Metabolic unit of pulp-dentinal complex of human tooth.

The change of dentin depends on odontoblast's metabolism (synthesis and secretion), and the result of those cells activity is apposition of dentin: physiological or reactive. Odontoblasts, dentinal tubuli with odontoblastic processus and peritubular zone, they all make metabolic unit of dentin, and they are the major part of circumpulpal dentin structure. Functional activities of the tooth are the base for constant changes during the entire life of circumpulpal dentin. The apposition, and also the resorption of dentinal tissue, can be found as the respond to trauma, pathological conditions, or after the therapeutic interventions.

Incidence and distribution of dehiscences and fenestrations on human skulls.

The aim of this study was to determine the incidence and distribution of dehiscences and fenestrations of the alveolar plate. The sample used in the study consisted of 163 adult jaw bones (78 maxillae and 85 mandibles) of a recent population from the north-western Croatia. The skulls are part of the skull collection of The Anatomy Institute, Zagreb, Croatia. The number and location of dehiscences and fenestrations for each tooth area above the total number of 2038 teeth were registrated. The total number of 696 (26.67%) dehiscences and 190 (9.32%) fenestrations was measured. Among the maxillary teeth, canines exhibited greatest and most frequent dehiscences and fenestrations. In the mandible, canines were most commonly associated with both defects, too. It was concluded that the canines were most frequently associated with either of the osseous defects.

Effect of unilateral function on craniofacial growth.

The present study is aimed at experimental research of the effects of functional matrices upon the formation of functional units. The sample consisted of 15 experimental dogs (five dogs per each experiment) and five controls. Three experiments were carried out: neurectomy of the right mandibular nerve, circumvention of the right nostril and enucleation of the right eyeball. The results showed no statistically significant difference between age and animal sacrifice time interval. The controls manifested the significant differences in the length, breadth and height of the upper mandibular body consistent with their natural asymmetry. Neurectomy of the right mandibular nerve did not manifest statistically significant differences whereas the sample was too small, animal sacrifice time interval too short and passive movements of that mandibular side were still present after the operation. Circumvention of the right nostril revealed in the nasal opening breadth, which for the very nature of the operation and only a partial exclusion of the right side function could have been anticipated. Enucleation of the right eyeball eliminated the visual function in the right face causing changes in the midface, i. e. in the breadth and height of the nostril. The findings confirmed the initial assumption on the correlation between the removal of potential growth factors and increase of the opposite face parameters. The changes were most prominent in the mid of the head which can be related to its developmental and structural features.