Can All-on-6 Dental Implants improve your overbite or make it worse? (Photos)

Hello. There are some prosthetic solutions such as toronto bridge to decrease this overjet (the more anterior position of upper jaw than lower) It may be as good as possible but it should be taken into consideration that your upper jaw is in a Class II relationship with lower jaw.this can not be totally changed only by implants or prostheses

discuss yr concern with your implant dentist before he/she order final prosthesis, implant position is very important , but it is possible to adjust upto certain limit. 

Your final prosthesis should be able to be designed to improve your overbite.  Your current dentist should be working with you to alter the smile/bite to your satisfaction.
Moving forward, I'd consider a second temporary to help correct the bite and improve cosmetics before moving forward with the final prosthesis.  Consult with a few doctors to help educate yourself and understand you case better.
One other item to consider is your mandibular (lower) teeth, they are currently set in a corrupted and quite possibly pathologic position.  If you are building and "ideal" upper off of a poor lower, your results may be limited by your lower dentition.  The photos are good, but a comprehensive diagnosis cannot truly be given in this format.