We present infrared observations with the integral field spectrometer SINFONI on the ESO-VLT (Very Large Telescope) Yepun of obscured stellar clusters in HII regions. The classification in spectral subclasses of the detected early type stars together with a determination of the interstellar extinction and the stellar apparent magnitudes enable us to obtain spectrophotometric distances, which are independent and complementary to kinematic distances and free from the ambiguity inherent to the determination of the latter. This study is part of a larger project, investigating the spatial distribution of Galactic Hii regions. Our primary aim is obtaining a more complete and less biased picture of the Milky Way's spiral structure.