I have a similar problem - my name in SQ profile does not include my middle name so my boarding pass name doesn't exactly match passport. I have never had a problem getting through security and boarding, in US or Singapore or any other airport, so you should be fine.

I have learned something that may be of interest, however. During check-in, the agent is able to enter a line of text that will appear directly under your name on SQ boarding passes. A few times when I have checked in, the agent has entered a line that says "name in passport: xxxxxx". You could ask the check-in agent to put this on your boarding pass.