Three long canals (anterior, posterior, and lateral) of the bony labyrinth. They are set at right angles to each other and are situated posterosuperior to the vestibule of the bony labyrinth (VESTIBULAR LABYRINTH). The semicircular canals have five openings into the vestibule with one shared by the anterior and the posterior canals. Within the canals are the SEMICIRCULAR DUCTS.

The narrow passage way that conducts the sound collected by the EAR AURICLE to the TYMPANIC MEMBRANE.

The cavity within the SPINAL COLUMN through which the SPINAL CORD passes.

Preparatory activities in ROOT CANAL THERAPY by partial or complete extirpation of diseased pulp, cleaning and sterilization of the empty canal, enlarging and shaping the canal to receive the sealing material. The cavity may be prepared by mechanical, sonic, chemical, or other means. (From Dorland, 28th ed, p1700)

Chemicals used mainly to disinfect root canals after pulpectomy and before obturation. The major ones are camphorated monochlorophenol, EDTA, formocresol, hydrogen peroxide, metacresylacetate, and sodium hypochlorite. Root canal irrigants include also rinsing solutions of distilled water, sodium chloride, etc.

The space in a tooth bounded by the dentin and containing the dental pulp. The portion of the cavity within the crown of the tooth is the pulp chamber; the portion within the root is the pulp canal or root canal.

Materials placed inside a root canal for the purpose of obturating or sealing it. The materials may be gutta-percha, silver cones, paste mixtures, or other substances. (Dorland, 28th ed, p631 & Boucher's Clinical Dental Terminology, 4th ed, p187)

The terminal segment of the LARGE INTESTINE, beginning from the ampulla of the RECTUM and ending at the anus.

The tip or terminal end of the root of a tooth. (Jablonski, Dictionary of Dentistry, 1992, p62)

Coagulated exudate isolated from several species of the tropical tree Palaquium (Sapotaceae). It is the trans-isomer of natural rubber and is used as a filling and impression material in dentistry and orthopedics and as an insulator in electronics. It has also been used as a rubber substitute.

Hand-held tools or implements especially used by dental professionals for the performance of clinical tasks.

It is used as an oxidizing and bleaching agent and as a disinfectant. (From Grant & Hackh's Chemical Dictionary, 5th ed)

The part of a tooth from the neck to the apex, embedded in the alveolar process and covered with cementum. A root may be single or divided into several branches, usually identified by their relative position, e.g., lingual root or buccal root. Single-rooted teeth include mandibular first and second premolars and the maxillary second premolar teeth. The maxillary first premolar has two roots in most cases. Maxillary molars have three roots. (Jablonski, Dictionary of Dentistry, 1992, p690)

Inflammation of the PERIAPICAL TISSUE. It includes general, unspecified, or acute nonsuppurative inflammation. Chronic nonsuppurative inflammation is PERIAPICAL GRANULOMA. Suppurative inflammation is PERIAPICAL ABSCESS.

A white powder prepared from lime that has many medical and industrial uses. It is in many dental formulations, especially for root canal filling.

A gelatinous membrane overlying the acoustic maculae of SACCULE AND UTRICLE. It contains minute crystalline particles (otoliths) of CALCIUM CARBONATE and protein on its outer surface. In response to head movement, the otoliths shift causing distortion of the vestibular hair cells which transduce nerve signals to the BRAIN for interpretation of equilibrium.

Death of pulp tissue with or without bacterial invasion. When the necrosis is due to ischemia with superimposed bacterial infection, it is referred to as pulp gangrene. When the necrosis is non-bacterial in origin, it is called pulp mummification.

Polymeric resins derived from OXIRANES and characterized by strength and thermosetting properties. Epoxy resins are often used as dental materials.

The most posterior teeth on either side of the jaw, totaling eight in the deciduous dentition (2 on each side, upper and lower), and usually 12 in the permanent dentition (three on each side, upper and lower). They are grinding teeth, having large crowns and broad chewing surfaces. (Jablonski, Dictionary of Dentistry, 1992, p821)

The vestibular part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The vestibular nerve fibers arise from neurons of Scarpa's ganglion and project peripherally to vestibular hair cells and centrally to the VESTIBULAR NUCLEI of the BRAIN STEM. These fibers mediate the sense of balance and head position.

A dental specialty concerned with the maintenance of the dental pulp in a state of health and the treatment of the pulp cavity (pulp chamber and pulp canal).

Adherent debris produced when cutting the enamel or dentin in cavity preparation. It is about 1 micron thick and its composition reflects the underlying dentin, although different quantities and qualities of smear layer can be produced by the various instrumentation techniques. Its function is presumed to be protective, as it lowers dentin permeability. However, it masks the underlying dentin and interferes with attempts to bond dental material to the dentin.

Either of a pair of compound bones forming the lateral (left and right) surfaces and base of the skull which contains the organs of hearing. It is a large bone formed by the fusion of parts: the squamous (the flattened anterior-superior part), the tympanic (the curved anterior-inferior part), the mastoid (the irregular posterior portion), and the petrous (the part at the base of the skull).

The essential part of the hearing organ consists of two labyrinthine compartments: the bony labyrinthine and the membranous labyrinth. The bony labyrinth is a complex of three interconnecting cavities or spaces (COCHLEA; VESTIBULAR LABYRINTH; and SEMICIRCULAR CANALS) in the TEMPORAL BONE. Within the bony labyrinth lies the membranous labyrinth which is a complex of sacs and tubules (COCHLEAR DUCT; SACCULE AND UTRICLE; and SEMICIRCULAR DUCTS) forming a continuous space enclosed by EPITHELIUM and connective tissue. These spaces are filled with LABYRINTHINE FLUIDS of various compositions.

A circular structural unit of bone tissue. It consists of a central hole, the Haversian canal through which blood vessels run, surrounded by concentric rings, called lamellae.

A reflex wherein impulses are conveyed from the cupulas of the SEMICIRCULAR CANALS and from the OTOLITHIC MEMBRANE of the SACCULE AND UTRICLE via the VESTIBULAR NUCLEI of the BRAIN STEM and the median longitudinal fasciculus to the OCULOMOTOR NERVE nuclei. It functions to maintain a stable retinal image during head rotation by generating appropriate compensatory EYE MOVEMENTS.

I'm sorry for any confusion, but the term "Panama Canal Zone" is geographical and historical, not medical. It refers to the area surrounding and including the Panama Canal that was controlled by the United States from 1903 to 1979, and it's not a medical concept that would have a definition in a medical context.

Measurement of tooth characteristics.

Narrowing of the spinal canal.

The largest and strongest bone of the FACE constituting the lower jaw. It supports the lower teeth.

Tumors or cancer of any part of the hearing and equilibrium system of the body (the EXTERNAL EAR, the MIDDLE EAR, and the INNER EAR).

Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Tissue surrounding the apex of a tooth, including the apical portion of the periodontal membrane and alveolar bone.

An illusion of movement, either of the external world revolving around the individual or of the individual revolving in space. Vertigo may be associated with disorders of the inner ear (EAR, INNER); VESTIBULAR NERVE; BRAINSTEM; or CEREBRAL CORTEX. Lesions in the TEMPORAL LOBE and PARIETAL LOBE may be associated with FOCAL SEIZURES that may feature vertigo as an ictal manifestation. (From Adams et al., Principles of Neurology, 6th ed, pp300-1)

Pathological processes of the ear, the hearing, and the equilibrium system of the body.

An oval, bony chamber of the inner ear, part of the bony labyrinth. It is continuous with bony COCHLEA anteriorly, and SEMICIRCULAR CANALS posteriorly. The vestibule contains two communicating sacs (utricle and saccule) of the balancing apparatus. The oval window on its lateral wall is occupied by the base of the STAPES of the MIDDLE EAR.

The seepage of fluids, debris, and micro-organisms between the walls of a prepared dental cavity and the restoration.

Surgery performed on the external, middle, or internal ear.

A tooth from which the dental pulp has been removed or is necrotic. (Boucher, Clinical Dental Terminology, 4th ed)

Pathological processes of the inner ear (LABYRINTH) which contains the essential apparatus of hearing (COCHLEA) and balance (SEMICIRCULAR CANALS).

Dental procedure in which the entire pulp chamber is removed from the crown and roots of a tooth.

Technique involving the passage of X-rays through oral structures to create a film record while a central tab or wing of dental X-ray film is being held between upper and lower teeth.

Hearing loss due to interference with the mechanical reception or amplification of sound to the COCHLEA. The interference is in the outer or middle ear involving the EAR CANAL; TYMPANIC MEMBRANE; or EAR OSSICLES.

A spectrum of septal defects involving the ATRIAL SEPTUM; VENTRICULAR SEPTUM; and the atrioventricular valves (TRICUSPID VALVE; BICUSPID VALVE). These defects are due to incomplete growth and fusion of the ENDOCARDIAL CUSHIONS which are important in the formation of two atrioventricular canals, site of future atrioventricular valves.

The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)

Elicitation of a rotatory nystagmus by stimulating the semicircular canals with water or air which is above or below body temperature. In warm caloric stimulation a rotatory nystagmus is developed toward the side of the stimulated ear; in cold, away from the stimulated side. Absence of nystagmus indicates the labyrinth is not functioning.

A porelike structure surrounding the entire circumference of the anterior chamber through which aqueous humor circulates to the canal of Schlemm.

Computed tomography modalities which use a cone or pyramid-shaped beam of radiation.

One of the eight permanent teeth, two on either side in each jaw, between the canines (CUSPID) and the molars (MOLAR), serving for grinding and crushing food. The upper have two cusps (bicuspid) but the lower have one to three. (Jablonski, Dictionary of Dentistry, 1992, p822)

The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.

The tunnel in the lower anterior ABDOMINAL WALL through which the SPERMATIC CORD, in the male; ROUND LIGAMENT, in the female; nerves; and vessels pass. Its internal end is at the deep inguinal ring and its external end is at the superficial inguinal ring.

A mixture of metallic elements or compounds with other metallic or metalloid elements in varying proportions for use in restorative or prosthetic dentistry.

Voluntary or involuntary motion of head that may be relative to or independent of body; includes animals and humans.

The posterior part of the temporal bone. It is a projection of the petrous bone.

The hard portion of the tooth surrounding the pulp, covered by enamel on the crown and cementum on the root, which is harder and denser than bone but softer than enamel, and is thus readily abraded when left unprotected. (From Jablonski, Dictionary of Dentistry, 1992)

An oval semitransparent membrane separating the external EAR CANAL from the tympanic cavity (EAR, MIDDLE). It contains three layers: the skin of the external ear canal; the core of radially and circularly arranged collagen fibers; and the MUCOSA of the middle ear.

Tumors or cancer of the ANAL CANAL.

One of a pair of irregularly shaped bones that form the upper jaw. A maxillary bone provides tooth sockets for the superior teeth, forms part of the ORBIT, and contains the MAXILLARY SINUS.

Pathological processes of the VESTIBULOCOCHLEAR NERVE, including the branches of COCHLEAR NERVE and VESTIBULAR NERVE. Common examples are VESTIBULAR NEURITIS, cochlear neuritis, and ACOUSTIC NEUROMA. Clinical signs are varying degree of HEARING LOSS; VERTIGO; and TINNITUS.

Acute and chronic conditions characterized by external mechanical compression of the SPINAL CORD due to extramedullary neoplasm; EPIDURAL ABSCESS; SPINAL FRACTURES; bony deformities of the vertebral bodies; and other conditions. Clinical manifestations vary with the anatomic site of the lesion and may include localized pain, weakness, sensory loss, incontinence, and impotence.

A dark-gray, metallic element of widespread distribution but occurring in small amounts; atomic number, 22; atomic weight, 47.90; symbol, Ti; specific gravity, 4.5; used for fixation of fractures. (Dorland, 28th ed)

Pathological processes of the VESTIBULAR LABYRINTH which contains part of the balancing apparatus. Patients with vestibular diseases show instability and are at risk of frequent falls.

A rapid, low-dose, digital imaging system using a small intraoral sensor instead of radiographic film, an intensifying screen, and a charge-coupled device. It presents the possibility of reduced patient exposure and minimal distortion, although resolution and latitude are inferior to standard dental radiography. A receiver is placed in the mouth, routing signals to a computer which images the signals on a screen or in print. It includes digitizing from x-ray film or any other detector. (From MEDLINE abstracts; personal communication from Dr. Charles Berthold, NIDR)

Endodontic diseases of the DENTAL PULP inside the tooth, which is distinguished from PERIAPICAL DISEASES of the tissue surrounding the root.

Any of the eight frontal teeth (four maxillary and four mandibular) having a sharp incisal edge for cutting food and a single root, which occurs in man both as a deciduous and a permanent tooth. (Jablonski, Dictionary of Dentistry, 1992, p820)

The teeth of the first dentition, which are shed and replaced by the permanent teeth.

One of the three ossicles of the middle ear. It transmits sound vibrations from the INCUS to the internal ear (Ear, Internal see LABYRINTH).

A phenol obtained from thyme oil or other volatile oils used as a stabilizer in pharmaceutical preparations, and as an antiseptic (antibacterial or antifungal) agent. It was formerly used as a vermifuge.

The third tooth to the left and to the right of the midline of either jaw, situated between the second INCISOR and the premolar teeth (BICUSPID). (Jablonski, Dictionary of Dentistry, 1992, p817)

A number of tests used to determine if the brain or balance portion of the inner ear are causing dizziness.

Inflammation of the OUTER EAR including the external EAR CANAL, cartilages of the auricle (EAR CARTILAGE), and the TYMPANIC MEMBRANE.

The first seven VERTEBRAE of the SPINAL COLUMN, which correspond to the VERTEBRAE of the NECK.

Removal of minerals from bones during bone examination.

X-RAY COMPUTERIZED TOMOGRAPHY with resolution in the micrometer range.

Use of a metal casting, usually with a post in the pulp or root canal, designed to support and retain an artificial crown.

The four cellular masses in the floor of the fourth ventricle giving rise to a widely dispersed special sensory system. Included is the superior, medial, inferior, and LATERAL VESTIBULAR NUCLEUS. (From Dorland, 27th ed)

Inflammation of the DENTAL PULP, usually due to bacterial infection in dental caries, tooth fracture, or other conditions causing exposure of the pulp to bacterial invasion. Chemical irritants, thermal factors, hyperemic changes, and other factors may also cause pulpitis.

Radiographic techniques used in dentistry.

A disinfectant and topical anti-infective agent used also as mouthwash to prevent oral plaque.

A surgical procedure that entails removing all (laminectomy) or part (laminotomy) of selected vertebral lamina to relieve pressure on the SPINAL CORD and/or SPINAL NERVE ROOTS. Vertebral lamina is the thin flattened posterior wall of vertebral arch that forms the vertebral foramen through which pass the spinal cord and nerve roots.

Recorded electrical responses from muscles, especially the neck muscles or muscles around the eyes, following stimulation of the EAR VESTIBULE.

Fluids found within the osseous labyrinth (PERILYMPH) and the membranous labyrinth (ENDOLYMPH) of the inner ear. (From Gray's Anatomy, 30th American ed, p1328, 1332)

The clear, watery fluid which fills the anterior and posterior chambers of the eye. It has a refractive index lower than the crystalline lens, which it surrounds, and is involved in the metabolism of the cornea and the crystalline lens. (Cline et al., Dictionary of Visual Science, 4th ed, p319)

The yellow or brown waxy secretions produced by vestigial apocrine sweat glands in the external ear canal.

The therapy of the same disease in a patient, with the same agent or procedure repeated after initial treatment, or with an additional or alternate measure or follow-up. It does not include therapy which requires more than one administration of a therapeutic agent or regimen. Retreatment is often used with reference to a different modality when the original one was inadequate, harmful, or unsuccessful.

Involuntary rhythmical movements of the eyes in the normal person. These can be naturally occurring as in end-position (end-point, end-stage, or deviational) nystagmus or induced by the optokinetic drum (NYSTAGMUS, OPTOKINETIC), caloric test, or a rotating chair.

A branch of the trigeminal (5th cranial) nerve. The mandibular nerve carries motor fibers to the muscles of mastication and sensory fibers to the teeth and gingivae, the face in the region of the mandible, and parts of the dura.

The dense rock-like part of temporal bone that contains the INNER EAR. Petrous bone is located at the base of the skull. Sometimes it is combined with the MASTOID PROCESS and called petromastoid part of temporal bone.

VERTEBRAE in the region of the lower BACK below the THORACIC VERTEBRAE and above the SACRAL VERTEBRAE.

The space and structures directly internal to the TYMPANIC MEMBRANE and external to the inner ear (LABYRINTH). Its major components include the AUDITORY OSSICLES and the EUSTACHIAN TUBE that connects the cavity of middle ear (tympanic cavity) to the upper part of the throat.

Peculiarities associated with the internal structure, form, topology, or architecture of organisms that distinguishes them from others of the same species or group.

A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.

Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al., Principles of Neurology, 6th ed, p272)

The process of generating three-dimensional images by electronic, photographic, or other methods. For example, three-dimensional images can be generated by assembling multiple tomographic images with the aid of a computer, while photographic 3-D images (HOLOGRAPHY) can be made by exposing film to the interference pattern created when two laser light sources shine on an object.

Stainless steel. A steel containing Ni, Cr, or both. It does not tarnish on exposure and is used in corrosive environments. (Grant & Hack's Chemical Dictionary, 5th ed)

The washing of a body cavity or surface by flowing water or solution for therapy or diagnosis.

Extraoral body-section radiography depicting an entire maxilla, or both maxilla and mandible, on a single film.

Acute or chronic inflammation of tissues surrounding the apical portion of a tooth, associated with the collection of pus, resulting from infection following pulp infection through a carious lesion or as a result of an injury causing pulp necrosis. (Dorland, 27th ed)

Tomography using x-ray transmission and a computer algorithm to reconstruct the image.

'Dental pulp calcification' is a pathological condition characterized by the deposition of hard tissue within the pulp chamber and root canal(s), which can result in the obliteration of pulpal space, potentially leading to various clinical symptoms such as pain or dental sensitivity.

The three membranous semicircular ducts within the bony semicircular canals. They open into the UTRICLE through five openings. Each duct has at one end a sensory area called the ampullary crest. AMPULLARY HAIR CELLS of the crests sense the movement of ENDOLYMPH resulting from rotation of the head.

A group of twelve VERTEBRAE connected to the ribs that support the upper trunk region.

The generic term for salts derived from silica or the silicic acids. They contain silicon, oxygen, and one or more metals, and may contain hydrogen. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th Ed)

A dead body, usually a human body.

A mass of KERATIN-producing squamous EPITHELIUM that resembles an inverted (suck-in) bag of skin in the MIDDLE EAR. It arises from the eardrum (TYMPANIC MEMBRANE) and grows into the MIDDLE EAR causing erosion of EAR OSSICLES and MASTOID that contains the INNER EAR.

Inorganic compounds that contain calcium as an integral part of the molecule.

Substances used to bond COMPOSITE RESINS to DENTAL ENAMEL and DENTIN. These bonding or luting agents are used in restorative dentistry, ROOT CANAL THERAPY; PROSTHODONTICS; and ORTHODONTICS.

A mild astringent and topical protectant with some antiseptic action. It is also used in bandages, pastes, ointments, dental cements, and as a sunblock.

A surgical operation for the relief of pressure in a body compartment or on a body part. (From Dorland, 28th ed)

Excision of the apical portion of a tooth through an opening made in the overlying labial, buccal, or palatal alveolar bone. (Dorland, 28th ed)

The lymph fluid found in the membranous labyrinth of the ear. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

X-ray visualization of the spinal cord following injection of contrast medium into the spinal arachnoid space.

A genus of the family Chinchillidae which consists of three species: C. brevicaudata, C. lanigera, and C. villidera. They are used extensively in biomedical research.

The 8th cranial nerve. The vestibulocochlear nerve has a cochlear part (COCHLEAR NERVE) which is concerned with hearing and a vestibular part (VESTIBULAR NERVE) which mediates the sense of balance and head position. The fibers of the cochlear nerve originate from neurons of the SPIRAL GANGLION and project to the cochlear nuclei (COCHLEAR NUCLEUS). The fibers of the vestibular nerve arise from neurons of Scarpa's ganglion and project to the VESTIBULAR NUCLEI.

A disease of the inner ear (LABYRINTH) that is characterized by fluctuating SENSORINEURAL HEARING LOSS; TINNITUS; episodic VERTIGO; and aural fullness. It is the most common form of endolymphatic hydrops.

The 7th cranial nerve. The facial nerve has two parts, the larger motor root which may be called the facial nerve proper, and the smaller intermediate or sensory root. Together they provide efferent innervation to the muscles of facial expression and to the lacrimal and SALIVARY GLANDS, and convey afferent information for TASTE from the anterior two-thirds of the TONGUE and for TOUCH from the EXTERNAL EAR.

Descriptive anatomy based on three-dimensional imaging (IMAGING, THREE-DIMENSIONAL) of the body, organs, and structures using a series of computer multiplane sections, displayed by transverse, coronal, and sagittal analyses. It is essential to accurate interpretation by the radiologist of such techniques as ultrasonic diagnosis, MAGNETIC RESONANCE IMAGING, and computed tomography (TOMOGRAPHY, X-RAY COMPUTED). (From Lane & Sharfaei, Modern Sectional Anatomy, 1992, Preface)

A fetal heart structure that is the bulging areas in the cardiac septum between the HEART ATRIA and the HEART VENTRICLES. During development, growth and fusion of endocardial cushions at midline forms the two atrioventricular canals, the sites for future TRICUSPID VALVE and BICUSPID VALVE.

The head of a long bone that is separated from the shaft by the epiphyseal plate until bone growth stops. At that time, the plate disappears and the head and shaft are united.

Iodinated hydrocarbons are organic compounds containing carbon and hydrogen atoms, with iodine atoms covalently bonded to them, which are used in medical imaging as radiocontrast agents.

Two membranous sacs within the vestibular labyrinth of the INNER EAR. The saccule communicates with COCHLEAR DUCT through the ductus reuniens, and communicates with utricle through the utriculosaccular duct from which the ENDOLYMPHATIC DUCT arises. The utricle and saccule have sensory areas (acoustic maculae) which are innervated by the VESTIBULAR NERVE.

The paired bands of yellow elastic tissue that connect adjoining laminae of the vertebrae. With the laminae, it forms the posterior wall of the spinal canal and helps hold the body erect.

Voluntary or reflex-controlled movements of the eye.

Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.

The front third of the eyeball that includes the structures between the front surface of the cornea and the front of the VITREOUS BODY.

Methods of creating machines and devices.

The result of pathological changes in the hard tissue of a tooth caused by carious lesions, mechanical factors, or trauma, which render the pulp susceptible to bacterial invasion from the external environment.

Sensory cells in the acoustic maculae with their apical STEREOCILIA embedded in a gelatinous OTOLITHIC MEMBRANE. These hair cells are stimulated by the movement of otolithic membrane, and impulses are transmitted via the VESTIBULAR NERVE to the BRAIN STEM. Hair cells in the saccule and those in the utricle sense linear acceleration in vertical and horizontal directions, respectively.

Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.

Substances used on humans and other animals that destroy harmful microorganisms or inhibit their activity. They are distinguished from DISINFECTANTS, which are used on inanimate objects.

Part of the back and base of the CRANIUM that encloses the FORAMEN MAGNUM.

Break or rupture of a tooth or tooth root.

A benign SCHWANNOMA of the eighth cranial nerve (VESTIBULOCOCHLEAR NERVE), mostly arising from the vestibular branch (VESTIBULAR NERVE) during the fifth or sixth decade of life. Clinical manifestations include HEARING LOSS; HEADACHE; VERTIGO; TINNITUS; and FACIAL PAIN. Bilateral acoustic neuromas are associated with NEUROFIBROMATOSIS 2. (From Adams et al., Principles of Neurology, 6th ed, p673)

An irregular unpaired bone situated at the SKULL BASE and wedged between the frontal, temporal, and occipital bones (FRONTAL BONE; TEMPORAL BONE; OCCIPITAL BONE). Sphenoid bone consists of a median body and three pairs of processes resembling a bat with spread wings. The body is hollowed out in its inferior to form two large cavities (SPHENOID SINUS).

The bonelike rigid connective tissue covering the root of a tooth from the cementoenamel junction to the apex and lining the apex of the root canal, also assisting in tooth support by serving as attachment structures for the periodontal ligament. (Jablonski, Dictionary of Dentistry, 1992)

A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.

Procedure that involves the removal of infectious products from a root canal space through use of special instruments and fillings. This procedure is performed when root canal treatment fails.

The part of the inner ear (LABYRINTH) that is concerned with hearing. It forms the anterior part of the labyrinth, as a snail-like structure that is situated almost horizontally anterior to the VESTIBULAR LABYRINTH.

Objective tests of middle ear function based on the difficulty (impedance) or ease (admittance) of sound flow through the middle ear. These include static impedance and dynamic impedance (i.e., tympanometry and impedance tests in conjunction with intra-aural muscle reflex elicitation). This term is used also for various components of impedance and admittance (e.g., compliance, conductance, reactance, resistance, susceptance).

A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)

Single preparations containing two or more active agents, for the purpose of their concurrent administration as a fixed dose mixture.

The upper part of the human body, or the front or upper part of the body of an animal, typically separated from the rest of the body by a neck, and containing the brain, mouth, and sense organs.

An increase in the rate of speed.

A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

A metallic element that has the atomic symbol Bi, atomic number 83 and atomic weight 208.98.

The upper chamber of the COCHLEA that is filled with PERILYMPH. It is connected to SCALA TYMPANI via helicotrema at the apex of the cochlea.

Sheets of latex rubber punched and placed over the teeth during dental procedures to isolate the field of operation from the rest of the oral cavity (Jablonski; Illustrated Dictionary of Dentistry, 1982). Rubber dams are useful in preventing the swallowing of instruments or restorations during dental work.

A richly vascularized and innervated connective tissue of mesodermal origin, contained in the central cavity of a tooth and delimited by the dentin, and having formative, nutritive, sensory, and protective functions. (Jablonski, Dictionary of Dentistry, 1992)

A degenerative spinal disease that can involve any part of the VERTEBRA, the INTERVERTEBRAL DISK, and the surrounding soft tissue.

The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.

A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.

Apparatus and instruments that generate and operate with ELECTRICITY, and their electrical components.

Elements of limited time intervals, contributing to particular results or situations.

Diseases of the facial nerve or nuclei. Pontine disorders may affect the facial nuclei or nerve fascicle. The nerve may be involved intracranially, along its course through the petrous portion of the temporal bone, or along its extracranial course. Clinical manifestations include facial muscle weakness, loss of taste from the anterior tongue, hyperacusis, and decreased lacrimation.

Inorganic compounds that contain aluminum as an integral part of the molecule.

A mobile chain of three small bones (INCUS; MALLEUS; STAPES) in the TYMPANIC CAVITY between the TYMPANIC MEMBRANE and the oval window on the wall of INNER EAR. Sound waves are converted to vibration by the tympanic membrane then transmitted via these ear ossicles to the inner ear.

Inability or inadequacy of a dental restoration or prosthesis to perform as expected.

Characteristics or attributes of the outer boundaries of objects, including molecules.

The fluid separating the membranous labyrinth from the osseous labyrinth of the ear. It is entirely separate from the ENDOLYMPH which is contained in the membranous labyrinth. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1396, 642)

Space between the dura mater and the walls of the vertebral canal.

Two extensive fibrous bands running the length of the vertebral column. The anterior longitudinal ligament (ligamentum longitudinale anterius; lacertus medius) interconnects the anterior surfaces of the vertebral bodies; the posterior longitudinal ligament (ligamentum longitudinale posterius) interconnects the posterior surfaces. The commonest clinical consideration is OSSIFICATION OF POSTERIOR LONGITUDINAL LIGAMENT. (From Stedman, 25th ed)

An adhesion procedure for orthodontic attachments, such as plastic DENTAL CROWNS. This process usually includes the application of an adhesive material (DENTAL CEMENTS) and letting it harden in-place by light or chemical curing.

A species of gram-positive, coccoid bacteria commonly isolated from clinical specimens and the human intestinal tract. Most strains are nonhemolytic.

Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.

Broken bones in the vertebral column.

Resorption in which cementum or dentin is lost from the root of a tooth owing to cementoclastic or osteoclastic activity in conditions such as trauma of occlusion or neoplasms. (Dorland, 27th ed)

A restoration designed to remain in service for not less than 20 to 30 years, usually made of gold casting, cohesive gold, or amalgam. (Jablonski, Dictionary of Dentistry, 1992)

Pathologic conditions which feature SPINAL CORD damage or dysfunction, including disorders involving the meninges and perimeningeal spaces surrounding the spinal cord. Traumatic injuries, vascular diseases, infections, and inflammatory/autoimmune processes may affect the spinal cord.

A genus of the family CEBIDAE consisting of four species: S. boliviensis, S. orstedii (red-backed squirrel monkey), S. sciureus (common squirrel monkey), and S. ustus. They inhabit tropical rain forests in Central and South America. S. sciureus is used extensively in research studies.

The outer part of the hearing system of the body. It includes the shell-like EAR AURICLE which collects sound, and the EXTERNAL EAR CANAL, the TYMPANIC MEMBRANE, and the EXTERNAL EAR CARTILAGES.

Outgrowth of immature bony processes or bone spurs (OSTEOPHYTE) from the VERTEBRAE, reflecting the presence of degenerative disease and calcification. It commonly occurs in cervical and lumbar SPONDYLOSIS.

A thin membrane that lines the CEREBRAL VENTRICLES and the central canal of the SPINAL CORD.

The part of the membranous labyrinth that traverses the bony vestibular aqueduct and emerges through the bone of posterior cranial fossa (CRANIAL FOSSA, POSTERIOR) where it expands into a blind pouch called the endolymphatic sac.

Junction between the cerebellum and the pons.

The outermost of the three MENINGES, a fibrous membrane of connective tissue that covers the brain and the spinal cord.

Region of the back including the LUMBAR VERTEBRAE, SACRUM, and nearby structures.

Abnormalities in any part of the HEART SEPTUM resulting in abnormal communication between the left and the right chambers of the heart. The abnormal blood flow inside the heart may be caused by defects in the ATRIAL SEPTUM, the VENTRICULAR SEPTUM, or both.

Benign and malignant neoplasms that arise from one or more of the twelve cranial nerves.

'Anus diseases' refer to various medical conditions affecting the anus, including structural abnormalities, inflammatory disorders, infections, and neoplasms, which can cause symptoms such as pain, bleeding, itching, or changes in bowel habits.

Pathological processes of the snail-like structure (COCHLEA) of the inner ear (LABYRINTH) which can involve its nervous tissue, blood vessels, or fluid (ENDOLYMPH).

Mechanical compression of nerves or nerve roots from internal or external causes. These may result in a conduction block to nerve impulses (due to MYELIN SHEATH dysfunction) or axonal loss. The nerve and nerve sheath injuries may be caused by ISCHEMIA; INFLAMMATION; or a direct mechanical effect.

Discharge of cerebrospinal fluid through the external auditory meatus or through the eustachian tube into the nasopharynx. This is usually associated with CRANIOCEREBRAL TRAUMA (e.g., SKULL FRACTURE involving the TEMPORAL BONE;), NEUROSURGICAL PROCEDURES; or other conditions, but may rarely occur spontaneously. (From Am J Otol 1995 Nov;16(6):765-71)

The lower part of the SPINAL CORD consisting of the lumbar, sacral, and coccygeal nerve roots.

Polymers of high molecular weight which at some stage are capable of being molded and then harden to form useful components.

An INTERVERTEBRAL DISC in which the nucleus pulposus has protruded through surrounding fibrocartilage. This occurs most frequently in the lower lumbar region.

"Panama" is not a recognized medical term or condition in healthcare and medicine. It might be a reference to a location, but it does not have a specific medical meaning in itself.

The degree of approximation or fit of filling material or dental prosthetic to the tooth surface. A close marginal adaptation and seal at the interface is important for successful dental restorations.

Acceleration produced by the mutual attraction of two masses, and of magnitude inversely proportional to the square of the distance between the two centers of mass. It is also the force imparted by the earth, moon, or a planet to an object near its surface. (From NASA Thesaurus, 1988)

Five fused VERTEBRAE forming a triangle-shaped structure at the back of the PELVIS. It articulates superiorly with the LUMBAR VERTEBRAE, inferiorly with the COCCYX, and anteriorly with the ILIUM of the PELVIS. The sacrum strengthens and stabilizes the PELVIS.

A group of congenital malformations involving the brainstem, cerebellum, upper spinal cord, and surrounding bony structures. Type II is the most common, and features compression of the medulla and cerebellar tonsils into the upper cervical spinal canal and an associated MENINGOMYELOCELE. Type I features similar, but less severe malformations and is without an associated meningomyelocele. Type III has the features of type II with an additional herniation of the entire cerebellum through the bony defect involving the foramen magnum, forming an ENCEPHALOCELE. Type IV is a form a cerebellar hypoplasia. Clinical manifestations of types I-III include TORTICOLLIS; opisthotonus; HEADACHE; VERTIGO; VOCAL CORD PARALYSIS; APNEA; NYSTAGMUS, CONGENITAL; swallowing difficulties; and ATAXIA. (From Menkes, Textbook of Child Neurology, 5th ed, p261; Davis, Textbook of Neuropathology, 2nd ed, pp236-46)

'Spinal diseases' is a broad term referring to various medical conditions that affect the structural integrity, function, or health of the spinal column, including degenerative disorders, infections, inflammatory processes, traumatic injuries, neoplasms, and congenital abnormalities.

A species of the genus MACACA which typically lives near the coast in tidal creeks and mangrove swamps primarily on the islands of the Malay peninsula.

The hearing and equilibrium system of the body. It consists of three parts: the EXTERNAL EAR, the MIDDLE EAR, and the INNER EAR. Sound waves are transmitted through this organ where vibration is transduced to nerve signals that pass through the ACOUSTIC NERVE to the CENTRAL NERVOUS SYSTEM. The inner ear also contains the vestibular organ that maintains equilibrium by transducing signals to the VESTIBULAR NERVE.

Dental procedure in which part of the pulp chamber is removed from the crown of a tooth.

A twisting deformation of a solid body about an axis. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Measurement of the pressure or tension of liquids or gases with a manometer.

The space between the arachnoid membrane and PIA MATER, filled with CEREBROSPINAL FLUID. It contains large blood vessels that supply the BRAIN and SPINAL CORD.

The large hole at the base of the skull through which the SPINAL CORD passes.

The salts or esters of salicylic acids, or salicylate esters of an organic acid. Some of these have analgesic, antipyretic, and anti-inflammatory activities by inhibiting prostaglandin synthesis.

A bicyclic monoterpene ketone found widely in plants, especially CINNAMOMUM CAMPHORA. It is used topically as a skin antipruritic and as an anti-infective agent.

Process whereby a cell, bodily structure, or organism (animal or plant) receives or detects a gravity stimulus. Gravity sensing plays an important role in the directional growth and development of an organism (GRAVITROPISM).

The properties, processes, and behavior of biological systems under the action of mechanical forces.