Mathematics. the identity element of a group in which the operation is addition. (of a function, especially of a function of a complex variable) a point at which a given function, usually a function of a complex variable, has the value zero; a root.
Mucosa buccalis. The inner lining of the cheeks and lips, which is an anatomic region that includes all the mucous membrane lining of the inner surface of the cheeks and lips, from the line of contact of the opposing lips to the line of attachment of mucosa to the alveolar ridges and pterygomandibular raphe, which occupies an area of 50â60 cm2.
orÂ·al vesÂ·tiÂ·bule. that part of the mouth bounded anteriorly and laterally by the lips and the cheeks, posteriorly and medially by the teeth and/or gums, and above and below by the reflections of the mucosa from the lips and cheeks to the gums. Synonym(s): vestibulum oris [TA], buccal cavity, vestibule of mouth.ne of two cavities between the floor of the cranium and the roof of the mouth, opening to the nose anteriorly and the nasopharynx posteriorly. Its lining of ciliated epithelium warms and moistens inhaled air, and traps dust and pathogens on mucus that are then swept toward the pharynx.