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capitation dentistry A capitation dental program is one in which a dentist or dentists contract with the program's sponsor or administrator to provide all or most of the dental services covered under the program to subscribers in return for payment on a per capita basis.

cast (dental) A plaster replica (plaster model) of the teeth and surrounding tissues, typically made from an alginate impression and used for diagnosis, treatment planning and appliance fabrication, and as a part of the patient's permanent record.

CDABO See College of Diplomates of the American Board of Orthodontics.

center of resistance A force acting through the center of resistance causes the body to translate in the direction of the line of force without rotation. The center of resistance can be considered an area rather than a point in three dimensions.

center of rotation The point about which a body appears to have rotated in a nontranslational plane (two-dimensional) displacement.

centric occlusion Mandibular position dictated by maximum and habitual intercuspation of the upper and lower teeth; variously referred to as intercuspal position, habitual centric, usual occlusal position. The condylar position may or may not be in harmony with centric relation. Because of this, the term habitual occlusion is preferable. Historically, a gnathologic and articulator oriented term.

centric relation A gnathologic term, signifying optimal condyle-articular eminence-glenoid fossa relationships, determined by muscle balance and not by tooth intercuspation. Changing concepts no longer accept the most retruded, rearmost or hinge axis definition, originally derived from prosthetic articulators. To the orthodontist, the condylar position can vary somewhat, but is generally recognized as high on the posterior surface of the articular eminence. Lack of harmony of centric occlusion and centric relation status is particularly important in diagnosis of TMJ problems.

cephalogram A term loosely used as a synonym for cephalometric radiograph: sometimes used to refer to a fine-line tracing on an acetate film overlay of the salient structures, landmarks and pertinent measurements, which is used for diagnostic purposes. However, measurements may be digitized directly from the film via computer.

cephalometer An instrument developed originally from the anthropologic cephalostat, used now on patients to obtain standardized and oriented craniofacial images on X-ray film. The design of the instrument permits longitudinal study with minimal positional and magnification error.

cephalometric analysis The process of evaluating dental and skeletal relationships by way of measurements obtained directly from the living head or, more commonly, from cephalometric radiographs and tracings. Refers also to the standardized sets of cephalometric measurements (e.g., Downs Analysis) commonly used in the evaluation.

cephalometric landmarks Points on a cephalometric radiograph or tracing representing certain hard or soft tissue anatomical structures (anatomical landmarks) or intersections of lines (constructed landmarks).

A point  Subspinal (Downs) The deepest (most posterior) midline point on the curvature between the ANS and prosthion.

ANS anterior nasal spine The tip of the bony anterior nasal spine at the inferior margin of the piriform aperture, in the midsagittal plane.

AR articulare A constructed point representing the intersection of three radiographic images: the inferior surface of the cranial base and the posterior outlines of the ascending rami or mandibular condyles.

B point (Downs) The deepest (most posterior) midline point on the bony curvature of the anterior mandible, between infradentale and pogonion.

Bolton point (Broadbent) The highest points on the outlines of the retrocondylar fossae of the occipital dome, approximates the center of the foramen magnum.

GO gonion The most posterior inferior point on the outline of the angle of the mandible.

key ridge The most inferior point on the zygomatic process of the maxilla as seen in a lateral cephalometric radiograph; the craniometric point zygomaxillare.

NA nasion The intersection of the internasal and frontonasal sutures, in the midsagittal plane.

OR orbitale The lowest point on the inferior orbital margin.

POG pogonion The most anterior point on the contour of the bony chin, in the midsagittal plane.

PO porion The most superior point of the outline of the external auditory meatus.

PNS posterior nasal spine The most posterior point on the bony hard palate in the midsagittal plane; the meeting point between the inferior and the superior surfaces of the bony hard palate (nasal floor) at its posterior aspect.

R point (Broadbent) A cephalometric reference point for registration of superimposed tracings.

S sella tursica The geometric center of the pituitary fossa (sella turcica), determined by inspection ? a constructed point in the mid-sagittal plane.

 cephalometric radiograph A standardized radiograph of the head characterized by a precisely defined relationship among x-ray source, subject and film. By convention, the distance between x-ray source and the 'center' of the subject (midsagittal plane or transporionic axis) is either 5 feet (1 52.4 cm.) or 150 cm. The distance between the midsagittal plane or transporionic axis of the subject and film is approximately 12 cm., but may be standardized at a different value or varied according to head size and recorded for each exposure. The standard projections are lateral (profile) and posteroanterior (P-A).

cephalometric tracing See cephalogram.

ceramic brackets Crystalline alumina tooth-shade or clear synthetic sapphire brackets that are esthetically more attractive than conventional metal attachments.

cervical anchorage See anchorage.

cervical appliance A primarily extraoral appliance that when activated delivers responsive force, by means of a pad, placed on the back of the neck.

chin cap A component of an extraoral orthopedic appliance capable of delivering superiorly and posteriorly directed force to the chin.

cleft lip A unilateral or bilateral congenital fissure in the upper lip, usually lateral to the midline. The defect can extend into the nares and may involve the alveolar process. Caused by a defect in the fusion of the maxillary and nasal processes; may be accompanied by cleft palate.

cleft palate A unilateral or bilateral congenital fissure in the palate. It is caused by a failure of the premaxilla and lateral palatine process to fuse and may be accompanied by a cleft lip.

clenching Nocturnal parafunctional activity of temporalis, masseter and pterygoid muscles that is considered to be part of a stress-strain-tension release syndrome, frequently associated with bruxism and temporomandibular joint disturbances.

clicking A term applied to abnormal sounds emanating from one or both temporomandibular joints, usually due to anterior or anters-medial or anters-lateral displacement of the articular disk during functional movements.

closed bite Excessive vertical overlap of the anterior teeth; deep bite.

closing loop An auxiliary fabricated of orthodontic wire that, upon mesiodistal-pulling activation, moves adjacent teeth together.

College of Diplomates of the American Board of Orthodontics (CDABO) An organization of orthodontists who are board-certified by the American Board of Orthodontics.  Any board-certified orthodontist is eligible to become a member of the CDABO.  The purpose of the CDABO is to support, encourage and facilitate the process of board certification for all orthodontists.  The CDABO also sponsors cutting edge, family-oriented, continuing education meetings for its members.

comprehensive orthodontic therapy The coordinated diagnosis and treatment leading to the improvement of a patient's craniofacial dysfunction and/or dentofacial deformity, including anatomical, functional and esthetic relationships. Treatment usually, but not necessarily, utilizes fixed orthodontic appliances. Adjunctive procedures, such as extractions, maxillofacial surgery, nasopharyngeal surgery, myofunctional or speech therapy and restorative or periodontal care, may be coordinated disciplines. Optimal care requires long-term consideration of patients' needs and periodic re-evaluation. Treatment may incorporate several phases with specific objectives at various stages of dentofacial development.

compressive deformation The shortening of a characteristic dimension of a body associated with pushing force.

computer-assisted tomography (CATscan) The presentation of anatomical information from a cross-sectional plane of the body by computer synthesis of an image from x-rays. Transmission data is obtained in many different directions through the plane under consideration.

computerized cephalometrics The process of entering cephalometric data in digital format for analysis by any one or more of a variety of analyses available in software format.

computerized digital imaging Substitution of a radiation detector plate for radiographic film in the film cassette. The detectors store the radiation energy at each pixel as a latent image for release into the computer in digital format. Advantages include elimination of the radiograph with a much wider dynamic range for improved edge enhancement, and ability to change contrast in specific regions.

condyle The rounded cartilage and bone articulating element in the mandible. The superior portion of the ramus that articulates with the temporal eminence in the glenoid fossa.

condylar displacement A functional abnormality in which one or both mandibular condyles are displaced from their normal relationships with their articular disks and eminentia in the glenoid fossae as the mandible is brought into habitual occlusion.

condylar guidance The functional movements of the mandible as determined by the morphology of the mandibular condyles and articular disks and eminentia in the glenoid fossae.

condylar growth Proliferation of condylar cartilage, followed by its endochondral ossification. The condyle is a site of growth that is important to the overall development of the mandible. Condylar growth normally stops shortly after that of the rest of the face, although it may continue well beyond adolescence, particularly in males, or it may stop and begin again.

condylion The highest point on the superior outline of the mandibular condyle.

continuous orthodontic force Action of an appliance against the dentition that decreases little in magnitude during the between-appointments period.

cosmetic orthodontics Orthodontic therapy whose purpose is limited to improving the appearance of the teeth or face.

couple A pair of equal and opposite non-collinear forces applied to a body. A couple always results in the creation of a pure moment with a tendency to rotate around the center of resistance.

couple-force ratio The ratio of magnitudes of the crown couple to the crown force, having net units of length (e.g., mm), in the two-dimensional analysis of tooth movement.

cranial base The endochondral bone that forms the anteroinferior aspect of the brain case. Because the bones of the cranial base stop growing relatively early, they are often used in the superimposition of serial cephalograms or tracings.

craniometry The direct measurement of dry skulls; a highly developed anthropometric technique that forms the basis of cephalometric radiography.

crepitus A grating or grinding sound in a moving joint or fracture.

crib A type of wrought-wire clasp that surrounds or encloses a tooth; occasionally, used to describe a fixed transpalatal tongue and/or finger interceptive appliance.

crossbite An abnormal relationship of a tooth or teeth to the opposing teeth, in which normal buccolingual or labiolingual relationships are reversed.

crowding Dental malalignment caused by inadequate space for the teeth.

Crozat appliance A wrought-wire removable orthodontic appliance originally introduced by George Crozat.

curve of spee The occlusal and incisal surfaces of the tooth crowns in either dental arch describe, from a sagittal perspective, a curve, ordinarily concave upward with reference to the mandibular arch and convex for the maxillary arch.

curve of Wilson Because the long axes of the mandibular molars and premolars converge towards the midline, the occlusal surfaces of these teeth bilaterally form a curve in a buccolingual direction.  This imaginary curve as defined by a line tangent to the buccal and lingual cusps of the mandibular posterior teeth bilaterally, is termed the curve of Wilson.