What to do if i'm 39 and have only 28 teeth why?

Nothing: Lucky you. If the missing teeth are the wisdom teeth (3rd molars), it sounds like you may be high on the evolutionary scale. Or, you just have 3 impacted third molars. Either way, you just have 4 fewer teeth to brush every day.

Take care of them: As adults, we usually have 32 teeth. When you say you have only 28 teeth, does this mean 28 you can see or 28 total teeth (no impacted/unerupted teeth confirmed by x-ray)? Wisdom teeth, premolars, and lateral incisors are some teeth that may have a higher incidence of being congenitally missing. If you have a space from a congenitally missing tooth, consult with your dentist regarding options.

28 teeth: Having 28 teeth is not a problem. Have you had your wisdom teeth removed? Maybe they are impacted, the most important thing is to keep these teeth healthy by good brushing and flossing, a healthy diet nd regular dental visits and teeth cleaning

OK: Some people never get wisdom teeth. Sometimes they are present but impacted. If there was a problem I'm sure your Dentist would have pointed it out to you on your x-rays. So go over this with your Dentist.