If I understand your question correctly, you are dual citizens, being citizens of Canada and citizens of Iran, and you want to know whether you can enter the US with your Canadian passports after arriving directly from Iran.
The answer to that question is yes.
The standard disclaimer applies, of course: the officer can always find you inadmissible for other reasons. An Iranian citizen arriving from Iran should probably expect a good deal of scrutiny and perhaps several hours of interviews, even when traveling on a passport from another country such as Canada.
That is even true for people with more tenuous connections to Iran. I know someone who was born in Iran, but lived as a refugee after the revolution, who became a French citizen, who has told me of spending hours in questioning when arriving in the US from the EU. Coming from Iran might make it worse, but it could be bad no matter where you were coming from. Do be prepared to be patient when you arrive.