored. Simple complexity indices based on degree of sutural interdigitation were calculated for 70 anomodont species and indicate that the naso-frontal sutures of Cistecephalidae, a clade inferred to be dedicated fossors based on aspects of postcranial morphology, are substantially more complex than those of other dicynodonts. The elevated complexity of the naso-frontal suture in this clade is interpreted as being related to compressive forces sustained during burrowing, paralleling the condition in some other fossorial vertebrate groups (e.g., amphisbaenians). The most highly interdigitated sutures in the cistecephalid skull are those oriented transversely to its long axis, which would experience the greatest longitudinal stresses from contact with the substrate. Although it is uncertain to what degree cistecephalid burrowing was based on scratch vs. head-lift digging, it is argued that the head played an important role during locomotion in this group. Increased sutural complexity, rather than cranial fusion, as an adaptation to resisting compressive forces during burrowing may be related to indeterminate growth in dicynodonts.
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Cheronet O, Ash A, Anders A, Dani J, Domboróczki L, Drozdova E, Francken M, Jovanovic M, Milasinovic L, Pap I, Raczky P, Teschler-Nicola M, Tvrdý Z, Wahl J, Zariņa G, Pinhasi R. Sagittal suture morphological variation in human archaeological populations. Anat Rec (Hoboken) 2021; 304:2811-2822. [PMID: 33773064 PMCID: PMC9291749 DOI: 10.1002/ar.24627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/17/2021] [Accepted: 02/20/2021] [Indexed: 11/10/2022]
Abstract
Cranial sutures join the many bones of the skull. They are therefore points of weakness and consequently subjected to the many mechanical stresses affecting the cranium. However, the way in which this impacts their morphological complexity remains unclear. We examine the intrinsic and extrinsic mechanisms of human sagittal sutures by quantifying the morphology from 107 individuals from archaeological populations spanning the Mesolithic to Middle ages, using standardized two‐dimensional photographs. Results show that the most important factor determining sutural complexity appears to be the position along the cranial vault from the junction with the coronal suture at its anterior‐most point to the junction with the lambdoid suture at its posterior‐most point. Conversely, factors such as age and lifeways show few trends in complexity, the most significant of which is a lower complexity in the sutures of Mesolithic individuals who consumed a tougher diet. The simple technique used in this study therefore allowed us to identify that, taken together, structural aspects play a more important role in defining the complexity of the human sagittal suture than extrinsic factors such as the mechanical forces imposed on the cranium by individuals' diet.
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Affiliation(s)
- Olivia Cheronet
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Abigail Ash
- Department of Archaeology, University of York, York, UK
| | - Alexandra Anders
- Institute of Archeological Sciences, Eötvös Loránd University, Budapest, Hungary
| | | | | | - Eva Drozdova
- Department of Experimental Biology, Section of Genetics and Molecular Biology, Laboratory of Biological and Molecular Anthropology, Faculty of Science, Masaryk Univerzity, Brno, Czech Republic
| | - Michael Francken
- Osteology, State Office for Cultural Heritage Baden-Wuerttemberg, Constance, Germany
| | | | | | - Ildiko Pap
- Department of Anthropology, Hungarian Natural History Museum, Budapest, Hungary
| | - Pál Raczky
- Institute of Archeological Sciences, Eötvös Loránd University, Budapest, Hungary
| | - Maria Teschler-Nicola
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria.,Department of Anthropology, Natural History Museum Vienna, Vienna, Austria
| | - Zdeněk Tvrdý
- Anthropos Institute, Moravian Museum, Brno, Czech Republic
| | - Joachim Wahl
- Institut für Naturwissenschaftliche Archäologie Abteilung Paläoanthropologie, University of Tübingen, Tübingen, Germany
| | - Gunita Zariņa
- University of Latvia, Institute of Latvian History, Riga, Latvia
| | - Ron Pinhasi
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
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9
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Botzenhart UU, Keil C, Tsagkari E, Zeidler-Rentzsch I, Gredes T, Gedrange T. Influence of botulinum toxin A on craniofacial morphology after injection into the right masseter muscle of dystrophin deficient (mdx-) mice. Ann Anat 2021; 236:151715. [PMID: 33675949 DOI: 10.1016/j.aanat.2021.151715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 01/22/2021] [Accepted: 01/29/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND Severe craniofacial and dental abnormalities, typical for patients with progressive Duchenne muscular dystrophy (DMD), are an exellcent demonstration of Melvin L. Moss "functional matrix theory", highlighting the influence of muscle tissue on craniofacial growth and morphology. However, the currently best approved animal model for investigation of this interplay is the mdx-mouse, which offers only a limited time window for research, due to the ability of muscle regeneration, in contrast to the human course of the disease. The aim of this study was to evaluate craniofacial morphology after BTX-A induced muscle paralysis in C57Bl- and mdx-mice, to prove the suitability of BTX-A intervention to inhibit muscle regeneration in mdx-mice and thus, mimicking the human course of the DMD disease. METHODS Paralysis of the right masseter muscle was induced in 100 days old C57Bl- and mdx-mice by a single specific intramuscular BTX-A injection. Mice skulls were obtained at 21 days and 42 days after BTX-A injection and 3D radiological evaluation was performed in order to measure various craniofacial dimensions in the sagittal, transversal and vertical plane. Statstical analysis were performed using SigmaStat®Version 3.5. In case of normal distribution, unpaired t-test and otherwise the Mann-Whitney-U test was applied. A statistical significance was given in case of p ≤ 0.05. RESULTS In contrast to C57Bl-mice, in mdx-mice, three weeks after BTX-A treatment a significant decrease of skull dimensions was noted in most of the measurements followed by a significant increase at the second investigation period. CONCLUSIONS BTX-A can induce changes in craniofacial morphology and presumably partially inhibit muscle regeneration in mdx-mice, but cannot completely intensify craniofacial effects elicited by dystrophy. Further research is necessary in order to fully understand muscle-bone interplay after BTX-A injection into dystrophic muscles.
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Affiliation(s)
| | - Christiane Keil
- Medical Faculty Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany; Department of Orthodontics, Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
| | - Eirini Tsagkari
- Department of Orthodontics, Faculty of Dentistry School of Health Sciences, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece
| | - Ines Zeidler-Rentzsch
- Department of Otorhinolaryngology, Head and Neck Surgery, Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
| | - Tomasz Gredes
- Medical Faculty Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany; Department of Orthodontics, Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
| | - Tomasz Gedrange
- Medical Faculty Carl Gustav Carus Campus, TU Dresden, 01307, Dresden, Germany
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Taguchi T, Lopez MJ. An overview of de novo bone generation in animal models. J Orthop Res 2021; 39:7-21. [PMID: 32910496 PMCID: PMC7820991 DOI: 10.1002/jor.24852] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 08/27/2020] [Accepted: 09/02/2020] [Indexed: 02/04/2023]
Abstract
Some of the earliest success in de novo tissue generation was in bone tissue, and advances, facilitated by the use of endogenous and exogenous progenitor cells, continue unabated. The concept of one health promotes shared discoveries among medical disciplines to overcome health challenges that afflict numerous species. Carefully selected animal models are vital to development and translation of targeted therapies that improve the health and well-being of humans and animals alike. While inherent differences among species limit direct translation of scientific knowledge between them, rapid progress in ex vivo and in vivo de novo tissue generation is propelling revolutionary innovation to reality among all musculoskeletal specialties. This review contains a comparison of bone deposition among species and descriptions of animal models of bone restoration designed to replicate a multitude of bone injuries and pathology, including impaired osteogenic capacity.
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Affiliation(s)
- Takashi Taguchi
- Laboratory for Equine and Comparative Orthopedic Research, Department of Veterinary Clinical Sciences, School of Veterinary MedicineLouisiana State UniversityBaton RougeLouisianaUSA
| | - Mandi J. Lopez
- Laboratory for Equine and Comparative Orthopedic Research, Department of Veterinary Clinical Sciences, School of Veterinary MedicineLouisiana State UniversityBaton RougeLouisianaUSA
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Oliveira PLE, Campos V, de Andrade RM, de Souza Araújo MT, Pithon MM, Sant'Anna EF. Deformation of the circummaxillary sutures during acute micro-implant assisted rapid palatal expansion and tooth-supported expansion: An ex vivo study. Orthod Craniofac Res 2020; 24:396-404. [PMID: 33277817 DOI: 10.1111/ocr.12450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 11/26/2020] [Accepted: 11/30/2020] [Indexed: 11/30/2022]
Abstract
INTRODUCTION This study aimed to assess and compare the deformation that develops in the circummaxillary sutures during activation of micro-implant assisted rapid palatal expander (MARPE) and tooth-supported expander (Hyrax) s, in the rapid maxillary expansion. SETTINGS AND SAMPLE 7 pigs Sus Scrofa received custom-made MARPE (n = 3) and Hyrax (n = 4) appliances. MATERIAL AND METHODS The devices were activated 25 times with strain readings captured by strain gauges attached to the following regions: posterior midpalatal suture (MPS), maxilla-premaxilla suture (MPM), maxilla-zygomatic suture (MZ) and maxilla pterygoid-process suture (MPP). The intermolar distance and suture width were measured immediately before activation and at the 20th and 25th activation. ANOVA and Kruskal-Wallis test was applied. RESULTS The MARPE group presented greater MPS displacement in all measured regions, and one of the devices produced a significant opening (1.7 mm) in the posterior region. The accumulated tension in the MPS was higher compared to the other sutures (P < .05). A MARPE animal presented higher median tension in the MPS region (294.77με) compared to all other animals except one Hyrax animal (P < .05). Regarding the median tensions of the different activation intervals, the median tension measured during the 16th to 25th activation interval in the Hyrax group was lower than that measured during the first 8 activations, in both the MPS and MZ (P < .05). CONCLUSIONS MARPE expanders developed more constant tensions during all activations (MPS and MZ), while Hyrax showed lower tension in the 16th to 25th activation.
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Affiliation(s)
- Pedro Lima Emmerich Oliveira
- Department of Orthodontics and Pediatric Dentistry, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil
| | - Vinicius Campos
- Department of Mechanical Engineering, Universidade Federal do Espírito Santo, UFES, Vitoria, Brazil
| | | | - Mônica Tirre de Souza Araújo
- Department of Orthodontics and Pediatric Dentistry, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil
| | - Matheus Melo Pithon
- Department of Orthodontics and Pediatric Dentistry, Universidade Estadual do Sudoeste da Bahia, UESB, Jequié, Brazil
| | - Eduardo Franzotti Sant'Anna
- Department of Orthodontics and Pediatric Dentistry, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil
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Farke D, Staszyk C, Failing K, Kirberger RM, Schmidt MJ. Sensitivity and specificity of magnetic resonance imaging and computed tomography for the determination of the developmental state of cranial sutures and synchondroses in the dog. BMC Vet Res 2019; 15:221. [PMID: 31262279 PMCID: PMC6604170 DOI: 10.1186/s12917-019-1967-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/17/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND During skull ontogenesis, growth centers in the skull base and calvarial bones allow gradual expansion of the cranial vault. Premature growth termination of cranial base synchondroses and/or calvarial sutures can result in devastating skull dysmorphologies. There is evidence to believe that a premature closure in one or more cranial growth centers contribute to the brachycephalic skull morphology in dogs. To provide a proof of concept for the non-invasive investigation of ontogenetic changes in cranial sutures and synchondroses in living dogs, we compared magnet resonance imaging (MRI) and computed tomography (CT) with histologic findings. Our aim was to determine the in vitro sensitivity and specificity for conventional clinical imaging methods in the assessment of cranial suture closure and synchondroses ossification in dogs. RESULTS The evaluation of cranial base synchondroses in MRI had a sensitivity of up to 93.1% and a specificity of 72.7% dependent on the observer. The evaluation of cranial base synchondroses in CT had a sensitivity of 92.2% and a specificity of 86.4%. Suture assessment on MRI suture assessment had a sensitivity of 82.1% dependent on the observer and a specificity of 19.3%. CT suture assessment had a sensitivity of 85.1% and a specificity of 40.4% in dependence of the observer. CONCLUSION Conventional cross-sectional imaging techniques (MRI and CT) allow reliable assessment of the open or closed state of synchondroses within the cranial base. In contrast CT and MRI are not suitable for a reliable assessment of the cranial sutures in dogs.
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Affiliation(s)
- Daniela Farke
- Department of Veterinary Clinical Sciences, Small Animal Clinic, Justus-Liebig-University, Frankfurter Strasse 108, 35392 Giessen, Germany
| | - Carsten Staszyk
- Institute of Veterinary-Anatomy, -Histology, and –Embryology, Justus-Liebig-University, Frankfurter Strasse 98, 35392 Giessen, Germany
| | - Klaus Failing
- Department of Biomathematics, Justus-Liebig-University, Frankfurter Strasse 95, 35392 Giessen, Germany
| | - Robert M. Kirberger
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria, 0110 South Africa
| | - Martin J. Schmidt
- Department of Veterinary Clinical Sciences, Small Animal Clinic, Justus-Liebig-University, Frankfurter Strasse 108, 35392 Giessen, Germany
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Buezas GN, Becerra F, Echeverría AI, Cisilino A, Vassallo AI. Mandible strength and geometry in relation to bite force: a study in three caviomorph rodents. J Anat 2019; 234:564-575. [PMID: 30768871 DOI: 10.1111/joa.12946] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2019] [Indexed: 11/30/2022] Open
Abstract
The monophyletic group Caviomorpha constitutes the most diverse rodent clade in terms of locomotion, ecology and diet. Caviomorph species show considerable variation in cranio-mandibular morphology that has been linked to the differences in toughness of dietary items and other behaviors, such as chisel-tooth digging. This work assesses the structural strength of the mandible of three caviomorph species that show remarkable differences in ecology, behavior and bite force: Chinchilla lanigera (a surface-dwelling species), Octodon degus (a semi-fossorial species) and Ctenomys talarum (a subterranean species). Finite element (FE) models of the mandibles are used to predict the stresses they withstand during incisor biting; the results are related to in vivo bite forces and interspecific variations in the mandibular geometries. The study concludes that the mandible of C. talarum is better able to withstand strong incisor bites. Its powerful adducting musculature is consistent with the notorious lateral expansion of the angular process and the masseteric crest, and the enhanced cortical bone thickness. Although it has a relatively low bite force, the mandible of O. degus also shows a good performance for mid-to-strong incisor biting, in contrast to that of C. lanigera, which exhibits, from a mechanical point of view, the worst performance. The mandibles of C. talarum and O. degus appear to be better suited to withstand stronger reaction forces from incisor biting, which is consistent with their closer phylogenetic affinity and shared digging behaviors. The contrast between the low in vivo bite force of C. lanigera and the relatively high estimations that result from the models suggests that its adductor musculature could play significant roles in functions other than incisor biting.
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Affiliation(s)
- Guido N Buezas
- Laboratorio de Morfología Funcional y Comportamiento, Instituto de Investigaciones Marinas y Costeras (IIMyC), Universidad Nacional de Mar del Plata (UNMdP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata, Argentina
| | - Federico Becerra
- Laboratorio de Morfología Funcional y Comportamiento, Instituto de Investigaciones Marinas y Costeras (IIMyC), Universidad Nacional de Mar del Plata (UNMdP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata, Argentina
| | - Alejandra I Echeverría
- Laboratorio de Morfología Funcional y Comportamiento, Instituto de Investigaciones Marinas y Costeras (IIMyC), Universidad Nacional de Mar del Plata (UNMdP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata, Argentina
| | - Adrián Cisilino
- División Mecánica de Materiales, Instituto de Investigaciones en Ciencia y Tecnolgía de Materiales (INTEMA), Universidad Nacional de Mar del Plata (UNMdP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata, Argentina
| | - Aldo I Vassallo
- Laboratorio de Morfología Funcional y Comportamiento, Instituto de Investigaciones Marinas y Costeras (IIMyC), Universidad Nacional de Mar del Plata (UNMdP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata, Argentina
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14
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Byron C, Segreti M, Hawkinson K, Herman K, Patel S. Dietary material properties shape cranial suture morphology in the mouse calvarium. J Anat 2018; 233:807-813. [PMID: 30298923 DOI: 10.1111/joa.12888] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2018] [Indexed: 11/29/2022] Open
Abstract
Cranial sutures are fibrous connective tissue articulations found between intramembranous bones of the vertebrate cranium. Growth and remodeling of these tissues is partially regulated by biomechanical loading patterns that include stresses related to chewing. Advances in oral processing structure and function of the cranium that enabled mammalian-style chewing is commonly tied to the origins and evolution of this group. To what degree masticatory overuse or underuse shapes the complexity and ossification around these articulations can be predicted based on prior experimental and comparative work. Here, we report on a mouse model system that has been used to experimentally manipulate dietary material properties in order to investigate cranial suture morphology. Experimental groups were fed diets of contrasting material properties. A masticatory overuse group was fed pelleted rodent chow, nuts with shells, and given access to cotton bedding squares. An underuse group was deprived of cotton bedding as well as diverse textured food, and instead received gelatinized food continuously. Animals were raised from weaning to adulthood on these diets, and sagittal, coronal and lambdoid suture morphology was compared between groups. Predicted intergroup variation was observed in mandibular corpus size and calvarial suture morphology, suggesting that masticatory overuse is associated with jaw and suture growth. The anterior region of the sagittal suture where it intersects with the coronal suture (bregma) showed no effect from the experiment. The posterior sagittal suture where it intersects with the lambdoid sutures (lambda) was more complex in the overuse group. In other words, the posterior calvarium was responsive to dietary material property demands while the anterior calvarium was not. This probably resulted from the different strain magnitudes and/or strain frequencies that occurred during overuse diets with diverse material properties as compared with underuse diets deprived of such enrichment. This work highlights the contrasting pattern of the sutural response to loading differences within the calvarium as a result of diet.
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Affiliation(s)
- Craig Byron
- Department of Biology, Mercer University, Macon, GA, USA
| | - Meghan Segreti
- Department of Biology, Mercer University, Macon, GA, USA
| | | | - Katelyn Herman
- Department of Biology, Mercer University, Macon, GA, USA
| | - Shivam Patel
- Department of Biology, Mercer University, Macon, GA, USA
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Abstract
Craniosynostosis is the premature fusion of the calvarial sutures that is associated with a number of physical and intellectual disabilities spanning from pediatric to adult years. Over the past two decades, techniques in molecular genetics and more recently, advances in high-throughput DNA sequencing have been used to examine the underlying pathogenesis of this disease. To date, mutations in 57 genes have been identified as causing craniosynostosis and the number of newly discovered genes is growing rapidly as a result of the advances in genomic technologies. While contributions from both genetic and environmental factors in this disease are increasingly apparent, there remains a gap in knowledge that bridges the clinical characteristics and genetic markers of craniosynostosis with their signaling pathways and mechanotransduction processes. By linking genotype to phenotype, outlining the role of cell mechanics may further uncover the specific mechanotransduction pathways underlying craniosynostosis. Here, we present a brief overview of the recent findings in craniofacial genetics and cell mechanics, discussing how this information together with animal models is advancing our understanding of craniofacial development.
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Affiliation(s)
- Zeinab Al-Rekabi
- Department of Mechanical Engineering, University of Washington, 3900 E Stevens Way NE, Seattle, WA, 98195, USA
- Seattle Children’s Research Institute, Center for Developmental Biology and Regenerative Medicine, 1900 9 Ave, Seattle, WA, 98101, USA
| | - Michael L. Cunningham
- Seattle Children’s Research Institute, Center for Developmental Biology and Regenerative Medicine, 1900 9 Ave, Seattle, WA, 98101, USA
- Department of Pediatrics, Division of Craniofacial Medicine and the, University of Washington, 1959 NE Pacific St., Seattle, WA, 98195, USA
| | - Nathan J. Sniadecki
- Department of Mechanical Engineering, University of Washington, 3900 E Stevens Way NE, Seattle, WA, 98195, USA
- Department of Bioengineering, University of Washington, 3720 15 Ave NE, Seattle WA, 98105, USA
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16
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Smith AL, Grosse IR. The Biomechanics of Zygomatic Arch Shape. Anat Rec (Hoboken) 2017; 299:1734-1752. [PMID: 27870343 DOI: 10.1002/ar.23484] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 06/11/2016] [Accepted: 07/11/2016] [Indexed: 11/05/2022]
Abstract
Mammalian zygomatic arch shape is remarkably variable, ranging from nearly cylindrical to blade-like in cross section. Based on geometry, the arch can be hypothesized to be a sub-structural beam whose ability to resist deformation is related to cross sectional shape. We expect zygomatic arches with different cross sectional shapes to vary in the degree to which they resist local bending and torsion due to the contraction of the masseter muscle. A stiffer arch may lead to an increase in the relative proportion of applied muscle load being transmitted through the arch to other cranial regions, resulting in elevated cranial stress (and thus, strain). Here, we examine the mechanics of the zygomatic arch using a series of finite element modeling experiments in which the cross section of the arch of Pan troglodytes has been modified to conform to idealized shapes (cylindrical, elliptical, blade-like). We find that the shape of the zygomatic arch has local effects on stain that do not conform to beam theory. One exception is that possessing a blade-like arch leads to elevated strains at the postorbital zygomatic junction and just below the orbits. Furthermore, although modeling the arch as solid cortical bone did not have the effect of elevating strains in other parts of the face, as had been expected, it does have a small effect on stress associated with masseter contraction. These results are counterintuitive. Even though the arch has simple beam-like geometry, we fail to find a simple mechanical explanation for the diversity of arch shape. Anat Rec, 299:1734-1752, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Amanda L Smith
- Department of Anthropology, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri, 63130
| | - Ian R Grosse
- Department of Mechanical & Industrial Engineering, University of Massachusetts, 160 Governor's Drive, Amherst, Massachusetts, 01003-2210
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17
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Savoldi F, Tsoi JKH, Paganelli C, Matinlinna JP. Biomechanical behaviour of craniofacial sutures during distraction: An evaluation all over the entire craniofacial skeleton. Dent Mater 2017; 33:e290-e300. [PMID: 28583671 DOI: 10.1016/j.dental.2017.04.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 04/15/2017] [Accepted: 04/28/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Sutures are fibrous joints connecting the bones of the head. Despite the fundamental role played by sutures in dentofacial orthopaedics, their biomechanical properties are not completely understood. This study evaluated anatomy, biomechanics, and acoustic emission (AE) during distraction of the sutural ligament (SL). METHODS Seventy-two suture samples were removed from a twelve-months-old swine (Sus scrofa) head. Each volume was acquired using micro-computed tomography (μCT), and the linear interdigitation index was calculated on both planes (LIICOR and LIISAG). Mechanical testing till failure was carried at 1mm/min, and four piezoelectric sensors were used for recording of amplitude (A), duration (D), and energy (E) of AE. The relationships between interdigitation, fracture types, tensile stress (σ0), and AE were statistically analysed with non-parametric tests (α=0.05). RESULTS σ0 of the SL had median values of 4.0MPa, and AE were characterised by A of 49.3dB (IQR=2.2), D of 826.3μs (IQR=533.4), and E of 57,715.8 eu (IQR=439,613.5). Most of the fractures happened in the SL (46%), some within the bone (34%), and fewer were combined (19%). LIICOR had correlation with A (0.383, p=0.028), D (0.348, p=0.048), and E (0.437, p=0.011) of the AE, and σ0 had similar relationship with A (0.500, p=0.003), D (0.495, p=0.003), and E (0.579, p<0.001). Maximum energy values were different between fractures within the bone and within the SL (p=0.021). SIGNIFICANCE Biomechanical properties under tension of most of the sutures of the craniofacial skeleton were reported. AE provided information about the sequence of events during SL distraction, and had significant relationship with its mechanical properties. Further studies are necessary to confirm these preliminary findings, and to identify their relationship with biological processes and dentofacial treatments.
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Affiliation(s)
- Fabio Savoldi
- Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong SAR, PR China; Department of Orthodontics, Dental School, University of Brescia, P.le Spedali Civili, 25123 Brescia, Italy.
| | - James K H Tsoi
- Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong SAR, PR China.
| | - Corrado Paganelli
- Department of Orthodontics, Dental School, University of Brescia, P.le Spedali Civili, 25123 Brescia, Italy.
| | - Jukka P Matinlinna
- Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong SAR, PR China.
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18
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Buezas G, Becerra F, Vassallo A. Cranial suture complexity in caviomorph rodents (Rodentia; Ctenohystrica). J Morphol 2017; 278:1125-1136. [DOI: 10.1002/jmor.20699] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 03/15/2017] [Accepted: 04/19/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Guido Buezas
- Departamento de Biología; IIMyC, Universidad Nacional de Mar del Plata; Mar del Plata Argentina
| | - Federico Becerra
- Departamento de Biología; IIMyC, Universidad Nacional de Mar del Plata; Mar del Plata Argentina
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Max Planck Institute for Evolutionary Anthropology; Leipzig Germany
| | - Aldo Vassallo
- Departamento de Biología; IIMyC, Universidad Nacional de Mar del Plata; Mar del Plata Argentina
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19
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Herring SW, Ochareon P. The Periosteum of the Zygomatic Arch: Vascularization and Growth. Anat Rec (Hoboken) 2016; 299:1661-1670. [DOI: 10.1002/ar.23482] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/05/2016] [Accepted: 04/12/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Susan W. Herring
- Department of Orthodontics; University of Washington; Seattle Washington
| | - Pannee Ochareon
- Department of Anatomy, Faculty of Dentistry; Mahidol University; Bangkok Thailand
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20
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Edmonds H. Zygomatic Arch Cortical Area and Diet in Haplorhines. Anat Rec (Hoboken) 2016; 299:1789-1800. [DOI: 10.1002/ar.23478] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 08/18/2016] [Accepted: 08/22/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Hallie Edmonds
- Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University; Arizona
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21
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Wang Q, Dechow PC. Divided Zygomatic Bone in Primates With Implications of Skull Morphology and Biomechanics. Anat Rec (Hoboken) 2016; 299:1801-1829. [DOI: 10.1002/ar.23448] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/12/2016] [Accepted: 04/15/2016] [Indexed: 01/06/2023]
Affiliation(s)
- Qian Wang
- Department of Biomedical Sciences Texas A&M University College of Dentistry; Dallas Texas
| | - Paul C. Dechow
- Department of Biomedical Sciences Texas A&M University College of Dentistry; Dallas Texas
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22
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Bailleul AM, Horner JR. Comparative histology of some craniofacial sutures and skull-base synchondroses in non-avian dinosaurs and their extant phylogenetic bracket. J Anat 2016; 229:252-85. [PMID: 27111332 DOI: 10.1111/joa.12471] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2016] [Indexed: 11/30/2022] Open
Abstract
Sutures and synchondroses, the fibrous and cartilaginous articulations found in the skulls of vertebrates, have been studied for many biological applications at the morphological scale. However, little is known about these articulations at the microscopic scale in non-mammalian vertebrates, including extant archosaurs (birds and crocodilians). The major goals of this paper were to: (i) document the microstructure of some sutures and synchondroses through ontogeny in archosaurs; (ii) compare these microstructures with previously published sutural histology (i.e. that of mammals); and (iii) document how these articulations with different morphological degrees of closure (open or obliterated) appear histologically. This was performed with histological analyses of skulls of emus, American alligators, a fossil crocodilian and ornithischian dinosaurs (hadrosaurids, pachycephalosaurids and ceratopsids). Emus and mammals possess a sutural periosteum until sutural fusion, but it disappears rapidly during ontogeny in American alligators. This study identified seven types of sutural mineralized tissues in extant and extinct archosaurs and grouped them into four categories: periosteal tissues; acellular tissues; fibrous tissues; and intratendinous tissues. Due to the presence of a periosteum in their sutures, emus and mammals possess periosteal tissues at their sutural borders. The mineralized sutural tissues of crocodilians and ornithischian dinosaurs are more variable and can also develop via a form of necrosis for acellular tissues and metaplasia for fibrous and intratendinous tissues. It was hypothesized that non-avian dinosaurs, like the American alligator, lacked a sutural periosteum and that their primary mode of ossification involved the direct mineralization of craniofacial sutures (instead of intramembranous ossification found in mammals and birds). However, we keep in mind that a bird-like sutural microstructure might have arisen within non-avian saurichians. While synchondroseal histology is relatively similar in archosaurs and mammals, the microstructural differences between the sutures of these two clades are undeniable. Moreover, the current results suggest that the degree of sutural closure can only accurately be known via microstructural analyses. This study sheds light on the microstructure and growth of archosaurian sutures and synchondroses, and reveals a unique, undocumented histological diversity in non-avian dinosaur skulls.
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Affiliation(s)
- Alida M Bailleul
- Museum of the Rockies and Department of Earth Sciences, Montana State University, Bozeman, MT, USA
| | - John R Horner
- Museum of the Rockies and Department of Earth Sciences, Montana State University, Bozeman, MT, USA
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23
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Cuff AR, Bright JA, Rayfield EJ. Validation experiments on finite element models of an ostrich (Struthio camelus) cranium. PeerJ 2015; 3:e1294. [PMID: 26500813 PMCID: PMC4614885 DOI: 10.7717/peerj.1294] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 09/15/2015] [Indexed: 11/20/2022] Open
Abstract
The first finite element (FE) validation of a complete avian cranium was performed on an extant palaeognath, the ostrich (Struthio camelus). Ex-vivo strains were collected from the cranial bone and rhamphotheca. These experimental strains were then compared to convergence tested, specimen-specific finite element (FE) models. The FE models contained segmented cortical and trabecular bone, sutures and the keratinous rhamphotheca as identified from micro-CT scan data. Each of these individual materials was assigned isotropic material properties either from the literature or from nanoindentation, and the FE models compared to the ex-vivo results. The FE models generally replicate the location of peak strains and reflect the correct mode of deformation in the rostral region. The models are too stiff in regions of experimentally recorded high strain and too elastic in regions of low experimentally recorded low strain. The mode of deformation in the low strain neurocranial region is not replicated by the FE models, and although the models replicate strain orientations to within 10° in some regions, in most regions the correlation is not strong. Cranial sutures, as has previously been found in other taxa, are important for modifying both strain magnitude and strain patterns across the entire skull, but especially between opposing the sutural junctions. Experimentally, we find that the strains on the surface of the rhamphotheca are much lower than those found on nearby bone. The FE models produce much higher principal strains despite similar strain ratios across the entirety of the rhamphotheca. This study emphasises the importance of attempting to validate FE models, modelling sutures and rhamphothecae in birds, and shows that whilst location of peak strain and patterns of deformation can be modelled, replicating experimental data in digital models of avian crania remains problematic.
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Affiliation(s)
- Andrew R Cuff
- GEE, University College London , London , United Kingdom ; Structure and Motion Laboratory, The Royal Veterinary College , Hatfield , United Kingdom ; School of Earth Sciences, University of Bristol , Bristol , United Kingdom
| | - Jen A Bright
- School of Earth Sciences, University of Bristol , Bristol , United Kingdom ; Department of Animal and Plant Sciences, University of Sheffield , Sheffield , United Kingdom
| | - Emily J Rayfield
- School of Earth Sciences, University of Bristol , Bristol , United Kingdom
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Descriptive anatomy and three-dimensional reconstruction of the skull of the early tetrapod Acanthostega gunnari Jarvik, 1952. PLoS One 2015; 10:e0118882. [PMID: 25760343 PMCID: PMC4356540 DOI: 10.1371/journal.pone.0118882] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 01/23/2015] [Indexed: 12/03/2022] Open
Abstract
The early tetrapod Acanthostega gunnari is an iconic fossil taxon exhibiting skeletal morphology reflecting the transition of vertebrates from water onto land. Computed tomography data of two Acanthostega skulls was segmented using visualization software to digitally separate bone from matrix and individual bones of the skull from each other. A revised description of cranial and lower jaw anatomy in this taxon based on CT data includes new details of sutural morphology, the previously undescribed quadrate and articular bones, and the mandibular symphysis. Sutural morphology is used to infer loading regime in the skull during feeding, and suggests Acanthostega used its anterior jaws to initially seize prey while smaller posterior teeth were used to restrain struggling prey during ingestion. Novel methods were used to repair and retrodeform the skull, resulting in a three-dimensional digital reconstruction that features a longer postorbital region and more strongly hooked anterior lower jaw than previous attempts while supporting the presence of a midline gap between the nasals and median rostrals.
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25
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Gabutti M, Draper-Rodi J. Osteopathic decapitation: Why do we consider the head differently from the rest of the body? New perspectives for an evidence-informed osteopathic approach to the head. INT J OSTEOPATH MED 2014. [DOI: 10.1016/j.ijosm.2014.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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26
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Naples VL, McAfee RK. Chewing through the Miocene: an examination of the feeding musculature in the ground sloth Hapalops from South America (Mammalia: Pilosa). F1000Res 2014; 3:86. [PMID: 25075299 PMCID: PMC4097365 DOI: 10.12688/f1000research.3282.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/18/2014] [Indexed: 11/23/2022] Open
Abstract
Hapalops, a smaller-sized and early sloth of the Megatheroidea, appeared in the middle Miocene Santa Cruz formation of Argentina. This genus is part of the group from which later, larger megatheroids arose, i.e.,
Nothrotheriops and
Megatherium. Many cranial characters support this idea; however
Hapalops is not merely a smaller antecedent of the later forms. Specifically,
Hapalops retains short anterior caniniform teeth, and a temporomandibular joint elevated above the cheek tooth row; a combination distinct among sloths. An elevated temporomandibular joint occurs in
Bradypus, a tree sloth with anterior chisel-shaped teeth instead of caniniforms, and the tree sloth
Choloepus, which is aligned with the megalonychids, has anterior caniniforms.
Hapalops has an elongated zygomatic ascending process that is reminiscent of that in
Bradypus; however, the
Bradypus skull is extremely foreshortened while that of
Hapalops is elongated, as in nothrotheres, but not deepened as in megatheres. Previous work identified many sloth cranial character complexes, and functional limitations on skull feature combinations. The unique
Hapalops character patterns indicate a selective feeder with a mediolaterally oriented grinding stroke during mastication.
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Affiliation(s)
- Virginia L Naples
- Department of Biological Sciences, Northern Illinois University, Illinois, 60115, USA
| | - Robert K McAfee
- Department of Biological & Allied Health Sciences, Ohio Northern University, Ada, Ohio, 45810, USA
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27
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Curtis N, Witzel U, Fagan MJ. Development and three-dimensional morphology of the zygomaticotemporal suture in primate skulls. Folia Primatol (Basel) 2014; 85:77-87. [PMID: 24481002 DOI: 10.1159/000357526] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 11/24/2013] [Indexed: 11/19/2022]
Abstract
Cranial sutures are an essential part of the growing skull, allowing bones to increase in size during growth, with their morphology widely believed to be dictated by the forces and displacements that they experience. The zygomaticotemporal suture in primates is located in the relatively weak zygomatic arch, and externally it appears a very simple connection. However, large forces are almost certainly transmitted across this suture, suggesting that it requires some level of stability while also allowing controlled movements under high loading. Here we examine the 2- and 3-dimensional (3D) morphology of the zygomaticotemporal suture in an ontogenetic series of Macaca fascicularis skulls. High resolution microcomputed tomography data sets were examined, and virtual and physical 3D replicas were created to assess both structure and general stability. The zygomaticotemporal suture is much more complex than its external appearance suggests, with interlocking facets between the adjacent zygomatic and temporal bones. It appears as if some movement is permitted across the suture in younger animals, but as they approach adulthood the complexity of the suture's interlocking bone facets reaches a level where these movements become minimal.
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28
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Characterization of craniofacial sutures using the finite element method. J Biomech 2014; 47:245-52. [DOI: 10.1016/j.jbiomech.2013.09.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Revised: 03/07/2013] [Accepted: 09/09/2013] [Indexed: 11/29/2022]
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29
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Sun Z, Herring SW, Tee BC, Gales J. Alveolar ridge reduction after tooth extraction in adolescents: an animal study. Arch Oral Biol 2013; 58:813-25. [PMID: 23380583 PMCID: PMC3665758 DOI: 10.1016/j.archoralbio.2012.12.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 11/28/2012] [Accepted: 12/26/2012] [Indexed: 01/07/2023]
Abstract
OBJECTIVE The mechanism for tooth extraction induced residual alveolar ridge reduction (RRR) during adolescence is poorly understood. This study investigated the alveolar bone morphology, growth, resorption and functional loading at normal and extraction sites using an adolescent pig model. DESIGN Sixteen 3-month-old pigs were divided into two groups - immediate post-extraction (IE) and 6-week post-extraction (SE). The IE group received an extraction of one deciduous mandibular molar, immediately followed by a final experiment to record masseter muscle EMGs and strains from the buccal surface of the extraction and contralateral non-extraction sites during function (mastication). The SE group was given the same tooth extraction, then kept for 6 weeks before the same final functional recording as the IE group. Both groups also received baseline (pre-extraction) EMGs and fluorescent vital stains 10 and 3 days before the final functional recording. Immediately after the final functional recording, animals were euthanized and alveolar bone specimens from extraction and contralateral non-extraction sites were collected and used to analyse alveolar bone morphology, apposition and resorption based on fluorescent and hematoxylin and eosin stained histological sections. RESULTS At control sites (IE-extraction, IE-non-extraction and SE-non-extraction), the alveolar ridges grew gingivally and buccally. Bone formation characterized the buccal surface and lingual bundle bone, whereas resorption characterized the lingual surface and buccal bundle bone. The SE-extraction sites showed three major alterations: convergence of the buccal and lingual gingival crests, loss of apposition on the lingual bundle bone, and decelerated growth at the entire buccal surface. These alterations likely resulted from redirected crestal growth as part of the socket healing process, loss of tongue pressure to the lingual side of the teeth which normally provides mechanical stimulation for dental arch expansion, and masticatory underloading during the initial post-extraction period, respectively. CONCLUSIONS These data indicate that the initial phase of RRR in adolescents is a product of modified growth, not resorption, possibly because of decreased mechanical stimulation at the extraction site.
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Affiliation(s)
- Zongyang Sun
- Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH 43210, USA.
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Curtis N, Jones MEH, Evans SE, O'Higgins P, Fagan MJ. Cranial sutures work collectively to distribute strain throughout the reptile skull. J R Soc Interface 2013; 10:20130442. [PMID: 23804444 PMCID: PMC3730698 DOI: 10.1098/rsif.2013.0442] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The skull is composed of many bones that come together at sutures. These sutures are important sites of growth, and as growth ceases some become fused while others remain patent. Their mechanical behaviour and how they interact with changing form and loadings to ensure balanced craniofacial development is still poorly understood. Early suture fusion often leads to disfiguring syndromes, thus is it imperative that we understand the function of sutures more clearly. By applying advanced engineering modelling techniques, we reveal for the first time that patent sutures generate a more widely distributed, high level of strain throughout the reptile skull. Without patent sutures, large regions of the skull are only subjected to infrequent low-level strains that could weaken the bone and result in abnormal development. Sutures are therefore not only sites of bone growth, but could also be essential for the modulation of strains necessary for normal growth and development in reptiles.
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Affiliation(s)
- Neil Curtis
- Medical and Biological Engineering Research Group, School of Engineering, University of Hull, Hull HU6 7RX, UK.
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Shibazaki-Yorozuya R, Wang Q, Dechow PC, Maki K, Opperman LA. Changes in biomechanical strain and morphology of rat calvarial sutures and bone after Tgf-β3 inhibition of posterior interfrontal suture fusion. Anat Rec (Hoboken) 2012; 295:928-38. [PMID: 22528365 DOI: 10.1002/ar.22474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Accepted: 03/15/2012] [Indexed: 11/07/2022]
Abstract
Craniofacial sutures are bone growth fronts that respond and adapt to biomechanical environments. Little is known of the role sutures play in regulating the skull biomechanical environment during patency and fusion conditions, especially how delayed or premature suture fusion will impact skull biomechanics. Tgf-β3 has been shown to prevent or delay suture fusion over the short term in rat skulls, yet the long-term patency or its consequences in treated sutures is not known. It was therefore hypothesized that Tgf-β3 had a long-term impact to prevent suture fusion and thus alter the skull biomechanics. In this study, collagen gels containing 3 ng Tgf-β3 were surgically placed superficial to the posterior interfrontal suture (IFS) and deep to the periosteum in postnatal day 9 (P9) rats. At P9, P24, and P70, biting forces and strains over left parietal bone, posterior IFS, and sagittal suture were measured with masticatory muscles bilaterally stimulated, after which the rats were sacrificed and suture patency analyzed histologically. Results demonstrated that Tgf-β3 treated sutures showed less fusion over time than control groups, and strain patterns in the skulls of the Tgf-β3-treated group were different from that of the control group. Although bite force increased with age, no alterations in bite force were attributable to Tgf-β3 treatment. These findings suggest that the continued presence of patent sutures can affect strain patterns, perhaps when higher bite forces are present as in adult animals.
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Affiliation(s)
- Reiko Shibazaki-Yorozuya
- Department of Biomedical Sciences, Texas A&M Health Science Center Baylor College of Dentistry, Dallas, USA
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Bright JA. The importance of craniofacial sutures in biomechanical finite element models of the domestic pig. PLoS One 2012; 7:e31769. [PMID: 22363727 PMCID: PMC3283651 DOI: 10.1371/journal.pone.0031769] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 01/18/2012] [Indexed: 11/19/2022] Open
Abstract
Craniofacial sutures are a ubiquitous feature of the vertebrate skull. Previous experimental work has shown that bone strain magnitudes and orientations often vary when moving from one bone to another, across a craniofacial suture. This has led to the hypothesis that craniofacial sutures act to modify the strain environment of the skull, possibly as a mode of dissipating high stresses generated during feeding or impact. This study tests the hypothesis that the introduction of craniofacial sutures into finite element (FE) models of a modern domestic pig skull would improve model accuracy compared to a model without sutures. This allowed the mechanical effects of sutures to be assessed in isolation from other confounding variables. These models were also validated against strain gauge data collected from the same specimen ex vivo. The experimental strain data showed notable strain differences between adjacent bones, but this effect was generally not observed in either model. It was found that the inclusion of sutures in finite element models affected strain magnitudes, ratios, orientations and contour patterns, yet contrary to expectations, this did not improve the fit of the model to the experimental data, but resulted in a model that was less accurate. It is demonstrated that the presence or absence of sutures alone is not responsible for the inaccuracies in model strain, and is suggested that variations in local bone material properties, which were not accounted for by the FE models, could instead be responsible for the pattern of results.
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Affiliation(s)
- Jen A Bright
- Department of Earth Sciences, University of Bristol, Bristol, United Kingdom.
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Curtis N, Jones MEH, Shi J, O'Higgins P, Evans SE, Fagan MJ. Functional relationship between skull form and feeding mechanics in Sphenodon, and implications for diapsid skull development. PLoS One 2011; 6:e29804. [PMID: 22216358 PMCID: PMC3247290 DOI: 10.1371/journal.pone.0029804] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 12/05/2011] [Indexed: 11/19/2022] Open
Abstract
The vertebrate skull evolved to protect the brain and sense organs, but with the appearance of jaws and associated forces there was a remarkable structural diversification. This suggests that the evolution of skull form may be linked to these forces, but an important area of debate is whether bone in the skull is minimised with respect to these forces, or whether skulls are mechanically "over-designed" and constrained by phylogeny and development. Mechanical analysis of diapsid reptile skulls could shed light on this longstanding debate. Compared to those of mammals, the skulls of many extant and extinct diapsids comprise an open framework of fenestrae (window-like openings) separated by bony struts (e.g., lizards, tuatara, dinosaurs and crocodiles), a cranial form thought to be strongly linked to feeding forces. We investigated this link by utilising the powerful engineering approach of multibody dynamics analysis to predict the physiological forces acting on the skull of the diapsid reptile Sphenodon. We then ran a series of structural finite element analyses to assess the correlation between bone strain and skull form. With comprehensive loading we found that the distribution of peak von Mises strains was particularly uniform throughout the skull, although specific regions were dominated by tensile strains while others were dominated by compressive strains. Our analyses suggest that the frame-like skulls of diapsid reptiles are probably optimally formed (mechanically ideal: sufficient strength with the minimal amount of bone) with respect to functional forces; they are efficient in terms of having minimal bone volume, minimal weight, and also minimal energy demands in maintenance.
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Affiliation(s)
- Neil Curtis
- Medical and Biological Engineering Research Group, Department of Engineering, University of Hull, Hull, United Kingdom.
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Wang Q, Wood SA, Grosse IR, Ross CF, Zapata U, Byron CD, Wright BW, Strait DS. The role of the sutures in biomechanical dynamic simulation of a macaque cranial finite element model: implications for the evolution of craniofacial form. Anat Rec (Hoboken) 2011; 295:278-88. [PMID: 22190334 DOI: 10.1002/ar.21532] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 10/04/2011] [Indexed: 11/08/2022]
Abstract
The global biomechanical impact of cranial sutures on the face and cranium during dynamic conditions is not well understood. It is hypothesized that sutures act as energy absorbers protecting skulls subjected to dynamic loads. This hypothesis predicts that sutures have a significant impact on global patterns of strain and cranial structural stiffness when analyzed using dynamic simulations; and that this global impact is influenced by suture material properties. In a finite element model developed from a juvenile Rhesus macaque cranium, five different sets of suture material properties for the zygomaticotemporal sutures were tested. The static and dynamic analyses produced similar results in terms of strain patterns and reaction forces, indicating that the zygomaticotemporal sutures have limited impact on global skull mechanics regardless of loading design. Contrary to the functional hypothesis tested in this study, the zygomaticotemporal sutures did not absorb significant amounts of energy during dynamic simulations regardless of loading speed. It is alternatively hypothesized that sutures are mechanically significant only insofar as they are weak points on the cranium that must be shielded from unduly high stresses so as not to disrupt vitally important growth processes. Thus, sutural and overall cranial form in some vertebrates may be optimized to minimize or otherwise modulate sutural stress and strain.
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Affiliation(s)
- Qian Wang
- Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, Georgia, USA.
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Bright JA, Gröning F. Strain accommodation in the zygomatic arch of the pig: a validation study using digital speckle pattern interferometry and finite element analysis. J Morphol 2011; 272:1388-98. [PMID: 21755526 DOI: 10.1002/jmor.10991] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 04/22/2011] [Accepted: 05/08/2011] [Indexed: 11/09/2022]
Abstract
It has been repeatedly suggested that mammalian cranial sutures act not only to allow growth but also to reduce the levels of strain experienced by the skull during feeding. However, because of the added complexity they introduce, sutures are rarely included in finite element (FE) models, despite their potential to influence strain results. Because sutures present different morphologies and with differing degrees of internal fusion, many different methods of modeling may be necessary to accurately measure strain environments. Alternatively, these variables may exert very little influence on the scale of a whole-skull model. To validate suture modeling methods, four alternative ways of including a suture in 3D FE models of the pig zygomatic arch were considered and compared with ex vivo experimental data from digital speckle pattern interferometry (DSPI). The use of DSPI rather than traditional strain gauge techniques allows strain gradients around the suture as well as the motions of the two bones to be observed. Results show that the introduction of 3D elements assigned more compliant material properties than the surrounding bone, is the most effective way of modeling both morphologies of suture, both in tension and compression. However, models containing no suture are almost indistinguishable from these compliant suture models, beyond the high strain gradient immediately adjacent to the suture. Conversely, modeling the suture as an open break in the mesh, or with spring elements assigned suture properties, fails to reproduce the experiment. Thus, although a solid but flexible model of sutures is preferred, the similarity between these models and those without sutures tentatively suggests that such extra detail may be unnecessary in pigs if the behavior of the whole skull is of interest.
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Affiliation(s)
- Jen A Bright
- Department of Earth Sciences, University of Bristol, Bristol, Avon, UK.
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Bright JA, Rayfield EJ. Sensitivity and ex vivo validation of finite element models of the domestic pig cranium. J Anat 2011; 219:456-71. [PMID: 21718316 DOI: 10.1111/j.1469-7580.2011.01408.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
A finite element (FE) validation and sensitivity study was undertaken on a modern domestic pig cranium. Bone strain data were collected ex vivo from strain gauges, and compared with results from specimen-specific FE models. An isotropic, homogeneous model was created, then input parameters were altered to investigate model sensitivity. Heterogeneous, isotropic models investigated the effects of a constant-thickness, stiffer outer layer (representing cortical bone) atop a more compliant interior (representing cancellous bone). Loading direction and placement of strain gauges were also varied, and the use of 2D membrane elements at strain gauge locations as a method of projecting 3D model strains into the plane of the gauge was investigated. The models correctly estimate the loading conditions of the experiment, yet at some locations fail to reproduce correct principal strain magnitudes, and hence strain ratios. Principal strain orientations are predicted well. The initial model was too stiff by approximately an order of magnitude. Introducing a compliant interior reported strain magnitudes more similar to the ex vivo results without notably affecting strain orientations, ratios or contour patterns, suggesting that this simple heterogeneity was the equivalent of reducing the overall stiffness of the model. Models were generally insensitive to moderate changes in loading direction or strain gauge placement, except in the squamosal portion of the zygomatic arch. The use of membrane elements made negligible differences to the reported strains. The models therefore seem most sensitive to changes in material properties, and suggest that failure to model local heterogeneity in material properties and structure of the bone may be responsible for discrepancies between the experimental and model results. This is partially attributable to a lack of resolution in the CT scans from which the model was built, and partially due to an absence of detailed material properties data for pig cranial bone. Thus, caution is advised when using FE models to estimate absolute numerical values of breaking stress and bite force unless detailed input parameters are available. However, if the objective is to compare relative differences between models, the fact that the strain environment is replicated well means that such investigations can be robust.
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Affiliation(s)
- Jen A Bright
- Department of Earth Sciences, University of Bristol, UK.
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Sun Z, Hueni S, Tee BC, Kim H. Mechanical strain at alveolar bone and circummaxillary sutures during acute rapid palatal expansion. Am J Orthod Dentofacial Orthop 2011; 139:e219-28. [PMID: 21392665 DOI: 10.1016/j.ajodo.2009.12.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 12/01/2009] [Accepted: 12/01/2009] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Palatal expansion can potentially affect alveolar bone and circummaxillary sutures. In this study, we characterized their mechanical strain during acute expansion. METHODS Eight 3- and 6-month-old fresh pig heads received acute palatal expansion with hyrax expanders. Strain gauges were used to measure strain at the buccal alveolar bone of anchor and adjacent nonanchor teeth, and at maxillary-premaxillary, maxillary-zygomatic, and zygomatic-temporal sutures during expansion. Intermolar width changes were measured from dental casts. RESULTS Intermolar width increased less than expander activation, and the midpalatal sutures were only opened slightly. Alveolar bone strain increased linearly with expander activation and decayed by 20% to 30% during postactivation intervals. Compressive strain at anchor-tooth alveolar bone locations was directed occlusally and apically, related to tooth tipping, and significantly higher than that at nonanchor tooth locations. With expander activation, suture strains increased monotonically and tended to plateau. Suture strain magnitude was generally similar to physiologic (masticatory) strains reported in the literature. The dominant strain polarity was compression at the maxillary-zygomatic and zygomatic-temporal sutures, but there was tension at the maxillary-premaxillary suture. CONCLUSIONS In these pigs, palatal expansion can cause significant occlusal-apical compression at buccal alveolar bone and physiologic-level strains at circummaxillary sutures.
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Affiliation(s)
- Zongyang Sun
- Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, Ohio, USA.
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Herring SW, Rafferty KL, Liu ZJ, Lemme M. Mastication and the postorbital ligament: dynamic strain in soft tissues. Integr Comp Biol 2011; 51:297-306. [PMID: 21593142 DOI: 10.1093/icb/icr023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although the FEED database focuses on muscle activity patterns, it is equally suitable for other physiological recording and especially for synthesizing different types of information. The present contribution addresses the interaction between muscle activity and ligamentary stretch during mastication. The postorbital ligament is the thickened edge of a septum dividing the orbital contents from the temporal fossa and is continuous with the temporal fascia. As a tensile element, this fascial complex could support the zygomatic arch against the pull of the masseter muscle. An ossified postorbital bar has evolved repeatedly in mammals, enabling resistance to compression and shear in addition to tension. Although such ossification clearly reinforces the skull against muscle pull, the most accepted explanation is that it helps isolate the orbital contents from contractions of the temporalis muscle. However, it has never been demonstrated that the contraction of jaw muscles deforms the unossified ligament. We examined linear deformation of the postorbital ligament in minipigs, Sus scrofa, along with electromyography of the jaw muscles and an assessment of changes in pressure and shape in the temporalis. During chewing, the ligament elongated (average 0.9%, maximum 2.8%) in synchrony with the contraction of the elevator muscles of the jaw. Although the temporalis bulged outward and created substantial pressure against the braincase, the superficial fibers usually retracted caudally, away from the postorbital ligament. In anesthetized animals, stimulating either the temporalis or the masseter muscle in isolation usually elongated the ligament (average 0.4-0.7%). These results confirm that contraction of the masticatory muscles can potentially distort the orbital contents and further suggest that the postorbital ligament does function as a tension member resisting the pull of the masseter on the zygomatic arch.
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Affiliation(s)
- Susan W Herring
- Department of Orthodontics, School of Dentistry, University of Washington, Seattle, USA.
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Cray J, Cooper GM, Mooney MP, Siegel MI. Timing of ectocranial suture activity in Gorilla gorilla as related to cranial volume and dental eruption. J Anat 2011; 218:471-9. [PMID: 21385182 DOI: 10.1111/j.1469-7580.2011.01358.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Research has shown that Pan and Homo have similar ectocranial suture synostosis patterns and a similar suture ontogeny (relative timing of suture fusion during the species ontogeny). This ontogeny includes patency during and after neurocranial expansion with a delayed bony response associated with adaptation to biomechanical forces generated by mastication. Here we investigate these relationships for Gorilla by examining the association among ectocranial suture morphology, cranial volume (as a proxy for neurocranial expansion) and dental development (as a proxy for the length of time that it has been masticating hard foods and exerting such strains on the cranial vault) in a large sample of Gorilla gorilla skulls. Two-hundred and fifty-five Gorilla gorilla skulls were examined for ectocranial suture closure status, cranial volume and dental eruption. Regression models were calculated for cranial volumes by suture activity, and Kendall's tau (a non-parametric measure of association) was calculated for dental eruption status by suture activity. Results suggest that, as reported for Pan and Homo, neurocranial expansion precedes suture synostosis activity. Here, Gorilla was shown to have a strong relationship between dental development and suture activity (synostosis). These data are suggestive of suture fusion extending further into ontogeny than brain expansion, similar to Homo and Pan. This finding allows for the possibility that masticatory forces influence ectocranial suture morphology.
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Affiliation(s)
- James Cray
- Department of Surgery, Division of Plastic and Reconstructive Surgery, University of Pittsburgh, PA, USA.
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Reed DA, Porro LB, Iriarte-Diaz J, Lemberg JB, Holliday CM, Anapol F, Ross CF. The impact of bone and suture material properties on mandibular function in Alligator mississippiensis: testing theoretical phenotypes with finite element analysis. J Anat 2010; 218:59-74. [PMID: 21091693 DOI: 10.1111/j.1469-7580.2010.01319.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The functional effects of bone and suture stiffness were considered here using finite element models representing three different theoretical phenotypes of an Alligator mississippiensis mandible. The models were loaded using force estimates derived from muscle architecture in dissected specimens, constrained at the 18th and 19th teeth in the upper jaw and 19th tooth of the lower jaw, as well as at the quadrate-articular joint. Stiffness was varied systematically in each theoretical phenotype. The three theoretical phenotypes included: (i) linear elastic isotropic bone of varying stiffness and no sutures; (ii) linear elastic orthotropic bone of varying stiffness with no sutures; and (iii) linear elastic isotropic bone of a constant stiffness with varying suture stiffness. Variation in the isotropic material properties of bone primarily resulted in changes in the magnitude of principal strain. By comparison, variation in the orthotropic material properties of bone and isotropic material properties of sutures resulted in: a greater number of bricks becoming either more compressive or more tensile, changing between being either dominantly compressive or tensile, and having larger changes in the orientation of maximum principal strain. These data indicate that variation in these model properties resulted in changes to the strain regime of the model, highlighting the importance of using biologically verified material properties when modeling vertebrate bones. When bones were compared within each set, the response of each to changing material properties varied. In two of the 12 bones in the mandible, varied material properties within sutures resulted in a decrease in the magnitude of principal strain in bricks adjacent to the bone/suture interface and decreases in stored elastic energy. The varied response of the mandibular bones to changes in suture stiffness highlights the importance of defining the appropriate functional unit when addressing relationships of performance and morphology.
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Affiliation(s)
- David A Reed
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA.
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Wang Q, Smith AL, Strait DS, Wright BW, Richmond BG, Grosse IR, Byron CD, Zapata U. The global impact of sutures assessed in a finite element model of a macaque cranium. Anat Rec (Hoboken) 2010; 293:1477-91. [PMID: 20652940 DOI: 10.1002/ar.21203] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The biomechanical significance of cranial sutures in primates is an open question because their global impact is unclear, and their material properties are difficult to measure. In this study, eight suture-bone functional units representing eight facial sutures were created in a finite element model of a monkey cranium. All the sutures were assumed to have identical isotropic linear elastic material behavior that varied in different modeling experiments, representing either fused or unfused sutures. The values of elastic moduli employed in these trials ranged over several orders of magnitude. Each model was evaluated under incisor, premolar, and molar biting conditions. Results demonstrate that skulls with unfused sutures permitted more deformations and experienced higher total strain energy. However, strain patterns remained relatively unaffected away from the suture sites, and bite reaction force was likewise barely affected. These findings suggest that suture elasticity does not substantially alter load paths through the macaque skull or its underlying rigid body kinematics. An implication is that, for the purposes of finite element analysis, omitting or fusing sutures is a reasonable modeling approximation for skulls with small suture volume fraction if the research objective is to observe general patterns of craniofacial biomechanics under static loading conditions. The manner in which suture morphology and ossification affect the mechanical integrity of skulls and their ontogeny and evolution awaits further investigation, and their viscoelastic properties call for dynamic simulations.
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Affiliation(s)
- Qian Wang
- Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, Georgia 31207, USA.
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Jasinoski SC, Rayfield EJ, Chinsamy A. Functional implications of dicynodont cranial suture morphology. J Morphol 2010; 271:705-28. [PMID: 20077504 DOI: 10.1002/jmor.10828] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cranial suture morphology of Lystrosaurus and the generalized dicynodont Oudenodon was investigated to determine the strain environment during mastication, which in turn may indicate a difference in cranial function between the two taxa. Finite element (FE) analysis indicated that less strain accumulated in the cranium of Lystrosaurus during orthal bite simulations than in Oudenodon. Despite the overall difference in strain magnitude, moderate to high FE-predicted strain accumulated in similar areas of the cranium of both taxa. The suture morphology in these cranial regions of Lystrosaurus and Oudenodon was investigated further by examination of histological sections and supplemented by observations of serial sections and computed tomography (CT) scans. The predominant type of strain from selected blocks of finite elements that contain sutures was determined, enabling comparison of suture morphology to strain type. Drawing from strain-suture correlations established in extant taxa, the observed patterns of sutural morphology for both dicynodonts were used to deduce cranial function. The moderate to high compressive and tensile strain experienced by the infraorbital bar, zygomatic arch, and postorbital bar of Oudenodon and Lystrosaurus may have been decreased by small adjustive movements at the scarf sutures in those regions. Disparities in cranial suture morphology between the two taxa may reflect differences in cranial function. For instance, the tongue and groove morphology of the postorbital-parietal suture in Oudenodon could have withstood the higher FE-predicted tensile strain in the posterior skull roof. The scarf premaxilla-nasal suture of Lystrosaurus provided an additional region of sutural mobility in the anterior surface of the snout, suggesting that Lystrosaurus may have employed a different biting regime than Oudenodon. The morphology of several sutures sampled in this study correlated with the FE-predicted strain, although other cranial functional hypotheses remain to be tested.
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Affiliation(s)
- Sandra C Jasinoski
- Department of Earth Sciences, University of Bristol, Wills Memorial Building, Bristol BS8 1RJ, UK.
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Smith TD, Burrows AM, Dumont ER. Microanatomical assessment of nasomaxillary suture patency. Anat Rec (Hoboken) 2010; 293:651-7. [PMID: 20235318 DOI: 10.1002/ar.21125] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In addition to acting as a growth site, sutures in the facial skeleton are important for distributing mechanical forces during mastication. In the present study, the extent of fusion of a facial suture is assessed in two samples of adult bushbabies (Galago moholi and Otolemur garnettii). Microanatomical techniques were used to determine the loci of osseous bridges across the nasomaxillary suture (NMS). Histological sections containing sutures with osseous bridging were rated as "fused." One of the specimens was studied using micro-computed tomography before paraffin embedding and serial sectioning. At all ages, O. garnettii shows more advanced fusion of the NMS than G. moholi. The youngest O. garnettii shows multiple foci of fusion of the NMS; however, 13% of the posterior most suture is patent. Throughout the NMS of this animal, sutural fusion is isolated to one or two small osseous bridges, typically of woven bone. These bridges are most often on the external (superficial) surface of the suture, but in numerous sections the site of fusion occurs deep to an external notch. In G. moholi, the youngest adults studied showed little or no fusion across the NMS. However, the nasal and maxillary bones were indirectly tethered at some levels by other bones that were fused to both nasal and maxillary bones. These results indicate that microanatomical evidence is required to fully assess the extent of fusion of facial sutures. These findings also support previous observations of differing magnitude of suture fusion between the two species.
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Affiliation(s)
- Timothy D Smith
- School of Physical Therapy, Slippery Rock University, Slippery Rock, PA 16057, USA.
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Vecchione L, Miller J, Byron C, Cooper GM, Barbano T, Cray J, Losee JE, Hamrick MW, Sciote JJ, Mooney MP. Age-related changes in craniofacial morphology in GDF-8 (myostatin)-deficient mice. Anat Rec (Hoboken) 2010; 293:32-41. [PMID: 19899116 DOI: 10.1002/ar.21024] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
It is well recognized that masticatory muscle function helps determine morphology, although the extent of function on final form is still debated. GDF-8 (myostatin), a transcription factor is a negative regulator of skeletal muscle growth. A recent study has shown that mice homozygous for the myostatin mutation had increased muscle mass and craniofacial dysmorphology in adulthood. However, it is unclear whether such dysmorphology is present at birth. This study examines the onset and relationship between hypermuscularity and craniofacial morphology in neonatal and adult mice with GDF-8 deficiency. Fifteen (8 wild-type and 7 GDF-8 -/-), 1-day-old and 16 (9 wt and 7 GDF-8 -/-), 180-day-old male CD-1 mice were used. Standardized radiographs were taken of each head, scanned, traced, and cephalometric landmarks identified. Significant mean differences were assessed using a group x age, two-way ANOVA. Myostatin-deficient mice had significantly (P < 0.01) smaller body and masseter muscle weights and craniofacial skeletons at 1 day of age and significantly greater body and masseter muscle weights at 180 days of age compared to controls. Myostatin-deficient mice showed significantly (P < 0.001) longer and "rocker-shaped" mandibles and shorter and wider crania compared to controls at 180 days. Significant correlations were noted between masseter muscle weight and all cephalometric measurements in 180-day-old Myostatin-deficient mice. Results suggest that in this mouse model, there may be both early systemic skeletal growth deficiencies and later compensatory changes from hypermuscularity. These findings reiterate the role that masticatory muscle function plays on the ontogeny of the cranial vault, base, and most notably the mandible.
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Affiliation(s)
- Lisa Vecchione
- Pittsburgh Cleft-Craniofacial Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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Holton NE, Franciscus RG, Nieves MA, Marshall SD, Reimer SB, Southard TE, Keller JC, Maddux SD. Sutural growth restriction and modern human facial evolution: an experimental study in a pig model. J Anat 2010; 216:48-61. [PMID: 19929910 PMCID: PMC2807975 DOI: 10.1111/j.1469-7580.2009.01162.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2009] [Indexed: 11/30/2022] Open
Abstract
Facial size reduction and facial retraction are key features that distinguish modern humans from archaic Homo. In order to more fully understand the emergence of modern human craniofacial form, it is necessary to understand the underlying evolutionary basis for these defining characteristics. Although it is well established that the cranial base exerts considerable influence on the evolutionary and ontogenetic development of facial form, less emphasis has been placed on developmental factors intrinsic to the facial skeleton proper. The present analysis was designed to assess anteroposterior facial reduction in a pig model and to examine the potential role that this dynamic has played in the evolution of modern human facial form. Ten female sibship cohorts, each consisting of three individuals, were allocated to one of three groups. In the experimental group (n = 10), microplates were affixed bilaterally across the zygomaticomaxillary and frontonasomaxillary sutures at 2 months of age. The sham group (n = 10) received only screw implantation and the controls (n = 10) underwent no surgery. Following 4 months of post-surgical growth, we assessed variation in facial form using linear measurements and principal components analysis of Procrustes scaled landmarks. There were no differences between the control and sham groups; however, the experimental group exhibited a highly significant reduction in facial projection and overall size. These changes were associated with significant differences in the infraorbital region of the experimental group including the presence of an infraorbital depression and an inferiorly and coronally oriented infraorbital plane in contrast to a flat, superiorly and sagittally infraorbital plane in the control and sham groups. These altered configurations are markedly similar to important additional facial features that differentiate modern humans from archaic Homo, and suggest that facial length restriction via rigid plate fixation is a potentially useful model to assess the developmental factors that underlie changing patterns in craniofacial form associated with the emergence of modern humans.
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Affiliation(s)
- Nathan E Holton
- Department of Orthodontics, University of Iowa, Iowa City, IA 52242, USA.
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Jasinoski SC, Rayfield EJ, Chinsamy A. Comparative feeding biomechanics of Lystrosaurus and the generalized dicynodont Oudenodon. Anat Rec (Hoboken) 2009; 292:862-74. [PMID: 19462456 DOI: 10.1002/ar.20906] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Differences in cranial morphology among the Dicynodontia have been correlated with changes in masticatory function, and hence, dietary preference. Although the derived masticatory apparatus of dicynodonts allowed propaliny, it has previously been hypothesized that Lystrosaurus primarily utilized powerful orthal jaw movements to process fibrous vegetation. Cranial specializations of Lystrosaurus, such as shortened and deepened cranium and a mobile premaxilla-nasal suture, are thought to have increased the efficiency of its masticatory system compared with generalized Permian dicynodonts. Here we aim to test this assertion using biomechanical modeling techniques. We use finite element analysis (FEA) and a study of cranial functional morphology to compare the biomechanical performance of the crania of Lystrosaurus and Oudenodon, a generalized dicynodont, during orthal bite simulations. Muscle forces were estimated for each dicynodont using the dry skull method and applied to each cranium to produce a reaction force at a bite point. Patterns and average magnitude of Von Mises stress in each dicynodont cranium and in segmented regions of interest were assessed. During orthal bite simulations, higher stress occurs throughout the Oudenodon cranium, indicating that the cranium of Lystrosaurus is more resistant to normal, static feeding loads. Despite this difference in stress magnitude, patterns of stress are similar within both taxa. The FE-stress results, along with mechanical advantage of adductor musculature, a broad symphyseal contact, and other cranial features suggest that Lystrosaurus may have used a snapping bite to cope with tough fibrous vegetation.
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Affiliation(s)
- Sandra C Jasinoski
- Department of Earth Sciences, University of Bristol, Bristol BS8 1RJ, United Kingdom.
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Jaslow CR, Biewener AA. Strain patterns in the horncores, cranial bones and sutures of goats (Capra hircus) during impact loading. J Zool (1987) 2009. [DOI: 10.1111/j.1469-7998.1995.tb05137.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Moazen M, Curtis N, O'Higgins P, Jones MEH, Evans SE, Fagan MJ. Assessment of the role of sutures in a lizard skull: a computer modelling study. Proc Biol Sci 2009; 276:39-46. [PMID: 18765341 DOI: 10.1098/rspb.2008.0863] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Sutures form an integral part of the functioning skull, but their role has long been debated among vertebrate morphologists and palaeontologists. Furthermore, the relationship between typical skull sutures, and those involved in cranial kinesis, is poorly understood. In a series of computational modelling studies, complex loading conditions obtained through multibody dynamics analysis were imposed on a finite element model of the skull of Uromastyx hardwickii, an akinetic herbivorous lizard. A finite element analysis (FEA) of a skull with no sutures revealed higher patterns of strain in regions where cranial sutures are located in the skull. From these findings, FEAs were performed on skulls with sutures (individual and groups of sutures) to investigate their role and function more thoroughly. Our results showed that individual sutures relieved strain locally, but only at the expense of elevated strain in other regions of the skull. These findings provide an insight into the behaviour of sutures and show how they are adapted to work together to distribute strain around the skull. Premature fusion of one suture could therefore lead to increased abnormal loading on other regions of the skull causing irregular bone growth and deformities. This detailed investigation also revealed that the frontal-parietal suture of the Uromastyx skull played a substantial role in relieving strain compared with the other sutures. This raises questions about the original role of mesokinesis in squamate evolution.
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Affiliation(s)
- Mehran Moazen
- Department of Engineering, University of Hull, Hull HU6 7RX, UK.
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Herring SW. Mechanical influences on suture development and patency. FRONTIERS OF ORAL BIOLOGY 2008; 12:41-56. [PMID: 18391494 DOI: 10.1159/0000115031] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In addition to their role in skull growth, sutures are sites of flexibility between the more rigid bones. Depending on the suture, predominant loading during life may be either tensile or compressive. Loads are transmitted across sutures via collagenous fibers and a fluid-rich extracellular matrix and can be quasi-static (growth of neighboring tissues) or intermittent (mastication). The mechanical properties of sutures, while always viscoelastic, are therefore quite different for tensile versus compressive loading. The morphology of individual sutures reflects the nature of local loading, evidently by a process of developmental adaptation. In vivo or ex vivo, sutural cells respond to tensile or cyclic loading by expressing markers of proliferation and differentiation, whereas compressive loading appears to favor osteogenesis. Braincase and facial sutures exhibit similar mechanical behavior and reactions despite their different natural environments.
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KATHE WOLFGANG. Comparative morphology and functional interpretation of the sutures in the dermal skull roof of temnospondyl amphibians. Zool J Linn Soc 2008. [DOI: 10.1111/j.1096-3642.1999.tb00605.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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