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Fiorenza Lab research

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About Dr Luca Fiorenza

Luca received his Bachelor/Master degree in Natural Sciences in 2003 at La Sapienza University in Rome (Italy), and completed his PhD in Biological Sciences between the Goethe University and the Senckenberg Research Institute (Frankfurt, Germany) at the end of 2009. During his doctoral degree he was part of an outstanding multidisciplinary network called EVAN (European Virtual Anthropology Network), where he mastered cutting-edge techniques for the study of anatomical variability, including medical imaging, 3D digitisation, display, modelling and programming. Luca's research interests mostly focus on functional morphology of the masticatory apparatus in human and non-human primates, and on the importance of the role of diet in human evolution.


Our research

Current projects

  1. Diet and ecology in Plio-Pleistocene African hominins
  2. The role of diet on early human evolution
  3. The evolutionary significance of dietary expansion in early homo
  4. Biomechanics of the Neanderthal anterior dentition
  5. Emergence of malocclusions in transitional hunter-gatherer societies

Visit Dr Fiorenza’s Monash research profile to see a full listing of current projects.

Research activities

Biologically speaking, we really are what we eat, but we still do not fully understand how past dietary changes have influenced human evolution. Understanding diet provides a window into the biology, ecology and evolution of an animal species. This becomes particularly important when dealing with extinct taxa, as fossilised and often fragmented remains are the only evidence left, and their behaviour and ecology cannot be directly observed.

Palaeontological diet studies so far have mostly been limited to one method, and have therefore been unable to accurately reconstruct the ecology of extinct human species. The Paleodiet Research Lab focuses on a multi-disciplinary approach that combines advanced 3D computer modeling with palaeocological and biogeochemical data. All this is possible with the help and expertise of our wonderful national and international collaborators.

Project 1: Diet and ecology of non-human primates
Our understanding of extinct hominin diets is usually based on a limited number of fossil specimens. One way to address the fragmentary nature of the hominin fossil record is to use large comparative samples. Extant non-human primates are an important source of comparative information for the reconstruction of the diets of extinct hominins. Teeth are the most commonly recovered elements of the hominin fossil record and fossil teeth are typically worn. When an animal chews, the sliding contacts between upper and lower dentition cause the loss of the superficial enamel layer, and teeth begin to wear down. Because of the intimate relationship between food and teeth, the study of dental macrowear (visible to the naked eye) can provide direct evidence of what an individual ate in the past. Unlike microwear (visible only under microscope), dental macrowear is a cumulative process that occurs throughout the individual’s lifetime and thus reflects long-term diet. The major aim of this research project is to build up a large comparative dataset, including all great apes (orangutan, gorilla and chimpanzee) and some non-human primate species with specialised diets, such as the gramnivorous baboon gelada (Theropithecus gelada), the folivorous black and white colobus (Colobus guereza) and the hard-object feeding grey-cheeked mangabey (Lophocebus albigena) and tufted capuchin (Cebus apella).

Project 2: The role of diet on early human evolution
Diet is a direct reflection and driver of the biology, ecology and evolution of any species. Dietary analysis is particularly important when studying extinct taxa where behaviour and ecology cannot be directly observed and anatomy is represented by partial or fragmentary remains. Changes in diet and in food processing technology are key events in human evolution. This is particularly true for Plio-Pleistocene hominins from East and South Africa, a time of climatic fluctuation, but overall characterised by pronounced, progressive cooling and increased aridity. Significant morphological differences found among these hominin species are commonly used for the identification of two distinct morphotypes: a “gracile” form that includes all Australopithecus species, and a “robust” type that includes all Paranthropus species. It is generally accepted that these distinctive morphologies reflect different feeding behaviours. However, interpretations of their feeding habits through morphological and biomechanical analysesare inconsistent with recent dietary reconstructions based on dental microwear and stable isotopes yielding conflict results. All methods used to reconstruct the diets of the past have their strengths and weaknesses, and while the intake of specific foods can be detected by certain techniques, specific foods and dietary changes can be invisible to others. Consequently, limiting these studies to one specific technology will always generate incomplete results. In this project we will for the first time combine information from the study of palaeoecology, palaeoclimate, tooth chemistry, morphology, dental wear and biomechanics. These comprehensive analyses will enable the reconstruction of the whole dietary spectrum, which is particularly important for the interpretation of diet in these hominin species that lived under radically changing climatic conditions.

Project 3: The evolutionary significance of dietary expansion in early homo
The evolution of early Homo coincided with dramatic climatic changes in Africa. This climatic variability determined the formation of various dynamic habitats, posing new ecological problems to our early hominin ancestors. The capability to adapt and adjust to environmental changes was one of the most successful elements, in evolutionary terms, of the human lineage. It is generally accepted that a significant dietary expansion, characterised by increased meat consumption, promoted the development of highly encephalised brains, allowing early Homo to expand their home range out of Africa. Three morphologically distinct species of Homo (H. habilis, H. rudolfensis, and H. ergaster) inhabited contemporaneously East Africa from 2 to 1,5 million years ago: did they occupy different niches? If so, did they exploit different food sources? In order to answer these questions, the Occlusal Fingerprint Analysis and Finite Element Analysis methods will be used to test if dental macrowear and morphological structures in early Homo were a result of different functional and biomechanical adaptations. These results will be compared with isotopic signals obtained from tooth chemistry analyses.

Project 4: Dental biomechanics
Biomechanics is the study of structure and function of biological systems, examining the internal and external forces acting on the body and the effects produced by these forces. In particular, dental biomechanics explores the mechanical relationships between tooth structures, occlusal loading and mastication. In this project we use a new 3D multi-disciplinary approach that combines Finite Element Analysis (FEA) with dental macrowear methods. The computer simulation of the interactions between upper and lower teeth during a normal chewing cycle will be used to calibrate the Finite Element models. Thus, we will be able to more realistically simulate and predict how stress and strain develop in teeth, cranium and mandible, allowing us to predict how these masticatory forces act on dental architecture in a comparative context and establish their significance and value in predicting diet. Integration of occlusal information with FEA will extend applications of new and exciting methods for functional analyses of the musculoskeletal system; an approach that may eventually inform on applied settings like orthodontics, where the relationship between morphology and dental occlusion is still not well understood.

Project 5: The emergence of malocclusions in transitional hunter-gatherer societies
The emergence of malocclusions in transitional hunter-gatherer societiesThe increase in malocclusion (or misalignment of teeth) took place recently, between 18th – 19th centuries with the adoption of the modern lifestyle. It is believed that the introduction of soft and energy-rich foodstuffs in the daily diet caused a strong reduction of the masticatory forces, decreasing the number of chewing cycles and consequently shortening the duration of mastication. The decrease in masticatory-functional demands has brought about a disequilibrium in the dynamic relationships between occlusion and dentition, causing the increase in occlusal variation characterized by a misalignment of teeth. Here we propose to analyse the relationships between craniofacial structures, occlusal wear and normal and altered masticatory function, building multi-functional computer models. These sophisticated virtual biomechanical models will give us the possibility to interpret occlusal dynamics and simulate functional loading on the masticatory system and the resulting stresses and strains in the skulls.

Techniques/expertise

The Palaeodiet Research Lab is a highly multidisciplinary and dynamic team that investigates important biological questions related to humans in an evolutionary context. We are collaborating with major international experts from different fields, ranging from Anthropology to Mechanical Engineering, and from Computer Science to Biogeochemistry. We are located at the Department of Anatomy and Developmental Biology (Clayton Campus at Monash University) and have access to a world-class 3D imaging laboratory.

Occlusal fingerprint analysis

The Occlusal Fingerprint Analysis (OFA) method uses 3D digital surface models of teeth to analyse wear facets and determine their structural parameters: area, perimeter, inclination and orientation. Wear facets are those enamel areas, characterised by a polished surface with well-delimited borders, that are created during attritional contacts between upper and lower teeth that occur during mastication. Three-dimensional data is collected using a white-light scanning 3D system (smartSCAN 3D C-5, Breuckmann GmbH) with a resolution of 45μ. These measurements describe the major movements of occlusal interaction between upper and lower teeth in a 3D space, generating individual occlusal compasses. The occlusal compasses are graphical illustrations that encode and document how contact areas are created and what movements are responsible for their formation. Because of the close relationships between jaw movements, occlusal wear and the physical properties of food, wear facet analyses allow us to reconstruct the dietary habits of fossil or extant species in which tooth-to-tooth occlusion occurs.

Furthermore, in order to better understand how occlusal contacts occur, we use an additional software, called Occlusal Fingerprint Analyser, that simulates the masticatory movements using virtual mandibular trajectories. This software was developed at the Senckenberg Research Institute (Frankfurt, Germany), and, with the help of a powerful collision detector algorithm, is able to reveal all the possible contacts between upper and lower tooth rows starting from a static position.

Moulding and casting
Generating polygonal models of teeth with white-light or laser 3D scanners faces one major problem, that is the reflection and transparency of the enamel layer. Both scanner systems are in fact, unable to accurately measure the surface information directly from the original tooth. One of the best solutions to overcome this problem is creating high-qualities replicas of teeth that can be later on scanned for generating 3D models. This methodology consists of two distinct phases: moulding and casting. Silicone impression materials are used to produce the negative replicas (or moulds) of the original dentition, that are later on filled with casting materials for the creation of their positive replicas. Dental casts can be of two types: gypsum (or die-stone), which possesses non-reflecting properties, more suitable for 3D digital scanning, and epoxy resins, which are better models for examining finer details, such as microwear surface texture.

Finite element analysis
Finite Element Analysis (FEA) is a numerical technique wherein a structure with theoretically infinite degrees of freedom is divided into a finite number of discrete elements that are interconnected at nodal points, or nodes. This interconnected network of elements and nodes constitutes the finite element mesh. The mesh is then programmed to contain the material and structural properties, which define how the structure will react to certain loading conditions. Originally developed for the aerospace industry, FEA is a powerful tool in the study of biological systems. It offers insights that could otherwise only be gained through experimental approaches that are impractical, at best, on living subjects, and impossible regarding fossil species. With advances in computer software and imaging technology, FEA has reached a level of sophistication and accessibility that make it a powerful tool in the testing of biomechanical hypotheses in studies of vertebrate form and function.

Facilities

3D imaging software
Most of our research is based on the application of high-resolution 3D computer models. We use a wide range of highly sophisticated software, including metrology [such as Geomagic® Control™ (3D Systems, Inc.) and Polyworks® (InnovMetric)], and medical image software for 3D data segmentation [such as Mimics® (Materialise®)], together with engineering (Strand7®, Pty Ltd) and virtual simulation computer tools (Occlusal Fingerprint Analyser). Moreover, we also have access to advanced 3D analysis software (Avizo®, FEI™) through MASSIVE platform (Multi-model Australian ScienceS Imaging and Visualisation Environment).

3D printing
Through the Centre for Human Anatomy Education we have access to advanced professional 3D printers. These include photo realistic full-color plastic [Projet® 4500 (3D Systems)] and gypsum-based [Projet® CJP 660Pro (3D Systems)] printers.

3D Data acquisition
3D data can be acquired using Computed Tomography (CT) or surface scans (depending on what you want to study and analyse). Here at Monash University we are lucky to have access to state-of-the-art imaging facilities through Monash Biomedical Imaging (MBI) including CT and MRI scanners. Moreover, just next to Monash campus in Clayton, there is the Australian Synchrotron, which could be used to generate high-quality micro-CT data.

Casting
In our lab we have all the necessary equipment to create very high-quality replicas of teeth in a safe environment, from epoxy to dental stone casts. These facilities include a vacuum chamber (Technomat, Heraeus Kulzer) and a portable ductless fume hood (Captair Flex S321).

Collection
Our anthropological dental cast collections is one of the largest in Australia, and consists of thousands of high-quality replicas (in gypsum and epoxy casts) of living primates, modern humans and extinct hominins, including Australopithecus species, early African Homo and Neanderthals. For most of these specimens we also have high-resolution 3D surface scan models. You are more than welcome to visit the collection and access to the 3D virtual models for research purposes. Please, contact us and tell us about your project.


Collaborations

We collaborate with many scientists and research organisations around the world. Some of our more significant national and international collaborators are listed below. Click on the map to see the details for each of these collaborators (dive into specific publications and outputs by clicking on the dots).

Alistair Evans
Al Evans’ research involves almost anything related to teeth – how they are made, how they work, and how they evolve. He is a co-inventor of the dental complexity method ‘orientation patch count’ (OPC) and co-discoverer of the inhibitory cascade mechanism of relative tooth size. Al is an ARC Future Fellow in the School of Biological Sciences, Monash University.

Email address: alistair.evans@monash.edu
Web: www.evomorph.org

Justin W. Adams
Justin W. Adams, PhD is a Senior Lecturer in the Centre for Human Anatomy Education, Department of Anatomy and Developmental Biology, Monash University in Clayton, Australia. Starting with his PhD research at the Gondolin hominin locality from 2002-2005, Dr. Adams has led fieldwork and the development of new palaeontological collections at multiple sites in and around the Cradle of Humankind UNESCO World Heritage Site. His ongoing research projects address outstanding questions on the palaeobiology of Pliocene and early Pleistocene South African mammalian faunas and the taphonomy and palaeoecology of palaeocave sites.

As a member of the Centre and Department, Dr. Adams has established the integrated Morphology and Palaeontology lab (iMAP), bringing together the advanced 3D imaging-based resources employed at Monash University to the study of living and fossil mammal anatomy.

Email: justin.adams@monash.edu
Website: www.sapalaeo.com/iMAP

Justin Ledogar
Justin Ledogar is a biological anthropologist who studies the evolution of humans and other primates. He received his PhD from the University at Albany in 2015 and is currently a Postdoctoral Research Fellow in the FEAR Lab at the University of New England. Justin uses a variety of experimental and quantitative techniques, including finite element analysis (FEA), dental topographic analysis, in vitro bone strain analysis, and geometric morphometrics, to address questions related to the evolutionary nature of: (1) dental and craniofacial variation in fossil hominins and living primates, including modern humans; (2) primate dietary ecology and feeding behavior; and (3) primate biogeography. Justin is also interested in the impact of dietary resource competition on primate community structure, primate conservation biology in the Guiana Shield, and the cranial mechanics of non-primate animals. Justin is with the Zoology Division, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia

Email: jledogar@gmail.com
Web: www.justinledogar.weebly.com

Stefano Benazzi
Stefano Benazzi is a physical anthropologist with special interest in paleoanthropology, bioarchaeology and biomechanics. He is particularly interested in the latest period of human evolution (Middle and Upper Palaeolithic periods), the appearance of modern humans in Europe and the demise of Neanderthals. Since teeth are the most frequent human fossil remains found in the archaeological record, he is particularly focused on developing computer-based methods for dental morphometric analysis, which are suitable in paleoanthropology for taxonomical assessment. He uses virtual approaches and geometric morphometric methods for the purposes of bone reconstruction and shape analysis of skeletal remains. He finds the relationship between function and morphology in primate dentition very intriguing and he wants to address this issue by means of finite element methods and macrowear analysis. Stefano is with the Department of Cultural Heritage, University of Bologna, Via degli Ariani 148121 Ravenna, Italy

Email: stefano.benazzi@unibo.it
Web: www.unibo.it/sitoweb/stefano.benazzi/en

Stephen Wroe
I am Director of the Function, Evolution & Anatomy Research (FEAR) Lab – a dynamic, multidisciplinary team – which includes collaborators from the University of Newcastle and University of New South Wales, as well as the University of New England. Understanding relationships between form and function is key to answering fundamental questions in fields ranging from palaeontology, evolutionary biology, palaeoecology and physical anthropology to biomedicine. Using and developing the very latest technologies to expand the digital tool-kit and shed light on these relationships is my passion. Stephen is with Zoology, the University of New England, 2351 NSW Armidale

Email: swroe@une.edu.au
Web: www.une.edu.au/staff-profiles/ers/swroe

Renaud Joannes-Boyau
Dr Renaud Joannes-Boyau’s research focuses on the development and application of direct dating methods and micro-analytical techniques to key questions in archaeological sciences, such as the timing of human evolution and the mobilization, incorporation and migration of isotopes and radionuclide into animal and human remains. He is especially interested in the evolution and timing of early hominid species in Africa, in particular the emergence of the Homo genus. Renaud was appointed senior lecturer at Southern Cross University and Head of the Geoarchaeology and Archaeometry research group (GARG), which includes the ESR dating laboratory and the Laser Ablation ICPMS facilities (SOLARIS). Renaud is with the Southern Cross University, Military Rd, Lismore, NSW 2480, Australia

Email: Renaud.joannes-boyau@scu.edu.au
Web: www.garg.org.au/dr-renaud-joannesboyau

Ottmar Kullmer
Dr. Ottmar Kullmer research focuses on East African Pliocene and Pleistocene faunas and paleoecology, hominid evolution, evolution of African suids, functional morphology, biomechanics and architecture of teeth, Occlusal Fingerprint Analysis (OFA), virtual anthropology, 3D imaging and topometry in paleontology and related topics. Ottmar is with Senckenberg Gesellschaft für Naturforschung, Section Tertiary Mammals, Senckenberganlage 25, 60325 Frankfurt am Main, Germany

Email: Ottmar.Kullmer@senckenberg.de
Web: www.senckenberg.de

Gregorio Oxilia
Gregorio is a paleoanthropologist specialized in dental anthropology by studying macrowear pattern developed on dental occlusal surface. His research interests are focused on medical anthropology and evolutionary medicine with particular attention to functional and para-functional asymmetries of masticatory system besides tooth alterations produced by masticatory and para-masticatory activity. Gregorio’s PhD research project, in Anthropology and Primatology at the University of Florence, was focused on the study of Human dental tissues in order to obtain information about dental caries manipulation, para-functional asymmetries of masticatory system and finally, taxonomy. In 2017 Gregorio will go on duty as ERC Research fellow at the department of Oral and Maxillo facial Science (Sapienza University) continuing my collaboration with the Department of Biology at the University of Florence and the Laboratory of Physical Anthropology and Ancient DNA at the University of Bologna. His contribution to HIDDEN FOODS (ERC project led by Emanuela Cristiani) is focused on the study of comparative patterns of dental enamel thickness topography and macrowear in modern human from Paleolithic until Renaissance populations paying special attention to Paleolithic and Mesolitic Italian and balcanic human groups. Gregorio is also working on a number of researches relating to the taxonomic identification, bone/teeth paleopathology and bioarchaeological analysis. In addition to research projects he also carries out scientific disseminations about Human Evolution and Darwin’s theory applied to medicine. Gregorio is with the Department of Oral and Maxillo Facial Sciences, Sapienza University, Via Caserta 6, Rome (Italy)

Email: gregorio.oxilia@uniroma1.it


Student research projects

The Fiorenza Lab offers a variety of Honours, Masters and PhD projects for students interested in joining our group. There are also a number of short term research opportunities available.

Please visit Supervisor Connect to explore the projects currently available in our Lab.