The periodontium includes the tissues that support and surround the teeth including the free gingiva, attached gingiva, alveolar mucosa, cementum, periodontal ligament, and alveolar process. Having a basic understanding of these structures allows clinicians to provide the best possible care to their patients by allowing them to accurately assess a patient’s oral health status. The free gingiva, attached gingiva, and alveolar mucosa make up the gingival unit and are the only components of the periodontium that are clinically visible.