I guess my question would be, are the teeth there (when they do an x-ray)? If so, then why worry about it? But if it's cause for stress, then get a "tie-breaker" opinion.
As an aside, my mom didn't have her 2 front teeth until she was well over 2 years old. Her mother had been told that surgery would be required, but she thought that sounded like a painful thing to put her baby through (this was in the 50's, so I imagine anesthesia was sketchier then), so she waited. And waited. And waited. And finally, one day, she saw a little tooth there! (By the way, these were her FIRST teeth, she didn't have any others yet!) Anyhow, my mom did eventually grow all of her baby teeth and her adult teeth are beautiful. She's never had a cavity and she's nearly 60. So maybe it's nothing to worry about...