The Ageing Mouth

Abstract

The oral cavity is not only the beginning of the digestive tract with a particularly sensitive tactile equipment but also the place of food comminution, mixing and salivating of the food bolus. All tissues of the oral cavity undergo physiological age-related changes that lead to altered morphology and function. Pathological processes like caries, periodontal disease, tooth loss, and oral cancer have a large impact on oral function. Ideally, a minimum of 20 natural teeth with antagonist contact should be maintained for adequate mastication and quality of life. Tooth loss often requires the replacement of lost teeth with dental prostheses to maintain oral function. The oral food processing (chewing, bolus formation, swallowing) takes place in the oral cavity as a partially conscious movement process. It largely depends on teeth, muscle force, and coordination, as well as the sensitivity of the tissues and input from the peripheral and central nervous system. Towards the pharynx, the process overlaps with the involuntary swallowing reflex that is coordinated with the respiratory act in a coordinated fashion. Furthermore, the oral cavity serves in the speech formation and the perception of taste. The mechano- and thermoreceptors are most closely aligned at the tip of the tongue and highly specialized mechano- and vibration receptors are located in the periodontal ligament. In addition to the sensory/physiological tasks, the mucosa of the oral cavity has the function of a secretory organ with its large and small salivary glands. There are age-related physiological changes in an ageing mouth that do not necessarily lead to functional loss as the physiological spare capacity of the oro-facial system seems to be very large; most pathological changes are associated with external factors, such as lifestyle choices and socio-economic factors.