Aleksandra Gawlikowska-Sroka1. 1. Katedra i Zakład Anatomii Prawidłowej Pomorskiej Akademii Medycznej, Szczecin.
Abstract
INTRODUCTION: Asymmetry is a common phenomenon in nature. It is typical for the human body and for the skull as its part. Knowledge of asymmetry and normal anatomy, especially of variability which does not represent pathology but distinguishes individuals is the basis for correct interpretation of radiological findings concerning the skull both in research and diagnostic examinations widely performed in surgery, neurology, neurosurgery, internal medicine, or pediatrics. Analysis of fluctuating asymmetry reveals the influence of stress factors on human development and the ability of the organism to defend itself against stress. The aim of this work was to analyse the asymmetry of skulls from some historic populations and to describe changes in their anatomy over the ages. MATERIAL AND METHODS: The material consisted of three skull groups: one contemporary with 82 skulls and two mediaeval (52 skulls from Cedynia and 77 skulls from Gródek on Bug). Direct measurements were done and the skull was X-rayed in the Posterior-Anterior and skull-base projections. Images were scanned and calibrated with MicroStation 95 Academic Edition software. Helmert's transformation with first-order polynomial was done to attain a suitable geometry. Vectorisation of axes and areas was performed on reference material. Using tools for measurement of vector elements, the distance between bilateral points of both sides of the skull were obtained. Data were analysed statistically. RESULTS: The results of measurements were used to study the directional and fluctuating asymmetry. It was found that asymmetry of the skull was present in both historic populations. The following conclusions were drawn: changes in the distribution of directional and fluctuating asymmetry for individual dimensions have taken place over the ages. A high level of directional asymmetry in the facial part and fluctuating asymmetry in the calvaria is typical for contemporary skulls. The reverse is true for relations in the case of mediaeval skulls. A greater level of fluctuating asymmetry in contemporary skulls reveals greater influence of the developmental stress on the contemporary population and its weaker ability for compensation.
INTRODUCTION: Asymmetry is a common phenomenon in nature. It is typical for the human body and for the skull as its part. Knowledge of asymmetry and normal anatomy, especially of variability which does not represent pathology but distinguishes individuals is the basis for correct interpretation of radiological findings concerning the skull both in research and diagnostic examinations widely performed in surgery, neurology, neurosurgery, internal medicine, or pediatrics. Analysis of fluctuating asymmetry reveals the influence of stress factors on human development and the ability of the organism to defend itself against stress. The aim of this work was to analyse the asymmetry of skulls from some historic populations and to describe changes in their anatomy over the ages. MATERIAL AND METHODS: The material consisted of three skull groups: one contemporary with 82 skulls and two mediaeval (52 skulls from Cedynia and 77 skulls from Gródek on Bug). Direct measurements were done and the skull was X-rayed in the Posterior-Anterior and skull-base projections. Images were scanned and calibrated with MicroStation 95 Academic Edition software. Helmert's transformation with first-order polynomial was done to attain a suitable geometry. Vectorisation of axes and areas was performed on reference material. Using tools for measurement of vector elements, the distance between bilateral points of both sides of the skull were obtained. Data were analysed statistically. RESULTS: The results of measurements were used to study the directional and fluctuating asymmetry. It was found that asymmetry of the skull was present in both historic populations. The following conclusions were drawn: changes in the distribution of directional and fluctuating asymmetry for individual dimensions have taken place over the ages. A high level of directional asymmetry in the facial part and fluctuating asymmetry in the calvaria is typical for contemporary skulls. The reverse is true for relations in the case of mediaeval skulls. A greater level of fluctuating asymmetry in contemporary skulls reveals greater influence of the developmental stress on the contemporary population and its weaker ability for compensation.