Ladislava Horáčková

A Case of Osteosarcoma in a Late Medieval–Early Modern Skull from Kyjov (Czech Republic)

After the reconstruction of the original parish church of the Moravian town of Kyjov in the latter part of the seventeenth century, human skeletal remains from the disturbed graves of the surrounding cemetery were gathered in a vault which was partially excavated in 1994. Among disarticulated bones of at least 106 individuals, a fragmented skull of a young male was found, with a massive outgrowth of bone on the right parietal, originally continuing fluently on the non-preserved frontal scale, on edges lifting the outer lamina. The inner lamina was covered less intensively by the bony growth. Radiography and CT scans showed a non-homogeneous structure, the inside being irregular and the outside granulated or radially striated. A metastatic lytic focus was detected in the same bone. Histology and SEM examination showed an uneven mineralization of the bone tissue, consisting of rough, thickened and irregularly spaced trabeculae, with cellular remains or mineralized matrix on the surface. The differential diagnosis took meningioma into consideration but the most probable diagnosis was osteogenic sarcoma, which is still infrequent in the palaeopathological record from the Old World and its localization in the cranial vault is very rare.

Two Unusual Benign Tumours in Skulls from the Ossuary at Křtiny (Czech Republic)

Among 554 skulls of adult individuals from the ossuary at K𝔯tiny, Moravia (late thirteenth to the mid-eighteenth centuryAD), three (0.54 per cent) showed evidence of malignant tumours and two others (0.36 per cent) had changes suggestive of unusual benign tumours, which are described in the present article. The calvarium of a 20–25-year-old female has two osteoplastic overgrowths in the region of the left tuber parietale and in the left lateral part of the frontal bone. A macroscopic section showed a porotic structure with regularily arranged trabeculae. This was confirmed by radiographic examination, which detected two similar smaller shadows, and by histology and scanning electron microscopy, which showed the non-lamellar, unevenly calcified structure of these curious multiple osteomatous formations (osteomas, hyperostosis). A calvarium of a 40–50-year-old male showed a horseshoe-shaped excavation in the posterior part of the processi palatini of the maxilla, with destruction of the lower half of the nasal septum and the paramedial structures of the nasal cavity. These defects were well delimited macroscopically, radiographically and histologically, and seemed to be the result of pressure atrophy, perhaps from a slow growing benign tumour such as a fibroma or angiofibroma.

Micro finite element analysis of dental implants under different loading conditions

Osseointegration is paramount for the longevity of dental implants and is significantly influenced by biomechanical stimuli. The aim of the present study was to assess the micro-strain and displacement induced by loaded dental implants at different stages of osseointegration using finite element analysis (FEA). Computational models of two mandible segments with different trabecular densities were constructed using microCT data. Three different implant loading directions and two osseointegration stages were considered in the stress-strain analysis of the bone-implant assembly. The bony segments were analyzed using two approaches. The first approach was based on Mechanostat strain intervals and the second approach was based on tensile/compression yield strains. The results of this study revealed that bone surrounding dental implants is critically strained in cases when only a partial osseointegration is present and when an implant is loaded by buccolingual forces. In such cases, implants also encounter high stresses. Displacements of partially-osseointegrated implant are significantly larger than those of fully-osseointegrated implants. It can be concluded that the partial osseointegration is a potential risk in terms of implant longevity.

A brief history of tuberculosis in the Czech Lands

Tuberculosis currently remains a serious medical problem, therefore increased attention is being paid to this disease. Paleopathological studies focused on the monitoring of morbid changes in skeletal remains of historical populations facilitate a detailed study of the development of this disease. They provide direct evidence of the existence of tuberculosis and its past forms. In addition to literary and iconographic sources, the present study is focused on recording the findings of bone tuberculosis in historical osteological sets from the Czech Lands and is the starting point for their detailed review. Approximately 76 cases of bone tuberculosis from the Czech Lands have been published and more or less reliably documented from 20 archeological sites dated back from the Eneolithic to the modern period.

A brief history of syphilis in the Czech Lands

From the end of the fifteenth century, the massive expansion of syphilis had a distinct effect on the historical development of Europe. Due to this disease, firstly the numbers of the European population were reduced; thereafter, moral and ethical principles were significantly affected and the combat readiness of armies decreased. The disease forced new legislation which was of vital importance for the development of health services. The Czech Lands, located in Central Europe, were also no exception. The material presented summarises the available information on this disease obtained from written sources and from the study of direct evidence of skeletal remains from archaeological sites of Bohemia, Moravia and Silesia. Traces of syphilitic bone affliction have observed in almost every large early modern osteological collection to date. A number of currently documented palaeopathological findings of syphilitic changes in bones from the Czech Lands do not by a long stretch correspond to the data presented in literary sources on the mass occurrence of this disease. The submitted study aims to extend current knowledge in this area and thereby to complete a complex view of the development of syphilis in Central Europe.

Microstructural Finite-Element Analysis of Influence of Bone Density and Histomorphometric Parameters on Mechanical Behavior of Mandibular Cancellous Bone Structure

Using porous bioceramics became recently an alternative approach to increase bone density which is a key factor for successful dental implant application. These novel biomaterials should substitute missing natural trabecular structures in terms of material strength as well as deformation characteristics. However, mechanical behavior of these materials used as bone fillers are still in question. This problem is made more difficult by the fact that bone structure itself exhibits a complex mechanical behavior which is still in question as well and, therefore, appropriate analytical criteria should to be established. The purpose of this paper is to determine typical mechanical behavior of trabecular structure of mandibular cancellous bone using computational simulations which can serve as a basis for establishing such criteria. For this purpose, four bone specimens of various bone density were μCT-scanned and high-level finite element models including detailed trabecular structure were created on their basis to analyze relevant mechanical quantities for various loadings in terms of bone density and various histomorphometric parameters.