2. the oral cavity, which forms the beginning of the
digestive system and in which the chewing of food takes place. The mouth is also the site of the organs of
taste and of the
teeth,
tongue, and
lips. It is not only the entrance to the body for food and sometimes air, but also a major organ of
speech and emotional expression.
Structure. Except for the teeth, the interior of the mouth is covered with mucous membrane. This thin lining extends out from the front of the mouth to form the lips. Salivary glands lie above and below the mouth and produce saliva, a liquid that protects the delicate membranes and mixes with food in the first step of digestion of food.
The
palate forms the roof of the mouth. The front two thirds of the palate comprises the hard palate, and the back third, the soft palate. The soft palate is hinged to the hard palate and is flanked on both sides by the
tonsils. In the middle of the soft palate is the
uvula, a projection pointing down to the tongue. At the root of the tongue, below the uvula, lies the
epiglottis.
Disorders. Because of its special functions the mouth is constantly exposed to infection and irritation. These can affect the whole mouth generally or only certain parts, such as the tongue. Inflammation of the mouth, or
stomatitis, can indicate the presence of either a mild or severe disease. Local conditions include
thrush,
gingivitis, and
herpes simplex. Generalized diseases can also give rise to inflammation of the mouth; these include diphtheria, tuberculosis, blood dyscrasias, vitamin deficiencies, and syphilis.
Cancer can afflict the sides of the mouth, the lips, the tongue, and occasionally the salivary glands. Continued irritation, such as pipe smoking, is thought to be a cause of many mouth cancers. Any persistent sore or swelling should be promptly examined by a health care worker.
Birth defects affecting the mouth include
cleft lip and
cleft palate. Both have the same cause: failure of adjacent parts of the body to unite properly in fetal life. A cleft lip (popularly called “harelip”) involves a split in the upper lip. Sometimes the cleft extends into the upper jaw, the floor of the nose, and the palate. The resulting deformity of nose and mouth interferes with sucking and speech unless corrected by surgery. A cleft palate, which may cause difficulties in speaking and eating, signifies a cleavage in the uvula and the soft palate. Both conditions can be successfully corrected by surgery.
mouth care techniques of
oral hygiene whose purpose is to preserve or restore and maintain normal physiology and function of the oral cavity. These include assessment of the mouth, cleaning, and removal of debris from the teeth, palate, tongue, and sides of the mouth. Periodically and systematically cleaning the mouth, brushing the teeth, and flossing help prevent
dental caries, inflammatory
periodontal disease, and
halitosis. Mouth care also promotes a sense of cleanliness and well-being, facilitates speech, and helps overcome loss of appetite. Additionally, a healthy oral mucosa is the first line of defense against infection in the oral cavity.
In the normal mouth a healthy oral mucosa is maintained in part by movements of the tongue, lips, and cheeks during speech, chewing, and swallowing. Salivation and the mechanical action of chewing foods also help keep the mucosa soft and moist. Brushing and flossing or other less forceful measures facilitate removal of debris, bacteria, and plaque and preserve the integrity of the teeth and gums.
Patients most in need of special mouth care include those who (1) breathe through their mouths because of nasal obstruction or other conditions, (2) are receiving nasal oxygen, (3) have a restricted oral intake or are being fed by tube, (4) are comatose or otherwise unable to care for their teeth and mouth, (5) are receiving radiation therapy to the head and neck, or (6) are receiving chemotherapy for a malignancy. Both radiation and chemotherapy can cause severe
stomatitis and
xerostomia.
Initial and ongoing assessment of the oral cavity can establish the type and frequency of mouth care needed. In general, the more easily damaged the integrity of the oral mucosa, the more gentle the chemical and mechanical cleansing. If brushing with a soft nylon toothbrush and nonabrasive toothpaste and flossing cannot be tolerated, the teeth can be cleaned with unflavored oral care sponges dipped into plain water or a physiologic saline solution. Flossing is contraindicated if the patient has a low platelet count or low white cell count. Mouthwashes are not a substitute for toothbrushing.
Xerostomia (excessive dryness of the mouth) can be relieved by artificial
saliva or by application of a water soluble lubricant such as KY jelly. If the patient is able to eat and drink, fluids and moist foods are encouraged. Dry, cracked lips respond best to
petroleum jelly or a camphor-based lip balm. Lemon juice and
glycerin are not recommended in patients with
mucositis because when used over a period of time
glycerin tends to dry oral tissues.
Thick and tenacious mucus in the oral cavity can be removed by diluted
hydrogen peroxide or
socium bicarbonate solution. The
hydrogen peroxide solution is prepared by mixing equal parts hydrogen peroxide (USP 3 per cent) and water just before application. A peroxide solution is contraindicated if the patient has
leukemia or there are freshly granulating surfaces or exposed bone in the oral cavity.
Sodium bicarbonate solution is made by adding one teaspoon of sodium bicarbonate to one pint (half a liter) of water. The same proportions of salt and water are used to prepare a 0.9 per cent solution of normal
saline.
If pain in the mouth prevents a patient from eating comfortably, it may be possible to provide temporary relief by rinsing the mouth with a solution of one part
lidocaine viscous 2 per cent added to two parts water. However, since this solution diminishes sensitivity to heat, the patient must not be fed hot food or drinks that could cause burns.
Diligent, systematic mouth care is an integral part of hospital care. Research has shown that such care prevents many problems of nutrition, infection, and pain associated with stomatitis, especially those occurring as a complication of chemotherapy and radiation therapy. Moreover, routine care of the mouth, teeth, and gums, no matter what the health status of the patient, can prevent many problems, maintain a healthy oral cavity, and do much to make the patient more comfortable.