The mouth and face are highly accessible parts of the body, sensitive to and able to reflect changes occurring internally. The mouth is the major portal of entry to the body and is equipped with formidable mechanisms for sensing the environment and defending against toxins or invading pathogens. In the event that the integrity of the oral tissues is compromised, the mouth can become a source of disease or pathological processes affecting other parts of the body
THE MOUTH AND FACE AS A MIRROR OF HEALTH AND DISEASE
A physical examination of the mouth and face can reveal signs of disease, drug use, domestic physical abuse, harmful habits or addictions such as smoking, and general health status. Imaging (e.g., x-ray, MRI, SPECT) of the oral and craniofacial structures may provide early signs of skeletal changes such as those occurring with osteoporosis and musculoskeletal disorders, and may also reveal salivary, congenital, neoplastic, and developmental disorders. Oral cells and fluids, especially saliva, can be tested for a wide range of substances, and oral-based diagnostics are increasingly being developed and used as a means to assess health and disease without the limitations and difficulties of obtaining blood and urine.
Physical Signs and Symptoms of Disease and Risk Factors
A number of signs and symptoms of disease, lifestyle behaviors, and exposure to toxins can be detected in or around the craniofacial complex. Pathogens entering the mouth may proliferate locally with oral and pharyngeal signs and symptoms; other pathogens may enter the bloodstream directly or through lymphatic channels and cause generalized disease. Oral signs suspected to be indications of systemic illness may be confirmed by the presence of rash, fever, headache, malaise, enlarged lymph nodes, or lesions elsewhere on the body.
Swollen parotid glands are a cardinal sign of infection with the mumps virus and can also be seen in individuals with Sjögren's syndrome and HIV. The salivary glands are also frequently involved in tuberculosis and histoplasmosis infections. Oral signs of infectious mononucleosis, caused by Epstein-Barr virus, include sore throat, gingival bleeding, and multiple pinpoint-sized hemorrhagic spots (pettechiae) on the oral mucosa.
The appearance of soft or hard tissue pigmentation is associated with a number of diseases and treatments. Malignant melanoma can appear in the mouth as brown or black flat or raised spots. Kaposi's sarcoma can appear as a flat or raised pigmented lesion. Addison's disease causes blotches or spots of bluish-black or dark brown pigmentation to occur early in the disease. Congenital discrete brown or black patches (nevi) can appear in any part of the mouth. Pigmentation of the tooth crowns may be seen in children with cystic fibrosis and porphyria and those exposed to tetracycline during tooth development.
The oral tissues can also reflect nutritional status and exposure to risk factors such as tobacco. The tongue appears smooth in pernicious anemia. Group B vitamin deficiency is associated with oral mucositis and ulcers, glossitis, and burning sensations of the tongue. Scurvy, caused by severe vitamin C deficiency, is associated with gingival swelling, bleeding, ulceration, and tooth loosening. Lack of vitamin D in utero or infancy impairs tooth development. Enamel hypoplasia may result from high levels of fluoride or from disturbances in calcium and phosphate metabolism, which can occur in hypoparathyroidism, gastroenteritis, and celiac disease. The mouth also can reflect the effects of tobacco use, perhaps providing the only visible evidence of its adverse effects.
Oral Manifestations of HIV Infection and of Osteoporosis
The mouth can serve as an early warning system, diagnostic of systemic infectious disease and predictive of its progression, such as with HIV infection. In the case where oral cells and tissues have counterparts in other parts of the body, oral changes may indicate a common pathological process. During routine oral examinations and perhaps in future screening tests, radiographic or magnetic resonance imaging of oral bone may be diagnostic of early osteoporotic changes in the skeleton. The following sections provide details.
Osteoporosis and Oral Bone Loss
some temporomandibular joint disorders are manifestations of osteoarthritis, rheumatoid arthritis, or myofascial pain. Paget's disease, characterized by enlarged and deformed bone, can be particularly painful and debilitating when it affects the cranial and jaw bones.
Osteoporosis, a degenerative disease characterized by the loss of bone mineral and associated structural changes, has long been suspected as a risk factor for oral bone loss
Oral Infections and Bacteremia
Oral microorganisms and cytotoxic by-products associated with local infections can enter the bloodstream or lymphatic system and cause damage or potentiate an inappropriate immune response elsewhere in the body. Dissemination of oral bacteria into the bloodstream (bacteremia) can occur after most invasive dental procedures, including tooth extractions, endodontic therapy, periodontal surgery, and scaling and root planing. Even routine oral hygiene procedures such as daily toothbrushing, subgingival irrigation, and flossing may cause bacteremia. However, these distant infections have been
Oral Infections as a Result of Therapy
Oral mucositis can be a major dose-limiting problem during chemotherapy with some anticancer drugs, such as 5-fluorouracil, methotrexate, and doxorubicin.
Radiation therapy disrupts cell division in healthy tissue as well as in tumors and also affects the normal structure and function of craniofacial tissues, including the oral mucosa, salivary glands, and bone. Oral-facial complications are common after radiation therapy to the head and neck. The most frequent, and often the most distressing, complication is mucositis, but adverse reactions can affect all oral-facial tissues
Radiation can cause irreversible damage to the salivary glands, resulting in dramatic increases in dental caries. Oral mucosal alterations may become portals for invasion by pathogens, which may be life-threatening to immunosuppressed or bone-marrow-suppressed patients. A less common but very serious adverse consequence is destruction of bone cells and bone death, called osteoradionecrosis (ORN). ORN can result in infection of the bone and soft tissue and can require surgery to excise the dead tissue, which can in turn leave the face badly disfigured as well as functionally impaired
Staining of the teeth or mucosa is associated with a variety of drugs, including tranquilizers, oral contraceptives, and antimalarials. The antibiotic tetracycline can cause enamel hypoplasia when taken by the mother during pregnancy and by children during tooth development. The antimicrobial mouthrinse agent chlorhexidine also can stain the teeth, but this staining is external and can be removed by dental prophylaxis.
ASSOCIATIONS AMONG ORAL INFECTIONS AND DIABETES, HEART DISEASE/STROKE, AND ADVERSE PREGNANCY OUTCOMES
The Periodontal Disease - Diabetes Connection
There is growing acceptance that diabetes is associated with increased occurrence and progression of periodontitis—so much so that periodontitis has been called the "sixth complication of diabetes". The risk is independent of whether the diabetes is type 1 or type 2. Type 1 diabetes is the condition in which the pancreas produces little or no insulin. It usually begins in childhood or adolescence. In type 2 diabetes, secretion and utilization of insulin are impaired; onset is typically after age 30. The goal of diabetic care is to lower blood glucose levels to recommended levels. Some investigators have reported a two-way connection between diabetes and periodontal disease, proposing that not only are diabetic patients more susceptible to periodontal disease, but the presence of periodontal disease affects glycemic control.
Several lines of evidence support the plausibility that periodontal infections contribute to problems with glycemic control, thus compromising the health of diabetic patients. It has been reported that the chronic release of tumor necrosis factor alpha (TNF-alpha) and other cytokines such as those associated with periodontitis interferes with the action of insulin and leads to metabolic alterations.
The Oral Infection - Heart Disease and Stroke Connection
During the past decade, infectious agents have become recognized as causes of systemic diseases, without fever or other traditional signs of infection. Helicobacter pylori is associated with peptic ulcers and, along with Chlamydia pneumoniae and cytomegalovirus, is now thought to be associated with increased risk for cardiovascular disease as well as malignancies (Wu et al. 2000). Studies investigating the relationship between oral and dental infections and the risk for cardiovascular disease suggest that there is potential for oral microorganisms, such as periodonto-pathic bacteria, and their effects to be linked with heart disease.