I've had my top 2nd molars removed but still have my bottom 2nd molars. will this cause problems in the future since adult teeth are constantgrowing?

Most likely: Your mandibular molars will slowly erupt since there are no antagonist teeth (your upper molars). This will make your bite uneven and may result in periodontal defects on the lower teeth. The lack of molars puts additional stress on the other teeth, causing premature breakdown. Consider replacing them with implants.

Likely: Your bottom teeth (2nd molars) will shift over time and the sinuses will begin to expand and decrease the amount of bone remaining where your teeth were extracted. See a Prosthodontist for evaluation and consider implants in those 2 areas for the best long term result. Very critical at your young age. Good Luck.

Imbalanced arches: Adult teeth are fully grown before they erupt, but continue to erupt if they wear down or if there is no opposing tooth. This, in turn, can cause an occlusal imbalance depending on your occlusion. Orthodontic treatment and/or replacement of the extracted teeth may be wise. Speak to your Dentist.