The CV value (combined variation) in the analysis of sagittal malocclusions.

In the study of a sample of eighty 9- to 13-year-old subjects with Class I malocclusions, it was found that a clear relationship exists between the SNA and NSAr angles, which vary according to an inverse ratio. Their combined value, called the CV value, is often constant, near 204.5 degrees. The same holds true when the NSAr angle is larger or smaller than average, which suggests the hypothesis that when dealing with a sagittal malocclusion one should consider the CV value rather than a single angle.