- 1. A two-dimensional flat surface. See planum. 2. An imaginary surface formed by extension of a point through any axis or two definite points, in reference especially to craniometry and to pelvimetry. SYN: planum. [L. planus, flat]- Addison clinical planes a series of planes used as landmarks in thoracoabdominal topography; the trunk is divided vertically by a median p. from the upper border of the manubrium of the sternum to the pubic symphysis, by a lateral p. drawn vertically on either side through a point halfway between the anterior superior iliac spine and the median p. at the interspinal p., and by an interspinal p. passing vertically through the anterior superior iliac spine on either side; transversely the trunk is divided by a transthoracic p. passing across the thorax 3.2 cm above the lower border of the body of the sternum, by a transpyloric p. midway between the jugular notch of the sternum and the pubic symphysis, corresponding to the disk between the first and second lumbar vertebrae, and by an intertubercular p. passing through the iliac tubercles and cutting usually the fifth lumbar vertebra; the planes formed on these lines, and also on transverse planes cutting the upper edge of the manubrium and the upper edge of the pubic symphysis, constitute the clinical planes of Addison.- Aeby p. in craniometry, a p. perpendicular to the median p. of the cranium, cutting the nasion and the basion.- auriculoinfraorbital p. SYN: orbitomeatal p..- axial p. transverse p. at right angles to long axis of body, as in CT scanning. SYN: transaxial p..- axiolabiolingual p. a p. parallel to the long axis of a tooth and extending in a labiolingual direction.- axiomesiodistal p. a p. parallel to the long axes of the teeth and extending in a mesiodistal direction.- Camper p. a p. running from the tip of the anterior nasal spine (acanthion) to the center of the bony external auditory meatus on the right and left sides.- canthomeatal p. p. passing through the two lateral angles of the eye and the center of the external acoustic meatus; this p. lies approximately midway between the Frankfort and the supraorbitomeatal planes.- cove p. a classic description of terminal inversion of the electrocardiographic T wave with the initial portion arched above the baseline and the terminal portion below it, the former being rounded and the latter pointed.- equatorial p. in metaphase of mitosis, the p. that touches all of the centromeres and their spindle attachments.- eye-ear p. SYN: orbitomeatal p..- Frankfort p. SYN: orbitomeatal p..- Frankfort horizontal p. SYN: orbitomeatal p..- frontal p. [TA] a vertical p. at right angles to a sagittal p., dividing the body into anterior and posterior portions, or any p. parallel to the central coronal p.. SYN: plana frontalia [TA], coronal p., plana coronalia.- guide p. a fixed or removable device used to displace a single tooth, an arch segment, or an entire arch toward an improved relationship.- horizontal planes [TA] p. parallel and relative to the horizon; in the anatomic position, horizontal planes are transverse planes; in the supine or prone positions, horizontal planes are frontal (coronal planes). SYN: plana horizontalia [TA].- infraorbitomeatal p. SYN: orbitomeatal p..- interspinous p. [TA] a transverse p. passing through the anterior superior iliac spines; it marks the boundary between the lateral and umbilical regions superiorly and the inguinal and pubic regions inferiorly. SYN: planum interspinale [TA], interspinal p., Lanz line.- intertubercular p. [TA] a transverse p. passing through the iliac tubercles. SYN: planum intertuberculare [TA].- mean foundation p. the mean of the various irregularities in form and inclination of the basal seat; the ideal condition for denture stability exists when the mean foundation p. is most nearly at right angles to the direction of force.- median p. [TA] a p. vertical in the anatomic position, through the midline of the body that divides the body into right and left halves. SEE ALSO: Addison clinical planes. SYN: planum medianum [TA].- p. of midpelvis SYN: pelvic p. of least dimensions.- nasion-postcondylar p. a p. passing through the nasion anteriorly and to a point immediately behind each condylar process of the mandible, posteriorly.- nuchal p. the external surface of the squamous part of the occipital bone below the superior nuchal line, giving attachment to the muscles of the back of the neck.- occipital p. [TA] the external surface of the occipital bone above the superior nuchal line. SYN: planum occipitale [TA].- occlusal p., p. of occlusion an imaginary surface that is related anatomically to the cranium and that theoretically touches the incisal edges of the incisors and the tips of the occluding surfaces of the posterior teeth; it is not a p. in the true sense of the word but represents the mean of the curvature of the surface. SEE ALSO: curve of occlusion. SYN: bite p..- orbital p. the orbital surface of the maxilla, lying perpendicular to the orbitomeatal p. at the orbitale. SYN: planum orbitale.- orbitomeatal p. 1. a line approximating the base of the skull, passing from the infraorbital ridge to the midline of the occiput, intersecting the superior margin of the external auditory meatus; the skull is in the anatomical position when the base line lies in the horizontal p. and right and left sides are level. 2. a standard craniometric reference p. passing through the right and left porion and the left orbitale; drawn on the profile radiograph or photograph from the superior margin of the acoustic meatus to the orbitale. SYN: auriculoinfraorbital p., eye-ear p., Frankfort horizontal p., Frankfort p., infraorbitomeatal p..- pelvic p. of greatest dimensions the p. extending from the middle of the posterior surface of the pubic symphysis to the junction of the second and third sacral vertebrae, and laterally passing through the ischial bones over the middle of the acetabulum. SYN: second parallel pelvic p., wide p..- pelvic p. of least dimensions the p. that extends from the end of the sacrum to the inferior border of the pubic symphysis; it is bounded posteriorly by the end of the sacrum, laterally by the ischial spines, and anteriorly by the inferior border of the pubic symphysis. SYN: midplane, p. of least pelvic dimensions, p. of midpelvis, third parallel pelvic p..- planes of reference planes that act as a guide to the location of other planes.- p. of regard an imaginary p. through which the point of regard moves as the eyes are turned from side to side.- sagittal p. [TA] p. parallel to the median p.; sagittal planes are vertical planes in the anatomic position. SYN: plana sagittalia [TA].- spectacle p. the p. at which spectacles are worn.- subcostal p. [TA] a transverse p. passing through the inferior limits of the costal margin, i.e., the tenth costal cartilages; it marks the boundary between the hypochondriac and epigastric regions superiorly and the lateral and umbilical regions inferiorly. SYN: planum subcostale [TA], infracostal line.- supracrestal p. SYN: supracristal p..- supracristal p. [TA] a transverse p. passing through the summits of the iliac crests; it usually passes through the fourth lumbar spinous process. SYN: planum supracristale [TA], supracrestal p..- supraorbitomeatal p. a p. passing the superior orbital margins and the superior margin of the external acoustic meatuses; it makes an angle of approximately 25°–30° with the Frankfort p.; routine CT scans of the brain are made parallel to this p. to limit exposure of eyeball to ionizing radiation.- suprasternal p. a transverse p. passing through the body at the level of the superior margin of the manubrium of the sternum.- temporal p. [TA] a slightly depressed area on the side of the cranium, below the inferior temporal line, formed by the temporal and parietal bones, the greater wing of the sphenoid, and a part of the frontal bone. SYN: planum temporale [TA].- tooth p. any one of the imaginary planes of section of a tooth, such as the axial, horizontal, or vertical.- transaxial p. SYN: axial p..- transpyloric p. [TA] a transverse p. midway between the superior margins of the manubrium sterni and the symphysis pubis; the pylorus may be located on this p. in the supine or prone positions, but in the erect (anatomic) position it descends to a lower level. SYN: planum transpyloricum [TA].- transverse p. [TA] a p. across the body at right angles to the coronal and sagittal planes; transverse planes are perpendicular to the long axis of the body or limbs, regardless of the position of the body or limb; in the anatomic position, transverse planes are horizontal planes; otherwise the two terms are not synonymous. SYN: plana transversalia [TA].- wide p. SYN: pelvic p. of greatest dimensions.
* * *plane 'plān n1 a) a surface that contains at least three points not all in a straight line and is such that a line drawn through any two points in it lies wholly in the surfaceb) an imaginary plane used to identify parts of the body or a part of the skull see FRANKFORT HORIZONTAL PLANE, MIDSAGITTAL PLANE2) a stage in surgical anesthesia <a light \plane of anesthesia is maintained with cyclopropane (Jour. Amer. Med. Assoc.)>
* * *n.a level or smooth surface, especially any of the hypothetical flat surfaces - orientated in various directions - used to divide the body; for example, the coronal and sagittal planes.
* * *(plān) [L. planus] 1. a surface such that a straight line connecting any two of its points lies wholly in the surface. In craniotomy and cephalometry, the term plane is sometimes used interchangeably with line because when viewed from the side (lateral projection), as in a radiograph, it appears as a line. 2. a specified level, as the plane of anesthesia. 3. to rub away or abrade; see planing. 4. a superficial incision in the wall of a cavity or between tissue layers, especially in plastic surgery, made so that the precise point of entry into the cavity or between the layers can be determined.
Planes of the body, with subject in the anatomical position.
Planes of the trunk.
Medical dictionary. 2011.