In South America, Africa, India, Arabia, and Europe, tongue cleansing has been practiced for ages. Archaeological discoveries have shown ancient civilizations used tools to clean their tongue starting more than 7,000 years ago.
Arabic, African, and Asian cultures
In Arabic, African, and Asian cultures, a teeth-cleaning twig called a “miswak” was commonly used in oral hygiene practices. These tribes would first brush their teeth before using a twig to scrape their tongues, in accordance with Koranic instructions. In addition, early accounts of tongue cleaning mention the use of "datun", an Indian toothbrush constructed from a tree wig of a fragrant plant. Furthermore, ancient Hindu tribes would utilise the end of a twig and chew on it until it was transformed into a soft brush. Next, they would break the twig, form it into an inverted V shape, and use it as a tongue scraper after brushing their teeth.
Ayurvedic Medicine
The practice of cleansing one's tongue has persisted in Ayurvedic medicine because of the many positive effects on oral health. The Ayurvedic method involves scraping the tongue with tools composed of copper, silver, gold, tin, or brass to get rid of the harmful material called "ama." Ama, which means "unripe or undigested", is characterized by a coated white tongue, bad breath, and a potent bodily odour. Regular tongue scraping helps to remove "ama" from the tongue, protecting the digestive system and dental health. In addition, Ayurveda views tongue scraping as a way to enhance the sensation of taste. Today, tongue scraping is still a common practice in Ayurvedic medical and Islamic cultures.
European Cultures
In European cultures, it was not until the fifteenth century that tongue scraping became prevalent. From the fifteenth century through the nineteenth century, various types of tongue scrapers were created, varying in shape and size, and sometimes attached to toothbrushes. Since the twentieth century, the scientific community has been investigating the effectiveness of tongue scraping and why it should be included in everyday oral hygiene practices.
References:
[1] Christen AG, Swanson BZ. Oral hygiene: a history of tongue scraping and brushing. J Am Dent Assoc 1978;96:215–9. https://doi.org/10.1016/s0002-8177(16)30453-6.
[2] Outhouse TL, Fedorowicz Z, Keenan JV, Al-Alawi R. A Cochrane systematic review finds tongue scrapers have short-term efficacy in controlling halitosis. Gen Dent 2006;54:352–9; 360, 367–8; quiz 360.