Vacuum tube See: X-ray tube.
Valsalva maneuver Forceful intraoperative attempt at nasal expiration by the patient with the nostrils held closed by the clinician to test the possible loss of integrity of the maxillary sinus membrane.1
Variance Degree of dispersion of data about the mean. The square root of the variance is the standard deviation. For bell-shaped curves, the larger the variance, the flatter the distribution curve; the smaller the variance, the more peaked the curve.2 See also: Standard deviation (SD).
VAS Abbreviation for Visual analog scale.
Vascular endothelial growth factor (VEGF) Peptide factor, existing in four forms with different lengths (ie, 121, 165, 189, and 206 amino acids) that is mitogenic for vascular endothelial cells and promotes tissue vascularization. Its levels are elevated in hypoxia, and it is important in tumor angiogenesis.
Vascular supply Supply of nutrients from the vasculature to an elevated flap or surgical site.
Vascularization See: Angiogenesis.
VDO Abbreviation for Vertical dimension of occlusion.
Vector Quantity described both in magnitude and in direction. A force vector is the application of force of a given magnitude applied in a given direction.
Nonviral v. See: Gene therapy, Nonviral; Gene transfer.
Viral v. See: Gene therapy Viral; Gene Transfer.
VEGF Abbreviation for Vascular endothelial growth factor.
Veneer Coating of predetermined thickness, usually resin or ceramic, attached to a crown restoration or pontic by bonding, cementation, or mechanical retention.3,4