1. Ritchie H, Roser M. Mental health. 2018. Online information available at: https://ourworldindata.org/mental-health (accessed February 2021).
2. British Society of Periodontology. BSP Flowchart Implementing the 2017 Classification. 2018. Online information available at: https://www.bsperio.org.uk/assets/downloads/111_153050_bsp-flowchart-implementing-the-2017-classification.pdf (accessed February 2021).
3. British Society of Periodontology. The Good Practitioners Guide to Periodontology. 2016. Online information available at: https://www.bsperio.org.uk/professionals/publications (accessed February 2021).
4. Spector A, Postolache T T, Akram F, Scott A J, Wadhawan A, Reynolds MA. Physiological stress: A predisposing and exacerbating factor in periodontitis. Curr Oral Health Rep 2020; 7: 208-215.
5. Warreth A, Abuhijleh E, Almaghribi M A, Mahwal G, Ashawish A. Tooth surface loss: A review of literature. Saudi Dent J 2020; 32: 53-60.