Vertical alignment of webfonts

Using one of my fonts for web, I noticed that the fallback font, Arial, is displayed closer to the top of the text box than my font. Is there any way I can adjust my font’s distance from the top of the text-box to the first baseline? – and without making my line-height shift.

Reduce the os/2 typoAscender, perhaps. But that is a more complex matter. Please read the Vertical Metrics tutorial.

Also, imitating Arial may not be such a good idea in this case (consider clippings or cut-offs), consider adjusting the CSS instead.