diff --git a/doc/itkBoneMorphometry.tex b/doc/itkBoneMorphometry.tex
index a7156c7..0363593 100644
--- a/doc/itkBoneMorphometry.tex
+++ b/doc/itkBoneMorphometry.tex
@@ -148,7 +148,7 @@ \section{Bone Morphometry Features Available}
 
 \textbf{Bone surface density} or BsBv (which stands for  stands for Bone Surface Bs over Bone Volume Bv) gives an indication on how many bone lining cells cover a given volume of bone (Bv).
 \begin{equation} \label{eqn:BsBv}
-BsBv = 2 \frac{TbN}{BsBv}
+BsBv = 2 \frac{TbN}{BvTv}
 \end{equation}
 
 \textbf{Trabecular thickness} (TbTh) is determined by filling maximal spheres into the structure using a distance transform. Then the average thickness of all maximal spheres is calculated to give an estimate of mean TbTh.