Introduction

Animal models refer to the ones that, through various treatments or operations on animals, present characteristics similar to specific human diseases in terms of physiology, pathology, and so on, and thus are used to study the occurrence mechanism, development process, and treatment effect evaluation of diseases. Excellent animal models provide powerful tools for disease research and are usually superior to in vitro studies or clinical studies. In the field of oral disease research, commonly used animal models include mice, rats, rabbits, dogs, and so on, which play a vital role in new drug research and development and medical research.

Classification of Animal Models

Animal models are of great value in oral disease research. However, due to the complexity of oral diseases and related structures, a single model can hardly fully explain a disease's mechanism and treatment. Thus, it's essential to consider the research goals and stages. Choosing proper animal models and species according to the experimental aim is crucial for research accuracy and effectiveness. Animal models are usually classified into three types: Genetically Engineered Animal Models, Induced Animal Models, and Syngenetic Animal Models.

Genetically Engineered Animal Model

The genetically engineered animal model precisely modifies the genome of animals through gene editing and other technologies to simulate gene changes related to specific diseases. For example, human cells, tissues, or genes can be introduced into animals to construct humanized animal models, enabling animals to possess certain human physiological or pathological characteristics to a certain extent.

Induced Animal Model

Induced animal model relies on external factors like chemical, physical, or biological agents to trigger symptoms in animals similar to human diseases. For instance, in creating a dental caries model, chemical poisons like acids can be given to animals in different ways to speed up caries formation. This model is then used to study the pathogenesis, pathological features, and treatment of dental caries.

Syngenetic Animal Model

The syngenetic animal model is one using animals with similar genetic backgrounds. These animals can have, either spontaneously or by induction, pathological processes like human diseases. For example, some inbred mice naturally get autoimmune oral mucosal diseases similar to human oral lichen planus. Such mouse models help explore the immune pathogenesis of oral lichen planus.

Application of Animal Models in Oral Diseases

Pulpitis

Pulpitis is an inflammatory reaction of the dental pulp due to damage or infection, featuring a series of closely regulated vascular and cellular events. Multiple animal models, such as non-human primate, mouse, rat, ferret, and pig models, are used in the study of pulpitis mechanism and drug screening. Different species' animal models have their advantages and disadvantages. Monkey models are more similar to humans in structure and have more reliable histopathology, yet with strict ethical constraints and high costs. Mouse and rat models are more prevalent and easier to obtain, though their anatomical structures vary from those of humans.

Fig.1 Animal Model of Pulpitis (Aubeux D., et al. 2021).

Periodontitis

Periodontitis is a chronic inflammatory disease caused by the imbalance of the oral microbiota, characterized by alveolar bone resorption, destruction of the periodontal ligament, gingival recession, and so on. A variety of animal models have been applied to simulate the occurrence and development process of periodontitis, study immune responses, and evaluate drugs, such as oral inoculation models, silk ligature models, and genetically engineered mouse models. In addition, animal models can also be used to assess the potential of new treatment technologies, such as stem cell therapy, gene therapy, biomaterial implantation, etc. in the treatment of periodontitis, providing experimental evidence and new ideas for clinical treatment.

Fig.2 Research on immunotherapy for oral tumors using murine models (Chiu W.C., et al. 2022).

Oral Cancer

Oral cancer, a major type of head and neck cancer, encompasses varieties like oral squamous cell carcinoma (OSCC). Multiple animal models, including mouse, rat, hamster, cat, and dog models, are utilized for researching cancer pathogenesis, assessing treatment efficacy, and screening anti-cancer drugs. These models offer a platform for heterogeneous oral cancer research, facilitating the development of personalized treatment strategies. Nevertheless, some models have limitations as they may not fully replicate the complexity and diversity of humans.

Conclusion

In oral disease research, animal models are widely applied to understand the basic biology of dentomaxillofacial anomalies and diseases and to evaluate diverse drugs and treatments. Reasonable utilization of different animal models offers a more comprehensive and profound view of research, driving continuous progress. It's believed that with technological advancements, animal models will present new opportunities for oral disease research.

What can we do?

Alta Stomatology can provide a range of animal models for oral diseases, such as oral ulcer animal models, caries animal models, periodontitis animal models, apical periodontitis animal models, oral squamous cell carcinoma animal models, etc. Additionally, we also provide in vitro oral static biofilm models for in vitro medical device evaluation and development. If you have any needs, please feel free to contact us .