The occurrence of teething may vary from children to children. Generally it is from 6- 24 months of age. I suggest you to keep calm and not worry.
You can check for the other growth factors in child like the hairs and nails and the child's ability to grasp and learn things. If these things are absolutely normal we can just wait for few months for teeth to erupt.
Next Steps
If this doesn't happens kindly visit nearby dentist and check for small iopa xray of the lower front region of jaw. This will help us to know that are the teeth about to erupt.
Health Tips
You can give some teething objects which is able to create pressure and help teeth to erupt.