Dental anomalies of number, shape, and position are frequently analysed in the orthodontic and clinical literature but are rarely discussed in an anthropological or archaeological context. While some of these anomalies are believed to follow Mendelian inheritance patterns and the importance of heredity is stressed, other developmental dental disorders are often hypothesised to be the result of a modern, urbanised lifestyle as a response to reduced masticatory stress and subsequent crowding of the dentition.
This study of 131 skulls and dentitions from 6 archaeological collections from England and Macedonia examines the relationship between craniometric variables and the expression of dental anomalies. A number of standard craniometric measurements were taken to estimate relative sizes of cranial functional complexes and determine whether or not, and to what extent, changes in the shape or size of these variables were associated with the expression of dental anomalies.
Statistical analyses determined that the null hypothesis, that there is no relationship between craniometrics and dental anomalies, can be rejected. A number of dental anomalies were found to have a relationship with reduced sizes in cranial and masticatory elements, although dental crowding was not as significant a factor in masticatory complex reduction. A cause and effect relationship cannot be determined but the data presented here suggests that both heredity and environmental causes may be influential in the expression of dental anomalies.
Keywords: anthropology, palaeopathology, palaeoepidemiology, craniometrics, epidemiology, orthodontics, dental, skull, dentition, crania, teeth, anomalies, Macedonia, England.
Contents
I. Introduction
II. Literature Review
Basis of human craniometric variation
Craniofacial development
Development of the masticatory complex
Environment, heredity, and craniofacial development
Occlusal variation and dental anomalies
III. Materials and Methods
Materials
Methods
Statistical Analysis
IV. Results
Relationships between anomalies
Preliminary craniometric analysis
Relationships between dental anomalies and craniometrics
V. Discussion
Palaeoepidemiology and dental anomalies
Dental anomalies and craniometrics
Heredity, population variation and dental anomalies
Arch dimensions and the aetiology of dental anomalies
VI. Conclusion
Research Objectives and Themes
This research aims to investigate the potential relationship between variations in skull size and shape and the occurrence of pathological dental anomalies (such as those of position, shape, and number). By examining premodern population samples from different geographic locations, the study seeks to determine if craniometric changes are associated with dental disorders, thereby contributing to a better understanding of the complex, multifactorial aetiology of these conditions within an anthropological and archaeological context.
- The influence of craniometric variables on the expression of dental anomalies.
- The role of environment, heredity, and diet in shaping the human masticatory complex.
- Comparative analysis of premodern skeletal populations from England and Macedonia.
- Evaluation of "disease of civilization" theories regarding modern occlusal variation.
Excerpt from the Book
Basis of Human Craniometric Variation
Change in the shape and size of the skull has been a hallmark of human evolution; a trajectory toward an expanded braincase and a less prognathic, smaller face has been a distinguishing feature of anatomically modern Homo sapiens (Lieberman et al 2002). The anteroposteriorly shortened and superoinferiorly heightened face has been hypothesized to have been a result of the increased maturation period in modern humans, the final globular shape of the adult human skull a response to increasing brain size (Bogin 2003; McBratney-Owen and Lieberman 2003). Despite the long evolutionary history of the expanding cranial vault in humans, and the clear pattern of craniofacial change from earlier hominoids, there has been continuing debate regarding the extent to which the changes are primarily genetic or environmental (Relethford 1994, 2004; Ackermann and Cheverud 2004; Roseman 2004; Roseman and Weaver 2007; Betti et al 2009, 2010). Significantly, the variation in craniometrics between modern human populations often exceeds that of the variation between species of many non-human primates (Strand Vidarsdóttir and O’Higgins 2003) and this craniometric variation has been used for decades in assessing population affinities.
The size and shape of the skull is largely polygenetic, and formed from the interaction of developmental plastic functional complexes with the environment within the constraints and parameters of genetic inheritance (Moss 1997a; Hallgrimssona et al 2007; Martínez-Abadías et al 2009, 2011), and adult skull dimensions are the result of the interplay between several functional complexes (see below; Moss and Young 1960; Moss 1997a; Bastir and Rosas 2005; Sardi and Ramírez Rozzi 2007). Thus it has been argued that geographic and climatic conditions are responsible for cranial shape rather than pure genetics (Relethford 2004; Betti et al 2009, 2010) although more recent studies have supported a more direct relationship between heredity and craniometrics (von Cramon-Taubadel and Smith 2012).
Summary of Chapters
Introduction: This chapter outlines the study's goal to explore the relationship between skull morphology and dental anomalies, identifying a lack of existing research in an anthropological context.
Literature Review: Provides a comprehensive overview of human craniometric variation, craniofacial development, the masticatory complex, and established theories on the aetiology of dental anomalies.
Materials and Methods: Details the selection of 131 adult skulls from English and Macedonian archaeological collections and explains the quantitative methods used to measure and analyze them.
Results: Presents the statistical findings regarding the prevalence of various dental anomalies and their associations with specific craniometric measurements.
Discussion: Interprets the results in light of existing palaeoepidemiological theories and explores the complex interplay of heredity, environment, and population variation.
Conclusion: Summarizes the findings, confirming that the null hypothesis (no relationship) can be rejected and discussing the implications for dental development.
Keywords
anthropology, palaeopathology, palaeoepidemiology, craniometrics, morphology, orthodontics, dental, skull, dentition, anomalies, heritability, masticatory complex, malocclusion
Frequently Asked Questions
What is the primary focus of this research?
The work investigates the potential relationship between variation in the size and shape of the human skull and the presence of pathological dental anomalies, such as those related to tooth number, shape, and position.
What are the central themes of this study?
The study centers on the complex interaction between genetic control of the skull and environmental influences, such as diet and urbanization, and how these factors contribute to dental and occlusal variations in premodern populations.
What is the primary research goal?
The core objective is to determine if adult skull shape and size—specifically the relative sizes of functional cranial components—affect the likelihood of expressing specific dental anomalies, and whether this link can be established through skeletal analysis.
Which scientific methods were applied?
The research employed a comparative analysis of 131 premodern skulls from six archaeological collections. This involved taking 16 standard craniometric measurements and using statistical tools like chi-square tests, t-tests, and Mann-Whitney tests to identify significant associations.
What topics are covered in the main body?
The main sections cover existing literature on craniometric variation, a detailed methodology for collecting data from archaeological remains, a presentation of statistical results from 131 skulls, and an in-depth discussion regarding the origins of occlusal and dental disorders.
Which keywords define this dissertation?
Key terms include anthropology, palaeopathology, craniometrics, orthodontics, heritability, the masticatory complex, and the aetiology of dental anomalies.
How did the Marvinci sample compare to others regarding dental crowding?
The Marvinci sample from Macedonia showed a notably higher prevalence of dental crowding, reaching almost 45%, compared to significantly lower rates found in other collections like the English Blackfriars sample.
What does the study conclude about the null hypothesis?
The study concludes that the null hypothesis, which posited that there is no relationship between craniometrics and dental anomalies, can be rejected based on the observed data.
- Citation du texte
- MA, MSc Joseph R. Krecioch (Auteur), 2012, Investigation of the relationship of craniometrics and dental anomalies, Munich, GRIN Verlag, https://www.grin.com/document/274696
