Hi doctor, my son's front, top tooth fell off on 1/1/2018 & it has not grown, it looks like a sharp pointy tip that's half a centimeter big?

Age?: How old is your son? I will guess approximately 7 years old, +/- 6 months. The "sharp, pointy tip" is the incisal edge of his secondary tooth. By this age your son should have established a relationship with a local dentist. Have the dentist take a look.

Eruption: It sounds as if your son's permanent tooth is trying to erupt, but something may be holding it up. All children should see a dent-facial growth and development specialist, an Orthodontist, by their 7th birthday. The Initial Examination appointment is usually free, and ther Orthodontist can give you a knowledgeable opinion as well as a path to follow. Ask your Dentist for a recommendation.