The pig represents a useful, large experimental model for biomedical research. Recently, it has been used in different areas of biomedical research. The aim of this study was to review the basic anatomical structures of the head region in the pig in relation to their use in current research. Attention was focused on the areas that are frequently affected by pathological processes in humans: the oral cavity with teeth, salivary gland, orbit, nasal cavity and paranasal sinuses, maxilla, mandible and temporomandibular joint. Not all of the structures have an equal morphology in the pig and human, and these morphological dissimilarities must be taken into account before choosing the pig as an experimental model for regenerative medicine.

Functional tooth germs in mammals, reptiles, and chondrichthyans are initiated from a dental lamina. The longevity of the lamina plays a role in governing the number of tooth generations. Monophyodont species have no replacement dental lamina, while polyphyodont species have a permanent continuous lamina. In diphyodont species, the dental lamina fragments and regresses after initiation of the second tooth generation. Regression of the lamina seems to be an important mechanism in preventing the further development of replacement teeth. Defects in the complete removal of the lamina lead to cyst formation and has been linked to ameloblastomas. Here, we show the previously unknown mechanisms behind the disappearance of the dental lamina, involving a combination of cell migration, cell-fate transformation, and apoptosis. Lamina regression starts with the loss of the basement membrane, allowing the epithelial cells to break away from the lamina and migrate into the surrounding mesenchyme. Cells deactivate epithelial markers (E-cadherin, cytokeratin), up-regulate Slug and MMP2, and activate mesenchymal markers (vimentin), while residual lamina cells are removed by apoptosis. The uncovering of the processes behind lamina degradation allows us to clarify the evolution of diphyodonty, and provides a mechanism for future manipulation of the number of tooth generations.

Infectious stomatitis represents the most common oral cavity ailments. Current therapy is insufficiently effective because of the short residence time of topical liquid or semisolid medical formulations. An innovative application form based on bioadhesive polymers featuring prolonged residence time on the oral mucosa may be a solution to this challenge. This formulation consists of a mucoadhesive oral film with incorporated nanocomposite biomaterial that is able to release the drug directly at the target area. This study describes the unique approach of preparing mucoadhesive oral films from carmellose with incorporating a nanotechnologically modified clay mineral intercalated with chlorhexidine. The multivariate data analysis was employed to evaluate the influence of the formulation and process variables on the properties of the medical preparation. This evaluation was complemented by testing the antimicrobial and antimycotic activity of prepared films with the aim of finding the most suitable composition for clinical application. Generally, the best results were obtained with sample containing 20 mg of chlorhexidine diacetate carried by vermiculite, with carmellose in the form of nonwoven textile in its structure. In addition to its promising physicomechanical, chemical, and mucoadhesive properties, the formulation inhibited the growth ofStaphylococcusandCandida; the effect was prolonged for tens of hours.