Periostin is a microcellular adapter protein. It plays a wide range of essential roles during the development and in immunomodulation. Periostin is a prominent contributor during the process of angiogenesis, tumorigenesis, and cardiac repair. It is expressed in periodontal ligaments, tendons, skin, adipose tissues, muscle, and bone. This is a protein-based biomolecule that has the diagnostic and monitoring capability and potentially be used as a biomarker to detect physiological and pathological conditions. The aim of the present review was to explore the periostin morphology and associated structural features. In addition, periostin's immunomodulatory effects and associated biomarkers in context of oral diseases have been discussed.