Ivory, or dentine, is the hard material which forms the chief bulk of the TEETH.
Both HIV-1 and HIV-2 are predominantly sexually transmitted and both are associated with secondary opportunistic infections. However, HIV-2 seems to result in slower damage to the immune system. HIV-1 is known to mutate rapidly and has given rise to other subtypes.
HIV is thought to have occurred in humans in the 1950s, but whether or not it infected humans from another primate species is uncertain. It became widespread in the 1970s but its latency in causing symptoms meant that the epidemic was not noticed until the following decade. Although it is a sexually transmitted disease, it can also be transmitted by intravenous drug use (through sharing an infected needle), blood transfusions with infected blood (hence the importance of e?ective national blood-screening programmes), organ donation, and occupationally (see health-care workers, below). Babies born of HIV-positive mothers can be infected before or during birth, or through breast feeding.
Although HIV is most likely to occur in blood, semen or vaginal ?uid, it has been found in saliva and tears (but not sweat); however, there is no evidence that the virus can be transmitted from these two body ?uids. There is also no evidence that HIV can be transmitted by biting insects (such as mosquitoes). HIV does not survive well in the environment and is rapidly destroyed through drying.
Prevalence At the end of 2003 an estimated 42 million people globally were infected with HIV – up from 40 million two years earlier. About one-third of those with HIV/AIDS are aged 15–24 and most are unaware that they are carrying the virus. During 2003 it is estimated that 5 million adults and children worldwide were newly infected with HIV, and that 3 million adults and children died. In Africa in 2003,
3.4 million people were newly infected and 2.3 million died, with more than 28 million carrying the virus. HIV/AIDS was the leading cause of death in sub-Saharan Africa where over half of the infections were in women and 90 per cent of cases resulted from heterosexual sex. In some southern African countries, one in three pregnant women had HIV.
In Asia and the Paci?c there were 1.2 million new infections and 435,000 deaths. The area with the fastest-growing epidemic is Eastern Europe, especially the Russian Federation where in 2002 around a million people had HIV and there were an estimated 250,000 new infections, with intravenous drug use a key contributor to this ?gure. Seventy-?ve per cent of cases occurred in men, with male-to-male sexual transmission an important cause of infection, though heterosexual activity is a rising cause of infection.
At the end of 2002 the UK had an estimated 55,900 HIV-infected adults aged between 15 and 59. More than 3,600 individuals were newly diagnosed with the infection in 2000, the highest annual ?gure since the epidemic started
– in 1998 the ?gure was 2,817 and in 1999 just over 3,000 (Department of Health and Communicable Disease Surveillance Centre). The incidence of AIDS in the UK has declined sharply since the introduction of highly active antiretroviral therapy (HAART) and HIV-related deaths have also fallen: in 2002 there were 777 reported new AIDS cases and 395 deaths, compared with 1,769 and 1,719 respectively in 1995. (Sources: UNAIDS and WHO, AIDS Epidemic Update, December 2001; Public Health Laboratory Services AIDS and STD Centre Communicable Disease Surveillance and Scottish Centre for Infection and Environmental Health, Quarterly Surveillance Tables.)
Poverty is strongly linked to the spread of AIDS, for various reasons including lack of health education; lack of e?ective public-health awareness; women having little control over sexual behaviour and contraception; and, by comparison with the developed world, little or no access to antiretroviral drugs.
Pathogenesis The cellular target of HIV infection is a subset of white blood cells called T-lymphocytes (see LYMPHOCYTE) which carry the CD4 surface receptor. These so-called ‘helper T-cells’ are vital to the function of cell-mediated immunity. Infection of these cells leads to their destruction (HIV replicates at an enormous rate – 109) and over the course of several years the body is unable to generate suf?cient new cells to keep pace. This leads to progressive destruction of the body’s immune capabilities, evidenced clinically by the development of opportunistic infection and unusual tumours.
Monitoring of clinical progression It is possible to measure the number of viral particles present in the plasma. This gives an accurate guide to the likely progression rate, which will be slow in those individuals with fewer than 10,000 particles per ml of plasma but progressively more rapid above this ?gure. The main clinical monitoring of the immune system is through the numbers of CD4 lymphocytes in the blood. The normal count is around 850 cells per ml and, without treatment, eventual progression to AIDS is likely in those individuals whose CD4 count falls below 500 per ml. Opportunistic infections occur most frequently when the count falls below 200 per ml: most such infections are treatable, and death is only likely when the CD4 count falls below 50 cells per ml when infection is developed with organisms that are di?cult to treat because of their low intrinsic virulence.
Simple, cheap and highly accurate tests are available to detect HIV antibodies in the serum. These normally occur within three months of infection and remain the cornerstone of the diagnosis.
Clinical features Most infected individuals have a viral illness some three weeks after contact with HIV. The clinical features are often non-speci?c and remain undiagnosed but include a ?ne red rash, large lymph nodes, an in?uenza-like illness, cerebral involvement and sometimes the development of opportunistic infections. The antibody test may be negative at this stage but there are usually high levels of virus particles in the blood. The antibody test is virtually always positive within three months of infection. HIV infection is often subsequently asymptomatic for a period of ten years or more, although in most patients progressive immune destruction is occurring during this time and a variety of minor opportunistic infections such as HERPES ZOSTER or oral thrush (see CANDIDA) do occur. In addition, generalised LYMPHADENOPATHY is present in a third of patients and some suffer from severe malaise, weight loss, night sweats, mild fever, ANAEMIA or easy bruising due to THROMBOCYTOPENIA.
The presentation of opportunistic infection is highly variable but usually involves either the CENTRAL NERVOUS SYSTEM, the gastrointestinal tract or the LUNGS. Patients may present with a sudden onset of a neurological de?cit or EPILEPSY due to a sudden onset of a STROKE-like syndrome, or epilepsy due to a space-occupying lesion in the brain – most commonly TOXOPLASMOSIS. In late disease, HIV infection of the central nervous system itself may produce progressive memory loss, impaired concentration and mental slowness called AIDS DEMENTIA. A wide variety of opportunistic PROTOZOA or viruses produces DYSPHAGIA, DIARRHOEA and wasting. In the respiratory system the commonest opportunistic infection associated with AIDS, pneumonia, produces severe shortness of breath and sometimes CYANOSIS, usually with a striking lack of clinical signs in the chest.
In very late HIV infection, when the CD4 count has fallen below 50 cells per ml, infection with CYTOMEGALOVIRUS may produce progressive retinal necrosis (see EYE, DISORDERS OF) which will lead to blindness if untreated, as well as a variety of gastrointestinal symptoms. At this stage, infection with atypical mycobacteria is also common, producing severe anaemia, wasting and fevers. The commonest tumour associated with HIV is Kaposi’s sarcoma which produces purplish skin lesions. This and nonHodgkin’s lymphoma (see LYMPHOMA), which is a hundred times more frequent among HIV-positive individuals than in the general population, are likely to be associated with or caused by opportunistic viral infections.
Prevention There is, as yet, no vaccine to prevent HIV infection. Vaccine development has been hampered
by the large number of new HIV strains generated through frequent mutation and recombination.
because HIV can be transmitted as free virus and in infected cells.
because HIV infects helper T-cells – the very cells involved in the immune response. There are, however, numerous research pro
grammes underway to develop vaccines that are either prophylactic or therapeutic. Vaccine-development strategies have included: recombinant-vector vaccines, in which a live bacterium or virus is genetically modi?ed to carry one or more of the HIV genes; subunit vaccines, consisting of small regions of the HIV genome designed to induce an immune response without infection; modi?ed live HIV, which has had its disease-promoting genes removed; and DNA vaccines – small loops of DNA (plasmids) containing viral genes – that make the host cells produce non-infectious viral proteins which, in turn, trigger an immune response and prime the immune system against future infection with real virus.
In the absence of an e?ective vaccine, preventing exposure remains the chief strategy in reducing the spread of HIV. Used properly, condoms are an extremely e?ective method of preventing exposure to HIV during sexual intercourse and remain the most important public-health approach to countering the further acceleration of the AIDS epidemic. The spermicide nonoxynol-9, which is often included with condoms, is known to kill HIV in vitro; however, its e?ectiveness in preventing HIV infection during intercourse is not known.
Public-health strategies must be focused on avoiding high-risk behaviour and, particularly in developing countries, empowering women to have more control over their lives, both economically and socially. In many of the poorer regions of the world, women are economically dependent on men and refusing sex, or insisting on condom use, even when they know their partners are HIV positive, is not a straightforward option. Poverty also forces many women into the sex industry where they are at greater risk of infection.
Cultural problems in gaining acceptance for universal condom-use by men in some developing countries suggests that other preventive strategies should also be considered. Microbicides used as vaginal sprays or ‘chemical condoms’ have the potential to give women more direct control over their exposure risk, and research is underway to develop suitable products.
Epidemiological studies suggest that male circumcision may o?er some protection against HIV infection, although more research is needed before this can be an established public-health strategy. Globally, about 70 per cent of infected men have acquired the virus through unprotected vaginal sex; in these men, infection is likely to have occurred through the penis with the mucosal epithelia of the inner surface of the foreskin and the frenulum considered the most likely sites for infection. It is suggested that in circumcised men, the glans may become keratinised and thus less likely to facilitate infection. Circumcision may also reduce the risk of lesions caused by other sexually transmitted disease.
Treatment AIDS/HIV treatment can be categorised as speci?c therapies for the individual opportunistic infections – which ultimately cause death – and highly active antiretroviral therapy (HAART) designed to reduce viral load and replication. HAART is also the most e?ective way of preventing opportunistic infections, and has had a signi?cant impact in delaying the onset of AIDS in HIV-positive individuals in developed countries.
Four classes of drugs are currently in use. Nucleoside analogues, including ZIDOVUDINE and DIDANOSINE, interfere with the activity of the unique enzyme of the retrovirus reverse transcriptase which is essential for replication. Nucleotide analogues, such as tenofovir, act in the same way but require no intracellular activation. Non-nucleoside reverse transcriptase inhibitors, such as nevirapine and EFAVIRENZ, act by a di?erent mechanism on the same enzyme. The most potent single agents against HIV are the protease inhibitors, such as lopinavir, which render a unique viral enzyme ineffective. These drugs are used in a variety of combinations in an attempt to reduce the plasma HIV viral load to below detectable limits, which is achieved in approximately 90 per cent of patients who have not previously received therapy. This usually also produces a profound rise in CD4 count. It is likely, however, that such treatments need to be lifelong – and since they are associated with toxicities, long-term adherence is di?cult. Thus the optimum time for treatment intervention remains controversial, with some clinicians believing that this should be governed by the viral load rising above 10,000 copies, and others that it should primarily be designed to prevent the development of opportunistic infections – thus, that initiation of therapy should be guided more by the CD4 count.
It should be noted that the drug regimens have been devised for infection with HIV-1; it is not known how e?ective they are at treating infection with HIV-2.
HIV and pregnancy An HIV-positive woman can transmit the virus to her fetus, with the risk of infection being particularly high during parturition; however, the risk of perinatal HIV transmission can be reduced by antiviral drug therapy. In the UK, HIV testing is available to all women as part of antenatal care. The bene?ts of antenatal HIV testing in countries where antiviral drugs are not available are questionable. An HIV-positive woman might be advised not to breast feed because of the risks of transmitting HIV via breastmilk, but there may be a greater risk associated with not breast feeding at all. Babies in many poor communities are thought to be at high risk of infectious diseases and malnutrition if they are not breast fed and may thus be at greater overall risk of death during infancy.
Counselling Con?dential counselling is an essential part of AIDS management, both in terms of supporting the psychological wellbeing of the individual and in dealing with issues such as family relations, sexual partners and implications for employment (e.g. for health-care workers). Counsellors must be particularly sensitive to culture and lifestyle issues. Counselling is essential both before an HIV test is taken and when the results are revealed.
Health-care workers Health-care workers may be at risk of occupational exposure to HIV, either through undertaking invasive procedures or through accidental exposure to infected blood from a contaminated needle (needlestick injury). Needlestick injuries are frequent in health care – as many as 600,000 to 800,000 are thought to occur annually in the United States. Transmission is much more likely where the worker has been exposed to HIV through a needlestick injury or deep cut with a contaminated instrument than through exposure of mucous membranes to contaminated blood or body ?uids. However, even where exposure occurs through a needlestick injury, the risk of seroconversion is much lower than with a similar exposure to hepatitis C or hepatitis B. A percutaneous exposure to HIV-infected blood in a health-care setting is thought to carry a risk of about one infection per 300 injuries (one in 1,000 for mucous-membrane exposure), compared with one in 30 for hepatitis C, and one in three for hepatitis B (when the source patient is e-antigen positive).
In the event of an injury, health-care workers are advised to report the incident immediately where, depending on a risk assessment, they may be o?ered post-exposure prophylaxis (PEP). They should also wash the contaminated area with soap and water (but without scrubbing) and, if appropriate, encourage bleeding at the site of injury. PEP, using a combination of antiretroviral drugs (in a similar regimen to HAART – see above), is thought to greatly reduce the chances of seroconversion; it should be commenced as soon as possible, preferably within one or two hours of the injury. Although PEP is available, safe systems of work are considered to o?er the greatest protection. Double-gloving (latex gloves remove much of the blood from the surface of the needle during a needlestick), correct use of sharps containers (for used needles and instruments), avoiding the resheathing of used needles, reduction in the number of blood samples taken from a patient, safer-needle devices (such as needles that self-blunt after use) and needleless drug administration are all thought to reduce the risk of exposure to HIV and other blood-borne viruses. Although there have been numerous cases of health-care workers developing HIV through occupational exposure, there is little evidence of health-care workers passing HIV to their patients through normal medical procedures.... aids/hiv
Habitat: The tropical Himalayas, going up to an altitude of 1,100 m. Also found throughout many forests of India, in Travancore, Assam and Uttar Pradesh.
English: Easter tree, Ivory tree, Tellicherry Bark.Ayurvedic: Kutaja, Girimallikaa, Kaalinga, Kalingaka, Indravrik- sha, Shakra, Vatsa, Vatsaka, Shakraahvya. Indrayava, Indrabija, Vatsabija (seed). Kurchi (bark).Unani: Inderjo talkh, Teewaaj-e- Khataai.Siddha/Tamil: Kudasappaalai-pattai, -vidai (bark, seed).Action: Root and bark—used in amoebic dysentery. Bark—astringent, anthelmintic, amoebicidal, diuretic. Used in colic, dyspepsia, piles, diseases of the skin and spleen. Seed—antibilious. Used for promoting conception, also for toning up vaginal tissues after delivery.
The bark contains the alkaloids, regholarrhenine-A, -B, -C, -D, -E and -F; pubescine, norholadiene, pubes- cimine, kurchinin, kurchinine, kur- chinidine, holarrifine, holadiene, kurchilidine, kurchamide, kurcholes- sine, kurchessine, conessine, cones- simine and isoconessimine, and the steroidal compounds kurchinicin and holadyson.The alkaloid conessine is used as a therapeutic drug for the treatment of dysentery and helminthic disorders. Conessine and conimine inhibited the growth of Shigella sonnei, S. flexneri and Salmonella enteritidis strains in vitro. In chronic amoebiasis, Bi-iodide compound of total alkaloids, given orally, compare favourably with emetine Bi-iodide.The plant possesses potent immuno- stimulant property.The Kurchi seeds are sold as a substitute for Strophanthus sp. seeds in Indian market. (Seeds of Strophanthus sp. contain a toxic glucoside, strophan- thin, and are poisonous.)Dosage: Stem bark—20-30 g for decoction. (API Vol. I); seed—3- 6 g powder; 20-30 g for decoction. (API Vol. III.)... holarrhena antidysentericaHabitat: Throughout India, ascending up to 2,100 m in the hills. (Native to tropical Africa and Madagascar.)
Folk: Amadok (Garhwal).Action: Disinfectant.
The plant is one of the major ingredients of an ointment used in the treatment of skin tumours in Chinese medicine. In Ivory Coast, Burkina Faso, Gabon and Tanganyika, different parts of the plant are used for the treatment of intercostal pain, rheumatic pain and fever. The leaf and root decoctions are used to treat pneumonia.The plant from Nigeria was found rich in phenolic ethers (45%), followed by monoterpenes (22%) and sesquiterpenes (12%). The major component of the oil was dimethyl thy- moquinone (44%). It showed activity against Gram-positive microorganisms. Dried powder of the plant contained artemisetin (artemetin).... laggera alataHabitat: Throughout India as a weed in moist places.
Ayurvedic: Parpata (substitute).Siddha/Tamil: Kodaga-saleh.Folk: Kharmor.Action: Herb—vermifuge, diuretic; dried and pulverized herb is used for cough and fever. Fresh, bruised leaves, mixed with castor oil, are applied to scalp to cure tinea capitis (a scaly fungoid infection).
The flavonoid pigments in ivory- white and pale yellow flowers (the plant also bears blue and pink flowers) showed the presence of luteolin and chrysoerial (3'-O-methyl luteolin) and their glucosides. Deep yellow flowers contain isosalipurposide; the bluish pink flowers showed presence of delphinidin-3,5-diglucoside.... rungia repensStructure Each tooth is composed of enamel, dentine, cement, pulp and periodontal membrane. ENAMEL is the almost translucent material which covers the crown of a tooth. It is the most highly calci?ed material in the body, 96–97 per cent being composed of calci?ed salts. It is arranged from millions of long, six-sided prisms set on end on the dentine (see below), and is thickest over the biting surface of the tooth. With increasing age or the ingestion of abrasive foods the teeth may be worn away on the surface, so that the dentine becomes visible. The outer sides of some teeth may be worn away by bad tooth-brushing technique. DENTINE is a dense yellowish-white material from which the bulk and the basic shape of a tooth are formed. It is like ivory and is harder than bone but softer than enamel. The crown of the tooth is covered by the hard protective enamel and the root is covered by a bone-like substance called cement. Decay can erode dentine faster than enamel (see TEETH, DISORDERS OF – Caries of the teeth). CEMENT or cementum is a thin bone-like material which covers the roots of teeth and helps hold them in the bone. Fibres of the periodontal membrane (see below) are embedded in the cement and the bone. When the gums recede, part of the cement may be exposed and the cells die. Once this has happened, the periodontal membrane can no longer be attached to the tooth and, if su?cient cement is destroyed, the tooth-support will be so weakened that the tooth will become loose. PULP This is the inner core of the tooth and is
composed of a highly vascular, delicate ?brous tissue with many ?ne nerve-?bres. The pulp is very sensitive to temperature variation and to touch. If the pulp becomes exposed it will become infected and usually cannot overcome this. Root-canal treatment or extraction of the tooth may be necessary. PERIODONTAL MEMBRANE This is a layer of ?brous tissue arranged in groups of ?bres which surround and support the root of a tooth in a bone socket. The ?bres are interspersed with blood vessels and nerves. Loss of the membrane leads to loss of the tooth. The membrane can release and re-attach the ?bres to allow the tooth to move when it erupts, or (to correct dental deformities) is being moved by orthodontic springs.
Arrangement and form Teeth are present in most mammals and nearly all have two sets: a temporary or milk set, followed by a permanent or adult set. In some animals, like the toothed whale, all the teeth are similar; but in humans there are four di?erent shapes: incisors, canines (eye-teeth), premolars (bicuspids), and molars. The incisors are chisel-shaped and the canine is pointed. Premolars have two cusps on the crown (one medial to the other) and molars have at least four cusps. They are arranged together in an arch in each jaw and the
cusps of opposing teeth interdigitate. Some herbivores have no upper anterior teeth but use a pad of gum instead. As each arch is symmetrical, the teeth in an upper and lower quadrant can be used to identify the animal. In humans, the quadrants are the same: in other words, in the child there are two incisors, one canine and two molars (total teeth 20); in the adult there are two incisors, one canine, two premolars and three molars (total 32). This mixture of tooth-form suggests that humans are omnivorous. Anatomically the crown of the tooth has mesial and distal surfaces which touch the tooth next to it. The mesial surface is the one nearer to the centre line and the distal is the further away. The biting surface is called the incisal edge for the anterior teeth and the occlusal surface for the posteriors.
Development The ?rst stage in the formation of the teeth is the appearance of a down-growth of EPITHELIUM into the underlying mesoderm. This is the dental lamina, and from it ten smaller swellings in each jaw appear. These become bell-shaped and enclose a part of the mesoderm, the cells of which become specialised and are called the dental papillae. The epithelial cells produce enamel and the dental papilla forms the dentine, cement and pulp. At a ?xed time the teeth start to erupt and a root is formed. Before the deciduous teeth erupt, the permanent teeth form, medial to them. In due course the deciduous roots resorb and the permanent teeth are then able to push the crowns out and erupt themselves. If this process is disturbed, the permanent teeth may be displaced and appear in an abnormal position or be impacted.
Eruption of teeth is in a de?nite order and at a ?xed time, although there may be a few months’ leeway in either direction which is of no signi?cance. Excessive delay is found in some congenital disorders such as CRETINISM. It may also be associated with local abnormalities of the jaws such as cysts, malformed teeth and supernumerary teeth.
The usual order of eruption of deciduous teeth is:
Middle incisors 6–8 months Lateral incisors 8–10 months First molars 12–16 months Canines (eye-teeth) 16–20 months Second molars 20–30 months
The usual order of eruption of permanent teeth is:
First molars 6–7 years Middle incisors 6–8 years Lateral incisors 7–9 years Canines 9–12 years First and second premolars 10–12 years Second molars 11–13 years Third molars (wisdom teeth) 17–21 years
The permanent teeth of the upper (top) and lower (bottom) jaws.
Teeth, Disorders of
Teething, or the process of eruption of the teeth in infants, may be accompanied by irritability, salivation and loss of sleep. The child will tend to rub or touch the painful area. Relief may be obtained in the child by allowing it to chew on a hard object such as a toy or rusk. Mild ANALGESICS may be given if the child is restless and wakens in the night. A serious pitfall is to assume that an infant’s symptoms of ill-health are due to teething, as the cause may be more serious. Fever and ?ts (see SEIZURE) are not due to teething.
Toothache is the pain felt when there is in?ammation of the pulp or periodontal membrane of a tooth (see TEETH – Structure). It can vary in intensity and may be recurring. The commonest cause is caries (see below) when the cavity is close to the pulp. Once the pulp has become infected, this is likely to spread from the apex of the tooth into the bone to form an abscess (gumboil – see below). A lesser but more long-lasting pain is felt when the dentine is unprotected. This can occur when the enamel is lost due to decay or trauma or because the gums have receded. This pain is often associated with temperature-change or sweet foods. Expert dental advice should be sought early, before the decay is extensive. If a large cavity is accessible, temporary relief may be obtained by inserting a small piece of cotton wool soaked, for example, in oil of cloves.
Alveolar abscess, dental abscess or gumboil This is an ABSCESS caused by an infected tooth. It may be present as a large swelling or cause trismus (inability to open the mouth). Treatment is drainage of the PUS, extraction of the tooth and/or ANTIBIOTICS.
Caries of the teeth or dental decay is very common in the more a?uent countries and is most common in children and young adults. Increasing awareness of the causes has resulted in a considerable improvement in dental health, particularly in recent years; this has coincided with a rise in general health. Now more than half of ?ve-year-old children are caries-free and of the others, 10 per cent have half of the remaining carious cavities. Since the start of the National Health Service, the emphasis has been on preventive dentistry, and now edentulous patients are mainly found among the elderly who had their teeth removed before 1948.
The cause of caries is probably acid produced by oral bacteria from dietary carbohydrates, particularly re?ned sugar, and this dissolves part of the enamel; the dentine is eroded more quickly as it is softer (see TEETH – Structure). The exposed smooth surfaces are usually protected as they are easily cleaned during normal eating and by brushing. Irregular and overcrowded teeth are more at risk from decay as they are di?cult to clean. Primitive people who chew coarse foods rarely get caries. Fluoride in the drinking water at about one part per million is associated with a reduction in the caries rate.
Prolonged severe disease in infancy is associated with poor calci?cation of the teeth, making them more vulnerable to decay. As the teeth are formed and partly calci?ed by the time of birth, the diet and health of the mother are also important to the teeth of the child. Pregnant mothers and children should have a good balanced diet with su?cient calcium and vitamin
D. A ?brous diet will also aid cleansing of the teeth and stimulate the circulation in the teeth and jaws. The caries rate can be reduced by regular brushing with a ?uoride toothpaste two or three times per day and certainly before going to sleep. The provision of sweet or sugary juices in an infant’s bottle should be avoided.
Irregularity of the permanent teeth may be due to an abnormality in the growth of the jaws or to the early or late loss of the deciduous set (see TEETH – Development). Most frequently it is due to an imbalance in the size of the teeth and the length of the jaws. Some improvement may take place with age, but many will require the help of an orthodontist (specialist dentist) who can correct many malocclusions by removing a few teeth to allow the others to be moved into a good position by means of springs and elastics on various appliances which are worn in the mouth.
Loosening of the teeth may be due to an accident or in?ammation of the GUM. Teeth loosened by trauma may be replaced and splinted in the socket, even if knocked right out. If the loosening is due to periodontal disease, the prognosis is less favourable.
Discoloration of the teeth may be intrinsic or extrinsic: in other words, the stain may be in the calci?ed structure or stuck on to it. Intrinsic staining may be due to JAUNDICE or the antibiotic tetracycline. Extrinsic stain may be due to tea, co?ee, tobacco, pan (a mixture of chuna and betel nuts wrapped in a leaf), iron-containing medicines or excess ?uoride.
Gingivitis or in?ammation of the gum may occur as an acute or chronic condition. In the acute form it is often part of a general infection of the mouth, and principally occurs in children or young adults – resolving after 10–14 days. The chronic form occurs later in life and tends to be progressive. Various microorganisms may be found on the lesions, including anaerobes. Antiseptic mouthwashes may help, and once the painful stage is past, the gums should be thoroughly cleaned and any calculus removed. In severe conditions an antibiotic may be required.
Periodontal disease is the spread of gingivitis (see above) to involve the periodontal membrane of the tooth; in its ?orid form it used to be called pyorrhoea. In this, the membrane becomes damaged by the in?ammatory process and a space or pocket is formed into which a probe can be easily passed. As the pocket becomes more extensive, the tooth loosens. The loss of the periodontal membrane also leads to the loss of supporting bone. Chronic in?ammation soon occurs and is di?cult to eradicate. Pain is not a feature of the disease but there is often an unpleasant odour (halitosis). The gums bleed easily and there may be DYSPEPSIA. Treatment is largely aimed at stabilising the condition rather than curing it.
Dental abscess is an infection that arises in or around a tooth and spreads to involve the bone. It may occur many years after a blow has killed the pulp of the tooth, or more quickly after caries has reached the pulp. At ?rst the pain may be mild and intermittent but eventually it will become severe and a swelling will develop in the gum over the apex of the tooth. A radiograph of the tooth will show a round clear area at the apex of the tooth. Treatment may be by painting the gum with a mild counter-irritant such as a tincture of aconite and iodine in the early stages, but later root-canal therapy or apicectomy may be required. If a swelling is present, it may need to be drained or the o?ending teeth extracted and antibiotics given.
Injuries to teeth are common. The more minor injuries include crazing and the loss of small chips of enamel, and the major ones include a broken root and avulsion of the entire tooth. A specialist dental opinion should be sought as soon as possible. A tooth that has been knocked out can be re-implanted if it is clean and replaced within a few hours. It will then require splinting in place for 4–6 weeks.
Prevention of dental disease As with other disorders, prevention is better than cure. Children should be taught at an early age to keep their teeth and gums clean and to avoid re?ned sugars between meals. It is better to ?nish a meal with a drink of water rather than a sweetened drink. Fluoride in some of its forms is useful in the reduction of dental caries; in some parts of the UK natural water contains ?uoride, and in some areas where ?uoride content is low, arti?cial ?uoridation of the water supply is carried out. Overcrowding of the teeth, obvious maldevelopment of the jaw and persistent thumbsucking into the teens are all indications for seeking the advice of an orthodontist. Generally, adults have less trouble with decay but more with periodontal disease and, as its onset is insidious, regular dental inspections are desirable.... teeth
FAMILY: Rutaceae
SYNONYM: Citrus aurantium subsp. bergamia.
GENERAL DESCRIPTION: A small tree, about 4.5 metres high with smooth oval leaves, bearing small round fruit which ripen from green to yellow, much like a miniature orange in appearance.
DISTRIBUTION: Native to tropical Asia. Extensively cultivated in Calabria in southern Italy and also grown commercially on the Ivory Coast.
OTHER SPECIES: Not to be confused with the herb bergamot or bee balm (Monarda didyma).
HERBAL/FOLK TRADITION: Named after the Italian city of Bergamo in Lombardy, where the oil was first sold. The oil has been used in Italian folk medicine for many years, primarily for fever (including malaria) and worms; it does not feature in the folk tradition of any other countries. However, due to recent research in Italy, bergamot oil is now known to have a wide spectrum of applications, being particularly useful for mouth, skin, respiratory and urinary tract infections.
ACTIONS: Analgesic, anthelmintic, antidepressant, antiseptic (pulmonary, genito-urinary), antispasmodic, antitoxic, carminative, digestive, diuretic, deodorant, febrifuge, laxative, parasiticide, rubefacient, stimulant, stomachic, tonic, vermifuge, vulnerary.
EXTRACTION: Essential oil by cold expression of the peel of the nearly ripe fruit. (A rectified or terpeneless oil is produced by vacuum distillation or solvent extraction.)
CHARACTERISTICS: A light greenish-yellow liquid with a fresh sweet-fruity, slightly spicy-balsamic undertone. On ageing it turns a brownish-olive colour. It blends well with lavender, neroli, jasmine, cypress, geranium, lemon, chamomile, juniper, coriander and violet.
PRINCIPAL CONSTTTUENTS Known to have about 300 compounds present in the expressed oil: mainly linalyl acetate (30–60 per cent), linalol (11–22 per cent) and other alcohols, sesquiterpenes, terpenes, alkanes and furocoumarins (including bergapten, 0.30–0.39 per cent).
SAFETY DATA: Certain furocoumarins, notably bergapten, have been found to be phototoxic on human skin; that is, they cause sensitization and skin pigmentation when exposed to direct sunlight (in concentration and in dilution even after some time!). Extreme care must be taken when using the oil in dermal applications – otherwise a rectified or ‘bergapten-free’ oil should be substituted. Available information indicates it to be otherwise non-toxic and relatively non-irritant.
AROMATHERAPY/HOME: USE
Skin Care: Acne, boils, cold sores, eczema, insect repellent and insect bites, oily complexion, psoriasis, scabies, spots, varicose ulcers, wounds.
Respiratory System: Halitosis, mouth infections, sore throat, tonsillitis.
Digestive System: Flatulence, loss of appetite.
Genito-URINARY SYSTEM: Cystitis, leucorrhoea, pruritis, thrush.
Immune System: Colds, fever, ’flu, infectious diseases.
Nervous System: Anxiety, depression and stress-related conditions, having a refreshing and uplifting quality.
OTHER USES: Extensively used as a fragrance and, to a degree, a fixative in cosmetics, toiletries, suntan lotions and perfumes – it is a classic ingredient of eau-de-cologne. Widely used in most major food categories and beverages, notably Earl Grey tea.... bergamot
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