LaTeX math overline/overrightarrow vertical alignment?

Question

When I use the following:

\begin{equation}
\overline{d} \overline{q}
\end{equation}

the overlines are misaligned, with the line on the q being lower than the line on the d. The same thing happens with \overrightarrow. Is there some way to fix this?

Answer 1

\vphantom could fix it:

\begin{equation}
\overline{d} \overline{q\vphantom{d}}
\end{equation}

\vphantom inserts vertical space according to the height of its argument and has zero width.