After extensive reading of the online postings, I am still confused in the midst of the battle of "conventional" versus "Mini-implants," and struggling as to which direction to go. My basic question is are mini implants or small diameter implants suitable for the Maxilla or upper jaw?
The short answer to your question is no. However, some dentists have used mini implants successfully in the upper jaw (maxilla) at least in the short term.
Generally, "conventional" implants are the best option when possible to restore the upper jaw. Mini implants were originally designed to support a denture, while "conventional" implants were healing to keep pressure off of the "conventional" implants.
It is not surprising that you are still confused on the mini and conventional debate as good long term research on mini dental implants is lacking. Until we have this data, I generally tell my patients that conventional implants are the best option as they have good, long term clinical research to support their use (95-98% longterm success rates).
I would not even consider mini implants for the upper jaw, in someone with normal teeth on the lower jaw against mini implants on the upper jaw. For the best advice in your case, I would recommend discussing this with your surgeon who can give you better guidance on your specific situation.