Some babies get their first tooth as early as 4 months, while others only see one pop up closer to 14 or 15 months, so 11 months with no teeth is still within a pretty normal range. My girl only got her first tooth at 13 months and her PD told us not to worry unless there were still no signs past 18 months. It can feel alarming when you compare with other babies but every child really does develop at their own pace. If you are feeling unsettled, a quick check at the polyclinic can give you peace of mind lah.