Areca: A plant genus of the family ARECACEAE. Members contain ARECOLINE and CATECHIN. The leaves and nuts have been used as masticatories, stimulants, and astringents in traditional medicine. The common name of betel is also used for PIPER BETLE. The common name of catechu is sometimes used for ACACIA CATECHU.Arecoline: An alkaloid obtained from the betel nut (Areca catechu), fruit of a palm tree. It is an agonist at both muscarinic and nicotinic acetylcholine receptors. It is used in the form of various salts as a ganglionic stimulant, a parasympathomimetic, and a vermifuge, especially in veterinary practice. It has been used as a euphoriant in the Pacific Islands.Oral Submucous FibrosisNuts: Botanically, a type of single-seeded fruit in which the pericarp enclosing the seed is a hard woody shell. In common usage the term is used loosely for any hard, oil-rich kernel. Of those commonly eaten, only hazel, filbert, and chestnut are strictly nuts. Walnuts, pecans, almonds, and coconuts are really drupes. Brazil nuts, pistachios, macadamias, and cashews are really seeds with a hard shell derived from the testa rather than the pericarp.Mastication: The act and process of chewing and grinding food in the mouth.Piper betle: A plant genus of the family PIPERACEAE that is indigenous in the Indian Malay region and cultivated in Madagascar, and the West Indies. It contains chavibetol, chavicol and cadinene. The leaf is chewed as a stimulant, antiseptic and sialogogue. The common name of betel is also used for ARECA.Micronesia: The collective name for islands of the Pacific Ocean east of the Philippines, including the Mariana, PALAU, Caroline, Marshall, and Kiribati Islands. (From Webster's New Geographical Dictionary, 1988, p761 & Room, Brewer's Dictionary of Names, 1992, p350)Tobacco, Smokeless: Powdered or cut pieces of leaves of NICOTIANA TABACUM which are inhaled through the nose, chewed, or stored in cheek pouches. It includes any product of tobacco that is not smoked.Mouth Mucosa: Lining of the ORAL CAVITY, including mucosa on the GUMS; the PALATE; the LIP; the CHEEK; floor of the mouth; and other structures. The mucosa is generally a nonkeratinized stratified squamous EPITHELIUM covering muscle, bone, or glands but can show varying degree of keratinization at specific locations.Habits: Acquired or learned responses which are regularly manifested.PakistanPlant Extracts: Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.Gingiva: Oral tissue surrounding and attached to TEETH.Mouth Neoplasms: Tumors or cancer of the MOUTH.