Changing <formalpara> title formatting

For <formalpara>, the <title> normally is formatted with a period added to the title. For example, this:

 <formalpara>

   <title>Formal Para Title</title>

   <para>
     Formal para content.
   </para>

Appears like this, with the title in bold:

Formal Para Title.  Formal para content.

I have a document that's being translated into Japanese. My translators tell me that for Japanese, it's better not to have the period added to the formalpara title.

I thought perhaps changing the document from lang="en" to lang="ja" might do the trick, but no dice. Is there a supported way to do this? I don't want to hack my stylesheets in an untoward way because I don't want to affect other documents. Thanks.