Traditional implant dentistry dictates that dental implants be placed vertically into the jaw bones, supporting the dental prosthesis from one end to the other.
In most patients who needs dental implants to replace the lower teeth, there are often not enough jaw bones above the nerves to place dental implants.
The top portion of the jaw bone is often too thin to house the dental implants.
Therefore these patients would require bone grafting procedures to build up the jaw bones (brown shaded area in the above diagram), which are additional surgeries with added time, healing, risks, and cost.
In fact, adding bone vertically onto the jaw is one of the most unreliable surgical procedures.
Even when there is enough jaw bone to place implants to fully support the dental prosthesis from one end to the other vertically, it is not recommended as the lower jaw flexes during movement. That is, the two back sides of the jaw move relative to the middle part of the jaw. A dental prosthesis, rigidly connected to the dental implants which are placed from one back end of the jaw to the other and rigidly fused to the jaw bone, would be greatly stressed and potentially break something when the lower jaw flexes.
In comparison, in the All-On-4(tm) approach, the 4 implants are mostly placed into the middle part of the jaw and avoiding the back sides of the jaw where most of the flexion movements happen.
This traditional implant approach also requires more dental implants and thus further increase the cost compared to the All-On-4(tm) treatment.
