Taste belongs to our chemical sensing system, or the chemosenses. The complex process of tasting begins when tiny molecules released by the substances around us stimulate special cells in the nose, mouth, or throat. These special sensory cells transmit messages through nerves to the brain, where specific tastes are identified.
Gustatory or taste cells react to food and beverages. These surface cells in the mouth send taste information to their nerve fibers. The taste cells are clustered in the taste buds of the mouth, tongue, and throat. Many of the small bumps that can be seen on the tongue contain taste buds.
Another chemosensory mechanism, called the common chemical sense, contributes to appreciation of food flavor. In this system, thousands of nerve endings–especially on the moist surfaces of the eyes, nose, mouth, and throat–give rise to sensations like the sting of ammonia, the coolness of menthol, and the irritation of chili peppers.
We can commonly identify at least five different taste sensations: sweet, sour, bitter, salty, and umami (the taste elicited by glutamate, which is found in chicken broth, meat extracts, and some cheeses). In the mouth, these tastes, along with texture, temperature, and the sensations from the common chemical sense, combine with odors to produce a perception of flavor. It is flavor that lets us know whether we are eating a pear or an apple. Some people are surprised to learn that flavors are recognized mainly through the sense of smell. If you hold your nose while eating chocolate, for example, you will have trouble identifying the chocolate flavor – even though you can distinguish the food’s sweetness or bitterness. That is because the distinguishing characteristic of chocolate, for example, what differentiates it from caramel, is sensed largely by its odor.
SIGNS OF ORAL INPUT DYSFUNCTION:
1. HYPERSENSITIVITY TO ORAL INPUT (oral defensiveness):
- picky eater, often with extreme food preferences; i.e., limited repertoire of foods, picky about brands, resistive to trying new foods or restaurants, and may not eat at other people’s houses).
- may only eat “soft” or pureed foods past 24 months of age
- may gag with textured foods
- has difficulty with sucking, chewing, and swallowing; may choke or have a fear of choking
- resists/refuses/extremely fearful of going to the dentist or having dental work done
- may only eat hot or cold foods
- refuses to lick envelopes, stamps, or stickers because of their taste
- dislikes or complains about toothpaste and mouthwash
- avoids seasoned, spicy, sweet, sour or salty foods; prefers bland foods
Oral Defensiveness Dysfunction is quite different from a child who dislikes certain foods or is a ‘fussy eater’; children with oral dysfunction have extremely limited repertoire of foods and increasing food repertoire is an often long term and challenging process. Unlike fussy eaters, children with oral dysfunction will ‘starve themselves’ in preference to what they experience as intolerable oral input.
2. HYPOSENSITIVITY TO ORAL INPUT (under-registers)
- may lick, taste, or chew on inedible objects
- prefers foods with intense flavor; i.e., excessively spicy, sweet, sour, or salty
- excessive drooling past the teething stage
- frequently chews on hair, shirt, or fingers
- constantly putting objects in mouth past the toddler years
- acts as if all foods taste the same
- can never get enough condiments or seasonings on his/her food
- loves vibrating toothbrushes and even trips to the dentist