Also found in: Dictionary, Thesaurus, Legal, Encyclopedia.
diameter(di-am'et-er) [ dia- + -meter]
The distance from any point on the periphery of a surface, body, or space to the opposite point.
anteroposterior diameter of pelvic cavity
The distance between the middle of the symphysis pubis and the upper border of the third sacral vertebra (about 13.5 cm in women).
anteroposterior diameter of pelvic inlet
The distance from the posterior surface of the symphysis pubis to the promontory of the sacrum (about 11 cm in women). Synonym: conjugata vera; true conjugate diameter of pelvic inlet
anteroposterior diameter of pelvic outlet
The distance between the tip of the coccyx and the lower edge of the symphysis pubis.
Baudelocque's diameterSee: Baudelocque, Jean-Louis
The distance between the two gonia. The gonion is the anthropometric point at the most inferior, posterior, and lateral points on the angle of the mandible.
biparietal diameterAbbreviation: BPD
The transverse distance between the parietal eminences on each side of the head (about 9.25 cm).
The distance between the temporal bones (about 8 cm).
The distance between the highest points of the greater trochanters.
The greatest transverse distance between the most prominent points of the zygomatic arches.
The measurement of a tooth from the buccal to the lingual surface.
The distance between the anterior fontanel and the junction of the neck with the floor of the mouth.
conjugate diameterConjugate (2).
diagonal conjugate diameter of pelvis
The distance from the upper part of the symphysis pubis to the most distant part of the brim of the pelvis.
external conjugate diameter
The anteroposterior diameter of the pelvic inlet measured externally; the distance from the skin over the upper part of the symphysis pubis to the skin over a point corresponding to the sacral promontory.
The distance from the top of the forehead to the point of the chin.
The distance between the two anterior superior spines of the ilia.
The distance between the ischial tuberosities. Most commonly, this measure of the female pelvic outlet is greater than 9 cm, allowing the exit of an average-sized term fetus.
The measurement of an anterior tooth from the labial to the lingual surface.
The distance from the chin to the middle of the anterior fontanel.
The measurement of a tooth from the ventral or mesial surface to the distal or dorsal surface.
obstetrical diameter of pelvic inlet
The shortest distance between the sacrum and the symphysis pubis. This diameter is shorter than the true conjugate.Synonym: obstetrical conjugate
The distance from the posterior fontanel to the root of the nose.
The greatest distance between the most prominent portion of the occiput and the point of the chin (about 13.5 cm).
diameter of pelvis
Any diameter of the pelvis found by measuring a straight line between any two points. The diameters are:anteroposterior, the distance between the sacrovertebral angle and the symphysis pubis; bi-ischial, the distance between the ischial spines; conjugata diagonalis, the distance between the sacrovertebral angle and the symphysis pubis; conjugata vera, the true conjugate between the sacrovertebral angle and the middle of the posterior aspect of the symphysis pubis (about 1.5 cm less than the diagonal conjugate); intercristal, the distance between the crests of the ilia; interspinous, the distance between the spines of the ilium; intertrochanteric, the distance between the greater trochanters when the hips are extended and the legs are held together; and obstetrical conjugate, the distance between the promontory of the sacrum and the upper edge of the symphysis pubis.See: pelvis