periodontal disease

Periodontal Disease 

Definition

Periodontal diseases are a group of diseases that affect the tissues that support and anchor the teeth. Left untreated, periodontal disease results in the destruction of the gums, alveolar bone (the part of the jaws where the teeth arise), and the outer layer of the tooth root.

Description

Periodontal disease is usually seen as a chronic inflammatory disease. An acute infection of the periodontal tissue may occur, but is not usually reported to the dentist. The tissues that are involved in periodontal diseases are the gums, which include the gingiva, periodontal ligament, cementum, and alveolar bone. The gingiva is a pink-colored mucus membrane that covers parts of the teeth and the alveolar bone. The periodontal ligament is the main part of the gums. The cementum is a calcified structure that covers the lower parts of the teeth. The alveolar bone is a set of ridges from the jaw bones (maxillary and mandible) in which the teeth are embedded. The main area involved in periodontal disease is the gingival sulcus, a pocket between the teeth and the gums. Several distinct forms of periodontal disease are known. These are gingivitis, acute necrotizing ulcerative gingivitis, adult periodontitis, and localized juvenile periodontitis. Although periodontal disease is thought to be widespread, serious cases of periodontitis are not common. Gingivitis is also one of the early signs of leukemia in some children.

Gingivitis

Gingivitis is an inflammation of the outermost soft tissue of the gums. The gingivae become red and inflamed, loose their normal shape, and bleed easily. Gingivitis may remain a chronic disease for years without affecting other periodontal tissues. Chronic gingivitis may lead to a deepening of the gingival sulcus. Acute necrotizing ulcerative gingivitis is mainly seen in young adults. This form of gingivitis is characterized by painful, bleeding gums, and death (necrosis) and erosion of gingival tissue between the teeth. It is thought that stress, malnutrition, fatigue, and poor oral hygiene are among the causes for acute necrotizing ulcerative gingivitis.

Adult periodontitis

Adult periodontitis is the most serious form of the periodontal diseases. It involves the gingiva, periodontal ligament, and alveolar bone. A deep periodontal pocket forms between the teeth, the cementum, and the gums. Plaque, calculus, and debris from food and other sources collect in the pocket. Without treatment, the periodontal ligament can be destroyed and resorption of the alveolar bone occurs. This allows the teeth to move more freely and eventually results in the loss of teeth. Most cases of adult periodontitis are chronic, but some cases occur in episodes or periods of tissue destruction.

Localized juvenile periodontitis

Localized juvenile periodontitis is a less common form of periodontal disease and is seen mainly in young people. Primarily, localized juvenile periodontitis affects the molars and incisors. Among the distinctions that separate this form of periodontitis are the low incidence of bacteria in the periodontal pocket, minimal plaque formation, and mild inflammation.

Herpetic gingivostomatitis

Herpes infection of the gums and other parts of the mouth is called herpetic gingivostomatitis and is frequently grouped with periodontal diseases. The infected areas of the gums turn red in color and have whitish herpetic lesions. There are two principal differences between this form of periodontal diseases and most other forms. Herpetic gingivostomatitis is caused by a virus, Herpes simplex, not by bacteria, and the viral infection tends to heal by itself in approximately two weeks. Also, herpetic gingivostomatitis is infectious to other people who come in contact with the herpes lesions or saliva that contains virus from the lesion.

Pericoronitis

Pericoronitis is a condition found in children who are in the process of producing molar teeth. The disease is seen more frequently in the lower molar teeth. As the molar emerges, a flap of gum still covers the tooth. The flap of gum traps bacteria and food, leading to a mild irritation. If the upper molar fully emerges before the lower one, it may bite down on the flap during chewing. This can increase the irritation of the flap and lead to an infection. In bad cases, the infection can spread to the neck and cheeks.

Desquamative gingivitis

Desquamative gingivitis occurs mainly in postmenopausal women. The cause of the disease is not understood. The outer layers of the gums slough off, leaving raw tissue and exposed nerves.

Trench mouth

Trench mouth is an acute, necrotizing (causing tissue death), ulcerating (causing open sores) form of gingivitis. It causes pain in the affected gums. Fever and fatigue are usually present also. Trench mouth, also known as Vincent's disease, is a complication of mild cases of gingivitis. Frequently, poor oral hygiene is the main cause. Stress, an unbalanced diet, or lack of sleep are frequent cofactors in the development of trench mouth. This form of periodontal disease is more common in people who smoke. The term "trench mouth" was created in World War I, when the disease was common in soldiers who lived in the trenches. Symptoms of trench mouth appear suddenly. The initial symptoms include painful gums and foul breath. Gum tissue between teeth becomes infected and dies, and starts to disappear. Often, what appears to be remaining gum is dead tissue. Usually, the gums bleed easily, especially when chewing. The pain can increase to the point where eating and swallowing become difficult. Inflammation or infection from trench mouth can spread to nearby tissues of the face and neck.

Periodontitis

Periodontitis is a condition in which gingivitis has extended down around the tooth and into the supporting bone structure. Periodontitis is also called pyorrhea. Plaque and tarter buildup sometimes lead to the formation of large pockets between the gums and teeth. When this happens, anaerobic bacteria grow in the pockets. The pockets eventually extend down around the roots of the teeth where the bacteria cause damage to the bone structure supporting the teeth. The teeth become loose and tooth loss can result. Some medical conditions are associated with an increased likelihood of developing periodontitis. These diseases include diabetes, Down syndrome, Cohn's disease, AIDS, and any disease that reduces the number of white blood cells in the body for extended periods of time.

Causes and symptoms

Several factors play a role in the development of periodontal disease. The most important are age and oral hygiene. The number and type of bacteria present on the gingival tissues also play a role in the development of periodontal diseases. The presence of certain species of bacteria in large enough numbers in the gingival pocket and related areas correlates with the development of periodontal disease. Also, removal of the bacteria correlates with reduction or elimination of disease. In most cases of periodontal disease, the bacteria remain in the periodontal pocket and do not invade surrounding tissue.

The mechanisms by which bacteria in the periodontal pocket cause tissue destruction in the surrounding region are not fully understood. Several bacterial products that diffuse through tissue are thought to play a role in disease formation. Bacterial endotoxin is a toxin produced by some bacteria that can kill cells. Studies show that the amount of endotoxin present correlates with the severity of periodontal disease. Other bacterial products include proteolytic enzymes, molecules that digest protein found in cells, thereby causing cell destruction. The immune response has also been implicated in tissue destruction. As part of the normal immune response, white blood cells enter regions of inflammation to destroy bacteria. In the process of destroying bacteria, periodontal tissue is also destroyed.

Gingivitis usually results from inadequate oral hygiene. Proper brushing of the teeth and flossing decreases plaque buildup. The bacteria responsible for causing gingivitis reside in the plaque. Plaque is a sticky film that is largely made from bacteria. Tartar is plaque that has hardened. Plaque can turn into tartar in as little as three days if not brushed off. Tartar is difficult to remove by brushing. Gingivitis can be aggravated by hormones, and sometimes becomes temporarily worse during pregnancy, puberty, and when the patient is taking birth control pills. Interestingly, some drugs used to treat other conditions can cause an overgrowth of the gingival tissue that can result in gingivitis because plaque builds up more easily. Drugs associated with this condition are phenytoin, used to treat seizures; cyclosporin, given to organ transplant patients to reduce the likelihood of organ rejection; and calcium blockers, used to treat several different heart conditions. Scurvy, a vitamin C deficiency, and pellagra, a niacin deficiency, can also lead to bleeding gums and gingivitis.

The initial symptoms of periodontitis are bleeding and inflamed gums, and bad breath. Periodontitis follows cases of gingivitis, which may not be severe enough to cause a patient to seek dental help. Although the symptoms of periodontitis are also seen in other forms of periodontal diseases, the key characteristic in periodontitis is a large pocket that forms between the teeth and gums. Another characteristic of periodontitis is that pain usually does not develop until late in the disease, when a tooth loosens or an abscess forms.

Diagnosis

Diagnosis is made by observation of infected gums. Usually, a dentist is the person to diagnose

Healthy gums support the teeth. When gingivitis goes untreated, the gums become weak and pockets form around the teeth. Plaque and tartar build up in the pockets, the gum recedes, and periodontitis occurs.

(Illustration by Argosy Inc.)

and characterize the various types of periodontal disease. In cases such as acute herpetic gingivostomatitis, there are characteristic herpetic lesions. Many of the periodontal diseases are distinguished based on the severity of the infection and the number and type of tissues involved.

Diagnosis of periodontitis includes measuring the size of the pockets formed between the gums and teeth. Normal gingival pockets are shallow. If periodontal disease is severe, jaw bone loss will be detected in x-ray images of the teeth. If too much bone is lost, the teeth become loose and can change position. This will also be seen in x-ray images.

Treatment

Tartar can only be removed by professional dental treatment. Following treatment, periodontal tissues usually heal quickly. Gingivitis caused by vitamin deficiencies is treated by administering the needed vitamin. There are no useful drugs to treat herpetic gingivostomatitis. Because of the pain associated with the herpes lesions, patients may not brush their teeth while the lesions are present. Herpes lesions heal by themselves without treatment. After the herpetic lesions have disappeared, the gums usually return to normal if good oral hygiene is resumed. Pericoronitis is treated by removing debris under the flap of gum covering the molar. This operation is usually performed by a dentist. Surgery is used to remove molars that are not likely to form properly.

Treatment for trench mouth starts with a complete cleaning of the teeth, removal of all plaque, tartar, and dead tissue on the gums. For the first few days after cleaning, the patient uses hydrogen peroxide mouth washes instead of brushing. After cleaning, the gum tissue will be very raw and rinsing minimizes damage to the gums that might be caused by the toothbrush. For the first few days, the patient should visit the dentist daily for checkups and then every second or third day for the next two weeks. Occasionally, antibiotic treatment is used to supplement dental cleaning of the teeth and gums. Surgery may be needed if the damage to the gums is extensive and they do not heal properly.

Key terms

Anaerobic bacteria — Microorganisms that grow in the absence of oxygen.

Inflammation — A painful redness and swelling of an area of tissue in response to infection or injury.

Treatment of periodontitis requires professional dental care. The pockets around the teeth must be cleaned, and all tartar and plaque removed. In periodontitis, tartar and plaque can extend far down the tooth root. Normal dental hygiene, brushing and flossing, cannot reach deep enough to be effective in treating periodontitis. In cases where pockets are very deep (more than 0.25 in [0.64 cm] deep), surgery is required to clean the pocket. This is performed in a dental office. Sections of gum that are not likely to reattach to the teeth may be removed to promote healing by healthy sections of gum. Abscesses are treated with a combination of antibiotics and surgery. The antibiotics may be delivered directly to the infected gum and bone tissues to ensure that high concentrations of the antibiotic reach the infected area. Abscess infections, especially of bone, are difficult to treat and require long term antibiotic treatments to prevent a reoccurrence of infection.

Prognosis

Periodontal diseases can be easily treated. The gums usually heal and resume their normal shape and function. In cases where they do not, prostheses or surgery can restore most of the support for proper functioning of the teeth.

Prevention

Most forms of periodontal disease can be prevented with good dental hygiene. Daily use of a toothbrush and flossing is sufficient to prevent most cases of periodontal disease. Tartar control toothpastes help prevent tartar formation, but do not remove tartar once it has formed.

Resources

Books

Gorbach, S. L., J. G. Bartlett, and N. R. Blacklow. Infectious Diseases. 2nd ed. Philadelphia: W. B. Saunders Co., 1998.

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disease /dis·ease/ (dĭ-zēz´) any deviation from or interruption of the normal structure or function of any body part, organ, or system that is manifested by a characteristic set of symptoms and signs and whose etiology, pathology, and prognosis may be known or unknown. See also entries under syndrome.

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acquired cystic disease of kidney  the development of cysts in the formerly noncystic failing kidney in end-stage renal disease.

Addison's disease  bronzelike pigmentation of the skin, severe prostration, progressive anemia, low blood pressure, diarrhea, and digestive disturbance, due to adrenal hypofunction.

Albers-Schönberg disease  osteopetrosis.

allogeneic disease  graft-versus-host reaction occurring in immunosuppressed animals receiving injections of allogeneic lymphocytes.

Alpers' disease  a rare disease of young children, characterized by neuronal deterioration of the cerebral cortex and elsewhere, progressive mental deterioration, motor disturbances, seizures, and early death.

alpha chain disease  heavy chain disease characterized by plasma cell infiltration of the lamina propria of the small intestine resulting in malabsorption with diarrhea, abdominal pain, and weight loss, possibly accompanied by pulmonary involvement.

Alzheimer's disease  progressive degenerative disease of the brain, of unknown cause; characterized by diffuse atrophy throughout the cerebral cortex with distinctive histopathological changes.

Andersen's disease  glycogen storage d., type IV.

apatite deposition disease  a connective tissue disorder marked by deposition of hydroxyapatite crystals in one or more joints or bursae.

Aran-Duchenne disease  spinal muscular atrophy.

arteriosclerotic cardiovascular disease  (ASCVD) atherosclerotic involvement of arteries to the heart and to other organs, resulting in debility or death; sometimes used specifically for ischemic heart disease.

arteriosclerotic heart disease  (ASHD) ischemic heart d.

autoimmune disease  any of a group of disorders in which tissue injury is associated with humoral or cell-mediated responses to the body's own constituents; they may be systemic or organ-specific.

Ayerza's disease  polycythemia vera with chronic cyanosis, dyspnea, bronchitis, bronchiectasis, hepatosplenomegaly, bone marrow hyperplasia, and pulmonary artery sclerosis.

Banti's disease  congestive splenomegaly.

Barlow disease  scurvy in infants.

Barraquer's disease  partial lipodystrophy.

Basedow's disease  Graves' d.

Batten disease , Batten-Mayou disease

1. Vogt-Spielmeyer d.

2. more generally, any or all of the group of disorders constituting neuronal ceroid lipofuscinosis.

Bayle's disease  general paresis.

Bazin's disease  erythema induratum.

Bekhterev's (Bechterew's) disease  ankylosing spondylitis.

Benson's disease  asteroid hyalosis.

Berger's disease  IgA glomerulonephritis.

Bernhardt's disease , Bernhardt-Roth disease meralgia paresthetica.

Besnier-Boeck disease  sarcoidosis.

Best's disease  congenital macular degeneration.

Bielschowsky-Janský disease  Janský-Bielschowsky d.

Binswanger's disease  a degenerative dementia of presenile onset caused by demyelination of the subcortical white matter of the brain.

black disease  a fatal disease of sheep, and sometimes of humans, in the United States and Australia, due to Clostridium novyi, marked by necrotic areas in the liver.

Blocq's disease  astasia-abasia.

Blount disease  tibia vara.

Boeck's disease  sarcoidosis.

Bornholm disease  epidemic pleurodynia.

Bowen's disease  a squamous cell carcinoma in situ, often due to prolonged exposure to arsenic; usually occurring on sun-exposed areas of skin. The corresponding lesion on the glans penis is termed erythroplasia of Queyrat.

Brill's disease  Brill-Zinsser d.

Brill-Symmers disease  giant follicular lymphoma.

Brill-Zinsser disease  mild recrudescence of epidemic typhus years after the initial infection, because Rickettsia prowazekii has persisted in body tissue in an inactive state, with humans as the reservoir.

broad beta disease  familial dysbetalipoproteinemia; named for the electrophoretic mobility of the abnormal chylomicron and very-low-density lipoprotein remnants produced.

Busse-Buschke disease  cryptococcosis.

Caffey's disease  infantile cortical hyperostosis.

calcium hydroxyapatite deposition disease  apatite deposition d.

calcium pyrophosphate deposition disease  (CPDD) an acute or chronic inflammatory arthropathy caused by deposition of calcium pyrophosphate dihydrate (CPPD) crystals in the joints, chondrocalcinosis, and crystals in the synovial fluid. Acute attacks are sometimes called pseudogout.

Calvé-Perthes disease  osteochondrosis of capitular epiphysis of femur.

Camurati-Engelmann disease  diaphyseal dysplasia.

Canavan disease , Canavan-van Bogaert-Bertrand disease spongy degeneration of the central nervous system.

Carrión's disease  bartonellosis.

Castleman disease  a benign or premalignant condition resembling lymphoma but without recognizable malignant cells; there are isolated masses of lymphoid tissue and lymph node hyperplasia, usually in the abdominal or mediastinal area.

cat-scratch disease  a usually benign, self-limited disease of the regional lymph nodes, caused by Bartonella henselae and characterized by a papule or pustule at the site of a cat scratch, subacute painful regional lymphadenitis, and mild fever.

celiac disease  a malabsorption syndrome precipitated by ingestion of gluten-containing foods, with loss of villous structure of the proximal intestinal mucosa, bulky, frothy diarrhea, abdominal distention, flatulence, weight loss, and vitamin and electrolyte depletion.

Chagas disease  trypanosomiasis due to Trypanosoma cruzi; its course may be acute, subacute, or chronic.

Charcot-Marie-Tooth disease  muscular atrophy of variable inheritance, beginning in the muscles supplied by the peroneal nerves and progressing to those of the hands and arms.

cholesteryl ester storage disease  (CESD) a lysosomal storage disease due to deficiency of lysosomal cholesterol esterase, variably characterized by some combination of hepatomegaly, hyperbetalipoproteinemia, and premature atherosclerosis.

Christmas disease  hemophilia B.

chronic granulomatous disease  frequent, severe infections of the skin, oral and intestinal mucosa, reticuloendothelial system, bones, lungs, and genitourinary tract associated with a genetically determined defect in the intracellular bactericidal function of leukocytes.

chronic obstructive pulmonary disease  (COPD) any disorder marked by persistent obstruction of bronchial air flow.

Coats' disease  exudative retinopathy.

collagen disease  any of a group of diseases characterized by widespread pathologic changes in connective tissue; they include lupus erythematosus, dermatomyositis, scleroderma, polyarteritis nodosa, thrombotic purpura, rheumatic fever, and rheumatoid arthritis. Cf. collagen disorder.

communicable disease  a disease the causative agents of which may pass or be carried from one person to another directly or indirectly.

Concato's disease  progressive malignant polyserositis with large effusions into the pericardium, pleura, and peritoneum.

constitutional disease  one involving a system of organs or one with widespread symptoms.

Cori's disease  glycogen storage d., type III.

coronary artery disease  (CAD) atherosclerosis of the coronary arteries, which may cause angina pectoris, myocardial infarction, and sudden death; risk factors include hypercholesterolemia, hypertension, smoking, diabetes mellitus, and low levels of high-density lipoproteins.

coronary heart disease  (CHD) ischemic heart d.

Cowden disease  a hereditary disease marked by multiple ectodermal, mesodermal, and endodermal nevoid and neoplastic anomalies.

Creutzfeldt-Jakob disease  a rare prion disease existing in sporadic, familial, and infectious forms, with onset usually in middle life, and having a wide variety of clinical and pathological features. The most commonly seen are spongiform degeneration of neurons, neuronal loss, gliosis, and amyloid plaque formation, accompanied by rapidly progressive dementia, myoclonus, motor disturbances, and encephalographic changes, with death occurring usually within a year of onset.

Crigler-Najjar disease  see under syndrome.

Crohn's disease  regional enteritis; a chronic granulomatous inflammatory disease usually in the terminal ileum with scarring and thickening of the wall, often leading to intestinal obstruction and formation of fistulas and abscesses.

Crouzon's disease  craniofacial dysostosis.

Cruveilhier's disease  spinal muscular atrophy.

Cushing's disease  Cushing's syndrome in which the hyperadrenocorticism is secondary to excessive pituitary secretion of adrenocorticotropic hormone.

cystic disease of breast  mammary dysplasia with formation of blue dome cysts.

cytomegalic inclusion disease , cytomegalovirus disease an infection due to cytomegalovirus and marked by nuclear inclusion bodies in enlarged infected cells. In the congenital form, there is hepatosplenomegaly with cirrhosis, and microcephaly with mental or motor retardation. Acquired disease may cause a clinical state similar to infectious mononucleosis. When acquired by blood transfusion, postperfusion syndrome results.

deficiency disease  a condition caused by dietary or metabolic deficiency, including all diseases due to an insufficient supply of essential nutrients.

degenerative joint disease  osteoarthritis.

Dejerine's disease , Dejerine-Sottas disease progressive hypertrophic neuropathy.

demyelinating disease  any condition characterized by destruction of the myelin sheaths of nerves.

disappearing bone disease  gradual resorption of a bone or group of bones, sometimes associated with multiple hemangiomas, usually in children or young adults and following trauma.

diverticular disease  a general term including the prediverticular state, diverticulosis, and diverticulitis.

Duchenne's disease 

1. spinal muscular atrophy.

2. progressive bulbar paralysis.

3. tabes dorsalis.

4. Duchenne's muscular dystrophy.

Duchenne-Aran disease  spinal muscular atrophy.

Duhring's disease  dermatitis herpetiformis.

Dukes' disease  a febrile disease of childhood marked by an exanthematous eruption, probably due to a virus of the Coxsackie-ECHO group.

Durand-Nicolas-Favre disease  lymphogranuloma venereum.

Duroziez's disease  congenital mitral stenosis.

Ebola virus disease  fatal acute hemorrhagic fever resembling Marburg virus disease but caused by Ebola virus, seen in the Sudan and Zaire.

Ebstein's disease  see under anomaly.

end-stage renal disease  chronic irreversible renal failure.

Erb's disease  Duchenne's muscular dystrophy.

Erb-Goldflam disease  myasthenia gravis.

Eulenburg's disease  paramyotonia congenita.

extrapyramidal disease  any of a group of clinical disorders marked by abnormal involuntary movements, alterations in muscle tone, and postural disturbances; they include parkinsonism, chorea, athetosis, etc.

Fabry's disease  an X-linked lysosomal storage disease of glycosphingolipid catabolism resulting from deficiency of α-galactosidase A and leading to accumulation of ceramide trihexoside in the cardiovascular and renal systems.

Farber's disease  a lysosomal storage disease due to defective ceramidase and characterized by hoarseness, aphonia, dermatitis, bone and joint deformities, granulomatous reaction, and psychomotor retardation.

Fazio-Londe disease  a rare type of progressive bulbar palsy occurring in childhood.

Feer disease  acrodynia.

fibrocystic disease of breast  a form of mammary dysplasia with formation of cysts of various size containing a semitransparent, turbid fluid that imparts a brown to blue color to the unopened cysts; believed due to abnormal hyperplasia of the ductal epithelium and dilatation of the ducts of the mammary gland, resulting from exaggeration and distortion of normal menstrual cycle–related breast changes.

fibrocystic disease of the pancreas  cystic fibrosis.

fifth disease  erythema infectiosum.

flint disease  chalicosis.

floating beta disease  familial dysbetalipoproteinemia.

focal disease  a localized disease.

foot-and-mouth disease  an acute, contagious viral disease of wild and domestic cloven-footed animals and occasionally humans, marked by vesicular eruption on the lips, buccal cavity, pharynx, legs, and feet.

Forbes' disease  glycogen storage d., type III.

fourth disease  Dukes' d.

fourth venereal disease  granuloma inguinale.

Fox-Fordyce disease  a persistent and recalcitrant, itchy, papular eruption, chiefly of the axillae and pubes, due to inflammation of apocrine sweat glands.

Freiberg's disease  osteochondrosis of the head of the second metatarsal bone.

Friedländer's disease  endarteritis obliterans.

Friedreich's disease  paramyoclonus multiplex.

functional disease  see under disorder.

Garré's disease  sclerosing nonsuppurative osteomyelitis.

gastroesophageal reflux disease  (GERD) any condition resulting from gastroesophageal reflux, characterized by heartburn and regurgitation; see also reflux esophagitis.

Gaucher's disease  a hereditary disorder of glucocerebroside metabolism, marked by the presence of Gaucher's cells in the marrow, and by hepatosplenomegaly and erosion of the cortices of long bones and pelvis. The adult form is associated with moderate anemia and thrombocytopenia, and yellowish pigmentation of the skin; in the infantile form there is, in addition, marked central nervous system impairment; in the juvenile form there are rapidly progressive systemic manifestations but moderate central nervous system involvement.

genetic disease  a general term for any disorder caused by a genetic mechanism, comprising chromosome aberrations (or anomalies), mendelian (or monogenic or single-gene) disorders, and multifactorial disorders.

gestational trophoblastic disease  see under neoplasia.

Gilbert disease  a familial, benign elevation of bilirubin levels without evidence of liver damage or hematologic abnormalities.

Gilles de la Tourette's disease  see under syndrome.

Glanzmann disease  see thrombasthenia.

glycogen storage disease  any of a number of rare inborn errors of metabolism caused by defects in specific enzymes or transporters involved in the metabolism of glycogen.

type I glucose-6-phosphatase deficiency: a severe hepatorenal form due to deficiency of the hepatic enzyme glucose-6-phosphatase, resulting in liver and kidney involvement, with hepatomegaly, hypoglycemia, hyperuricemia, and gout

type IA glycogen storage d., type I.

type IB a form resembling type I but additionally predisposing to infection due to neutropenia and to chronic inflammatory bowel disease; due to a defect in the transport system for glucose 6-phosphate.

type II a disorder due to deficiency of the lysosomal enzyme α-1,4,-glucosidase, the severe infant form resulting in generalized glycogen accumulation, with cardiomegaly, cardiorespiratory failure, and death, and a milder adult form being a gradual skeletal myopathy that sometimes causes respiratory problems.

type III a form due to deficiency of debrancher enzyme (amylo-1,6-glucosidase) in muscle, liver, or both; defects in the liver enzyme are characterized by hepatomegaly and hypoglycemia while defects in the muscle enzyme are characterized by progressive muscle wasting and weakness.

type IV brancher enzyme deficiency; cirrhosis of the liver, hepatosplenomegaly, progressive hepatic failure, and death due to deficiency of the glycogen brancher enzyme (1,4-α-glucan branching enzyme).

type V muscle cramps and fatigue during exercise due to a defect in the skeletal muscle isozyme of glycogen phosphorylase (muscle phosphorylase).

type VI hepatomegaly, mild to moderate hypoglycemia and mild ketosis, due to deficiency of the liver isozyme of glycogen phosphorylase (hepatic phosphorylase).

type VII muscle weakness and cramping after exercise due to deficiency of the muscle isozyme of 6-phosphofructokinase.

type VIII phosphorylase .

graft-versus-host (GVH) disease  disease caused by the immune response of histoincompatible, immunocompetent donor cells against the tissue of immunocompromised host, as a complication of bone marrow transplantation, or as a result of maternal-fetal blood transfusion, or therapeutic transfusion to an immunocompromised recipient.

Graves' disease  an association of hyperthyroidism, goiter, and exophthalmos, with accelerated pulse rate, profuse sweating, nervous symptoms, psychic disturbances, emaciation, and elevated basal metabolism.

Greenfield's disease  former name for the late infantile form of metachromatic leukodystrophy.

Gull's disease  atrophy of the thyroid gland with myxedema.

Günther disease  congenital erythropoietic porphyria.

H disease  Hartnup d.

Hailey-Hailey disease  benign familial pemphigus.

Hallervorden-Spatz disease  an autosomal recessive disorder caused by decreased numbers of myelin sheaths of the globus pallidus and substantia nigra, with accumulation of iron pigment, progressive rigidity beginning in the legs, choreoathetoid movements, dysarthria, and mental deterioration.

Hand's disease  Hand-Schüller-Christian d.

hand-foot-and-mouth disease  a mild, highly infectious viral disease of children, with vesicular lesions in the mouth and on the hands and feet.

Hand-Schüller-Christian disease  a chronic, progressive form of multifocal Langerhans cell histiocytosis, sometimes with accumulation of cholesterol, characterized by the triad of calvarial bone defects, exophthalmos, and diabetes insipidus.

Hansen's disease  leprosy.

Hartnup disease  a hereditary disorder of intestinal and renal transport of neutral α-amino acids, marked by a pellagra-like skin rash, with transient cerebellar ataxia, constant renal aminoaciduria, and other biochemical abnormalities.

Hashimoto's disease  a progressive disease of the thyroid gland with degeneration of its epithelial elements and replacement by lymphoid and fibrous tissue.

heavy chain diseases  a group of malignant neoplasms of lymphoplasmacytic cells marked by the presence of immunoglobulin heavy chains or heavy chain fragments; they are classified according to heavy chain type, e.g., alpha chain disease.

Heine-Medin disease  the major form of poliomyelitis.

hemoglobin disease  any of various hereditary molecular diseases characterized by abnormal hemoglobins in the red blood cells; the homozygous form is manifested by hemolytic anemia.

hemolytic disease of the newborn  erythroblastosis fetalis.

hemorrhagic disease of the newborn  a self-limited hemorrhagic disorder of the first few days of life, due to deficiency of vitamin K–dependent coagulation factors II, VII, IX, and X.

Hers' disease  glycogen storage d., type VI.

Heubner-Herter disease  the infantile form of celiac disease.

hip-joint disease  tuberculosis of the hip joint.

Hippel's disease  von Hippel's d.

Hirschsprung's disease  congenital megacolon.

His disease , His-Werner disease trench fever.

Hodgkin's disease  a form of malignant lymphoma marked clinically by painless, progressive enlargement of lymph nodes, spleen, and general lymphoid tissue; other symptoms may include anorexia, lassitude, weight loss, fever, pruritus, night sweats, and anemia. Reed-Sternberg cells are characteristically present. Four types have been distinguished on the basis of histopathologic criteria.

hoof-and-mouth disease  foot-and-mouth d.

hookworm disease  infection with the hookworm Ancylostoma duodenale or Necator americanus, whose larvae enter the body through the skin or in contaminated food or water and migrate to the small intestine where, as adults, they attach to the mucosa and ingest blood; symptoms may include abdominal pain, diarrhea, colic or nausea, and anemia.

hyaline membrane disease  a type of respiratory distress syndrome of the newborn in which there is formation of a hyaline-like membrane lining the terminal respiratory passages; extensive atelectasis is attributed to lack of surfactant.

hydatid disease  an infection, usually of the liver, due to larval forms of tapeworms of the genus Echinococcus, marked by development of expanding cysts.

hypophosphatemic bone disease  an inherited disorder resembling a mild form of X-linked hypophosphatemia, similarly due to a defect in renal tubular function but usually showing osteomalacia without radiographic evidence of rickets.

immune complex disease  local or systemic disease caused by the formation of circulating immune complexes and their deposition in tissue, due to activation of complement and to recruitment and activation of leukocytes in type III hypersensitivity reactions.

infectious disease  one due to organisms ranging in size from viruses to parasitic worms; it may be contagious in origin, result from nosocomial organisms, or be due to endogenous microflora from the nose and throat, skin, or bowel.

inflammatory bowel disease  any idiopathic inflammatory disease of the bowel, such as Crohn's disease and ulcerative colitis.

intercurrent disease  one occurring during the course of another disease with which it has no connection.

iron storage disease  hemochromatosis.

ischemic bowel disease  ischemic colitis.

ischemic heart disease  (IHD) any of a group of acute or chronic cardiac disabilities resulting from insufficient supply of oxygenated blood to the heart.

Janský-Bielschowsky disease  the late infantile form of neuronal ceroid lipofuscinosis, occurring between two and four years of age, characterized by abnormal accumulation of lipofuscin; beginning as myoclonic seizures and progressing to neurologic and retinal deterioration and death by age 8 to 12.

jumping disease  any of several culture-specific disorders characterized by exaggerated responses to small stimuli, muscle tics including jumping, obedience even to dangerous suggestions, and sometimes coprolalia or echolalia.

juvenile Paget disease  hyperostosis corticalis deformans juvenilis.

Kashin-Bek (Kaschin-Beck) disease  a disabling degenerative disease of the peripheral joints and spine, endemic in northeastern Asia; believed to be caused by ingestion of cereal grains infected with the fungus Fusarium sporotrichiella.

Katayama disease  schistosomiasis japonica.

Kawasaki disease  a febrile illness usually affecting infants and young children, with conjunctival injection, changes to the oropharyngeal mucosa, changes to the peripheral extremities including edema, erythema, and desquamation, a primarily truncal polymorphous exanthem, and cervical lymphadenopathy. It is often associated with vasculitis of the large coronary vessels.

Kienböck's disease  slowly progressive osteochondrosis of the lunate bone; it may affect other wrist bones.

kinky hair disease  Menkes' syndrome.

Köhler's bone disease 

1. osteochondrosis of the tarsal navicular bone in children.

2. thickening of the shaft of the second metatarsal bone and changes about its articular head, with pain in the second metatarsophalangeal joint on walking or standing.

Krabbe's disease  a lysosomal storage disease beginning in infancy, due to deficiency of β-galactosidase. Pathologically, there is rapidly progressive cerebral demyelination and large globoid bodies (swollen with accumulated cerebroside) in the white substance.

Kufs' disease  the adult form of neuronal ceroid lipofuscinosis, with onset prior to age 40; characterized by progressive neurologic deterioration but not blindness, excessive storage of lipofuscin, and shortened life expectancy;

Kümmell's disease  compression fracture of vertebra, with symptoms a few weeks after injury, including spinal pain, intercostal neuralgia, lower limb motor disturbances, and kyphosis.

Kyasanur Forest disease  a fatal viral disease of monkeys in the Kyasanur Forest of India, communicable to humans, in whom it produces hemorrhagic symptoms.

Kyrle's disease  a chronic disorder of keratinization marked by keratotic plugs that develop in hair follicles and eccrine ducts, penetrating the epidermis and extending down into the corium, causing foreign-body reaction and pain.

Lafora's disease  see under epilepsy.

Leber's disease 

1. Leber's hereditary optic neuropathy.

2. Leber's congenital amaurosis.

legionnaires' disease  an often fatal bacterial infection caused by Legionella pneumophila, not spread by person-to-person contact, characterized by high fever, gastrointestinal pain, headache, and pneumonia; there may also be involvement of the kidneys, liver, and nervous system.

Leiner's disease  a disorder of infancy characterized by generalized seborrhea-like dermatitis and erythroderma, severe intractable diarrhea, recurrent infections, and failure to thrive.

Leriche disease  post-traumatic osteoporosis.

Letterer-Siwe disease  a Langerhans cell histiocytosis of early childhood, of autosomal recessive inheritance, characterized by cutaneous lesions resembling seborrheic dermatitis, hemorrhagic tendency, hepatosplenomegaly, lymphadenitis, and progressive anemia. If untreated it is rapidly fatal. Called also acute disseminated Langerhans cell histiocytosis.

Libman-Sacks disease  see under endocarditis.

Lindau's disease , Lindau-von Hippel disease von Hippel-Lindau d.

Little's disease  congenital spastic stiffness of the limbs, a form of cerebral palsy due to lack of development of the pyramidal tracts.

Lobstein's disease  see osteogenesis imperfecta.

Lou Gehrig disease  amyotrophic lateral sclerosis.

Lowe disease  oculocerebrorenal syndrome.

Lutz-Splendore-Almeida disease  paracoccidioidomycosis.

Lyme disease  a recurrent multisystemic disorder caused by the spirochete Borrelia burgdorferi, the vectors being the ticks Ixodes scapularis and I. pacificus; usually initially characterized by lesions of erythema chronicum migrans, followed by various manifestations including arthritis of the large joints, myalgia, and neurologic and cardiac abnormalities.

lysosomal storage disease  an inborn error of metabolism with (1) a defect in a specific lysosomal enzyme; (2) intracellular accumulation of an unmetabolized substrate; (3) clinical progression affecting multiple tissues or organs; (4) considerable phenotypic variation within a disease.

MAC disease  complex d.

McArdle disease  glycogen storage d., type V.

mad cow disease  bovine spongiform encephalopathy.

Madelung's disease 

1. see under deformity.

2. see under neck.

maple bark disease  hypersensitivity pneumonitis in logging and sawmill workers due to inhalation of spores of a mold, Cryptostroma corticale, growing under the maple bark.

maple syrup urine disease  (MSUD) a hereditary enzyme defect in metabolism of branched chain amino acids, marked clinically by mental and physical retardation, severe ketoacidosis, feeding difficulties, and a characteristic maple syrup odor in the urine and on the body.

Marburg virus disease  a severe, often fatal, viral hemorrhagic fever first reported in Marburg, Germany, among laboratory workers exposed to African green monkeys.

Marchiafava-Micheli disease  paroxysmal nocturnal hemoglobinuria.

Marie-Bamberger disease  hypertrophic pulmonary osteoarthropathy.

Marie-Strümpell disease  ankylosing spondylitis.

Marie-Tooth disease  Charcot-Marie-Tooth d.

Mediterranean disease  thalassemia major.

medullary cystic disease  familial juvenile nephronophthisis.

Meniere's disease  deafness, tinnitus, and dizziness, in association with nonsuppurative disease of the labyrinth.

mental disease  see under disorder.

Merzbacher-Pelizaeus disease  Pelizaeus-Merzbacher d.

metabolic disease  one caused by a disruption of a normal metabolic pathway because of a genetically determined enzyme defect.

Meyer's disease  adenoid vegetations of the pharynx.

Mikulicz's disease  benign, self-limited lymphocytic infiltration and enlargement of the lacrimal and salivary glands of uncertain etiology.

Milroy disease  hereditary permanent lymphedema of the legs due to lymphatic obstruction.

Minamata disease  a severe neurologic disorder due to alkyl mercury poisoning, with permanent neurologic and mental disabilities or death; once prevalent among those eating contaminated seafood from Minamata Bay, Japan.

minimal change disease  subtle alterations in kidney function demonstrable by clinical albuminuria and the presence of lipid droplets in cells of the proximal tubules, seen primarily in young children.

mixed connective tissue disease  a combination of scleroderma, myositis, systemic lupus erythematosus, and rheumatoid arthritis, and marked serologically by the presence of antibody against extractable nuclear antigen.

Möbius disease  ophthalmoplegic migraine.

molecular disease  any disease in which the pathogenesis can be traced to a single molecule, usually a protein, which is either abnormal in structure or present in reduced amounts.

Mondor's disease  phlebitis affecting the large subcutaneous veins normally crossing the lateral chest wall and breast from the epigastric or hypochondriac region to the axilla.

Monge's disease  chronic mountain sickness.

Morquio's disease , Morquio-Ullrich disease see under syndrome.

motor neuron disease , motor system disease any disease of a motor neuron, including spinal muscular atrophy, progressive bulbar paralysis, amyotrophic lateral sclerosis, and lateral sclerosis.

Mycobacterium avium complex disease  MAC disease; systemic disease caused by infection with organisms of the Mycobacterium avium-intracellulare complex in patients with human immunodeficiency virus infection.

Newcastle disease  a viral disease of birds, including domestic fowl, transmissible to humans, characterized by respiratory, gastrointestinal or pulmonary, and encephalitic symptoms.

new variant Creutzfeldt-Jakob disease  (nvCJD) a variant of Creutzfeldt-Jakob disease having a younger age of onset than is seen in Creutzfeldt-Jakob disease, and caused by the same agent that causes bovine spongiform encephalopathy.

Nicolas-Favre disease  lymphogranuloma venereum.

Niemann's disease , Niemann-Pick disease a lysosomal storage disease due to sphingomyelin accumulation in the reticuloendothelial system; there are five types distinguished by age of onset, amount of central nervous system involvement, and degree of enzyme deficiency.

nil disease  minimal change d.

Norrie's disease  an X-linked disorder consisting of bilateral blindness from retinal malformation, mental retardation, and deafness.

notifiable disease  one required to be reported to federal, state, or local health officials when diagnosed, because of infectiousness, severity, or frequency of occurrence.

oasthouse urine disease  methionine malabsorption syndrome.

obstructive small airways disease  chronic bronchitis with irreversible narrowing of the bronchioles and small bronchi with hypoxia and often hypercapnia.

occupational disease  disease due to various factors involved in one's employment.

Oguchi's disease  a form of hereditary night blindness and fundus discoloration following light adaptation.

organic disease  one associated with demonstrable change in a bodily organ or tissue.

Osgood-Schlatter disease  osteochondrosis of the tuberosity of the tibia.

Osler's disease 

1. polycythemia vera.

2. hereditary hemorrhagic telangiectasia.

Owren's disease  parahemophilia.

Paget's disease 

1. (of bone) osteitis deformans.

2. (of breast) an intraductal inflammatory carcinoma of the breast, involving the areola and nipple.

3. an extramammary counterpart of Paget's disease (2), usually involving the vulva, and sometimes other sites, as the perianal and axillary regions.

Parkinson's disease  a slowly progressive form of parkinsonism, usually seen late in life, marked by masklike facies, tremor of resting muscles, slowing of voluntary movements, festinating gait, peculiar posture, muscular weakness, and sometimes excessive sweating and feelings of heat.

Parrot's disease  see under pseudoparalysis.

parrot disease  psittacosis.

Parry's disease  Graves' d.

Pelizaeus-Merzbacher disease  a progressive familial form of leukoencephalopathy, marked by nystagmus, ataxia, tremor, parkinsonian facies, dysarthria, and mental deterioration.

Pellegrini's disease , Pellegrini-Stieda disease calcification of the medial collateral ligament of the knee due to trauma.

pelvic inflammatory disease  (PID) any pelvic infection involving the upper female genital tract beyond the cervix.

periodontal disease  any disease or disorder of the periodontium.

Perthes' disease  osteochondrosis of capitular femoral epiphysis.

Peyronie's disease  induration of the corpora cavernosa of the penis, producing a painful fibrous chordee and penile curvature.

Pfeiffer's disease  infectious mononucleosis.

Pick's disease 

1. progressive atrophy of the cerebral convolutions in a limited area (lobe) of the brain, with clinical manifestations and course similar to Alzheimer's disease.

2. Niemann-Pick d.

polycystic kidney disease , polycystic disease of kidneys either of two unrelated heritable disorders marked by cysts in both kidneys: the autosomal dominant or adult form is more common, appears in adult life, and is marked by loss of renal function that can be either rapid or slow; the autosomal recessive or infantile form is more rare, may be congenital or may appear later in childhood, and almost always progresses to renal failure.

polycystic renal disease  polycystic kidney d..

Pompe's disease  glycogen storage d., type II.

Pott's disease  spinal tuberculosis.

primary electrical disease  serious ventricular tachycardia, and sometimes ventricular fibrillation, in the absence of recognizable structural heart disease.

prion disease  any of a group of fatal, transmissible neurodegenerative diseases, which may be sporadic, familial, or acquired, caused by abnormalities of prion protein metabolism resulting from mutations in the prion protein gene or from infection with pathogenic forms of the protein.

pulseless disease  Takayasu's arteritis.

Raynaud's disease  a primary or idiopathic vascular disorder, most often affecting women, marked by bilateral attacks of Raynaud's phenomenon.

Recklinghausen's disease 

1. neurofibromatosis.

2. (of bone) osteitis fibrosa cystica generalisata.

Refsum's disease  an inherited disorder of lipid metabolism, characterized by accumulation of phytanic acid, chronic polyneuritis, retinitis pigmentosa, cerebellar ataxia, and persistent elevation of protein in cerebrospinal fluid.

remnant removal disease  familial dysbetalipoproteinemia.

reversible obstructive airway disease  a condition characterized by bronchospasm reversible by intervention, as in asthma.

rheumatic heart disease  the most important manifestation and sequel to rheumatic fever, consisting chiefly of valvular deformities.

rheumatoid disease  a systemic condition best known by its articular involvement (rheumatoid arthritis) but emphasizing nonarticular changes, e.g., pulmonary interstitial fibrosis, pleural effusion, and lung nodules.

Ritter's disease  dermatitis exfoliativa neonatorum.

Roger's disease  a ventricular septal defect; the term is usually restricted to small, asymptomatic defects.

runt disease  a graft-versus-host disease produced by immunologically competent cells in a foreign host that is unable to reject them, resulting in gross retardation of host development and in death.

Salla disease  an inherited disorder of sialic acid metabolism characterized by accumulation of sialic acid in lysosomes and excretion in the urine, mental retardation, delayed motor development, and ataxia.

Sandhoff's disease  a type of GM2 gangliosidosis resembling Tay-Sachs disease, seen in non-Jews, marked by a progressively more rapid course, and due to a defect in hexosaminidase, both isozymes A and B.

Schamberg's disease  a slowly progressive purpuric and pigmentary disease of the skin affecting chiefly the shins, ankles, and dorsa of the feet.

Schilder's disease  subacute or chronic leukoencephalopathy in children and adolescents, similar to adrenoleukodystrophy; massive destruction of the white substance of the cerebral hemispheres leads to blindness, deafness, bilateral spasticity, and mental deterioration.

Schönlein's disease  see under purpura.

secondary disease 

1. one subsequent to or as a consequence of another disease.

2. one due to introduction of incompatible, immunologically competent cells into a host rendered incapable of rejecting them by heavy exposure to ionizing radiation.

self-limited disease  one that runs a limited and definite course.

serum disease  see under sickness.

severe combined immunodeficiency disease  (SCID) see under immunodeficiency .

sexually transmitted disease  venereal disease; any of a diverse group of infections transmitted by sexual contact; in some this is the only important mode of transmission, and in others transmission by nonsexual means is possible.

sickle cell disease  any disease associated with the presence of hemoglobin S.

Simmonds' disease  see panhypopituitarism.

sixth disease  exanthema subitum.

small airways disease  chronic obstructive bronchitis with irreversible narrowing of the bronchioles and small bronchi. See also obstructive small airways d.

Smith-Strang disease  methionine malabsorption syndrome.

Spielmeyer-Vogt disease  Vogt-Spielmeyer d.

Steinert's disease  myotonic dystrophy.

Still's disease  juvenile rheumatoid arthritis.

storage disease  a metabolic disorder in which a specific substance (a lipid, a protein, etc.) accumulates in certain cells in unusually large amounts.

storage pool disease  a blood coagulation disorder due to failure of the platelets to release adenosine diphosphate (ADP) in response to aggregating agents; characterized by mild bleeding episodes, prolonged bleeding time, and reduced aggregation response to collagen or thrombin.

Strümpell's disease 

1. hereditary lateral sclerosis with the spasticity mainly limited to the legs.

2. cerebral poliomyelitis.

Strümpell-Leichtenstern disease  hemorrhagic encephalitis.

Strümpell-Marie disease  ankylosing spondylitis.

Sutton's disease 

1. halo nevus.

2. periadenitis mucosa necrotica recurrens.

3. granuloma fissuratum.

Swift's disease , Swift-Feer disease acrodynia.

Takayasu's disease  see under arteritis .

Tangier disease  a familial disorder characterized by a deficiency of high-density lipoproteins in the blood serum, with storage of cholesteryl esters in tissues.

Tarui's disease  glycogen storage d., type VII.

Tay-Sachs disease  (TSD) the most common GM2 gangliosidosis, seen almost exclusively in northeastern European Jews, characterized by infantile onset, doll-like facies, cherry-red macular spot, early blindness, hyperacusis, macrocephaly, seizures, hypotonia, and death in early childhood.

Thomsen's disease  myotonia congenita.

thyrotoxic heart disease  heart disease associated with hyperthyroidism, marked by atrial fibrillation, cardiac enlargement, and congestive heart failure.

transmissible neurodegenerative disease  prion d..

trophoblastic disease  gestational trophoblastic neoplasia.

tsutsugamushi disease  scrub typhus.

tunnel disease  decompression sickness.

uremic bone disease  renal osteodystrophy.

venereal disease  sexually transmitted d.

venoocclusive disease of the liver  symptomatic occlusion of the small hepatic venules caused by ingestion of Senecio tea or related substances, by certain chemotherapy agents, or by radiation.

vinyl chloride disease  acro-osteolysis resulting from exposure to vinyl chloride, characterized by Raynaud's phenomenon and skin and bony changes on the limbs.

Vogt-Spielmeyer disease  the juvenile form of neuronal ceroid lipofuscinosis with onset between ages 5 and 10 years; characterized by rapid cerebroretinal degeneration, excessive neuronal storage of lipofuscin, and death within 10 to15 years.

Volkmann's disease  congenital deformity of the foot due to tibiotarsal dislocation.

von Hippel's disease  hemangiomatosis confined principally to the retina; when associated with hemangioblastoma of the cerebellum, it is known as von Hippel-Lindau d.

von Hippel-Lindau disease  a hereditary condition marked by hemangiomas of the retina and hemangioblastomas of the cerebellum, sometimes with similar lesions of the spinal cord and cysts of the viscera; there may be neurologic symptoms such as seizures and mental retardation.

von Willebrand's disease  an autosomal dominant bleeding disorder characterized by prolonged bleeding time, deficiency of von Willebrand's factor, and often impairment of adhesion of platelets on glass beads, associated with epistaxis and increased bleeding after trauma or surgery, menorrhagia, and postpartum bleeding.

Waldenström's disease  osteochondrosis of the capitular femoral epiphysis.

Weber-Christian disease  nodular nonsuppurative panniculitis.

Werlhof's disease  idiopathic thrombocytopenic purpura.

Wernicke's disease  see under encephalopathy.

Westphal-Strümpell disease  hepatolenticular degeneration.

Whipple's disease  a malabsorption syndrome marked by diarrhea, steatorrhea, skin pigmentation, arthralgia and arthritis, lymphadenopathy, central nervous system lesions, and infiltration of the intestinal mucosa with macrophages containing PAS-positive material.

Whitmore's disease  melioidosis.

Wilson's disease  an inherited, progressive disorder of copper metabolism, with accumulation of copper in liver, brain, kidney, cornea, and other tissues; it is characterized by cirrhosis in the liver, degenerative changes in the brain, and a pigmented ring at the outer margin of the cornea.

Wolman's disease  a lysosomal storage disease due to deficiency of the lysosomal sterol esterase, occurring in infants, and associated with hepatosplenomegaly, adrenal steatorrhea, calcification, abdominal distention, anemia, and inanition.

woolsorter's disease  inhalational anthrax.

---

periodontal disease,

a pathologic condition of the tissues that support a tooth or teeth, such as an inflammation of the periodontal membrane or periodontal ligament.

---

disease(s) (dizēz´),

n a definite deviation from the normal state characterized by a series of symptoms. Disease may be caused by developmental disturbances, genetic factors, metabolic factors, living agents, or physical, chemical, or radiant energy, or the cause may be unknown.

disease, Adams-Stokes (Adams-Stokes syndrome),

n.pr a disease characterized by a slow and perhaps irregular pulse, vertigo, syncope, occasional pseudoepileptic convulsions, and Cheyne-Stokes respirations.

disease, adaptation (adaptation syndrome),

n the metabolic disorders occurring as a result of adaptation or resistance to severe physical or psychologic stress. See also syndrome, general adaptation.

disease, Addison's,

n.pr a chronic adrenocortical insufficiency caused by bilateral tuberculosis, aplasia, atrophy, or degeneration of the adrenal glands. Symptoms include severe weakness, weight loss, low blood pressure, digestive disturbances, hypoglycemia, lowered resistance to infection, and abnormal pigmentation (bronze color of the skin, with associated melanotic pigmentation of the oral mucosa, especially of the gingival tissues).

disease, adrenocortical,

n the disorders of adrenocortical function, giving rise to Addison's disease, Cushing's syndrome, adrenogenital syndrome, and primary aldosteronism.

disease, Albers-Schönberg,

n.pr See osteopetrosis.

disease, autoallergic,

n See disease, autoimmune.

disease, autoimmune (autoallergic disease, autoimmunization syndrome, chronic hypersensitivity),

n a disease that is believed to be caused in part by reactions of hypersensitivity of the host tissue (antigens). Includes various hemolytic anemias, idiopathic thrombocytopenias, rheumatoid arthritis, systemic lupus erythematosus, glomerulonephritis, scleroderma, Hashimoto's thyroiditis, and Sjögren's syndrome.

disease, Barlow's,

n.pr See scurvy, infantile.

disease, Basedow's,

n.pr See goiter, exophthalmic.

disease, Behçet's,

n.pr See syndrome, Behçet's.

disease, Besnier-Boeck-Schaumann,

n.pr See sarcoidosis.

disease, bleeder's,

n See hemophilia.

disease, blood,

n a disease affecting the hematologic system (e.g., anemia, leukemia, agranulocytosis purpura, infectious mononucleosis). Such a disease often results in lesions of the oral structures, particularly the mucosal surfaces.

disease, Bowen's,

n.pr See carcinoma in situ.

disease, Brill-Symmers,

n.pr See lymphoblastoma, giant follicular.

disease, brittle bone,

n See osteogenesis imperfecta.

disease, Caffey's,

n.pr See hyperostosis, infantile cortical.

disease, Cannon's,

n.pr See nevus, white sponge.

disease, cardiac,

n a disease affecting the heart.

disease, cat-scratch,

n a granulomatous disease caused by
B. henselae that occurs at the site of a scratch or bite of a house cat. Local lesions occur at the site of injury with a regional adenitis that is out of proportion to the primary lesion occurring within 1 to 3 weeks. Systemic symptoms of infection may occur. Diagnosis is confirmed by serologic tests.

Cat-scratch disease.

disease, celiac,

n See celiac sprue.

disease, Cheadle's,

n.pr See scurvy, infantile.

disease, Christmas,

n.pr See hemophilia B.

disease, chronic hypersensitivity,

n See disease, autoimmune.

disease, chronic obstructive pulmonary (COPD),

n a disease marked by decreased expiratory flow rates resulting in increased total lung capacity. Patients with this condition are prone to acute respiratory failure from infections or general anesthesia.

disease, collagen (group disease, visceral angiitis)

(kol´jin),
n a group of diseases affecting the collagenous connective tissue of several organs and systems. These diseases have similar biochemical structural alterations and include rheumatic fever, scleroderma, rheumatoid arthritis, systemic lupus erythematosus, periarteritis, and serum sickness.

diseases, communicable,

n a disease that may be transmitted directly or indirectly to a well person or animal from an infected person or animal. A disease with the capacity for maintenance by natural modes of spread (e.g., by contact, by airborne routes, through drinking water or food, by arthropod vectors).

disease, congenital,

n a disease present at birth, or, more specifically, one that is acquired in utero.

disease, Coxsackie A,

n.pr See herpangina.

disease, Crouzon,

n.pr See syndrome, Crouzon.

disease, Cushing's,

n.pr hypercortisolism that results from an adrenal or pituitary neoplasm. The term
Cushing's syndrome refers to hypercortisolism that is not related to an endogenous process.

disease, cytomegalic inclusion, generalized,

n See disease, salivary gland.

disease, Darier's (keratosis follicularis),

n.pr an apparently genetic dermatologic disease that also involves mucous membranes. The oral lesions are whitish papules of the gingiva, tongue, or palate. It is characterized histologically by the presence of corps ronds.

disease, deficiency,

n a disturbance produced by lack of nutritional or metabolic factors. Used mainly in reference to avitaminosis.

disease, degenerative joint,

n See osteoarthritis.

disease, dermatologic,

n a disease affecting the skin; often accompanied by pathologic manifestations of various mucosal surfaces (e.g., the oral mucosa, genital mucosa, conjunctiva).

disease, end-stage,

n the last phase of an illness, at which point the patient's life is gravely endangered.

disease, Engman's,

n.pr See dermatitis infectiosa eczematoides.

disease, exanthematous

n a group of diseases caused by a number of viruses but having as a prominent feature a skin rash (e.g., smallpox, chickenpox, cowpox, measles, rubella).

disease, familial,

n a disease occurring in several members of the same family. Often used to mean members of the same generation and occasionally used synonymously with hereditary disease.

disease, Feer's,

n.pr See erythredema polyneuropathy and acrodynia.

disease, fibrocystic (mucoviscidosis)

(fī´brōsis´tik mū´kōvis´idō´sis),
n a hereditary defect of most of the exocrine glands in the body, including the salivary glands. The secretion of the affected mucous glands is abnormally viscous.

disease, fifth,

n a viral infection caused by the human parvovirus B19; spread via the upper respiratory tract, this virus impacts on children more strongly than adults. Also called
erythema infectiosum.

disease, Fordyce's,

n.pr See Fordyce granules.

disease, functional,

n a disease that has no observable or demonstrable cause.

disease, Gaucher's

(gôshāz´),
n.pr a constitutional defect in the metabolism of the cerebroside kerasin. This glycoprotein accumulates in the reticuloendothelial system and leads to splenomegaly, hepatomegaly, lymph node enlargement, and bone defects.

disease, graft-versus-host (GVHD),

n a potentially deadly condition resulting from allogenically transplanted hematopoietic cells that reject host cells in the transplant recipient. In early stages, this condition may result in lichenoid and erosive lesions on the oral mucosa.

disease, Graves',

n.pr See goiter, exophthalmic.

disease, hand-foot-and-mouth (aphthous fever, epidemic stomatitis, epizootic stomatitis)

(af´ths),
n primarily a disease of animals caused by a filterable virus that may be transmitted to humans and that occasionally produces symptoms. The human form is characterized by fever, nausea, vomiting, malaise, and ulcerative stomatitis. Skin lesions consisting of vesicles may appear, usually on the palms of the hands and soles of the feet. Spontaneous regression usually occurs within 2 weeks.

Hand, foot, and mouth disease.

disease, Hand-Schūller-Christian (chronic disseminated histiocytosis X),

n.pr a type of cholesterol lipoidosis characterized clinically by defects in membranous bones, exophthalmos, and diabetes insipidus.

disease, Hansen's,

n.pr See leprosy.

disease, heart,

n an abnormal condition of the heart (organic, mechanical, or functional) that causes difficulty.

disease, heart, arteriosclerotic,

n a variety of functional changes of the myocardium that result from arteriosclerosis.

disease, heart, congenital,

n a defective formation of the heart or of the major vessels of the heart.

disease, heart, ischemic

(iskē´mik),
n a heart condition in which an inadequate supply of oxygenated blood reaches the heart, resulting in damage to the heart muscle; it is usually caused by atherosclerosis, a buildup of fatty plaque deposits in the main coronary arteries that leads to narrowing or hardening of the arteries. Symptoms include chest pain or discomfort (angina pectoris), ventricular fibrillation, heart attack (myocardial infarction), or sudden death. Also known as
coronary artery disease and
coronary heart disease.

disease, heart, rheumatic,

n a scarring of the endocardium resulting from involvement in acute rheumatic fever. The process most often involves the mitral valve.

disease, heart, thyrotoxic

n cardiac failure occurring as the result of hyperthyroidism or its superimposition on existing organic heart disease. Thyrotoxicosis is an important cause of auricular fibrillation.

disease, hemoglobin C,

n a disease resulting from an abnormal hemoglobin (hemoglobin C); occurs primarily in African Americans and causes a mild normochromic anemia, target cells, and vague, intermittent arthralgia.

disease, hemolytic, of newborn,

n a hemolysis caused by isoimmune reactions associated with Rh incompatibility or with blood transfusions in which there is an incompatibility of the ABO blood system. Several forms of the disease occur: erythroblastosis fetalis, congenital hemolytic disease, icterus gravis neonatorum, and hydrops fetalis.

disease, hemophilioid

n a hemophilic states (conditions) that clinically resemble hemophilia (e.g., parahemophila, hemophilia B [Christmas disease]).

disease, hemorrhagic, of newborn

(hem´raj´ik),
n a hemorrhagic tendency in newborn infants occurring usually on the third or fourth day of life; believed to be caused by defects of prothrombin and factor VII, resulting from a deficiency of vitamin K.

disease, hereditary,

n a disease transmitted from parent to offspring through genes. Three main types of mendelian heredity are recognized: dominant, recessive, and sex-linked.

disease, hidebound,

n See scleroderma.

disease, Hodgkin,

n.pr See lymphoma, Hodgkin.

disease, hypersensitivity,

n See disease, autoimmune.

disease, iatrogenic

(īat´rjen´ik),
n a disease arising as a result of the actions or words of a health care professional.

disease, idiopathic

n a disease in which the etiology is not recognized or determined.

disease, infectious,

n the pathologic alterations induced in the tissues by the action of microorganisms and/or their toxins. Some infectious diseases involving the oral tissues are herpes zoster, herpetic gingivostomatitis, moniliasis, syphilis, and tuberculosis.

disease, inflammatory neoplastic,

n See granuloma; tumor, inflammatory.

disease, kissing,

n See mononucleosis, infectious.

disease, Langerhans cell (Langerhans cell histiocytosis),

n a group of three diseases identified by an abundance of Langerhans cells–eosinophils combined with histiocytic cells. See also disease, Letterer-Siwe; disease, Hand-Schūller-Christian; and granuloma, eosinophili.

disease, Letterer-Siwe

n.pr (acute disseminated histiocytosis X, nonlipid histiocytosis, nonlipid reticuloendotheliosis), a fatal febrile disease of unknown cause occurring in infants and children; characterized by focal granulomatous lesions of the lymph nodes, spleen, and bone marrow. Results in enlargement of the lymph nodes, spleen, and liver, defects of the flat and long bones, anemia, and sometimes purpura.

disease, lipoid storage (lipoidosis, reticuloendothelial granuloma)

(lip´oid ritik´ylōen´dōthē´lēl gran´ylō´m lipoidō´sis),
n group of diseases in which lipid substances accumulate in the fixed cells of the reticuloendothelial system. Included are Gaucher's disease, Niemann-Pick disease, and the Hand-Schūller-Christian disease complex. Other storage diseases include lipochondrodystrophy (gargoylism) and cerebral sphingolipidosis.

disease, Lobstein's,

n.pr See osteogenesis imperfecta.

disease, macrovascular,

n a disease of the large blood vessels, including the aorta, and coronary arteries. Fatty plaque buildup and thrombosis formation in these vessels may lead to a myocardial infarction, cerebral infarction, and circulation problems in the limbs. It is often a complication of long-term diabetes.

disease, Marie's,

n.pr See acromegaly.

disease, Mediterranean,

n.pr See thalassemia major.

disease, metabolic bone,

n.pl the diseases of the bone which may be attributed to cellular changes or to nutritional deficiencies/excesses brought on by dietary imbalances. These include hyperparathyroidism, osteoporosis, osteomalacia, rickets, and the many diseases associated with an abnormal abundance of Langerhans cells.

disease, Mikulicz'

(mik´ūlich´z),
n.pr a benign hyperplasia of the lymph nodes of the parotid or other salivary glands and/or the lacrimal glands.

disease, Moeller's,

n.pr See scurvy, infantile.

disease, molecule,

n a disease associated with genetically determined abnormalities of protein synthesis at the molecular level.

disease, muscle,

n the pathologic muscle tissue changes that can lead to disease. Such changes reveal few structural alterations, and the highly differentiated contents of muscle fibers tend to react as a whole. The pathologic features that distinguish one muscle disease from another are the age and character of changes within a muscle, distribution of those changes within one or several muscles, presence of inflammatory cells and parasites, and coexistence of pathologic changes in other organs. Muscles undergo a number of degenerative changes. There are alterations in the striation in certain pathologic states caused by cloudy swelling, granular degeneration, waxy or hyaline degeneration, and other cellular modifications such as multiplication of the sarcolemmic nuclei and phagocytosis of muscle fibers.

disease, neuromuscular,

n a condition in which various areas of the central nervous system are affected; results in dysfunction or degeneration of the musculature and disabilities of the organ.

disease, Niemann-Pick

n.pr a congenital, familial disorder occurring mainly in Jewish female infants that terminates fatally before the third year and is characterized by the accumulation of the phospholipid sphingomyelin in the cells of the reticuloendothelial system.

disease, oral, hereditary,

n the heritable defects of oral and paraoral structures (excluding the dentition) without generalized defects; includes ankyloglossia, hereditary gingivofibromatosis, and possibly cleft lip and cleft palate. Many oral and paraoral defects are associated with generalized defects (e.g., Peutz-Jeghers, Franceschetti, Ehlers-Danlos, Pierre Robin, and Sturge-Weber syndromes; hemorrhagic telangiectasia; Crouzon's disease; sickle cell disease; acatalasemia; white spongy nevus; xeroderma pigmentosum; gargoylism; neurofibromatosis; familial amyloidosis; and achondroplasia).

disease, oral manifestations of systemic,

n the lesions in association with systemic disease, often influenced by the local environmental factors within the oral cavity.

disease, organic,

n a disease in which actual structural changes have occurred in the organs or tissues.

disease, Osler's,

n.pr See erythremia.

disease, Owren's,

n.pr See parahemophilia.

disease, Paget's, of bone (osteitis deformans),

n.pr a bone disease characterized by thickening and bowing of the long bones and enlargement of the skull and maxillae. It is represented radiographically by a cotton-wool appearance of the bone and microscopically by a mosaic bone pattern with so-called reversal lines. Hypercementosis and loosening of the teeth may be significant manifestations. Increased serum alkaline phosphatase may be an early finding.

Paget's disease of the bone.

disease, Parkinson's,

n.pr a progressive neurologic disorder for which there is no known cure that is thought to be the result of neuron degeneration in the section of the brain controlling spontaneous movement and balance. The disease causes postural changes, tremors, muscle rigidity, and weakness. Oral manifestations include difficulty in swallowing and excess salivation.

disease, periodic,

n See disorder(s), periodic.

disease, periodontal

n a disturbance of the periodontium. Diseases affecting the periodontium include aggressive and necrotizing types, as well as gingivitis. Etiologic factors may be local or systemic or may involve an interplay between the two. Periodontal diseases may be involved in increasing the risk and course of systemic diseases.

disease, periodontal, etiologic factors of,

n.pl the local and systemic factors, singly or in combination, that initiate periodontal lesions.

disease, periodontal, local factors of,

n.pl the environmental conditions within the oral cavity that initiate, enable, or alter the course of diseases of the periodontium (e.g., calculus, diastemata between teeth, food impaction, prematurities in the centric path of closure, and tongue habits).

disease, peripheral vascular,

n a disease of arteries, veins, and/or lymphatic vessels.

disease, pink,

n See acrodynia.

disease, Pott's,

n.pr a spinal curvature (kyphosis) resulting from tuberculosis.

disease progression,

n the course of the disease within a patient/host from onset to resolution.

disease, psychosomatic

(sī´kōsōmat´ik),
n a disease that appears to have been precipitated or prolonged by emotional stress; manifested largely through the autonomic nervous system. Various conditions may be included (e.g., certain forms of asthma, dermatosis, migraine headache, and hypertension). See also disorder, psychophysiologic, autonomic, and visceral.

disease, Quincke's,

n.pr See edema, angioneurotic.

disease, Rendu-Osler-Weber (ron´doo),

n.pr See telangiectasia, hereditary hemorrhagic.

disease, rheumatic,

n See rheumatism.

disease, rickettsial

(riket´sēl),
n a disease caused by microorganisms of the order Rickettsiales (e.g., Rocky Mountain spotted fever, rickettsialpox, typhus, and Q fever).

disease, Riga-Fede

(rē´g-fā´d), an ulceration of the lingual frenum of infants caused by abrasion by natal or neonatal teeth.

disease, Sainton's,

n.pr See dysplasia, cleidocranial.

disease, salivary gland (generalized cytomegalic inclusion),

n a generalized infection in infants caused by intrauterine or postnatal infection with a cytomegalovirus of the group of herpesviruses. Manifestations include jaundice, purpura, hemolytic anemia, vomiting, diarrhea, chronic eczema, and failure to gain weight.

disease, Schūller's

n.pr See osteoporosis.

disease, Selter's,

n.pr See acrodynia.

disease, sex-linked,

n a hereditary disorder transmitted by the gene that also determines sex (e.g., hemophilia).

disease, sickle cell,

n a hematologic disorder caused by the presence of an abnormal hemoglobin (hemoglobin S) that permits the formation or results in the formation of sickle-shaped red blood cells. Two forms of the disease occur: sickle cell trait and sickle cell anemia. See also anemia, sickle cell; trait, sickle cell.

disease, Simmonds' (pituitary cachexia, hypophyseal cachexia, hypopituitary cachexia),

n.pr a panhypopituitarism resulting from destruction of the pituitary gland, usually from hemorrhage or infarction.

disease, Sturge-Weber-Dimitri (encephalotrigeminal angiomatosis),

n.pr See angiomatosis, Sturge-Weber.

disease susceptibility,

n the degree to which a patient or host is vulnerable to a disease.

disease, Sutton's,

n.pr See periadenitis mucosa necrotica recurrens.

disease, Swift's,

n.pr See acrodynia.

disease, systemic,

n a disease involving the whole body.

disease, Takahara's

n.pr a form of rare progressive oral gangrene occurring in childhood and seen only in Japan. Apparently related to a congenital lack of the enzyme catalase (acatalasemia). Characterized by a mild to severe form of a peculiar type of oral gangrene that may develop at the roots of the teeth or the tonsils. Loss of teeth occurs, with necrosis of the alveolar bone. Patients become symptom free after puberty.

disease, transmissible,

n a disease capable of being transmitted from one individual to another; a disease capable of being maintained in successive passages through a susceptible host, usually under experimental conditions such as by injection. See also disease, communicable.

disease transmission,

n the method by which a disease is passed from one patient or host to another. The three most common methods of transmission are direct contact, aerosols, and vectors, such as insects.

disease, Vaquez'

n.pr See erythremia.

disease vectors,

n.pl the intermediary hosts that carry the disease from one species to another, such as mosquitoes, ticks, and rabid animals.

disease, von Recklinghausen's,

n.pr See hyperparathyroidism; osteitis; generalized fibrosa cystica; and neurofibromatosis.

disease, von Recklinghausen's, of bone

(fōn rek´linghouzenz),
n.pr See hyperparathyroidism; osteitis fibrosa cystica.

disease, von Recklinghausen's, of skin,

n.pr See neurofibromatosis.

disease, von Willebrand's

(fōn vil´ebränts),
n.pr an inherited blood coagulation disorder attributed to a deficiency or malfunction of factor VIII. It may cause prolonged or excessive gingival bleeding.

disease, Weil's (epidemic jaundice)

n.pr an acute febrile disease caused by
Leptospira icterohaemorrhagiae or
L. canicola. Manifestations include fever, petechial hemorrhage, myalgia, renal insufficiency, hepatic failure, and jaundice.

disease, Werlhof's

(verl´hofs),
n.pr See purpura, thrombocytopenic.

diseases, demyelinating

n the diseases that have in common a loss of myelin sheath, with preservation of the axis cylinders (e.g., multiple sclerosis, Schilder's disease).

diseases, dental, hereditary,

n.pl the heritable defects of the dentition without generalized disease, which include amelogenesis imperfecta, dentinogenesis imperfecta, dentinal dysplasia, localized and generalized hypoplasia of enamel, peg-shaped lateral incisors, familial dentigerous cysts, missing teeth, giantism, and fused primary mandibular incisors. Dental defects occurring with generalized disease include dentinogenesis imperfecta with osteogenesis imperfecta, missing teeth with ectodermal dysplasia, enamel hypoplasia with epidermolysis bullosa dystrophica, retarded eruption with cleidocranial dysostosis, missing lateral incisors with ptosis of the eyelids, missing premolars with premature whitening of the hair, and enamel hypoplasia in vitamin D resistant rickets.

diseases, group,

n See disease, collagen.

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periodontal (per´ēōdon´tl),

adj relating to the periodontium.

periodontal abscess,

n a localized area of acute or chronic inflammation found in the gingival tissues, infrabony pockets, or periodontal ligament. If it is located at the apex of the tooth, it is known as a
periapical abscess. If located between the apex and the alveolar crest, it is known as a
lateral abscess.

periodontal atrophy,

n See atrophy, periodontal.

periodontal attachment loss,

n a reduction in the connective tissue attaching the root of the tooth to the alveolar bone, usually caused by persistent inflammation of the gingival and periodontal tissues.

periodontal disease,

n a group of inflammatory and infectious diseases affecting the periodontium of the teeth, with various classes noted.

periodontal disease, aggressive,

n marked by the early onset of periodontal disease that affects the gingiva and periodontal tissues. If untreated, it may result in loss of teeth.

periodontal dressing,

n a protective obtundent covering of the gingival and periodontal tissues used after periodontal surgery.

Aggressive periodontal disease.

periodontal index,

n a method for rating or ranking the severity of periodontal disease. An early index was the PMA, which ranked the number of
papillary,
marginal, and
attached gingiva affected by gingivitis. A more contemporary index is the Russell Periodontal Index (PI), which is based on a 0-to-8 score system: from negative to advanced destruction.

periodontal ligament,

n a system of collagenous connective tissue fibers that attaches the root of a tooth to its alveolus of bone by way of Sharpey's fibers. It contains blood vessels, lymph vessels, and nerves. The ligament consists of five groups of fibers: interdental, alveolar crestal, horizontal, oblique, and apical and possibly interradicular fibers if the tooth is multirooted.

periodontal pack,

n See pack, periodontal.

periodontal pocket,

n See pocket, periodontal.

periodontal probe,

n See probe, periodontal.

periodontal prosthesis,

n See prosthesis, periodontal.

Periodontal Screening and Recording (PSR),

n.pr a proprietary method of briefly examining all of a patient's teeth, and recording the highest score in each of six regions of the oral cavity (mid-, mesio-, and distofacial and corresponding lingual areas). The process utilizes a blunt-tipped probe instrument and is intended to take only 2 to 3 minutes.

periodontal therapy,

n See therapy, periodontal.

periodontal treatment planning,

n the sequential arrangement of therapeutic procedures required to obtain a healthy periodontium.

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periodontal

around a tooth; pertaining to the periodontium.

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periodontal abscess

a localized, acute infection that may drain into the gingival pocket or directly through the gum. There is often local bone destruction. See also malar abscess.

periodontal charting

recording the periodontal indices in dental records.

periodontal disease

any disease or disorder of the periodontium. See also periodontitis and periodontosis.

periodontal fibrous hyperplasia

see periodontal fibromatous epulis.

periodontal indices

indicators of periodontal health; includes amount of plaque and calculus, changes in the gingiva, probing depth, evaluation of attachment, and grade of mobility.

periodontal ligament

the connective tissue that occupies the space between each tooth and its socket and that suspends the tooth.

periodontal pocket

a deep space between the gingiva and the crown or root of a tooth. It can be the result of hyperplasia of the gingiva (false pocket) or migration of the epithelial attachment toward the apex (true pocket).

periodontal probe

a dental instrument used to measure the depth of the periodontal pocket.

periodontal pseudopocket

gingival hyperplasia or swelling may be responsible for increased sulcus depth but the periodontal membrane and alveolar bone are normal.

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periodontal disease

Dentistry Any disease of the periodontium–eg, chronic gingivitis, extension of infection into periodontal ligaments and alveolar bone destruction; PD is the most common cause of loss of teeth in adults, the result of combined bacterial infection and impaired host response; 300 different bacterial spp occur in healthy mouths; most are gram-positive–eg, actinomyces and streptococci; in gingivitis, oral flora changes, streptococci ↓, actinomyces ↑, Fusobacterium nucleatum, Lactobacillus, Veillonella, Treponema spp, Actinobacillus actinomycetemcomitans, Bacteroides gingivalis DiffDx Hypophosphatasia, Langerhans' cell histiocytosis–histiocytosis X, leukemia, vitamin C and/or vitamin D deficiencies