Lately my 17 month old son has been talking and smiling out of the side of his mouth. he doesnt do it all the time and eats and drinks normally. im hoping its nothing to worry about and that he will grow out of it?

Discuss this with your pediatrician, it may be habit that will resolve itself.

Facial movements that become one sided instead of being balanced, suggest a nerve palsy in the nerves supplying the involved muscles. I would have the kid seen by his doc to understand why this is happening and if there is need for treatment. A condition called Bells Palsy can produce such symptoms.

Play with your son and practice smiling during story time. Ask him to repeat back words and phrases. If he seems to be in pain, and if the facial movements seem involuntary, he should be seen in the Emergency room. Watch for drooling, difficulty with verbalization and fever. Most likely though this is a behavior which will self correct.