The UV 105 also has a concave front element. Few lenses at its time of inception had, and still uncommon although the feature is shared with e.g. the current 50mm f/1.8 S-Line Nikkor for the Z system.
By the way, although the UV-Nikkor (and Rayfact UV105) is super sharp, you need to use it for UV to appreciate its quality. For visible range, a UV/IR cut filter has to be used. And the bokeh of the Micro 105/4 is so much nicer. Each to their own [use].