Dental nerve Health Dictionary

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Dental Nerve: From 1 Different Sources

either of two nerves that supply the teeth; they are branches of the trigeminal nerve. The inferior dental nerve supplies the lower teeth and for most of its length exists as a single large bundle; thus anaesthesia of it has a widespread effect (see inferior dental block). The superior dental nerve, which supplies the upper teeth, breaks into separate branches at some distance from the teeth and it is possible to anaesthetize these individually with less widespread effect for the patient.

Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Auditory Nerve

See VESTIBULOCOCHLEAR NERVE.... auditory nerve

Cranial Nerves

Cranial nerves are those arising from the BRAIN.... cranial nerves

Facial Nerve

The seventh cranial nerve (arising from the BRAIN), supplying the muscles of expression in the face, being purely a motor nerve. It enters the face immediately below the ear after splitting up into several branches. (See BELL’S PALSY.)... facial nerve

Hypoglossal Nerve

The 12th cranial nerve, which supplies the muscles of the tongue, together with some others lying near it. This nerve is responsible for movements required for swallowing and talking. (See also NERVOUS SYSTEM.)... hypoglossal nerve

Nerve Block

See ANAESTHESIA – Local anaesthetics.... nerve block

Nerve

A nerve is a bundle of conductory ?bres called axons (see AXON) that emanate from neurones (see NEURON(E)) – the basic anatomical and functional units of the NERVOUS SYSTEM. Nerves make up the central nervous system (BRAIN and SPINAL CORD) and connect that system to all parts of the body, transmitting information from sensory organs via the peripheral nerves to the centre and returning instructions for action to the relevant muscles and glands.

Nerves vary in size from the large pencil-sized sciatic nerve in the back of the thigh muscles to the single, hair-sized ?bres distributed to the skin. A nerve, such as the sciatic, possesses a strong, outer ?brous sheath, called the epineurium, within which lie bundles of nerve-?bres, divided from one another by partitions of ?brous tissue, in which run blood vessels that nourish the nerve. Each of these bundles is surrounded by its own sheath, known as the perineurium, and within the bundle ?ne partitions of ?brous tissue, known as endoneurium, divide up the bundle into groups of ?bres. The ?nest subdivisions of the nerves are the ?bres, and these are of two kinds: medullated and non-medullated ?bres. (See NEURON(E) and NERVOUS SYSTEM for more details on structure and functions of neurons and nerves.)... nerve

Optic Nerve

See EYE.... optic nerve

Radial Nerve

This NERVE arises from the BRACHIAL plexus in the axilla. At ?rst descending posteriorly and then anteriorly, it ends just above the elbow by dividing into the super?cial radial and interosseous nerves. It supplies motor function to the muscles which extend the arm, wrist, and some ?ngers, and supplies sensation to parts of the posterior and lateral aspects of the arm, forearm and hand.... radial nerve

Sacral Nerves

These are five pairs of CNS nerves that exit through the sacral foramen and sacral hiatus, and bring information in and out of the spinal cord. Much of their function relates to the sciatic nerve, and they bring information in from the skin sensory zones (dermatomes) of the heel, back of the legs, buttocks, and the pelvic floor.... sacral nerves

Trochlear Nerve

The fourth cranial nerve (arising from the BRAIN), which acts upon the superior oblique muscle of the EYE.... trochlear nerve

Ulnar Nerve

A major NERVE in the arm, it runs from the brachial plexus to the hand. The nerve controls the muscles that move the ?ngers and thumb and conveys sensation from the ?fth and part of the fourth and from the adjacent palm. Muscle weakness and numbness in the areas supplied by the nerve is usually caused by pressure from an abnormal outgrowth from the epicondyle at the bottom of the humerus (upper-arm bone).... ulnar nerve

Trigeminal Nerve

The ?fth cranial nerve (arising from the BRAIN). It consists of three divisions: (1) the ophthalmic nerve, which is purely sensory in function, being distributed mainly over the forehead and front part of the scalp; (2) the maxillary nerve, which is also sensory and distributed to the skin of the cheek, the mucous membrane of the mouth and throat, and the upper teeth; and (3) the mandibular nerve, which is the nerve of sensation to the lower part of the face, the tongue and the lower teeth, as well as being the motor nerve to the muscles concerned in chewing. The trigeminal nerve is of special interest, owing to its liability to NEURALGIA – TRIGEMINAL NEURALGIA, or tic douloureux as it is also known, being the most painful form known.... trigeminal nerve

Vagus Nerve

Also called the pneumogastric nerve, this is the tenth cranial nerve, with many fibers leading to parasympathetic ganglia in internal organs, and can be considered the presynapse starter for the upper parts of the parasympathetic functions.... vagus nerve

Vestibulocochlear Nerve

The eighth cranial nerve. It consists of two sets of ?bres, which constitute two separate nerves. One is known as the vestibular nerve, which connects the semicircular canals and inner ear to the BRAIN and conveys information on posture and movement of the body; it is the nerve of equilibration or balance. The other is known as the cochlear nerve, which links the COCHLEA (organ that responds to sounds) with the brain and is the nerve of hearing. Disturbance of the former causes giddiness (VERTIGO), whilst disturbance of the latter causes DEAFNESS.... vestibulocochlear nerve

Abducent Nerve

This is the sixth nerve rising from the brain and controls the external rectus muscle of the EYE, which turns the eye outwards. It is particularly liable to be paralysed in diseases of the nervous system, thus leading to an inward squint.... abducent nerve

Decay, Dental

See TEETH, DISORDERS OF – Caries of the teeth.... decay, dental

Dental Caries

Decay of teeth... dental caries

Dental Emergencies

See TEETH, DISORDERS OF.... dental emergencies

General Dental Council

A statutory body set up by the Dentists Act which maintains a register of dentists (see DENTAL SURGEON), promotes high standards of dental education, and oversees the professional conduct of dentists. Membership comprises elected and appointed dentists and appointed lay members. Like other councils responsible for registering health professionals, the General Dental Council now comes under the umbrella of the new Council for Regulatory Excellence, a statutory body. (See APPENDIX 7: STATUTORY ORGANISATIONS.)... general dental council

General Dental Services

See DENTAL SURGEON.... general dental services

Lacrimal Nerve

A branch of the ophthalmic nerve supplying the lacrimal gland and conjunctiva of the EYE.... lacrimal nerve

Nerve Cell

See NEURON(E).... nerve cell

Phrenic Nerve

The NERVE which chie?y supplies the DIAPHRAGM. A phrenic nerve arises on each side of the SPINAL CORD from the third, fourth and ?fth cervical spinal nerves; both follow a long course down the neck, and through the chest to the diaphragm. They play a key part in RESPIRATION through control of the diaphragm. Injury to one nerve paralyses one half of the diaphragm. Occasionally the phrenic nerve may be surgically crushed as part of the treatment to repair a HIATUS HERNIA or, rarely, to stop intractable hiccups.... phrenic nerve

Pudendal Nerve

The nerve that operates the lowest muscles of the ?oor of the PELVIS and also the anal SPHINCTER muscle. It may be damaged in childbirth, resulting in INCONTINENCE.... pudendal nerve

Accessory Nerve

The 11th cranial nerve. Unlike the other cranial nerves, most of the accessory nerve originates from the spinal cord. The small part of the nerve that originates from the brain supplies many muscles of the palate, pharynx (throat), and larynx (voice box). Damage to this part of the nerve may cause difficulty in speaking and swallowing. The spinal part of the nerve supplies large muscles of the neck and back, notably the sternomastoid and trapezius. Damage to the spinal fibres of the nerve paralyses these muscles.... accessory nerve

Acoustic Nerve

The part of the vestibulocochlear nerve (the 8th cranial nerve) that is concerned with hearing. It is also known as the auditory nerve.... acoustic nerve

Femoral Nerve

One of the main nerves of the leg. The nerve fibres making up the femoral nerve emerge from the lower spine and run down into the thigh, where they branch to supply the skin and quadriceps muscles.

Damage to the femoral nerve (which impairs the ability to straighten the knee) is usually caused by a slipped disc in the lumbar region of the spine (see disc prolapse). Damage may also result from a backward dislocation of the hip or a neuropathy.... femoral nerve

Glossopharyngeal Nerve

The ninth cranial nerve.

This nerve performs both sensory and motor functions.

It conveys sensations, especially taste, from the back of the tongue, regulates secretion of saliva by the parotid gland, and controls movement of the throat muscles.... glossopharyngeal nerve

Oculomotor Nerve

The 3rd cranial nerve, controlling most of the muscles that move the eye. The oculomotor nerve also supplies the muscle that constricts the pupil, that which raises the upper eyelid, and the ciliary muscle, which focuses the eye. The nerve may be damaged due to a fracture to the base of the skull or a tumour. Symptoms include ptosis, squint, dilation of the pupil, inability to focus the eye, double vision, and slight protrusion of the eyeball. (See also trochlear nerve; abducent nerve.)... oculomotor nerve

Olfactory Nerve

The first cranial nerve, which conveys sensations of smell as nerve impulses from the nose to the brain. Each of the 2 olfactory nerves has receptors in the mucous membrane lining the nasal cavity. These receptors detect smells and send signals along nerve fibres, which pass through tiny holes in the roof of the nasal cavity and combine to form the olfactory bulbs. From here, nerve fibres come together to form the olfactory nerve, leading to the olfactory centre in the brain. Sense of smell may be lost or impaired due to damage to the olfactory nerves, usually as a result of head injury.... olfactory nerve

Sciatic Nerve

The main nerve in each leg and the largest nerve in the body.The sciatic nerves are formed from nerve roots in the spinal cord.... sciatic nerve

Spinal Nerves

A set of 31 pairs of nerves that connect to the spinal cord. Spinal nerves emerge in 2 rows from either side of the spinal cord and leave the spine through gaps between adjacent vertebrae. The nerves then branch out to supply all parts of the trunk, arms, and legs with sensory and motor nerve fibres.

Disc prolapse may lead to pressure on a spinal nerve, causing pain. Injury to a nerve may lead to loss of sensation or movement in the area supplied by the nerve. (See also nerve injury; neuropathy.)... spinal nerves

Transcutaneous Electrical Nerve Stimulation

See TENS.... transcutaneous electrical nerve stimulation

British Dental Association

See APPENDIX 8: PROFESSIONAL ORGANISATIONS.... british dental association

Dental Hygienist

A person quali?ed to carry out the scaling (removal of calculus [deposits]) from the teeth and to advise patients on how to keep their teeth and gums healthy. Hygienists usually work in a quali?ed dentist’s surgery.... dental hygienist

Dental Surgeon

A dental surgeon, or dentist, is an individual trained to diagnose and treat disorders of the teeth and gums, as well as to advise on preventive measures to ensure that these areas remain healthy. Dentists qualify after a four-year course at dental school and then register with the GENERAL DENTAL COUNCIL, which is responsible for maintaining educational and professional standards. Around 25,000 dentists practise in the NHS and private sector.

Over the past four decades the ?nancial outlay on NHS dental services has been around 5 per cent of total NHS funding. This contrasts with 10 per cent during the service’s early years, when the NHS was coping with decades of ‘dental neglect’. The population’s dental health has, however, been steadily improving: in 1968 more than one-third of people had no natural teeth; by the late 1990s the proportion had fallen to 13 per cent.

Dentistry is divided into several groupings.

General dental practitioners Concerned with primary dental care, the prevention, diagnosis and treatment of diseases of the gums and teeth – for example, caries (see TEETH, DISORDERS OF). They also deal with diffculties in biting and the effects of trauma, and are aware that oral disorders may re?ect disease elsewhere in the body. They will refer to the hospital dental services, patients who require treatment that cannot be satisfactorily carried out in a primary-care setting.

Most routine dental prevention and treatment is carried out in general dental practitioners’ surgeries, where the dentists also supervise the work of hygienists and dental auxiliaries. Appliances, such as dentures, crowns, bridges and orthodontic appliances are constructed by dental technicians working in dental laboratories.

There are around 18,800 dentists providing general dental services in the UK. These practitioners are free to accept or reject any potential patient and to practise where they wish. Those dentists treating patients under an NHS contract (a mixture of capitation fees and items of service payments) can also treat patients privately (for an appropriate fee). Some dentists opt for full-time private practice, and their numbers are increasing in the wake of changes in 1990 in the contracts of NHS general dental practitioners.

Community dental practitioner Part of the public-health team and largely concerned with monitoring dental health and treating the young and the handicapped.

In the hospitals and dental schools are those who are involved in only one of the specialities.

Around 2,800 dentists work in NHS hospitals and 1,900 in the NHS’s community services. In some parts of the UK, people wanting NHS treatment are having diffculties ?nding dentists willing to provide such care.

Restorative dentist Concerned with the repair of teeth damaged by trauma and caries, and the replacement of missing teeth.

Orthodontist Correction of jaws and teeth which are misaligned or irregular. This is done with appliances which may be removable or ?xed to the teeth which are then moved with springs or elastics.... dental surgeon

Idiopathic Facial Nerve Palsy

See BELL’S PALSY.... idiopathic facial nerve palsy

Nerves Twelve Nerves Come Off The Brain:

I. Olfactory, to the nose (smell).

II. Optic, to the eye (sight).

III. Oculomotor

Trochlear, to eye-muscles.

Abducent

VI. Trigeminal, to skin of face.

VII. Facial, to muscles of face.

VIII. Vestibulocochlear, to ear (hearing and balancing).

IX. Glossopharyngeal, to tongue (taste).

X. Vagus, to heart, larynx, lungs, and stomach.

XI. Spinal accessory, to muscles in neck.

XII. Hypoglossal, to muscles of tongue.... nerves twelve nerves come off the brain:

Nerves, Injuries To

These have several causes. Continued or repeated severe pressure may damage a nerve seriously, as in the case of a crutch pressing into the armpit and causing drop-wrist. Bruising due to a blow which drives a super?cially placed nerve against a bone may damage, say, the radial nerve behind the upper arm. A wound may sever nerves, along with other structures; this accident is specially liable to occur to the ulnar nerve in front of the wrist when a person accidentally puts a hand and arm through a pane of glass.

Symptoms When a sensory nerve is injured or diseased, sensation is immediately more or less impaired in the part supplied by the nerve. Ulceration or death of the tissue supplied by the defective nerve may occur. When the nerve in question is a motor one, the muscles governed through it are instantly paralysed. In the latter case, the portion of nerve beyond the injury degenerates and the muscles gradually waste, losing their power of contraction in response to electrical applications. Finally, deformities result and the joints become ?xed. This is particularly noticeable when the ulnar nerve is injured, the hand and ?ngers taking up a claw-like position. The skin may also be affected.

Treatment Damaged or severed (peripheral) nerve ?bres should be sewn together, using microsurgery. Careful realignment of the nerve endings gives the ?bres an excellent chance of regenerating along the right channels. Full recovery is rare but, with regular physiotherapy to keep paralysed muscles in good shape and to prevent their shortening, the patient can expect to obtain a reasonable return of function after a few weeks, with improvement continuing over several months.... nerves, injuries to

Olfactory Nerves

The nerves of SMELL. Each nerve detects smell by means of hair-like receptors positioned in the mucous membrane lining the roof of the nasal cavity (see NOSE).... olfactory nerves

Recurrent Laryngeal Nerve

A branch of the vagus NERVE which leaves the latter low down in its course, and – hooking around the right subclavian artery on the right side and round the arch of the aorta on the left

– runs up again into the neck, where it enters the larynx and supplies branches to the muscles which control the vocal cords.... recurrent laryngeal nerve

Transcutaneous Electrical Nerve Stimulation (tens)

A method of electrical stimulation that is being used for the relief of PAIN, including that of MIGRAINE, NEURALGIA and phantom limbs (see AMPUTATION). Known as TENS, its mode of action appears to have some resemblance to that of ACUPUNCTURE. Several controlled trials suggest that it provides at least a modicum of relief of pain after operations, thereby reducing the amount of ANALGESICS that may be called for.... transcutaneous electrical nerve stimulation (tens)

Tea For Nerves

Nerve damage can include neuropathy or neuritis, which can be caused by diabetes, nerve injury, autoimmune disease, viral infections, muscle spasms or vitamin deficiencies. Traditional medicine found a lot of treatments for nerve damage, but alternative medicine fans think that you don’t need to take a lot of pills for something that can be treated with just a cup of tea. How a Tea for Nerves Works A Tea for Nerves’ main purpose is to nourish your nervous system and induce a state of relaxation to all your nervous cells. Also, these teas can reconstruct the damaged tissue and make your body heal all affected areas. In order to be useful, a Tea for Nerves needs to contain tannins, volatile oils and minerals (manganese, magnesium, iron, preferably). Efficient Tea for Nerves When choosing a Tea for Nerves, remember that it must be both one hundred percent safe and very efficient. If you don’t know which teas to choose from, here’s a list to help you out: - Saint John’s Wort Tea – is useful for sciatica and it can bring relief to patients suffering from depression and spinal nerves damages. Take only a cup per day and avoid it at all costs if you’re on antidepressants. Also, if you’re pregnant, talk to your doctor before starting a treatment based on Saint John’s Wort Tea. - Skullcap Tea – treats a number of affections such as inflammation, arteriosclerosis, high cholesterol and epilepsy thanks to its active constituents: antioxidant flavonoids, which can repair the nervous damages and baicalin (has anti-spastic and nerve-relaxant properties). Don’t take more than 2 cups per day for a short amount of time and don’t combine it with anti-depressants and sedatives. Basil Tea – this Tea for Nerves has many medical uses and not only that it can repair the nervous ailments, but it’s also a great energy and health enhancer. You can also use it to treat asthenia, anemia, loss of appetite and digestive tract problems. Drink one or two cups per day for a short amount of time and enjoy the health benefits! Tea for Nerves Side Effects When taken properly, these teas are generally safe. However, make sure you don’t exceed the number of cups recommended per day or you’ll get diarrhea, constipation, nausea, headaches or skin rashes. If you’ve been taking one of these teas for a while and you’re experiencing some unusual reactions, talk to your doctor as soon as possible! Don’t take a Tea for Nerves if you’re pregnant, breastfeeding, on blood thinners, anticoagulants or preparing for a major surgery (these teas contains substances that may interfere with your anesthetic). The same advice for children: there are no studies to examine the treatment’s effect on them. If your doctor says it’s ok to try a Tea for Nerves, choose one that fits best your needs and enjoy its wonderful health benefits!... tea for nerves

Vasomotor Nerves

Small nerve ?bres that lie upon the walls of blood vessels and connect the muscle ?bres of their middle coat with the NERVOUS SYSTEM. Through these nerves the blood vessels are retained in a state of moderate contraction. There are vasodilator nerves, through which are transmitted impulses that dilate the vessels, and, in the case of the skin vessels, produce the condition of blushing; there are also vasoconstrictor nerves which transmit impulses that constrict, or narrow, the blood vessels – as occurs on exposure to cold (see HYPOTHERMIA). Various drugs produce dilatation or contraction of the blood vessels, and several of the substances produced by ENDOCRINE GLANDS in the body have these effects: for example, ADRENALINE.... vasomotor nerves

Dental Problems

See: TEETH DECAY, TEETH EXTRACTION, ALOE VERA. DEOBSTRUENT. That which clears obstruction by dilating natural passages of the body. Usually of the intestines (Ispaghula seeds) or colon (Buckbean). ... dental problems

Nerve Relaxant

See: SEDATIVE. ... nerve relaxant

Nerve Restoratives

All degenerative changes in the nervous system arise from breakdown of cell integrity through causes including stress, disease or faulty nutrition. J.M. Thurston classifies the restorative effect of herbs as:

Stomach and intestines: Wild Cherry bark, Black Haw.

Heart: Lily of the Valley, Cactus. Liver: Wild Yam.

Eye: Blue Cohosh, Poke root.

Brain: Oats, Black Cohosh.

Spine: Damiana, Oats, Kola, Unicorn root (Aletris). Hops. Womb: False Unicorn root (Helonias).

General Restoratives: St John’s Wort, Vervain. ... nerve restoratives

Nerve Stimulants

Often necessary to bring added vitality to the body or one of its parts. Often combined with circulatory stimulants to help support the nervous system in the presence of nerve weakness and paralysis.

Ephedra, Ginseng, Siberian Ginseng, Oats, Damiana, Kola, Gotu Kola, Thuja, Vervain. ... nerve stimulants

Nerve Tonics

To invigorate and restore. Regarded as nutrients for strengthening nerve fibres and their protective sheaths. Help resolve effects of stress and replace mineral deficiencies in nerve tissue. They bring a new vigour in place of enervation and debility.

Betony, Damiana, Oats, St John’s Wort, Skullcap, Vervain.

Combination. Tea: Equal parts, Skullcap, Betony, Vervain. 1 heaped teaspoon to each cup boiling water; infuse 15 minutes. Half-1 cup freely. ... nerve tonics

Nerve Tension

Nervous excitability, irritability, prone to over-reaction by anger or other destructive emotion.

Teas. Cowslip flowers, St John’s Wort flowers, Passion flower, Valerian, Hops, Lime flowers, Balm, Motherwort, Woodruff, Skullcap, Oats.

Formula, tea: equal parts, Balm, Motherwort, Passion flower. 1 heaped teaspoon to each cup boiling water; infuse 5-10 minutes. 1 cup thrice daily.

Tablets. Valerian. Pulsatilla. Natracalm. (English Grains) 500mg Passion flower tablets: 1 tablet thrice daily.

See: SEDATIVES. ... nerve tension

Abrasion, Dental

The wearing away of tooth enamel, often accompanied by the erosion of dentine (the layer beneath the enamel) and cementum (the bonelike tissue that covers the tooth root), usually through too-vigorous brushing. Abraded areas are often sensitive to cold or hot food or drink, and a desensitizing toothpaste and/or protection with a bonding (see bonding, dental) agent or filling may be needed.... abrasion, dental

Abscess, Dental

A pus-filled sac in the tissue around the root of a tooth. An abscess may occur when bacteria invade the pulp (the tissues in the central cavity of a tooth) as a result of dental caries, which destroys the tooth’s enamel and dentine, allowing bacteria to reach the pulp. Bacteria can also gain access to the pulp when a tooth is injured. The infection in the pulp then spreads into the surrounding tissue to form an abscess. Abscesses can also result from periodontal disease, in which bacteria accumulate in pockets that form between the teeth and gums.

The affected tooth aches or throbs, and biting or chewing is usually extremely painful. The gum around the tooth is tender and may be red and swollen. An untreated abscess eventually erodes a sinus (channel) through the jawbone to the gum surface, where it forms a swelling known as a gumboil. As the abscess spreads, the glands in the neck and the side of the face may become swollen, and fever may develop. Treatment may consist of draining the abscess, followed by root-canal treatment of the affected tooth, but in some cases extraction of the tooth is necessary. Antibiotics are prescribed if the infection has spread beyond the tooth.

An abscess in a periodontal pocket can usually be treated by the dentist scraping away infected material.... abscess, dental

Alignment, Dental

The movement of teeth by using either fixed or removable orthodontic appliances (braces) to correct malocclusion (incorrect bite).... alignment, dental

Alveolus, Dental

The bony cavity or socket supporting each tooth in the jaw.... alveolus, dental

Amalgam, Dental

A material, consisting of an alloy of mercury with other metals, that is used as fillings for teeth (see filling, dental).... amalgam, dental

Anaesthesia, Dental

Loss of sensation induced in a patient to prevent pain during dental treatment.

For minor procedures, a local anaesthetic (see anaesthesia, local) is injected either into the gum at the site being treated or into the nerve a short distance away (called a peripheral nerve block).

In addition, topical anaesthetics are often used on the gums.

For more complicated procedures, such as periodontal (gum) surgery and multiple tooth extractions, general anaesthesia is carried out (see anaesthesia, general).... anaesthesia, dental

Bleaching, Dental

A cosmetic procedure for lightening certain types of discoloured teeth, including nonvital ‘dead’ teeth.

The surface of the affected tooth is painted with oxidizing agents and then exposed to ultraviolet light.... bleaching, dental

Bonding, Dental

Dental techniques that use plastic resins and acrylic or porcelain veneers to repair, restore, or improve the appearance of damaged or defective teeth.

It is sometimes used as an alternative to crowning (see crown, dental) and may also be used as a preventive technique to protect the teeth.... bonding, dental

Brace, Dental

See orthodontic appliances.... brace, dental

Bridge, Dental

False teeth that are attached to natural teeth on either side of a gap left by a missing tooth or teeth. (See also denture.)... bridge, dental

Calcification, Dental

The deposition of calcium salts in developing teeth. Primary teeth begin to calcify in a fetus at between 3 and 6 months gestation; calcification of permanent teeth (other than the wisdom teeth) begins between birth and 4 years. Abnormal calcification occurs in amelogenesis imperfecta, an inherited disorder of the enamel (see hypoplasia, enamel), and can also result from the absorption of high levels of fluoride (see fluorosis).... calcification, dental

Calculus, Dental

A hard, crust-like deposit (also known as tartar) found on the crowns and roots of the teeth. Calculus forms when mineral salts in saliva are deposited in existing plaque. Supragingival calculus is a yellowish or white deposit that forms above the gum margin, on the crowns of teeth near the openings of salivary gland ducts. Subgingival calculus forms below the gum margin and is brown or black. Toxins in calculus cause gum inflammation (see gingivitis), which may progress to destruction of the supporting tissues (see periodontitis). Calculus is removed by professional scaling. Attention to oral hygiene reduces recurrence.... calculus, dental

Capping, Dental

See crown, dental.... capping, dental

Caries, Dental

Tooth decay; the gradual erosion of enamel (the covering of the tooth) and dentine (the substance beneath the enamel). Initial decay usually occurs on the grinding surfaces of the back teeth and areas around the gum line. The main cause is plaque, a sticky substance consisting of food deposits, saliva by-products, and bacteria that collects on the teeth. The breakdown of food deposits by bacteria creates an acid that eats into the enamel to form cavities. Unchecked decay spreads to the dentine, and as the cavity enlarges, bacteria may invade and destroy the pulp

at the tooth’s core. Advanced decay causes toothache and bad breath.

Treatment consists of drilling away the area of decay and filling the cavity (see filling, dental). In advanced decay, it may be necessary to remove the infected pulp (see extraction, dental).

Water fluoridation and the use of fluoride toothpaste helps prevent caries.

The risk of caries is also reduced by cutting sugar consumption, practising good oral hygiene, and visiting the dentist regularly.... caries, dental

Cavity, Dental

A hole in a tooth, commonly caused by dental caries (see caries, dental).... cavity, dental

Crowding, Dental

See overcrowding, dental.... crowding, dental

Crown, Dental

An artificial replacement for the crown of a tooth that has become decayed, discoloured, or broken. A porcelain crown is usually used on front teeth, but back teeth require the greater strength of a crown made from gold or porcelain fused to metal.

A crown may be fitted by filing the natural tooth to form a peg and cementing the crown over the top. If the tooth is... crown, dental

Curettage, Dental

The scraping of the wall of a cavity or other surface with a dental curette.

Dental curettage is one method used to remove the lining of periodontal pockets and diseased tissue from root surfaces in periodontitis.... curettage, dental

Cusp, Dental

A protrusion on the grinding surface of a tooth.... cusp, dental

Decalcification, Dental

The dissolving of minerals in a tooth. Dental decalcification is the first stage of tooth decay. It is caused by the bacteria in plaque acting on refined carbohydrates (mainly sugar) in food to produce acid, which leads to changes on the surface of the tooth. If the decalcification penetrates the enamel, it spreads into the dentine and permits bacteria to enter the pulp.

(See also caries, dental.)... decalcification, dental

Dental Examination

An examination of the mouth, gums, and teeth by a dentist as a routine check or as part of the assessment a person complaining of a symptom. Routine examinations enable tooth decay and gum disease to be detected and treated at an early stage.

During a routine dental examination, the dentist uses a metal instrument to

probe for dental cavities, chipped teeth, or fillings. Dental X-rays are sometimes carried out to check for problems that may not be visible. Dentists also check how well the upper and lower teeth come together. Regular examinations in children enable the monitoring of the replacement of primary teeth by permanent, or secondary, teeth. Referral for orthodontic treatment may be made. dental extraction See tooth extraction. dental X-ray An image of the teeth and jaws that provides information for detecting, diagnosing, and treating conditions that can threaten oral and general health. There are 3 types of dental X-ray: periapical X-ray, bite-wing X-ray, and panoramic X-ray.

Periapical X-rays are taken using X-ray film held behind the teeth. They give detailed images of whole teeth and the surrounding tissues. They show unerupted or impacted teeth, root fractures, abscesses, cysts, and tumours, and can help diagnose some skeletal diseases. Bite-wing X-rays show the crowns of the teeth and can detect areas of decay and changes in bone due to periodontal disease. Panoramic X-rays show all the teeth and surrounding structures on one large film. They can show unerupted or impacted teeth, cysts, jaw fractures, or tumours. The amount of radiation received from dental X-rays is extremely small. However, dental X-rays should be avoided during pregnancy.... dental examination

Enamel, Dental

The hard outer layer of a tooth that covers and protects the inner structures.... enamel, dental

Erosion, Dental

Loss of enamel from a tooth’s surface due to attack by plaque acids or other chemicals. Erosion of the

outer surfaces of the front teeth is most frequently caused by excessive intake of fruit juices and carbonated drinks. Erosion of the inner surfaces of the molars may be a result of the regurgitation of stomach acid, as occurs in people suffering from acid reflux or bulimia. (See also caries, dental.)... erosion, dental

Extraction, Dental

Removal of teeth by a dentist. Extraction may be performed when a tooth is severely decayed or too badly broken to be repaired, or when an abscess (see abscess, dental) has formed. Teeth may also be removed if there is crowding or malocclusion, if the teeth are loose due to gum disease, or if they are preventing another tooth from erupting (see eruption of teeth).

For most extractions, local anaesthesia is used (see anaesthesia, dental). Teeth are usually extracted with dental forceps, which grasp the root of the tooth. In difficult extractions, some gum and bone may also need to be removed from around the tooth.... extraction, dental

Filling, Dental

The process of replacing a chipped or decayed area of tooth with an inactive material. Dental filling is also used to describe the restorative material itself. Amalgam, a hard-wearing mixture of silver, mercury, and other metals is generally used for back teeth. If a front tooth is chipped, a bonding technique (see bonding, dental) may be used, in which plastic or porcelain tooth-coloured material is attached to the surface of the tooth.... filling, dental

Flossing, Dental

The removal of plaque (see plaque, dental) and food particles from around the teeth and gums by

using soft nylon or silk thread or tape.

Dental floss may be waxed or unwaxed.

Flossing should be carried out as an adjunct to toothbrushing.... flossing, dental

Fracture, Dental

A break in a tooth (see teeth) most commonly caused by falling onto a hard surface or by being hit in the mouth with a hard object.

Fractures may involve the crown or the root of a tooth, or both.

Fractures of the enamel can usually be repaired by bonding (see bonding, dental); in some cases, a replacement crown may be fitted (see crown, dental).

Pulpotomy may be performed if the pulp of a tooth is damaged.

Fractures of the root may be treated by splinting (see splinting, dental), root-canal treatment, or removing the tooth (see extraction, dental).... fracture, dental

Impaction, Dental

Failure of a tooth to emerge completely from the gum. It may occur because of overcrowding or when a tooth grows in the wrong direction.

Impacted wisdom teeth are common, and, if symptomless, may not need to be removed.

In some cases, however, symptoms necessitate their removal.... impaction, dental

Implant, Dental

A post, surgically embedded in the jaw for the attachment of a dental prosthesis (an artificial tooth). Titanium or synthetic materials may be used. A dental implant is fitted under local anaesthesia. A hole is drilled in the jaw and a post inserted. Several months later, an attachment that protrudes from the gum is screwed into the post; a few weeks after that, the prosthesis is fitted.... implant, dental

Impression, Dental

A mould taken of the teeth, gums, and palate.

A quick-setting material, such as alginate, is placed in a mould over the teeth.

The mould is removed, and plaster of Paris is poured into it to obtain a model of the area.

This model is then used as a base on which to build a denture, bridge, or dental inlay.

Dental impressions are also used in orthodontics to study the position of the teeth and to make orthodontic appliances to correct irregularities.... impression, dental

Inlay, Dental

A filling of porcelain or gold used to restore a badly decayed tooth.

An inlay may be needed for the back teeth or to protect a weakened tooth.... inlay, dental

Laryngeal Nerve

One of a pair of nerves that carry instructions from the brain to the larynx and send sensations from the larynx to the brain.... laryngeal nerve

Median Nerve

One of the main nerves of the arm. It is a branch of the brachial plexus and runs down the arm from the shoulder into the hand. The median nerve controls the muscles that carry out bending movements of the wrist, fingers, and thumb, and that rotate the forearm palm-inwards. The nerve also conveys sensations from the thumb and first 3 fingers, and from the region of the palm at their base.

Damage to the nerve may result from injury to the shoulder, a Colles’ fracture just above the wrist, or pressure on the nerve where it passes through the wrist (carpal tunnel syndrome).

Symptoms of damage include numbness and weakness in areas controlled by the nerve.... median nerve

Mineralization, Dental

The deposition of calcium crystals and other mineral salts in developing teeth. (See calcification, dental.)... mineralization, dental

Plaque, Dental

A rough, sticky coating on the teeth consisting of saliva, bacteria, and food debris.

It is the chief cause of tooth decay (see caries, dental) and gingivitis, and forms the basis of a hard deposit (see calculus, dental).

Some of the microorganisms in plaque, particularly STREPTOCOCCUS MUTANS, break down sugar in the remains of carbohydrate food that sticks to the mucus, creating an acid that can erode tooth enamel.... plaque, dental

Nerve Conduction Studies

Tests carried out to assess the extent of nerve damage caused by disorders of the peripheral nervous system (see neuropathy). In the test, an electrical stimulus is applied to a nerve, and the speed at which the nerve responds to the stimulus and transmits a signal is recorded.

nerve injury Damage or severance of conducting fibres within a nerve as a result of trauma, causing loss of skin sensation and muscle power. (See neuropathy for nerve damage from cause.

other than injury.)

If a peripheral nerve (a nerve outside the brain or spinal cord) is only partially severed, the cut fibres may be able to regenerate. Provided the severed ends are still aligned, new fibres can grow across the cut to rejoin the connection, restoring function. If a nerve is totally severed, the individual fibres cannot regenerate successfully and there is no recovery of function. Nerve tracts within the brain and spinal cord are structurally different from the peripheral nerves, and severed fibres in these tracts do not regenerate. For example, vision cannot be restored if the optic nerves are cut.Microsurgery can sometimes be used to stitch a severed peripheral nerve into place, but recovery is rarely complete.... nerve conduction studies

Nerve, Trapped

Compression or stretching of a nerve, causing numbness, tingling, weakness, and, sometimes, pain. Common examples of a trapped nerve include carpal tunnel syndrome, in which pressure on the median nerve as it passes through the wrist causes symptoms in the thumb, index, and middle fingers; a disc prolapse, in which pressure on the nerve root leading from the spinal cord produces symptoms in the back and legs; and crutch palsy, in which the radial nerve presses against the humerus (upper-arm bone), producing symptoms in the wrist and hand.

A damaged nerve may take some time to heal. In severe cases, surgical decompression to relieve pressure on the nerve may be necessary.... nerve, trapped

Overcrowding, Dental

Excessive crowding of the teeth so that they are unable to assume their normal positions in the jaw. Dental overcrowding is commonly inherited and may occur because the teeth are too large for the jaw or the jaw is too small to accommodate the teeth. Premature loss of primary molar (back) teeth can cause the permanent teeth beneath them to move out of position and crowd the teeth further forward.

Overcrowded teeth may lead to malocclusion or may prevent certain teeth from erupting through the gum (see impaction, dental). They can be difficult to clean, increasing the risk of dental decay (see caries, dental) and periodontal disease.

Teeth may need to be extracted to allow room for others. Usually an orthodontic appliance is fitted to the remaining teeth to position them correctly.... overcrowding, dental

Prosthetics, Dental

The branch of dentistry concerned with the replacement of missing teeth and their supporting structures. It includes dentures, overdentures (semipermanent fittings over existing teeth), crowns (see crown, dental), and bridges (see bridge, dental).

protease inhibitors A type of antiviral drug used to delay the progression of HIV infection (see AIDS).... prosthetics, dental

Pulp, Dental

The soft tissue containing blood vessels and nerves in the middle of each tooth (see teeth).... pulp, dental

Reimplantation, Dental

Replacement of a tooth in its socket after an accident so that it can become reattached to supporting tissues. The front teeth are most commonly involved. The tooth needs to be reimplanted soon after the accident and is maintained with a splint (see splinting, dental) while it heals. Healing may take several weeks.... reimplantation, dental

Resorption, Dental

Loss of substance from teeth. The loss may be external (affecting the surface of the root) or internal (affecting the wall of the pulp cavity). External resorption is part of the processs by which primary teeth are lost. Some degree of external resorption also occurs as part of the aging process, and may also be due to injury, inflammation of surrounding tissues, or pressure, for example from an impacted tooth.

Internal resorption is rare, occurring in about 1 percent of adults.... resorption, dental

Restoration, Dental

The reconstruction of part of a damaged tooth. Restoration also refers to the material or substitute part used to rebuild the tooth. Small repairs are usually made by filling the tooth. For extensive repairs, a dental inlay or a crown may be used. Chipped front teeth may be repaired by bonding (see bonding, dental).... restoration, dental

Scaling, Dental

Removal of dental calculi (see calcuus, dental) from the teeth to prevent or treat periodontal disease.... scaling, dental

Sealants, Dental

Plastic coatings that are applied to the chewing surfaces of the back teeth to help prevent decay.... sealants, dental

Splinting, Dental

The mechanical joining of several teeth to hold them firmly in place while an injury heals or while periodontal disease is treated.... splinting, dental

Titanium Dental Implants

See implants, dental.... titanium dental implants

Trapped Nerve

See nerve, trapped.... trapped nerve

X-rays, Dental

See dental X-rays.... x-rays, dental

Abducens Nerve

the sixth *cranial nerve (VI), which supplies the lateral rectus muscle of each eyeball, responsible for turning the eye outwards.... abducens nerve

Circumflex Nerve

a mixed sensory and motor nerve of the upper arm. It arises from the fifth and sixth cervical segments of the spinal cord and is distributed to the deltoid muscle of the shoulder and the overlying skin.... circumflex nerve

Cochlear Nerve

(acoustic nerve, auditory nerve) the nerve connecting the cochlea to the brain and therefore responsible for transmitting the nerve impulses relating to hearing. It forms part of the *vestibulocochlear nerve (cranial nerve VIII).... cochlear nerve

Dental Care Professional

any of several professionals supporting a dentist, formerly referred to as dental auxiliaries and professionals complementary to dentistry. A dental hygienist performs scaling and instruction in oral hygiene. A dental nurse helps the dentist at the chairside by preparing materials, passing instruments, and aspirating fluids from the patient’s mouth. A dental technician constructs dentures, crowns, and orthodontic appliances in the laboratory for the dentist. A clinical dental technician provides dentures directly to patients. A dental therapist performs non-complex treatment under the prescription of a dentist. In the UK dental care professionals are required to be statutorily registered with the General Dental Council (GDC).... dental care professional

Dental Chair

a reclinable chair on which a patient lies for dental treatment. Electric switches change the position of the patient, and the chair is frequently attached to the *dental unit.... dental chair

Dental Floss

a fine thread, usually of nylon, used to clean the surfaces between teeth. A thicker version is known as dental tape. It may be waxed to help the user slide it past the tooth contacts.... dental floss

Dental Handpiece

a piece of dental equipment (high-speed or low-speed) for holding a dental *bur or *file. It is made of corrosion-resistant materials to allow sterilization. See drill.... dental handpiece

Dental Implant

see implant.... dental implant

Dental Nurse

see dental care professional.... dental nurse

Dental Pantomogram

(DPT) a special form of tomogram (see tomography) that provides a picture of all the teeth of both jaws on one film. Newer equipment can produce three-dimensional images of part of the jaw.... dental pantomogram

Dental Unit

a major fixed piece of dental equipment to which are attached the dental drills, aspirator, compressed air syringe, and ultrasonic scaler. It is frequently integral with the *dental chair.... dental unit

House–brackmann Facial Nerve Grading System

(House–Brackmann score, House–Brackmann scale, House–Brackmann facial weakness scale) a six-point grading system for patients with *Bell’s palsy or other forms of facial nerve palsy. Grade I is normal function; grade VI is a total palsy. [J. W. House and D. E. Brackmann (21st century), US otorhinolarygologists]... house–brackmann facial nerve grading system

Inferior Dental Block

(inferior alveolar nerve block) a type of injection to anaesthetize the inferior *dental nerve. Inferior dental block is routinely performed to allow dental procedures to be carried out on the lower teeth on one side of the mouth.... inferior dental block

Inferior Dental Canal

a bony canal in the *mandible on each side. It carries the inferior *dental nerve and vessels and for part of its length its outline is visible on a radiograph.... inferior dental canal

Medullated Nerve Fibre

(myelinated nerve fibre) see myelin.... medullated nerve fibre

Motor Nerve

one of the nerves that carry impulses outwards from the central nervous system to bring about activity in a muscle or gland. Compare sensory nerve.... motor nerve

Musculocutaneous Nerve

a nerve of the *brachial plexus that supplies some muscles of the arm and the skin of the lateral part of the forearm.... musculocutaneous nerve

Nerve Conduction Study

a test done to assess the peripheral nervous system. It involves activating the nerves electronically with electrical pulses and measuring the responses obtained.... nerve conduction study

Nerve Ending

the final part (terminal) of one of the branches of a nerve fibre, where a *neuron makes contact either with another neuron at a synapse or with a muscle or gland cell at a neuromuscular or neuroglandular junction.... nerve ending

Nerve Entrapment Syndrome

any syndrome resulting from pressure on a nerve from surrounding structures. Examples include the *carpal tunnel syndrome and *meralgia paraesthetica.... nerve entrapment syndrome

Nerve Fibre

the long fine process that extends from the cell body of a *neuron and carries nerve impulses. Bundles of nerve fibres running together form a *nerve. Each fibre has a sheath, which in medullated nerve fibres is a relatively thick layer containing the fatty insulating material *myelin.... nerve fibre

Nerve Gas

any gas that disrupts the normal functioning of nerves and thus of the muscles they supply. There are two groups, the G agents and the V agents. The latter are more than 300 times as deadly as mustard gas: one inhalation can kill by paralysing the respiratory muscles. V agents also act through the skin, therefore gas masks are ineffective protection against them.... nerve gas

Nerve Growth Factor

(NGF) a protein (see growth factor), consisting of two polypeptide chains, that is required for the development and longevity of some neurons, including those in the sympathetic nervous system and some central nervous system and sensory neurons. Nerve growth factor is necessary for axon growth and also for initiating new neuronal connections with other cells. The role of NGFs in preventing the degeneration of brain cells is being explored in research into Alzheimer’s disease.... nerve growth factor

Nerve Impulse

the electrical activity in the membrane of a *neuron that – by its rapid spread from one region to the next – is the means by which information is transmitted within the nervous system along the axons of the neurons. The membrane of a resting nerve is charged (polarized) because of the different concentrations of ions inside and outside the cell. When a nerve impulse is triggered, a wave of *depolarization spreads, and ions flow across the membrane (see action potential). Until the nerve has undergone *repolarization no further nerve impulses can pass.... nerve impulse

Nerve Regeneration

the growth of new nerve tissue, which occurs at a very slow rate (1–2 mm per day) after a nerve has been severed and is often partially or totally incomplete. *Microsurgery has improved the results by facilitating primary repair in the immediate aftermath of injury. See also axonotmesis; neurotmesis.... nerve regeneration

Ophthalmic Nerve

the smallest of the three branches of the *trigeminal nerve. It supplies sensory fibres to the eyeball, conjunctiva, and lacrimal gland, to a small region of the nasal mucous membrane, and to the skin of the nose, brows, and scalp.... ophthalmic nerve

Pilomotor Nerves

sympathetic nerves that supply muscle fibres in the skin, around the roots of hairs. Activity of the sympathetic nervous system causes the muscles to contract, raising the hairs and giving the *gooseflesh effect of fear or cold.... pilomotor nerves

Saphenous Nerve

a large branch of the *femoral nerve that arises in the upper thigh, travels down on the inside of the leg, and supplies the skin from the knee to below the ankle with sensory nerves.... saphenous nerve

Sensory Nerve

a nerve that carries information inwards, from an outlying part of the body towards the central nervous system. Different sensory nerves convey information about temperature, pain, touch, taste, etc., to the brain. Compare motor nerve.... sensory nerve

Singular Nerve

a small subdivision of the *vestibular nerve that carries information from the posterior *semicircular canal to the brain. Singular neurectomy is a surgical procedure to divide the singular nerve, occasionally used in the treatment of *benign paroxysmal positional vertigo.... singular nerve

Spinal Accessory Nerve

see accessory nerve.... spinal accessory nerve

Splanchnic Nerves

the series of nerves in the sympathetic system that are distributed to the blood vessels and viscera, passing forwards and downwards from the chain of sympathetic ganglia near the spinal cord to enter the abdomen and branch profusely.... splanchnic nerves

Vasomotor Nerve

any nerve, usually belonging to the autonomic nervous system, that controls the circulation of blood through blood vessels by its action on the muscle fibres within their walls or its action on the heartbeat. The *vagus nerve slows the heart and reduces its output, but sympathetic nerves increase the rate and output of the heart and increase blood pressure by causing the constriction of small blood vessels at the same time.... vasomotor nerve

Vestibular Nerve

the division of the *vestibulocochlear nerve that carries impulses from the semicircular canals, utricle, and saccule of the inner ear to the brain, conveying information about the body’s posture and movements in space and allowing coordination and balance.... vestibular nerve

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