Ian Towle

Monash University (Australia)

Objectives: A variety of mechanical processes can result in antemortem dental chipping. In this study, chipping data in the teeth of Homo naledi are compared with those of other pertinent dental samples to give insight into their etiology. Materials and methods: Permanent teeth with complete crowns evidencing occlusal wear were examined macrosco...

This report describes a case of amelogenesis imperfecta in the dentition of a female chimpanzee. Amelogenesis imperfecta is a group of rare genetic conditions that create severe enamel defects, which, although well researched in humans, has not yet been investigated in wild non-human primates.

Tooth root grooves and other ante-mortem dental tissue loss, not associated with caries found on or near the cementoenamel junction (CEJ), are commonly termed non-carious cervical lesions. Three main processes are implicated in forming these lesions: abrasion, dental erosion, and abfraction. As yet, these lesions have not been described in non-Homo...

We report the frequencies of linear enamel hypoplasia (LEH) and, specifically, pitting enamel hypoplasia (PEH) defects in the teeth of Paranthropus robustus, for comparison with four other South African hominin species and three extant nonhuman primate species. Unlike LEH, the lesser known PEH is characterized by multiple circular depression defect...

Tertiary dentine forms when an odontoblast is directly affected by stimuli, commonly through occlusal wear and caries. In this study the presence of tertiary dentine was recorded in three South African fossil hominin species (Australopithecus africanus, Homo naledi and Paranthropus robustus), and two extant great ape species (Gorilla gorilla gorill...

Sediments of the Usno Formation and the Shungura Formation date from ca. 3.75 Ma to 1.09 Ma, during which time the genus Homo appeared, Australopithecus disappeared, and the eastern African robust hominins did both. We performed an in-depth analysis of size, shape, and morphology of 108 Omo permanent postcanine dental specimens. First, we compared...

Intraoral scanners are widely used in a clinical setting for orthodontic treatments and tooth restorations, and are also useful for assessing dental wear and pathology progression. In this study, we assess the utility of using an intraoral scanner and associated software for quantifying dental tissue loss in non-human primates. An upper and lower s...

Computed tomography (CT) and microcomputed tomography (μCT) require calibration against density phantoms scanned with specimens or during routine internal calibration for assessment of mineral concentration (MC) and density. In clinical studies involving bone, alternative calibration methods using bodily tissues and fluids (“phantomless” calibratio...

Intraoral scanners are widely used in a clinical setting for orthodontic treatments and tooth restorations, and are also useful for assessing dental wear and pathology progression. In this study, we assess the utility of using an intraoral scanner and associated software for quantifying dental tissue loss in non-human primates. An upper and lower s...

Dental evolutionary studies in hominins are key to understanding how our ancestors and close fossil relatives grew from the early stages of embryogenesis into adults. In a sense, teeth are like an airplane's ‘black box’ as they record important variables for assessing developmental timing, enabling comparisons within and between populations, specie...

Plane-form enamel hypoplasia (PFEH) is a severe dental defect in which large areas of the crown are devoid of enamel. This condition is rare in humans and even rarer in wild primates. The etiology of PFEH has been linked to exposure to severe disease, malnutrition, and environmental toxins and associated with systemic conditions. In this study, we...

Objectives Fossils from the Fayum Depression, Egypt, are crucial for understanding anthropoid evolution due to the abundance of taxa and the time interval they represent (late Eocene to early Oligocene). Dietary and foraging behavioral interpretations suggest fruits were their dominant food source, although hard foods (e.g., seeds and nuts) and lea...

Enamel mechanical properties vary across molar crowns, but the relationship among mechanical properties, tooth function, and phylogeny are not well understood. Fifteen primate lower molars representing fourteen taxa (catarrhine, n = 13; platyrrhine, n = 1) were sectioned in the lingual-buccal plane through the mesial cusps. Gradients of enamel mech...

Objective: Dental pathology and tooth wear data can offer valuable insights into the diet and behaviour of past populations. This study aimed to investigate the presence of dietary continuity by examining different types of dental pathology and tooth wear in a medieval sample from the United Kingdom, comparing them to earlier and later samples fro...

Objective: Variation in enamel and dentine mineral concentration and total effective density can be reliably collected using Micro-CT scans. Both variables are suggested to reflect mechanical properties such as hardness and elastic modulus in dental tissues, meaning Micro-CT methods allow relative composition and mechanical properties to be collec...

Plane-form enamel hypoplasia (PFEH) is a severe dental defect in which large areas of the crown are devoid of enamel. This condition is rare in humans and rarer in wild primates. The etiology of PFEH has been linked to exposure to severe disease, malnutrition, environmental toxins, and other systemic conditions. Similar defects have also been assoc...

Objectives: Archaeolemur is a recently extinct genus of lemur that is often compared to some Cercopithecidae, especially baboons. This is due in part to their derived dentition, with large anterior teeth and reduced bilophodont molars. Research involving comparative morphology, analysis of coprolites, isotopes, and enamel structure, have suggested...

Objectives Atypical tooth wear, including macroscopically visible striations on anterior teeth and within root grooves on posterior teeth, are often regarded as evidence of non‐masticatory, tool use behavior in fossil hominins. Both these types of dental tissue loss are often considered unique to the genus Homo and suggested to be the earliest evid...

Dental caries has been reported in a variety of primates, although it is still considered rare in wild populations. In this study, 11 catarrhine primate taxa (n = 339 individuals; 7946 teeth) were studied for the presence of caries. A differential diagnosis of lesions in interproximal regions of anterior teeth was undertaken, since they had been pr...

Fluctuating Asymmetry (FA) in morphology is used as a proxy for developmental instability in response to stress factors. FA has important implications for understanding the impact of differential environments and stressors on the skeletal phenotype. Here, we explore FA in the mandibular morphology of wild and captive Macaca fuscata to detect differ...

Fluctuating Asymmetry (FA) in morphology is used as a proxy for developmental instability in response to stress factors. FA has important implications for understanding the impact of differential environments and stressors on the skeletal phenotype. Here, we explore FA in the mandibular morphology of wild and captive Macaca fuscata to detect differ...

Mechanical properties of enamel are known to vary across molar crowns in some primates, but the association of this variation with phylogeny, structural properties and tribological behaviour is not well understood. In this study, 20 molars from a range of primate taxa (n=15) were studied using nanoindentation, micro-CT scanning, and SEM imaging. Af...

Dental caries has been reported in a variety of primates, although is still considered rare in wild populations. In this study, 11 catarrhine primates were studied for the presence of caries. A differential diagnosis of lesions found in interproximal regions of anterior teeth was undertaken, since they had been previously described as both carious...

Once considered rare in fossil hominins, caries has recently been reported in several hominin species, requiring a new assessment of this condition during human evolution. Caries prevalence and location on the teeth of South African fossil hominins were observed and compared with published data from other hominin samples. Teeth were viewed macrosco...

The paranthropines, including Paranthropus boisei and Paranthropus robustus , have often been considered hard-food specialists. The large post-canine teeth, thick enamel, and robust craniofacial features are often suggested to have evolved to cope with habitual mastication of hard foods. Yet, direct evidence for Paranthropus feeding behaviour often...

Objectives A tooth chip occurs when a hard object forcefully contacts the surface of the tooth, typically removing enamel from the occlusal edge. In this study, chipping patterns in extant primates were compared, and hard‐object‐feeding assessed alongside other factors (e.g., grit mastication and dental properties), to elucidate dietary and behavio...

Enamel hypoplasia is often split into several macroscopic categories, including pit, localised, linear and plane-form defects. All types have been considered a sign of 'non-specific stress' during dental development in archaeological, as well as palaeoanthropological and other samples. There is growing evidence suggesting many defects may not be ca...

Periapical lesions can develop after exposure of a tooth's pulp chamber and are commonly associated with heavy crown wear, trauma or caries. In this study, maxilla and mandible fragments from the South African fossil hominin collections were studied, including specimens assigned to Homo naledi, Paranthropus robustus, Australopithecus africanus and...

Objectives: Dental caries is often perceived as a modern human disease. However, their presence is documented in many early human groups, various nonhuman primates and, increasingly, our hominin ancestors and relatives. In this study, we describe an antemortem lesion on the root of a Paranthropus robustus third molar from Drimolen, South Africa, w...

Caries frequencies in South African fossil hominins were observed and compared with other hominin samples. Species studied include Paranthropus robustus , Homo naledi , Australopithecus africanus , early Homo and A. sediba . Teeth were viewed macroscopically with Micro-CT scans used to confirm lesions. Position and severity of each lesion were also...

Abscesses and other periapical lesions are found in abundance in recent archeological samples, yet are scarce in the fossil hominin record. Periapical voids commonly develop after exposure of a tooth's pulp chamber and are commonly associated with heavy crown wear, trauma or caries. In this study, all available maxilla and mandible fragments from t...

Objectives: Dental caries is often perceived as a modern human disease. However, their presence is documented in many early human groups, various non-human primates and, increasingly, our hominin ancestors and relatives. In this study we describe an antemortem lesion on the root of a Paranthropus robustus third molar from Drimolen, South Africa, wh...

We report the frequencies of linear enamel hypoplasia (LEH) and, specifically, pitting enamel hypoplasia (PEH) defects in the teeth of Paranthropus robustus , for comparison with four other South African hominin species and three extant nonhuman primate species. Unlike LEH, the lesser known PEH is characterized by multiple circular depression defec...

Tertiary dentine forms when an odontoblast is directly affected by stimuli, commonly through occlusal wear. In this study the presence of tertiary dentine is recorded in three South African fossil hominin species ( Australopithecus africanus , Homo naledi and Paranthropus robustus ), and two extant great ape species ( Gorilla gorilla gorilla and Pa...

Dental pathology and wear data can provide valuable insights into diet, cultural practices, and the health of populations. In this study, various dental pathologies and types of wear were recorded for 41 individuals (914 permanent teeth), excavated from the medieval cemetery of St. Owens Church in Southgate Street, Gloucester. Teeth were studied ma...

Tooth root grooves and other ante-mortem dental tissue loss not associated with caries found on or near the cementoenamel junction (CEJ) are commonly termed non-carious cervical lesions. Three main processes are implicated in forming these lesions: abrasion, dental erosion, and abfraction. As yet, these lesions have not been described in non-Homo h...

Studying different types of dental pathology, wear and developmental defects can allow insight into diet and behaviour in a variety of ways. In this study data on these different variables are collected for South African hominins and extant primates. The species studied include Paranthropus robustus, Australopithecus africanus, A. sediba, early Hom...

Enamel defects can provide insight into the life histories of past individuals and populations, in-cluding information on a wide range of disturbances during childhood. This study investigates a particularly severe case of plane-form enamel hypoplasia from a Roman site in Gloucester, UK. Dentine protrudes above the occlusal enamel of upper central...

Developmental defects, wear, and pathologies can give insight into the diet, behavior, and environmental stresses of past populations. There have been a number of key studies looking at particular defects and types of wear but as yet no broad scale study looking at multiple types across these species. We focus on frequencies of dental caries, chipp...

An examination of possible congenital syphilis dental stigmata present on juvenile skeletons from a Romano-British mass grave, and two medieval cemeteries. The two medieval cemeteries located in Poulton and Gloucester were in use from the 12th century.

An examination of the different dental pathologies found within a probably small pox mass grave. This research highlights dental pathologies and caries tampering that would have not been represented in non-catastrophic burial sites due to tooth loss and tooth wear.

Studying enamel defects can provide insight into the health, diet and environmental stresses of past populations. Previous research has focused on differences in enamel hypoplasia frequencies in and between a range of populations, including South African hominins. Here we build on this research by analyzing the interaction between different forms o...

When assessing bioarcheological remains for paleodietary analysis, there is often concern regarding the processes used to attain results. Until recently, destructive sampling to obtain collagen has been the primary option to understand the impact of diet on the biochemical components of the human skeleton. As a potential alternative, researchers ha...