(American) One who is clear-minded Claritey, Claritee, Claritea, Clariteah, Clariti, Claritie, Claryty, Clarytey, Clarytee, Clarytea, Claryteah, Claryti, Clarytie
Structure 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
Diagnosis: dementia requires six months mental impairment, whereas acute confusional states may develop in a few days. Distinguish from Alzheimer’s disease.
Causes: Oxygen deficiency in the tissues (Vitamin E). Toxaemia (eliminatives). Delirium (nerve relaxants). Infections (Echinacea). Metabolism (Dandelion). Drugs (Ginseng). Hypothermia (Cayenne). Nutritional (Slippery Elm, thiamine).
Tea. Combine herbs, equal parts: Agrimony, Skullcap, Balm. 2 teaspoons to each cup boiling water; infuse 5-15 minutes. 1 cup freely.
Ginkgo: Favourable results reported.
Vitamins. B-complex. B12. Thiamine. E (1000iu daily). Minerals. Dolomite. Zinc. ... confusional state
Progressive loss of visual clarity is common with advancing age and may be due to a number of disorders (see vision, disorders of).
Sudden loss of vision may be caused by disorders such as hyphaema, severe uveitis, vitreous haemorrhage, or retinal haemorrhage.
Optic neuritis can reduce vision in 1 eye.
Damage to the nerve connections between the eyes and brain, or to the visual area of the brain, can cause loss of peripheral vision and may be a result of embolism, ischaemia, tumour, inflammation, or injury.... vision, loss of
Causes Blood supply to the brain may be interrupted by arteries furring up with ATHEROSCLEROSIS (which is accelerated by HYPERTENSION and DIABETES MELLITUS, both of which are associated with a higher incidence of strokes) or being occluded by blood clots arising from distant organs such as infected heart valves or larger clots in the heart (see BLOOD CLOT; THROMBOSIS). Hearts with an irregular rhythm are especially prone to develop clots. Patients with thick or viscous blood, clotting disorders or those with in?amed arteries – for example, in SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) – are particularly in danger of having strokes. Bleeding into the brain arises from areas of weakened blood vessels, many of which may be congenital.
Symptoms Minor episodes due to temporary lack of blood supply and oxygen (called TRANSIENT ISCHAEMIC ATTACKS OR EPISODES (TIA, TIE)) are manifested by short-lived weakness or numbness in an arm or leg and may precede a major stroke. Strokes cause sudden weakness or complete paralysis of the muscles controlled by the part of the brain affected, as well as sensory changes (e.g. numbness or tingling). In the worst cases these symptoms and signs may be accompanied by loss of consciousness. If the stroke affects the area of the brain controlling the larynx and throat, the patient may suffer slurring or loss of speech with di?culty in initiating swallowing. When the face is involved, the mouth may droop and the patient dribble. Strokes caused by haemorrhage may be preceded by headaches. Rarely, CVAs are complicated by epileptic ?ts (see EPILEPSY). If, on the other hand, numerous small clots develop in the brain rather than one major event, this may manifest itself as a gradual deterioration in the patient’s mental function, leading to DEMENTIA.
Investigations Tests on the heart or COMPUTED TOMOGRAPHY or ultrasonic scans (see ULTRASOUND) on arteries in the neck may indicate the original sites of distantly arising clots. Blood tests may show increased thickness or tendency to clotting, and the diagnosis of general medical conditions can explain the presence of in?amed arteries which are prone to block. Special brain X-rays show the position and size of the damaged brain tissue and can usually distinguish between a clot or infarct and a rupture of and haemorrhage from a blood vessel in the brain.
Management It is better to prevent a stroke than try to cure it. The control of a person’s diabetes or high blood pressure will reduce the risk of a stroke. Treatment with ANTICOAGULANTS prevents the formation of clots; regular small doses of aspirin stop platelets clumping together to form plugs in blood vessels. Both treatments reduce the likelihood of minor transient ischaemic episodes proceeding to a major stroke.
Once the latter has occurred, there is no e?ective treatment to reduce the damage to brain tissue. Function will return to the affected part of the body only if and when the brain recovers and messages are again sent down the appropriate nerves. Simple movements are more likely to recover than delicate ones, and sophisticated functions have the worst outlook. Thus, movement of the thigh may improve more easily than ?ne movements of ?ngers, and any speech impairment is more likely to be permanent. A rehabilitation team can help to compensate for any disabilities the subject may have. Physiotherapists maintain muscle tone and joint ?exibility, whilst waiting for power to return; occupational therapists advise about functional problems and supply equipment to help patients overcome their disabilities; and speech therapists help with diffculties in swallowing, improve the clarity of remaining speech or o?er alternative methods of communication. District nurses or home helps can provide support to those caring for victims of stroke at home. Advice about strokes may be obtained from the Stroke Association.... stroke
Causes The disease is caused by the bacillus Clostridium tetani, found generally in earth and dust and especially in places where animal manure is collected. Infection usually follows a wound, especially a deeply punctured or gunshot wound, with the presence of some foreign body. It is a hazard in war and also among farmers, gardeners and those in the construction industry. The bacillus develops a toxin in the wound, which is absorbed through the motor nerves into the spinal cord where it renders the nerves excitable and acutely sensitive to mild stimuli.
Symptoms Most commonly appearing within four to ?ve days of the wound, the patient’s symptoms may be delayed for several weeks – by which time the wound may have healed. Initially there is muscle sti?ness around the wound followed by sti?ness around the jaw, leading to lockjaw, or trismus. This extends to the muscles of the neck, back, chest, abdomen, and limbs, leading to strange, often changing, contorted postures, accompanied by frequent seizures – often provoked by quite minor stimuli such as a sudden noise. The patient’s breathing may be seriously affected, in severe cases leading to ASPHYXIA; the temperature may rise sharply, often with sweating; and severe pain is common. Mental clarity is characteristic adding to the patient’s anxiety. In severe infections death may be from asphyxia, PNEUMONIA, or general exhaustion. More commonly, the disease takes a chronic course, leading to gradual recovery. Outcome depends on several factors, chie?y the patient’s immune status and age, and early administration of appropriate treatment.
Tetanus may occur in newborn babies, particularly when birth takes place in an unhygienic environment. It is particularly common in the tropics and developing countries, with a high mortality rate. Local tetanus is a rare manifestation, in which only muscles around the wound are affected, though sti?ness may last for several months. STRYCHNINE poisoning and RABIES, although similar in some respects to tetanus, may be easily distinguished by taking a good history.
Prevention and treatment The incidence of tetanus in the United Kingdom has been almost abolished by the introduction of tetanus vaccine (see IMMUNISATION). Children are routinely immunised at two, three and four months of age, and boosters are given later in life to at-risk workers, or those travelling to tropical parts.
Treatment should be started as soon as possible after sustaining a potentially dangerous wound. An intravenous injection of antitoxin should be given immediately, the wound thoroughly cleaned and PENICILLIN administered. Expert nursing is most important. Spasms may be minimised by reducing unexpected stimuli, and diazepam (see BENZODIAZEPINES; TRANQUILLISERS) is helpful. Intravenous feeding should be started immediately if the patient cannot swallow. Aspiration of bronchial secretions and antibiotic treatment of pneumonia may be necessary.... tetanus
FAMILY: Lamiaceae (Labiatae)
SYNOYNMS Common basil, joy-of-the-mountain, ‘true’ sweet basil, European basil.
GENERAL DESCRIPTION: A tender annual herb, with very dark green, ovate leaves, greyish-green beneath, an erect square stem up to 60 cms high, bearing whorls of two-lipped greenish or pinky-white flowers. The whole plant has a powerful aromatic scent.
DISTRIBUTION: Native to tropical Asia and Africa, it is now widely cultivated throughout Europe, the Mediterranean region, the Pacific Islands, North and South America. The European, French or ‘true’ sweet basil oil is produced in France, Italy, Egypt, Bulgaria, Hungary and the USA.
OTHER SPECIES: There are many varieties of basil occurring all over the world, used both for their culinary and medicinal applications, such as bush basil (O. minimum), holy basil (O. sanctum), both from India, camphor basil (O. kilimanjaricum) from East Africa (also grown in India), and the fever plant (O. viride) from West Africa. However, there are two principal chemotypes most commonly used for the extraction of essential oil: the so-called ‘French basil’ and the ‘exotic basil’ – see separate entry.
HERBAL/FOLK TRADITION: Widely used in Far Eastern medicine especially in the Ayurvedic tradition, where it is called tulsi. It is used for respiratory problems such as bronchitis, coughs, colds, asthma, ’flu and emphysema but is also used as an antidote to poisonous insect or snake bites. It has also been used against epidemics and fever, such as malaria. It improves blood circulation and the digestive system and in China it is used for stomach and kidney ailments.
In the West it is considered a ‘cooling’ herb, and is used for rheumatic pain, irritable skin conditions and for those of a nervous disposition. It is a popular culinary herb, especially in Italy and France.
ACTIONS: Antidepressant, antiseptic, antispasmodic, carminative, cephalic, digestive, emmenagogue, expectorant, febrifuge, galactagogue, nervine, prophylactic, restorative, stimulant of adrenal cortex, stomachic, tonic.
EXTRACTION: Essential oil by steam distillation from the flowering herb.
CHARACTERISTICS: ‘True’ sweet basil oil is a colourless or pale yellow liquid with a light, fresh sweet-spicy scent and balsamic undertone. It blends well with bergamot, clary sage, lime, opopanax, oakmoss, citronella, geranium, hyssop and other ‘green’ notes.
PRINCIPAL CONSTITUENTS: Linalol (40–45 per cent), methyl chavicol (23.8 per cent) and small amounts of eugenol, limonene and citronellol, among others.
SAFETY DATA: Relatively non-toxic, non-irritant, possible sensitization in some individuals. Avoid during pregnancy.
AROMATHERAPY/HOME: USE
Skin Care: Insect bites (mosquito, wasp), insect repellent.
Circulation, Muscles and Joints: Gout, muscular aches and pains, rheumatism.
Respiratory Syste: Bronchitis, coughs, earache, sinusitis.
Digestive System: Dyspepsia, flatulence, nausea.
Genito-Urinary System: Cramps, scanty periods.
Immune System: Colds, fever, ’flu, infectious disease.
Nervous System: Anxiety, depression, fatigue, insomnia, migraine, nervous tension: ‘Oil of Basil is an excellent, indeed perhaps the best, aromatic nerve tonic. It clears the head, relieves intellectual fatigue, and gives the mind strength and clarity.’8
OTHER USES: The oil is used in soaps, cosmetics and perfumery; it is also used extensively in major food categories, especially savouries.... basil, french
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