Anatomical and functional features of the paranasal sinuses of cattle in ontogenesis

The functional significance of the paranasal sinuses of cattle was analyzed from the anatomical point of view. The absence of the detailed information about the morphofunctional definition of the paranasal sinuses of cattle in the literature determined the subject of our research. Heads of fetuses, calves and ephebic cattle of black-and-white breed served the object of the study. 35 osteotopic models were prepared, using the method of maceration and molds making of the paranasal sinuses, that were sawed, measured and afterwards photo- graphed. 16 models were studied using the method of filling vessels with latex followed by preparation. This way it was found that the shape of the paranasal sinuses changes during fetal and postnatal gestation periods of cattle, especially vividly it appears in relation to the maxillary, lacrimal and palatal sinuses, with functional posi- tions representing the unified whole. The relation between the change of the shape of the lacrimal bulla bone with a functional load on the molar teeth was revealed. Maxillary sinuses of cattle begin to be fully functional in the postnatal period, when they get their final shapes of rectangular triangle. The triangular shape of the maxil- lary, lacrimal and palatal sinuses and their position at an angle to each other is optimal to perform the basic func- tion - to absorb the pressure coming from the alveolar bone. With increasing pressure from the alveolar bone maxillary and palatal sinuses gain a position when the angle between them is close to the minimum. The research shows that the maxillary, lacrimal and palatal sinuses of the calves in the early postnatal period are not fully formed, that should be considered in clinical veterinary practice.