Kornelius Kupczik

University of Chile · Departamento de Antropología

Purpose This pilot study aimed to assess the relationship between bite force variation and dental arch and facial shape using geometric morphometrics, an advanced method of statistical analysis that provides a detailed shape analysis of a structure considering the spatial relationship of its parts. Methods The sample consisted of 16 German adult m...

Mice are commonly used to study mandibular dynamics due to their similarity in chewing cycle patterns with humans. Adult mice treated unilaterally with botulinum toxin type A (BoNTA) in the masseter exhibit atrophy of this muscle characterized by an increase in the gene expression of atrophy-related molecular markers, and a reduction in both muscle...

The Miocene was a key time in the evolution of African ecosystems witnessing the origin of the African apes and the isolation of eastern coastal forests through an expanding arid corridor. Until recently, however, Miocene sites from the southeastern regions of the continent were unknown. Here, we report the first Miocene fossil teeth from the shoul...

Objectives: Chimpanzees (Pan troglodytes) possess a relatively generalized molar morphology allowing them to access a wide range of foods. Comparisons of crown and cusp morphology among the four subspecies have suggested relatively large intraspecific variability. Here, we compare molar crown traits and cusp wear of two geographically close popula...

Feces are a treasure trove in the study of animal behavior and ecology. Stable carbon and nitrogen isotope analysis allows to assess the dietary niches of elusive primate species and primate breastfeeding behavior. However, some fecal isotope data may unwillingly be biased toward the isotope ratios of undigested plant matter, requiring more consist...

Any change in the energetic cost of mammalian mastication will affect the net energy gain from foods. Although the energetic efficiency of masticatory effort is fundamental in understanding the evolution of the human masticatory system, nothing is known currently about the associated metabolic costs of chewing different items. Here, using respirome...

The masticatory system is a finely coordinated machine, where minimal deregulation induces alterations of the whole system. Botulinum toxin type A (BoNTA) injection in masseter muscle is widely used as a clinical/aesthetic procedure. However, the non‐desirable effects of masseter muscle paralysis in neighbor masticatory muscles or mandibular bone a...

The Miocene is a key time in the evolution of African mammals and their ecosystems witnessing the origin of the African apes and the isolation of eastern coastal forests through an expanding biogeographic arid corridor. Until recently, however, Miocene sites from the southeastern regions of the continent were unknown. Here we report discovery of th...

Objectives This study aims to examine primate postcanine tooth root surface area (TRSA) in the context of two ecological variables (diet and bite force). We also assess scaling relationships within distinct taxonomic groups and across the order as a whole. Materials and Methods Mandibular postcanine TRSA was measured using a three-dimensional comp...

Diet is a driving force in human evolution. Two species of Plio-Pleistocene hominins, Paranthropus robustus and Australopithecus africanus , have derived craniomandibular and dental morphologies which are often interpreted as P. robustus having a more biomechanically challenging diet. While dietary reconstructions based on dental microwear generall...

Facial orientation (projection and degree of prognathism) and form in hominins is highly variable, likely related to evolutionary modifications of the microscopic process of bone modeling (the simultaneous cellular activities of bone formation and resorption) during ontogeny. However, in anteriorly projected faces such as those of early hominins, l...

In recent years, new applications of microremain dietary analysis using dental calculus as a source of dietary data on ancient human subsistence and behaviours have accelerated. The dental calculus of contemporary human and non-human populations with known diets have been used as reference datasets, including the chimpanzees of Taï National Park (C...

Dental wear analyses have been widely used to interpret the dietary ecology in primates. However, it remains unclear to what extent a combination of wear analyses acting at distinct temporal scales can be beneficial in interpreting the tooth use of primates with a high variation in their intraspecific dietary ecology. Here, we combine macroscopic t...

Movement analysis of primate molar teeth under load using synchrotron X-ray microtomography, Journal of Structural Biology (2020), doi: https://doi. Abstract Mammalian teeth have to sustain repetitive and high chewing loads without failure. Key to this capability is the periodontal ligament (PDL), a connective tissue containing a collagenous fibre...

The masticatory system is a complex and highly organized group of structures, including craniofacial bones (maxillae and mandible), muscles, teeth, joints, and neurovascular elements. While the musculoskeletal structures of the head and neck are known to have a different embryonic origin, morphology, biomechanical demands, and biochemical character...

Objectives: One role of dental pulp is in the upkeep and maintenance of dentine. Under wear, odontoblasts in the pulp deposit tertiary dentine to ensure the sensitive internal dental tissues are not exposed and vulnerable to infection. It follows that there may be an adaptive advantage for increasing molar pulp volume in anthropoid primate taxa th...

Objectives: This study compares the ontogenetic bone modeling patterns of the maxilla to the related morphological changes in three human populations to better understand how morphological variability within a species is established during ontogeny at both micro- and macroscopic levels. Materials and methods: The maxillary bones of an ontogeneti...

Although Neandertals are the best-known fossil hominins, the tempo and evolutionary processes in their lineage are strongly debated. This is in part due to the scarcity of the fossil record, in particular before the marine isotopic stage (MIS) 5. In 2010, a partial hominin mandible was discovered at the Middle Paleolithic site of Payre (France) in...

Extrinsic fibers (EFs) are a type of penetrating collagenous fiber, closely related to the periodontal ligament, which help anchor soft tissue into bone. These fibers are associated with muscle attachment sites (entheses). Their size and grouping patterns are thought to be indicative of the loading history of the muscle. EFs are of particular signi...

Microscopic tooth wear studies on primates have largely focused on interspecific dietary comparisons, while few have addressed intraspecific variations, such as those among age groups. Here, we examined to what extent dietary shifts during ontogeny can be revealed from microscopic tooth wear in a western chimpanzee population using 3D surface textu...

Objectives: Gorilla diets are characterized by large amounts of fruit and tough fibrous plant material. Hard-object feeding is not generally associated with this genus as the high crests on their molar teeth would be at risk of damage from the mechanically challenging woody endocarp. This study aims to demonstrate that at least one population of w...

Dental topography is a widely used method for quantifying dental morphology and inferring dietary ecology in animals. Differences in methodology have brought into question the comparability of different studies. Using primate mandibular second molars, we investigated the effects of mesh preparation parameters smoothing, cropping, and triangle count...

Five-way ANOVA results. Results from five-way ANOVA. (XLSX)

Transformation equations. Transformation equations for smoothing and cropping. (XLSX)

Descriptive statistics. Descriptive statistics for data. (XLSX)

One-way ANOVA results. Results from one-way ANOVAs. (XLSX)

Correlations among metrics. Correlations between topographic variables. (XLSX)

Statistics for slopes and intercepts. ANOVAS, Tukey HSDs, and DFAs for intercepts and slopes. (XLSX)

Boxplots. 880 boxplots for topographic values. (PPTX)

Boxplots for slopes and intercepts. . Boxplots for DNE and OPCR slopes and intercepts vs. diet. (PPTX)

All data dental topography. Raw data for analyses. (XLSX)

Linear plots. Linear plots, effect of triangle count and resolution on topographic variables. (PPTX)

Tukey HSD visualization. Graphical representations of Tukey HSD results. (PPTX)

Tukey HSD results. Results for Tukey HSD analyses. (XLSX)

Slopes and intercepts. Slopes and intercepts of DNE and OPCR vs. triangle count and resolution. (XLSX)

Tukey HSD visualization. Tukey HSD visualized for triangle count and resolution. (PPTX)

The craniomandibular morphology of Homo naledi shows variable resemblances with species across Homo, which confounds an easy assessment of its phylogenetic position. In terms of skull shape, H. naledi has its closest affinities with Homo erectus, while mandibular shape places it closer to early Homo. From a tooth crown perspective, the smaller mola...

Recently, ambient occlusion, quantified through portion de ciel visible (PCV) was introduced as a method for quantifying dental morphological wear resistance and reconstructing diet in mammals. Despite being used to reconstruct diet and investigate the relationship between dental form and function, no rigorous analysis has investigated the correlat...

Raw data for analyses. Raw PCV values used for analyses. (CSV)

Averages and standard deviations. Descriptive statistics for PCV values. (CSV)

Background Based on its morphology, Rudapithecus hungaricus (~10Ma, Rudabánya, Hungary), a Late Miocene fossil ape, is thought to be a member of the African ape and human clade (Begun, 2009). Therefore, investigating its biology and behaviour will contribute to a better understanding of the earliest hominines. The morphology and wear of its tooth c...

Background: Mouse molar is a widely used model for teeth development. However , the effect of masticatory function on enamel and dentine in adult individuals remains poorly understood. As reported, the unilateral masseter hypofunction induced by botulinum toxin type A (BoNTA) resulted in mandibular bone damage and signs of unilateral chewing in adu...

Objectives In humans it has been shown that abrasive particles in the diet result in increased tooth wear and less intense chewing behavior, both of which decrease chewing efficiency. This behavioral response may also exist in non‐human primates as a means to reduce the wear effect of dust‐laden food. Here we tested whether the periodical occurrenc...

The injection of botulinum toxin type A (BoNT/A) in the masticatory muscles, to cause its temporary paralysis, is a widely used intervention for clinical disorders such as oromandibular dystonia, sleep bruxism, and aesthetics (i.e., masseteric hypertrophy). Considering that muscle contraction is required for mechano-transduction to maintain bone ho...

These results demonstrate adverse effects such as bone damage of the mandibular condyle and asymmetry in functional dental wearing after unilateral BoNTA-induced masseter atrophy, in a mouse model.

Background Masseter muscle function influences mandibular bone homeostasis. As previously reported, bone resorption markers increased in the mouse mandibular condyle two days after masseter paralysis induced with botulinum toxin type A (BoNTA), followed by local bone loss. Objective This study aimed to evaluate the bone quality of both the mandibu...

The morphology of both crowns and tooth-roots reflects dietary specialisation in mammalian carnivores. In this article, we analyse the tooth-root morphology of maxillary teeth from CT scans of living bears (Ursus arctos, Ursus americanus, Ursus maritimus, Ursus thibetanus, Melursus ursinus, Helarctos malayanus, Tremarctos ornatus and Ailuropoda mela...

We previously showed that the well-studied Western chimpanzee population (Pan troglodytes verus) of the Taï National Park (Côte d'Ivoire) has distinct occlusal molar wear facet signatures in the dry and wet season [1]. These wear signatures were linked to seasonal variations in the diet and the variable presence of external abrasives, such as dust,...

Plio-Pleistocene hominins from South Africa remain poorly understood. Here, we focus on how Australopithecus africanus and Paranthropus robustus exploited and—in part—partitioned their environment. Specifically, we explore the extent to which first maxillary molar roots (M1) are oriented and thus, by proxy, estimate the direction of loads habituall...

Plio-Pleistocene hominins from South Africa remain poorly understood. Here, we focus on how Australopithecus africanus and Paranthropus robustus exploited and—in part—partitioned their environment. Specifically, we explore the extent to which first maxillary molar roots (M1) are oriented and thus, by proxy, estimate the direction of loads habituall...

Chimpanzees are traditionally described as ripe fruit specialists with large incisors but relatively small postcanine teeth, adhering to a somewhat narrow dietary niche. Field observations and isotopic analyses suggest that environmental conditions greatly affect habitat resource utilisation by chimpanzee populations. Here we combine measures of di...

Objectives Changes to soft‐ and hard‐tissue components of the masticatory complex during development can impact functional performance by altering muscle excursion potential, maximum muscle forces, and the efficiency of force transfer to specific bitepoints. Within Macaca fascicularis, older individuals exploit larger, more mechanically resistant f...

These results demonstrate that the 3D bone microstructure of the mandibular condyle correlates with the masseter muscle mass in this mouse model. We conclude that BoNTA-induced masseter muscle atrophy reduces bone quality of the associated mandibular condyle.

Though late Middle Pleistocene in age, Homo naledi is characterized by a mosaic of Australopithecus-like (e.g., curved fingers, small brains) and Homo-like (e.g., elongated lower limbs) traits, which may suggest it occupied a unique ecological niche. Ecological reconstructions inform on niche occupation, and are particularly successful when using d...

The fascicular architecture of skeletal muscle dictates functional parameters such as force production and contractile velocity. Muscle microarchitecture is typically determined by means of manual dissection, a technique that is inherently destructive to specimens. Furthermore, fascicle lengths and pennation angles are commonly assessed at only a l...

Ficus trees are adapted to diverse environments and have some of the highest rates of photosynthesis among trees.Ficusleaves can deposit one or more of the three major mineral types found in leaves: amorphous calcium carbonate cystoliths, calcium oxalates, and silica phytoliths. In order to better understand the functions of these minerals and the...

Hairless dog breeds show a form of ectodermal dysplasia characterised by a lack of hair and abnormal tooth morphology. This has been attributed to a semi-dominant 7-base-pair duplication in the first exon of the forkhead box I3 gene (FOXI3) shared by all three breeds. Here, we identified this FOXI3 variant in a historical museum sample of pedigreed...

Masseter muscle paralysis induced by botulinum toxin type A produces mandibular head bone loss in adult mice after 14 d.

The temporomandibular joint (TMJ) conducts and restrains masticatory movements between the mammalian cranium and the mandible. Through this functional integration, TMJ morphology in wild mammals is strongly correlated with diet, resulting in a wide range of TMJ variations. However, in artificially selected and closely related domestic dogs, dietary...

The dental study from the occlosual area and the area between the root and the dental crown in bears, has allowed to anaiyze the relationship between bite force and diet. We analized from CT scan of the 8 species of living bears an two species of extinct cave bears

The skull shape variation in domestic dogs exceeds that of grey wolves by far. The artificial selection of dogs has even led to breeds with mismatching upper and lower jaws and maloccluded teeth. For that reason, it has been advocated that their skulls (including the teeth) can be divided into more or less independent modules on the basis of geneti...

The bones of the mammalian skull respond plastically to changes in masticatory function. However, the extent to which muscle function affects the growth and development of the skull, whose regions have different maturity patterns, remains unclear. Using muscle dissection and 3D landmark-based geometric morphometrics we investigated the effect of ch...

Based on stable isotope analyses, the dietary ranges of the South African Plio-Pleistocene largely overlapped. Yet, enamel prism orientation and the relatively steep walls of Paranthropus robustus teeth imply predominantly vertical loading, whereas the enamel microstructure and substantive lateral buttress of Australopithecus africanus teeth sugges...

Primate diets are highly diversified and including fruits, leaves, pith, flowers, bark, and animal resources. Previous studies on primates focused on inter-species variation on the surface texture (ST) of teeth in connection with diet [1], using published dietary data from the literature only. The present study made use of primary feeding ecologica...

Previous dietary studies on primates focused on interspecific variation in the surface texture (ST) of teeth only, using dietary data from various published sources. In the present study we compiled feeding ecological data (1994-2005) of 17 Western Chimpanzees (Pan troglodytes verus Schwarz, 1934) of the Taï National Park (Côte d’Ivoire) and matche...

Bite force is an important ecological and evolutionary variable related to animal feeding and social behavior. Intraspecific variation in bite force can be substantial, and can be due to sexually dimorphic behaviors, differences in feeding ecologies, and allometry. Therefore, domestic dogs are an ideal model for studying allometric effects of intra...