  Several two-dimensional studies in spiral galaxies show that HII star
formation regions have a fractal distribution, with a fractal dimension of
approximately 2.3. In this work, the fractal dimension is calculated through
the box-counting method implemented in an R code. The innovation of the work
lies in calculating the fractal dimension directly in 3 dimensions, without the
need for the use of projections, using position and distance data from Gaia
(Data version 2). The estimated fractal dimension for the regions studied in
the Milky Way are 2.468 (M16), 2.126 (Orion Nebula) and 2.435 (RCW 38).
