facebow n. 1. A device used in dental prosthodontics to measure the positions of the *temporomandibular joints relative to the maxillary teeth so that such positions may be transferred to an *articulator. It essentially consists of two arms with calliper ends (condyle rods) that can be accurately adjusted to locate the axis of rotation of the mandible, together with a connecting structure which carries a *bite fork on which an impression of the occlusal surfaces of the maxillary teeth is located. The calliper arms make contact immediately anterior to the external auditory meatus, but may fit into it (earbow). The frame carrying the bite fork is capable of being adjusted relative to the two arms. 2. An orthodontic appliance used as extra-oral *anchorage for the posterior teeth during active orthodontic treatment. It is made of steel, is bow-shaped, and is inserted into tubes fixed on the molar teeth. The outer part of the bow protrudes from the mouth, presenting two hooked arms extending posteriorly over the cheeks which are attached to straps that pass around the neck or back of the head.
face height The vertical dimension of the face measured from the mid-point between the eyebrows and the base of the chin. It is divided into the upper face height, the vertical distance between the base of the nose and the mid-point between the eyebrows, and the lower face height, the vertical distance between the base of the nose and the base of the chin.
facemask n. A disposable barrier used to protect the oral and nasal mucous membranes of the wearer from inhaled spray, splashes, spatter, and aerosols. Face masks can also be effective against droplets being expelled into the environment by the wearer.
face shield n. A transparent barrier extending from the forehead to the chin protecting the face and eyes from aerosols, spatter, and debris generated particularly by *ultrasonic scalers and high-speed *turbines.
facet n. A small flat surface on a bone or tooth. It usually indicates an area of tooth wear on a surface contacting another tooth or tooth restoration (*wear facet).
facial bone n. One of the 14 separate bones of the face that make up the jaws, cheeks, and nose. Six are paired, namely the maxilla, palatine, zygomatic, nasal, lacrimal, and inferior concha; the mandible and vomer are single unpaired bones.
facial index The relation of the length of the face to its width multiplied by 100. The length is measured from the nasion to the mental tubercle and the width is the maximum distance between the zygomatic prominences.
facial nerve paralysis (palsy) See BELL’S PALSY.
facial neuralgia n. See TRIGEMINAL NEURALGIA.
facial pain A generic description of pain of non-dental origin. It includes conditions such as trigeminal *neuralgia and post-herpetic neuralgia. Atypical facial pain (sometimes called persistent idiopathic facial pain) affects middle-aged women more than men and is characterized by continuous pain for months or even years. It is often described as gripping or vice-like. it affects the maxilla more than the mandible, and may cross the midline and other anatomical boundaries. There are no clear precipitating factors although patients are frequently depressed.
Further Reading: Woda A., Tubert-Jeannin S., Bouhassira D., Attal N., Fleiter B., Goulet J. P., Gremeau-Richard C., Navez M.L., Picard P., Pionchon P., Albuisson E. Towards a new taxonomy of idiopathic orofacial pain. Pain 2005;116 (3):396–406.
facial seal See BORDER SEAL.
facies n. The appearance or facial expression of an individual. It is used to describe a facial expression suggestive, diagnostic, or indicative of a specific diagnosis or condition.
facing n. A tooth-coloured material, usually either porcelain or resin, used to provide a more aesthetic labial or buccal surface for a metal crown.
factitious adj. Artificially produced, either deliberately or by accident. Patients with factitious disorders produce or exaggerate the symptoms of a physical or mental illness. Factitial gingival trauma in children is often associated with finger or pencil sucking habits. Factitious gingivitis See GINGIVITIS ARTEFACTA.
factor analysis (in statistics) A *multivariate technique used to identify whether the *correlations between a series of *variables are due to their relationships with one or more latent variables in the *data.
Factor VIII (antihaemophilic factor) A blood-clotting factor normally present in the blood, a deficiency of which results in haemophilia A. It binds with *von Willebrand factor. See COAGULATION.
Factor IX (Christmas factor) A blood-clotting factor normally present in the blood, a deficiency of which results in haemophilia B (Christmas disease). See COAGULATION.
Factor XI A blood-clotting factor normally present in the blood, a deficiency of which can lead to excessive bleeding after surgery or trauma to the blood vessels. See COAGULATION.
Factor XII A blood-clotting factor normally present in the blood, a deficiency of which can lead to a prolonged clotting time. See COAGULATION.
facultative adj. Describing an organism that is capable of surviving under different or varying environmental conditions. See also ANAEROBE.
Faculty of General Dental Practice (UK) The Faculty of General Dental Practice (FGDP) is the academic home for general dental practitioners (GDPs) and dental care professionals (DCPs) in the UK. Part of the Royal College of Surgeons of England, it aims to promote excellence in the standards of patient care in general dental practice by encouraging involvement in postgraduate training and assessment, education, and research. The FGDP (UK) supports the career development of both GDPs and DCPs and recognizes the value of an integrated dental team in modern dentistry.
The Faculty of General Dental Practice (UK) website.
faint n. See SYNCOPE.
false negative A falsely drawn negative conclusion; in diagnostic tests it is a conclusion that a person does not have the disease or condition being tested, when they actually do. Compare FALSE POSITIVE.
false positive A falsely drawn positive conclusion; in diagnostic tests it is a result that indicates that a person has the disease or condition when in fact they do not. Compare FALSE NEGATIVE.
false (pseudo) pocket n. See POCKET.
familial adj. Describing a tendency to occur in more members of a family than would be expected by chance alone.
familial adenomatous polyposis (FAP) An inherited autosomal dominant disorder characterized by many thousands of glandular tissue *polyps throughout the colorectal part of the digestive tract. There is a very high risk of developing colorectal *carcinoma if patients are not treated with colectomy. Bone lesions of the mandible and maxilla and dental abnormalities such as impacted teeth other than third molars, *supernumerary teeth, congenitally missing teeth, and fused roots are present in more than 70% of individuals. It is also known as *Gardner’s syndrome.
fascia n. (pl. fasciae) Layers of connective tissue of variable thickness. The superficial fascia is found immediately below the skin and deep fascia invests muscles, nerves, and other organs.
fasciculus (fascicule) n. A bundle of anatomical fibres such as muscle or nerve.
fasciitis n. Inflammation of the fascia due to bacterial infection or rheumatic disease. See also NECROTIZING FASCIITIS.
fat n. A substance that contains one or more *fatty acids and is the principal form of storing energy in the body. Fat serves as a cushion to protect organs, as a carrier of fat-soluble vitamins (*vitamins A, D, E, and K and carotene), and as an insulation layer under the skin. It is also involved in the maintenance of cell membranes.
fatty acids An organic acid that occurs naturally, either singly or combined, and consists of strongly linked carbon and hydrogen atoms in a chain-like structure. They are the constituents of many important *lipids such as triglycerides.
fauces n. The region between the oral cavity and the *pharynx. It is formed by the *tongue, *soft palate, and the pillars of the fauces. The two pillars are curved folds of tissue running from the palate to the base of the tongue. The anterior pillar is called the palatoglossal arch and the posterior pillar the palatopharyngeal arch. Between the two arches lie the palatine *tonsils.
Fauchard, Pierre (1678–1761) Fauchard was born in Brittany and trained as a surgeon in the French navy, which he left in 1700 to become a dentist in Angers, western France. In 1719 he established a practice in Paris and was the first person to use the title of surgeon–dentist (chirurgien–dentiste). He published the first dental textbook, ‘Le Chirugien Dentiste ou Treatise des Dents’ (‘The Surgeon Dentist or Treatise on the Teeth’) in 1728 (the first English translation was not published until 1946), in which he described 103 diseases of the teeth and oral cavity including pyorrhoea alveolaris. He introduced many new radical ideas, such as the treatment of patients in the chair (as opposed to the then conventional approach of lying them on the floor). He coined the term ‘dental caries’ and dismissed the idea of worms being the causative agent of dental decay. Because he appreciated the benefits of the judicious extraction of teeth to prevent malocclusion, he is regarded as one of the world’s first orthodontic specialists. In his honour, in 1936 the Pierre Fauchard Academy was established. The academy maintains a ‘Hall of Fame’ that recognizes the achievements of over 7000 leading members of the dental profession.
Further Reading: Lynch C. D., O’Sullivan V. R., McGillycuddy C. T. Pierre Fauchard: the ‘Father of Modern Dentistry’. Br Dent J 2006;201:779–81.
FDI See FEDERATION DENTAIRE INTERNATIONALE.
FDI tooth notation See TOOTH NOTATION.
febrile adj. Pertaining to a raised body temperature or fever.
Federation Dentaire Internationale (FDI) (World Dental Federation) A federation of National Dental Associations and, as such, its main roles are to bring together the world of dentistry, to represent the dental profession of the world, and to stimulate and facilitate the exchange of information across all borders with the aim of optimal oral health for all peoples.
fee n. Payment for professional services rendered. The usual fee (customary, reasonable) is the fee that an individual dentist most frequently charges for a specific dental service.
feldspar n. Any of a group of hard grey crystalline minerals that consist of aluminium silicates of potassium, sodium, calcium, or barium. A mixture of feldspar, quartz, and *kaolin is used in the manufacture of *porcelain denture teeth and in the construction of some porcelain crowns and inlays.
felt need n. See NEED.
felypressin n. A synthetic octapeptide which resembles the *pituitary hormone *vasopressin. It is a *vasoconstrictor which causes vascular smooth muscle to contract. It is included in dental *anaesthetic solutions in order to produce constriction of the venous vessels, thus reducing the rate at which the local anaesthetic is carried away by the bloodstream, and thereby extending the duration of the local anaesthetic to produce a deeper and more effective level of anaesthesia. Trade name: Octapressin®.
fenestration n. A procedure in which a hole is opened in the bone, e.g. alveolar fenestration in which access is gained to the apical root area through a window in the alveolar cortical plate. Fenestration can occur pathologically, producing a window-like defect in the cortical jaw bone to give an isolated area of exposed root surface. This lesion will be seen when the alveolar bone is exposed by flap surgery; it is associated with localized periodontal destruction.
ferric oxide n. The impure form of naturally occurring iron oxide, used as a metal polishing agent and as a colouring agent in resins and ceramics. It is also known as jeweller’s or red rouge.
ferric sulphate n. A chemical applied in aqueous solution to the pulpal surface of primary teeth to achieve *haemostasis in a *pulpotomy procedure. It is the active ingredient in some *gingival retraction cords.
Further Reading: Ibricevic H., Al-Jame Q. Ferric sulphate and formocresol in pulpotomy of primary molars: long term follow-up study. Eur J Paediatr Dent 2003 Mar;4(1):28–32.
ferrous sulphate n. An iron salt used in the treatment of iron deficiency anaemia. It may cause constipation or diarrhoea and will darken the colour of the stools. If in tablet form and dissolved sublingually it can result in mucosal ulceration.
Further Reading: Jones T. A., Parmer S. C. Oral mucosal ulceration due to ferrous sulphate tablets: report of a case. Dent Update 2006;33:632–3.
ferrule effect The protective effect achieved by the supra-marginal extension of the dentine coronal to the shoulder of a post and core crown preparation. This procedure creates a ferrule of dentine designed to reduce stress within a tooth.
Further Reading: Stankiewicz N., Wilson P. The ferrule effect. Dent Update 2008;35:222–8.
festoon 1. v. To shape and contour a denture base material to simulate the natural contour of the tissues including the gingival tissues replaced by the appliance. 2. n. The shape of a prosthesis which simulates that of natural tissues. 3. n. The vertical grooving of bone during osseous surgery. 4. n. Semi-lunar enlargements of the marginal gingivae (see MCCALL’S FESTOONS).
fetid adj. See FOETID.
fever n. See PYREXIA.
fiberotomy n. See PERICISION.
fibre n. 1. (in anatomy) A threadlike structure such as a muscle cell, a collagen fibre, or a nerve fibre. The free gingival and periodontal fibres of the *periodontal ligament (e.g. the apical, transseptal, and circumferential) are important in maintaining the integrity of the tooth interrelationship. 2. (in dietetics) Dietary fibre (roughage) is that part of food that cannot be digested and absorbed to produce energy; it is mainly found in vegetables, fruits, and cereals, and adds bulk to the diet.
fibre optic light A light source which uses flexible fibreglass to conduct light over long distances with little or no distortion. It may be used as an intra-oral light attached to a mouth mirror or handpiece.
fibre optic transillumination (FOTI) See TRANSILLUMINATION.
fibre reinforced resin composite See RESIN COMPOSITE, FIBRE REINFORCED.
fibrillation n. The disorganized random depolarization of muscle fibres of the heart producing a wriggling effect due to rapid, irregular, and unsynchronized activity. It prevents normal coordinated muscular contraction. Atrial fibrillation is a common condition found more frequently in elderly women and produces a fast irregular pulse rate. Ventricular fibrillation is a common cause of ‘out of hospital’ cardiac arrest.
fibrin n. An insoluble protein formed as the final product in *blood coagulation by the action of *thrombin on *fibrinogen.
fibrinogen n. A soluble protein found in blood *plasma that is acted upon by the *enzyme *thrombin to produce insoluble *fibrin as the final stage of *blood coagulation.
fibrinolysis n. (adj. fibrinolytic) The process of *fibrin breakdown by the enzyme fibrinolysin during the removal of small fibrin blood clots from the circulation.
fibroadenoma n. A benign tumour of epithelial origin containing recognizable fibrous tissue.
fibroblast n. A cell found in *connective tissue responsible for the production of *collagen fibres and *ground substance.
fibrocartilage n. A type of *cartilage in which there are dense bundles of fibres.
fibro-epithelial polyp n. See POLYP.
fibroma n. (pl. fibromas or fibromata) A non-malignant (benign) neoplasm of *connective tissue: they are rare in the oral cavity and most nodules of fibrous tissue are reactive *hyperplasia to trauma and not neoplasms. An ameloblastic fibroma is a circumscribed benign odontogenic neoplasm composed of cellular fibrous tissue resembling the dental papilla containing small islands of odontogenic epithelium. They are normally found in the mandible over unerupted molars of young patients and appear as a circumscribed *radiolucency; the soft tissue mass can cause expansion of the *bone cortex. Treatment is by conservative surgical excision. An ossifying fibroma (cemento-ossifying fibroma) is a well-demarcated lesion composed of cellular fibrous tissue in which calcification is laid down and which arises in the periodontal ligament of young individuals. They are most common in the posterior mandible and cause jaw expansion; radiographically they appear as a well-defined mixed radiolucency or radiopacity and are treated by surgical removal. An odontogenic fibroma is a benign odontogenic neoplasm of unknown aetiology derived from odontogenic connective tissue: it contains scattered islands of odontogenic epithelium and foci of calcification; treatment is by enucleation or curettage.
fibromatosis, oral (gingival) n. A rare benign overgrowth of fibrous tissue of hereditary or *idiopathic origin primarily affecting children and young adults. It is characterized by painless firm *hyperplastic tissue enlargement of the *gingivae which covers the teeth; there may also be associated gingival inflammation and bleeding where the oral hygiene is poor; one or more quadrants of the mouth may be affected. It is treated by wide excision (*gingivectomy), although it has a locally aggressive behaviour possibly leading to recurrence. The condition of fibrous gingival hyperplasia may also be drug-induced, e.g. by *phenytoin or *nifedipine, in which the hyperplasia occurs three or more years after the onset of drug use; treatment is by plaque control and may also include a change in drug therapy. Symmetrical fibromatosis of the tuberosity can occur in adults and is characterized by large, smooth, fleshy, hyperplasia of the tissues overlying the maxillary tuberosities; treatment is usually unnecessary unless there is interference with a denture fitting surface.
fibronectin n. A high molecular weight glycoprotein compound consisting of two disulfide-linked *polypeptides. It is found on cell surfaces, in connective tissues, in the blood, and in other body fluids. It may enhance the adherence of *fibroblasts to the tooth root surface.
fibrosarcoma n. A malignant tumour of *connective tissue of which the basic cell type is a *fibroblast. Although rare, they can occur in the oral region.
fibrosis n. (adj. fibrotic) A thickening and scarring of connective tissue due to excess collagen, usually as a result of chronic inflammation or injury. In oral submucous fibrosis, progressive fibrosis of the oral cavity leads to difficulty in opening (*trismus) and the lesion is regarded as *premalignant with an increased risk of oral cancer development. It is common in persons who chew paan or betel quid. fibrotic adj.
fibrous dysplasia n. See DYSPLASIA.
Fickling, Ben, CBE (1909–2007) A dental surgeon who played a pivotal role in the development of modern oral and maxillo-facial surgery. He designed several surgical instruments (see FORCEPS) and together with William Warwick James published ‘Injuries of Jaws and Face’ in 1940 and the translation of Le Fort’s work into English. He was a founder member, and helped to write the constitution, of the British Association of Oral Surgeons and planned and inaugurated the Royal College of Surgeons’ first higher examinations in general surgery. He was dean of the Faculty of Dental Surgery in the Royal College of Surgeons in England from 1968 to 1971 and was awarded the CBE in 1973.
fifth disease n. See ERYTHEMA INFECTIOSUM.
Filatov’s spots [N. F. Filatov (1847–1902), Russian paediatrician] A synonym for Koplick’s spots.
file n. A metal tool with a roughened surface or surfaces used for smoothing or shaping. A bone file is a hand instrument used to smooth a sharp or high bony surface during a surgical procedure. Interproximal bone files are double safe-sided instruments with either curved or straight tapering blades used for the reduction of interproximal bone during periodontal surgery. An endodontic file is a metal instrument used in endodontic procedures to *debride and shape the root canal system; they may be hand-held or mounted in a dental *handpiece. They are manufactured in different shapes and sizes to conform to the root canal structure. A K-type-file is made by twisting a square metal blank. A Hedstrom file is made by machining a continuous groove into a metal blank. A K-flex file is more flexible than a K-type-file and is made by twisting a rhomboid shape blank. A flex-o-file is more flexible than the K-type-file and is made from a triangular blank with a blunt tip. The *International Standards Organization (ISO) defines a colour coding related to the size of the file.
Files have traditionally been made of steel but newer varieties are made of nickel titanium (NiTi) because of the metal’s greater flexibility. Finishing files are used for preparing the apical third of a root canal and producing a variable taper.
filler n. An inert material added to *resin composite to increase strength and abrasion resistance. Filler particles are usually composed of quartz or glasses containing barium or strontium (added to give the resin radiopacity). Fillers provide a means of controlling various aesthetic features such as colour, translucency, and fluorescence. The filler particles may be large (macrofilled), small (microfilled or nanofilled), or a mixture of both (hybrid). See also RESIN COMPOSITE.
filler paste n. See PASTE.
filling n. See RESTORATION.