Meaning of Yasyadvirada VaktradyaH

Vishvaksena is the chief lieutenat of Lord Vishnu's army. He resembles Ganesha with an elephant face.  However, he differs from Ganesha in having two tusks.  Hence, many people mistake him as Ganesha.  Vishwaksena is the deity you will definitely see in Vaishnava temples, such as Lord Venkateswara (Balaji) temple.  Vishvaksena is also remembered for protecting the devotees, providing them shelter and destroying the obstacles similar to Ganesha.  Here is a shloka which is often follows the shloka on Ganesha - Suklambaradharam Vishnum" in some versions of "Sri Vishnu Sahasranama Stotram".

Yasya Dvirada VaktradaH ParishadyaH Parassatam

Vighnam Nighnanti Satatam Vishvaksenam Tamashraye

यस्य द्विरद वक्त्रादाह पारिशाद्याह परश्शातम

विघ्नं निघ्नन्ति सततं विश्वक्सेनाम तमाश्रये  

Word to word meaning: yasya = where; dvi = two; rada = tooth (tusk); dvirada = two-tusked, meaning elephant; vaktra = face; aadyaH = having / possessing; paari = remove; shadyaH = immediately ; paraH = other; shatam = hundred; vighnam = obstacle; nighnanti = kills; satatam = always; Vishvaksenam = Vishvaksena, who is the chief of lieutenant of Vishnu ganas (army); tam = them;  aashraye = seek shelter. 

Meaning (Taatparyam): I seek shelter of Lord Vishvaksena, the elephant faced God who possesses two tusks, and who always removes another hundred obstacles.